Electrical machines

Abstract

To provide highly versatile electric machines.SOLUTION: A stator 104 of an electrical machine, includes first stator coils, and second stator coils. A power electronic switching assembly of the electrical machine includes: a plurality of first switching module assemblies; and a plurality of second switching module assemblies. Each of the first switching module assemblies includes one or more interconnected first switching modules. Each of the first switching module assemblies is electrically connected to each of first stator coil groups. Each of the second switching module assemblies includes one or more interconnected second switching modules Each of the second switching module assemblies is electrically connected to each of second stator coil groups.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to electric machines, such as motors and generators. The present invention also relates to power systems including one or more electric machines and optionally other electrical components. Each electric machine may be configured to supply or receive a direct current (DC) voltage and / or a single-phase or multi-phase alternating current (AC) voltage as required.

[0002] Each electric machine includes a stator having a stator winding that includes a number of stator coil groups, each of which is electrically connected to a respective switching module. Each stator coil group may include a single stator coil that defines a respective stator phase, or may include two or more interconnected stator coils that define respective stator phases. Such stators are called "active stators" and employ power electronics in the switching modules for active control. [Background technology]

[0003] Power systems employing active front end (AFE) power converters are known. FIG. 1 shows an example of a power system for a marine vessel with first and second alternating current (AC) buses 2a, 2b electrically connected by a bus tie 4. Two AC generators G1, G2 are electrically connected to the first AC bus 2a, and two AC generators G3, G4 are electrically connected to the second AC bus 2b. The rotors of each AC generator G1, G2, ~, G4 are mechanically connected to prime movers D1, D2, ~, D4, such as diesel engines or gas turbine engines. When driven by the prime movers D1, D2, ~, D4, the AC generators G1, G2, ~, G4 provide AC power to the AC buses 2a, 2b.

[0004] The first and second AC buses 2a, 2b may be provided with protective switchgear including circuit breakers and associated controls. Power systems also include additional components such as switchboards, which are typically bulky and expensive.

[0005] The two AC motors M1, M2 are electrically connected to a first AC bus 2a by AFE power converters 6, 8. The two AC motors M3, M4 are electrically connected to a second AC bus 2b by AFE power converters 10, 12.

[0006] Each AFE power converter includes a first active rectifier / inverter 14 (or “front end” bridge) having AC terminals electrically connected to a respective AC bus and a second active rectifier / inverter 16 having AC terminals electrically connected to a respective AC motor. The first and second active rectifier / inverters 14, 16 include DC terminals electrically connected by a DC link 18. A harmonic filter 20 may be electrically connected to the AC terminals of each first active rectifier / inverter 14, as shown.

[0007] In normal operation, the first active rectifier / inverter 14 of each AFE power converter operates as an active rectifier supplying power from the respective AC bus 2a, 2b to the DC link 18, and the second active rectifier / inverter 16 operates as an inverter (or variable speed drive) supplying power from the DC link to the respective AC motor. However, in certain situations, e.g., during regenerative braking, when the motors M1, M2, ..., M4 are operated in generate mode and supply AC power to the first and second AC buses 2a, 2b via their respective AFE power converters, reverse power flow operation may be possible.

[0008] Each active rectifier / inverter 14, 16 typically comprises a number of controllable semiconductor switches (e.g., insulated gate bipolar transistors (IGBTs)) arranged in a suitable topology and switched to control power flow through the AFE power converter. In particular, each AFE power converter 6, 10, ~, 12 can be used to control the rotational speed of a respective AC motor M1, M2, ~, M4, the rotor of which may be mechanically connected to, for example, a propulsion load.

[0009] The first and second AC buses 2a, 2b may carry any suitable power supply voltage, for example 690V AC.

[0010] The third AC bus 22a is electrically connected to the first AC bus 2a by a first transformer 24. The fourth AC bus 22b is electrically connected to the second AC bus 2b by a second transformer 26. Although not shown, the third and fourth AC buses 22a, 22b may be electrically connected by, for example, a second bus tie. The third and fourth AC buses 22a, 22b may carry any suitable supply voltage, for example, 440 VAC, and may be used to provide AC power to ship or hotel services.

[0011] Other known power systems may use DC generators. Each DC generator may be electrically connected to the AC bus by a respective power converter, e.g. an inverter. The power system may also have AC generators electrically connected to the DC bus by a respective power converter, e.g. a rectifier. One or more electrical loads are electrically connected to the DC bus of the power system by respective power converters, e.g. an inverter.

[0012] Electronically commutated DC electric machines (e.g., motors or generators) are known and may include a power electronic switching assembly that includes a plurality of switching modules, each electrically connected to a respective stator coil (i.e., having an "active stator"). The stator coils are received in the winding slots to form a plurality of stator phases, many greater than three. The switching modules are controlled to commutate the coil current flowing through the respective stator coil during operation of the electrical machine in a way that either generates a DC output voltage or which uses a DC input voltage to drive the rotor of the electrical machine.

[0013] As shown in Figures 2 and 3, each switching module 30 may include a pair of AC terminals 32a, 32b electrically connected to a respective stator coil 34, and a pair of DC terminals 36a, 36b. Each switching module 30 includes a converter circuit (or H-bridge circuit) configured as a current source converter. The H-bridge circuit includes four bidirectional switches S1, S2, ..., S4. Each switch includes a pair of metal-oxide-semiconductor field effect transistors (MOSFETs) connected in anti-series (i.e., back to back), although it will be understood that other switch arrangements are possible. Although an anti-parallel diode is shown for each MOSFET in each switch S1, S2, ..., S4, it will be understood that in practice this is provided by the body diode of each MOSFET. For each switch S1, S2, ..., S4 the reverse blocking function is provided by the lower one of the pair of anti series connected MOSFETs and the forward blocking function is provided by the upper one of the pair of anti series connected MOSFETs.

[0014] The DC terminal 36a1 of the first switching module 301 is electrically connected to a first DC conductor 38a, and the nth switching module 30 n DC terminal 36b n is electrically connected to the second DC conductor 38b. n The remaining DC terminals of the stator coils 341, 342, . . . 34n are electrically connected in series as shown in Figure 2. DC conductor 38a may be a positive DC conductor and DC conductor 38b may be a negative DC conductor, or vice versa. The power electronics switching assembly includes a plurality of switching modules 301, 302, . . . 30n electrically connected to respective stator coils 341, 342, . . . 34n and machine conductors 38a, 38b as shown in Figure 2.

[0015] In known electric machines, the DC conductors 38a, 38b define a pair of DC machine terminals 40a, 40b that are electrically connected to a DC load or bus or to an AC load or bus by means of a power converter, for example. Summary of the Invention

[0016] The electric machine provided by the present invention comprises: a first machine terminal electrically connectable to one or more first loads or power sources; a second machine terminal electrically connectable to one or more second loads or power sources; a stator including a plurality of first stator coil groups and a plurality of second stator coil groups; a power electronics switching assembly including a plurality of first switching module assemblies and a plurality of second switching module assemblies; Each first stator coil group defines a respective stator phase and includes one or more interconnected first stator coils; Each second stator coil group defines a respective stator phase and includes one or more interconnected second stator coils; the plurality of first switching module assemblies are electrically connected to or between first mechanical terminals, each first switching module assembly including one or more interconnected first switching modules, each first switching module electrically connected to a respective first stator coil group; the plurality of second switching module assemblies are electrically connected to or between second mechanical terminals, each second switching module assembly including one or more interconnected second switching modules, each second switching module being electrically connected to a respective second stator coil group; The first switching module is adapted to be selectively controlled independently of the second switching module, i.e., different voltages or currents may be supplied to the first and second machine terminals when the electric machine is operated as a generator, and different voltages or currents may be supplied to the first and second machine terminals when the electric machine is operated as a motor.

[0017] The stator coils of the plurality of first and second stator coil groups define a stator winding of the electric machine.

[0018] When the electric machine is operating, the first stator coil groups define a plurality of phase shifted first coil voltages that are commutated by the first switching modules, and the second stator coil groups define a plurality of phase-shifted second coil voltages that are commutated by the second switching modules.

[0019] That is, the coil voltages of the interconnected stator coils of each stator coil group are in phase (more precisely, the fundamental components of the open circuit voltages are in phase) and are rectified by the respective switching modules. The stator coils of each stator coil group may, for example, be electrically connected in series. The electric machine may have any convenient number of first and second stator coil groups and thus a large number of phases. In practice, each electric machine may, for example, have between 5 and 120 phases.

[0020] The stator coils are received in slots formed in a stator of the electric machine, and may be of any suitable type (e.g., single layer, two layer etc.) and may be arranged around the stator to have any suitable stator winding topology.

[0021] The power electronics switching assembly may be formed as part of a stator of an electric machine, and in particular the switching modules may be spaced circumferentially around the stator, for example around a stator frame, and may be mounted to the stator frame in any suitable configuration or grouping.

[0022] The first and second machine terminals may be located within a terminal box of the electric machine, which may be used to facilitate electrical connections to an external load or power source.

[0023] Each first switching module assembly may include two or more interconnected first switching modules, e.g., the first switching modules having direct current (DC) terminals electrically connected in series. Each second switching module assembly may include two or more interconnected second switching modules, e.g., the second switching modules having DC terminals electrically connected in series. Such interconnected switching modules may be described, for example, as having a "chain link" configuration.

[0024] The first switching module assemblies can be electrically connected in parallel to the first mechanical terminals. For example, each of the first mechanical terminals can be electrically connected to a respective mechanical conductor, and the first switching module assemblies can be electrically connected in parallel to the mechanical conductors. If the first mechanical terminals are DC terminals, the electric machine can include, for example, a positive DC mechanical conductor electrically connected to the positive DC mechanical terminal and a negative DC mechanical conductor electrically connected to the negative DC mechanical terminal. Each first switching module assembly can include a positive DC module terminal electrically connected to the positive DC mechanical conductor and a negative DC module terminal electrically connected to the negative DC mechanical conductor. If each first switching module assembly includes only one first switching module, the positive and negative DC module terminals can be defined by the positive and negative DC terminals of the first switching module. On the other hand, if each first switching module assembly includes two or more interconnected first switching modules, the positive and negative DC module terminals may be defined by a positive DC terminal of one of the first switching modules and a negative DC terminal of another one of the first switching modules. The first switching module defining the positive and negative DC module terminals may be, for example, an end switching module of a series-connected group of first switching modules. If the first machine terminals are alternating current (AC) terminals, the electric machine may include, for example, two or more AC machine conductors defining respective AC phases or neutrals. Each first switching module assembly may include two or more AC module terminals electrically connected to corresponding AC phase or neutral AC machine conductors. In one arrangement, the electric machine may include three or four AC machine terminals and three or four AC machine conductors, facilitating electrical connection to one or more three-phase AC loads or sources, optionally including a neutral connection.

[0025] The first mechanical conductors (or first conductor assemblies) may have any suitable configuration. In one arrangement, each mechanical conductor may be formed as an annular ring (or "end ring") or in one or more sections. Each mechanical conductor may be formed from a conductive material, for example copper. The first mechanical conductors may be conveniently located at the axial ends of the stator and may be spaced apart axially.

[0026] The first switching module assemblies may be electrically connected in series between the first mechanical terminals. For example, if the first mechanical terminals are DC terminals, the electric machine may include a positive DC mechanical terminal and a negative DC mechanical terminal. Each first switching module assembly may include a positive DC module terminal and a negative DC module terminal. If there are n first switching module assemblies, the positive DC module terminal of a first one of the first switching module assemblies may be electrically connected to the positive DC mechanical terminal and the negative DC module terminal of the nth one of the first switching module assemblies may be electrically connected to the negative DC mechanical terminal. The negative DC module terminal of a first one of the first switching module assemblies may be electrically connected to the positive DC module terminal of a second one of the first switching module assemblies. The negative DC module terminal of a second one of the first switching module assemblies may be electrically connected to the positive DC module terminal of a third one of the first switching module assemblies, and so on until the negative DC module terminal of the (n-1)th one of the first switching module assemblies is electrically connected to the positive DC module terminal of the nth one of the first switching module assemblies. The first switching module assemblies may be electrically connected to each other and the first machine terminals using suitable cabling or buses, for example.Two or more series-connected groups of first switching module assemblies may be electrically connected between the first machine terminals in parallel.

[0027] The second switching module assemblies can be electrically connected in parallel to the second machine terminals. For example, each of the second machine terminals can be electrically connected to a respective machine conductor, and the second switching module assemblies can be electrically connected in parallel to the machine conductors. If the second machine terminals are DC terminals, the electric machine can include, for example, a positive DC machine conductor electrically connected to the positive DC machine terminal and a negative DC machine conductor electrically connected to the negative DC machine terminal. Each second switching module assembly can include a positive DC module terminal electrically connected to the positive DC machine conductor and a negative DC module terminal electrically connected to the negative DC machine conductor. If each second switching module assembly includes only one second switching module, the positive and negative DC module terminals can be defined by the positive and negative DC terminals of the second switching module. On the other hand, if each second switching module assembly includes two or more interconnected second switching modules, the positive and negative DC module terminals may be defined by the positive DC terminal of one of the second switching modules and the negative DC terminal of another one of the second switching modules. The second switching module defining the positive and negative DC module terminals may be, for example, an end switching module of a series-connected group of second switching modules. If the second machine terminals are AC terminals, the electric machine includes, for example, two or more AC machine conductors defining respective AC phases or neutrals. Each second switching module assembly includes two or more AC module terminals electrically connected to the AC machine conductors of the corresponding AC phases or neutrals. In one arrangement, the electric machine includes three or four AC machine terminals and three or four AC machine conductors, thereby facilitating electrical connection to one or more three-phase AC loads or sources, and optionally including a neutral connection.

[0028] The second machine conductor (or second conductor assembly) may have any suitable configuration. In one arrangement, each machine conductor may be formed as an annular ring (or "end ring") or in one or more sections. Each machine conductor may be formed from a conductive material, for example copper. The second machine conductor may be conveniently located at an axial end of the stator, or may be axially spaced apart. The first machine conductor may be located at the first axial end of the stator, and the second machine conductor may be located at either the first or second axial end of the stator. In general terms, any convenient number of machine conductors may be employed, and may be located at one or both axial ends of the stator as required.

[0029] The second switching module assemblies may be electrically connected in series between the second machine terminals. For example, if the second machine terminals are DC terminals, the electric machine may include a positive DC machine terminal and a negative DC machine terminal. Each second switching module assembly may include a positive DC module terminal and a negative DC module terminal. If there are p second switching module assemblies, the positive DC module terminal of a first one of the second switching module assemblies may be electrically connected to the positive DC machine terminal and the negative DC module terminal of the pth one of the second switching module assemblies may be electrically connected to the negative DC machine terminal. The negative DC module terminal of the first one of the second switching module assemblies may be electrically connected to the positive DC module terminal of the second one of the second switching module assemblies. The negative DC module terminal of a second one of the second switching module assemblies may be electrically connected to the positive DC module terminal of a third one of the second switching module assemblies, and so on until the negative DC module terminal of the (p-1)th one of the second switching module assemblies is electrically connected to the positive DC module terminal of the pth one of the second switching module assemblies. The second switching module assemblies may be electrically connected to each other and to the second mechanical terminal, for example, using appropriate cabling or buses. A group of two or more series-connected second switching module assemblies may also be electrically connected in parallel between the second mechanical terminals.

[0030] The switching modules may be of any suitable type. Each switching module includes one or more converter circuits and other electrical components, such as inductors, capacitors, etc., as needed. These optional electrical components may be distributed per converter circuit, per switching module, or per switching module assembly, as needed. For example, there may be one inductor per series-connected group of switching modules, or one inductor per switching module or converter circuit. Each converter circuit may include multiple controllable semiconductor switches. Any suitable controllable semiconductor switch or combination of switches may be used. The controllable semiconductor switch of each switching module may be on / off controlled by a gate drive controller to commutate the coil current of the electrically connected stator coil group.

[0031] The converter circuit can be configured as a current source converter or a voltage source converter depending on the operational requirements of the power electronic switching assembly. A voltage source converter can be operated using pulse width modulation (PWM) to adapt a common DC voltage to the individual coil voltage requirements and vice versa. A voltage source converter typically requires the switching module or switching module assembly to include one or more capacitors, for example in a DC link electrically connected to the DC terminals of the converter circuit or switching module assembly. A current source converter may require the direct current to be substantially constant and therefore typically requires the switching module or switching module assembly to include one or more inductors, for example in a DC link electrically connected to the DC terminals of the converter circuit or switching module assembly. Discrete inductors of appropriate size may be used or may be designed to have the required inductance in the stator coils or interconnecting cables, buses, etc. A switching module configured to supply or receive an AC voltage may include two converter circuits connected together by a DC link. More specifically, a first converter circuit is electrically connected to the respective stator coil groups, and a second converter circuit electrically connected to the first converter circuit by a DC link is electrically connected, for example, to the respective AC machine terminals or any AC machine conductors. In one arrangement, the first converter circuit is a current source converter and the second converter circuit is a voltage source converter controlled, for example, using PWM. However, it will be appreciated that different converter circuit arrangements are possible. The DC link may include one or more capacitors, inductors, etc. configured as a DC link filter.In another arrangement, the switching module configured to supply or receive an AC voltage may include a converter circuit, e.g., a direct frequency converter or a matrix converter controlled using PWM. The converter circuit is electrically connected to the respective stator coil groups and the respective AC machine terminals. In either arrangement, an AC filter may be provided in the AC circuit, e.g., electrically connected to the AC terminals of the converter circuit or the switching module. It will be readily appreciated that different types of converter circuits that may be used by the switching module may have different control strategies and may have particular operational advantages and disadvantages. For example, a converter circuit configured as a voltage source converter and operating in a rectification mode may not be able to limit load short circuit current and therefore may be suitable for use with electric machines operating as motors. A converter circuit configured as a current source converter may limit DC fault current and parallel connected current source converters may have to use current sharing controls. Voltage and current source converters arranged back-to-back may limit the AC output fault current. Converter circuits configured as direct frequency converters can operate at any suitable frequency that includes down to 0 Hz.This output may be regulated down to DC or may reverse so it may limit both DC and AC fault currents. Therefore, these operating advantages and disadvantages must be kept in mind when selecting a suitable converter circuit for the switching module of an electric machine.

[0032] The converter circuit includes, for example, an H-bridge circuit, - first and second bridge terminals, for example electrically connected to respective stator coil groups; a third bridge terminal; a fourth bridge terminal; a first switch electrically connected between the first bridge terminal and the third bridge terminal; a second switch electrically connected between the first bridge terminal and the fourth bridge terminal; a third switch electrically connected between the second bridge terminal and the third bridge terminal; a fourth switch electrically connected between the second bridge terminal and the fourth bridge terminal.

[0033] In each H-bridge circuit, the first and second switches are electrically connected in series between the third and fourth bridge terminals as a first bridge leg. The third and fourth switches are electrically connected in series between the third and fourth bridge terminals as a second bridge leg. A connection point between the first and second switches defines a first bridge terminal, and a connection point between the third and fourth switches defines a second bridge terminal.

[0034] Each switch of each H-bridge circuit may include one or more controllable semiconductor switches. Any suitable controllable semiconductor switch or combination of switches may be used, such as metal-oxide-semiconductor field effect transistors (MOSFETs), vertical junction field effect transistors (VJFETs), insulated gate bipolar transistors (IGBTs), and gate commutated thyristors (GCTs). A separate diode may be electrically connected in anti-parallel with each semiconductor switch, or the anti-parallel diode may be an inherent feature of the semiconductor switch itself, such as the body diode of a MOSFET structure. Each controllable semiconductor switch is typically turned on and off by a gate drive signal generated by a gate drive controller.

[0035] When the H-bridge circuit is configured as a current source converter, each switch may be a bidirectional switch, i.e., each switch may provide gate controlled bidirectional voltage blocking capability with unidirectional current carrying capability. Each bidirectional switch may include two semiconductor devices, i.e., (a) a pair of controllable semiconductor switches, or (b) a controllable semiconductor switch and a diode, the pair of semiconductor devices being electrically connected in anti-series (or back-to-back), i.e., one semiconductor device blocks voltage in a first direction and the other semiconductor device blocks voltage in a second direction opposite to the first direction. (In this specification, the term "semiconductor device" may refer to a semiconductor switch or a diode, as appropriate.) When a current flows through one of the semiconductor switches in a particular direction, the current may flow through an anti parallel diode of the other anti series connected semiconductor switch. For example, if each semiconductor switch is a MOSFET, the body diode will inherently act as an anti-parallel diode. If a pair of semiconductor switches are MOSFETs, they may be electrically connected in anti-series in either a common-source or common-drain configuration, although the common-source configuration is often preferred to simplify the gate arrangement.This is because both MOSFETs are preferably set to the on state simultaneously in order to benefit from simultaneous conduction of the body diode and reverse conduction in the MOSFET that provides the reverse voltage blocking function. When the pair of semiconductor switches are VJFETs, there are no body diodes or anti-parallel diodes, so reverse conduction of the VJFETs that provide the reverse voltage blocking function is essential when the pair of VJFETs need to carry current. A pair of VJFETs may be electrically connected in anti-series in either a common source or common drain arrangement, although a common source arrangement is often preferred to simplify gate arrangement. For other semiconductor switches, the reverse voltage blocking function is provided by the reverse blocking junction, and only one gate control is required for each bidirectional switch.

[0036] When the H-bridge circuit is configured as a voltage source converter, each switch may be a unipolar switch, i.e., each switch may provide a gate-controlled unidirectional voltage blocking capability with bidirectional current carrying capability. Each switch typically comprises a controllable semiconductor switch with an anti-parallel diode. Suitable semiconductor switches include, for example, IGBTs and GCTs with built-in anti-parallel diodes. As described herein, the H-bridge circuit may operate as a single-phase voltage source converter, but it will be apparent to one skilled in the art that a so-called "Graetz bridge" derivative with six switches may operate as a three-phase voltage source converter.

[0037] When the H-bridge circuit is configured as a direct frequency converter, each switch may be a bidirectional switch, i.e., each switch may provide a gate-controlled bidirectional voltage blocking capability with a bidirectional current carrying capability. Each switch may include a pair of controllable semiconductor switches electrically connected in anti-series, each semiconductor switch having an anti-parallel diode. Suitable semiconductor switches may include, for example, IGBTs and GCTs with built-in anti-parallel diodes. As described herein, the H-bridge circuit may operate as a single-phase to single-phase direct frequency converter, but it will be apparent to one skilled in the art that a derivative having six switches may operate as a single-phase to three-phase direct frequency converter.

[0038] The third and fourth bridge terminals of the H-bridge circuit may define DC terminals of the converter circuit. In one arrangement, where each switching module assembly includes only one switching module with a converter circuit that comprises an H-bridge circuit, the third bridge terminal may be, for example, a positive DC module terminal electrically connected to a positive DC mechanical conductor, and the fourth bridge terminal may be, for example, a negative DC terminal electrically connected to a negative DC mechanical conductor. Individual switching modules may also be electrically connected in series. For example, if there are n first switching modules electrically connected in series between the first mechanical terminals or conductors, the third bridge terminal of a first one of the first switching modules may be a positive DC terminal electrically connected to a positive DC mechanical terminal or conductor, and the fourth bridge terminal of the nth one of the first switching modules may be a negative DC terminal electrically connected to a negative DC mechanical terminal or conductor. The fourth bridge terminal of the first one of the first switching modules may be a negative DC terminal electrically connected to the third bridge terminal (i.e., the positive DC terminal) of the second one of the first switching modules.The fourth bridge terminal (i.e., the negative DC terminal) of the second one of the first switching modules may be electrically connected to the third bridge terminal (i.e., the positive DC terminal) of the third one of the first switching modules, and similarly, the fourth bridge terminal (i.e., the negative DC terminal) of the (n-1)th one of the first switching modules may be electrically connected to the third bridge terminal (i.e., the positive DC terminal) of the nth one of the first switching modules until the fourth bridge terminal (i.e., the negative DC terminal) of the (n-1)th one of the first switching modules is electrically connected to the third bridge terminal (i.e., the positive DC terminal) of the nth one of the first switching modules.

[0039] The first switching modules are electrically connected to each other and to a first machine terminal or conductor, for example using a suitable cable or bus.

[0040] A plurality of second switching modules may be electrically connected in series between the second mechanical terminals or conductors in a manner similar to that described above.

[0041] The electric machine may be a rotating electric machine. In this case, the electric machine may include a rotor that rotates relative to a stationary stator and is radially spaced therefrom by an air gap. The rotor may have any suitable configuration. The rotor may include rotor windings or may be a permanent magnet rotor including a plurality of permanent magnets circumferentially spaced around the rotor. The permanent magnets may be located on the rotor surface, for example using a magnet carrier assembly fixed to the rotor surface, or may be held in place using a sleeve or band. The permanent magnets may also be embedded within the rotor.

[0042] The electric machine may be a linear electrical machine, in which case it may include a mover that moves relative to a stationary stator, and the mover may have any suitable configuration.

[0043] When the electric machine is operated as a generator, the first switching module is operated in a coordinated manner to supply power to one or more first loads via the first machine terminals and any intervening first machine conductors or conductor assemblies. The second switching module can be operated in a coordinated manner to supply power to one or more second loads via the second machine terminals and any intervening second machine conductors or conductor assemblies. As described in more detail below, the one or more first and second loads can include, for example, energy storage devices (e.g., charging batteries, supercapacitors, hybridised super-capacitors and batteries, flywheel energy storage systems, etc.), dynamic braking systems, power networks, and static converters, or other electrical machines operating as motors. A first machine terminal of the electric machine can be electrically connected to corresponding machine terminals of a second electric machine, thereby enabling the electric machine to operate as a generator supplying power to the second electric machine without the need for an intervening power converter, switchboard, or the like.

[0044] The first and second loads may be electrically connected to the first and second machine terminals, if appropriate, through one or more intervening power converters. In other words, the first and second loads need not be directly electrically connected to the first and second machine terminals. If the electric machine is used on a ship, the power network loads may be, for example, a DC or AC power network used to supply the service loads of a ship or hotel. The DC power network may be directly electrically connected to the machine terminals, which typically provide a DC voltage. The AC power network may be directly electrically connected to the machine terminals, which typically provide an AC voltage, or indirectly electrically connected to the machine terminals, which typically provide a DC voltage, through an intervening power converter. Although reference is sometimes made in this specification to a ship, it will be readily understood that the electric machine and the power system incorporating the same may be used in any suitable application and is in no way limited to use on a ship.

[0045] When the electric machine is operated as a motor, the first switching module can receive power from one or more first power sources via the first machine terminals and any intervening first machine conductors or conductor assemblies. The second switching module can receive power from one or more second power sources via the second machine terminals and any intervening second machine conductors or conductor assemblies. As described in more detail below, the one or more first and second power sources can include static components such as, for example, energy storage devices (e.g., discharge batteries, supercapacitors, hybridized supercapacitors and batteries, flywheel energy storage systems, etc.), fuel cells, and power networks or other electric machines operating as generators. The first machine terminals of the electric machine can be electrically connected to corresponding machine terminals of the second electric machine operating as a generator, thereby allowing the electric machine to receive power from the second electric machine without the need for intervening power converters, switchboards, etc. The first and second power sources can be electrically connected to the first and second machine terminals by one or more intervening power converters, if appropriate. In other words, the first and second power sources need not be directly electrically connected to the first and second machine terminals.

[0046] The first switching module can be controlled to supply a fixed or variable DC voltage or can receive a DC voltage. In this case, the first mechanical terminal can include a positive DC mechanical terminal and a negative DC mechanical terminal. The electric machine can optionally include a positive DC mechanical conductor electrically connected to the positive DC mechanical terminal and a negative DC mechanical conductor electrically connected to the negative DC mechanical terminal.

[0047] If properly configured, the first switching module is typically controlled to supply or receive a fixed AC voltage, such as AC 440V or AC 690V. For example, the AC voltage can be selected from two or more different voltages (e.g., 440VAC and 690VAC) depending on the operational requirements. The AC voltage can have any suitable frequency (e.g., 50 or 60Hz). The first machine terminals can include two or more AC machine terminals that define respective AC phases or neutrals. The electric machine can also include two or more AC machine conductors that are electrically connected to the AC machine terminals of corresponding phases. In one arrangement, the electric machine may include three or four AC machine terminals and three or four AC machine conductors, facilitating electrical connection of one or more three-phase AC loads or sources to the first machine terminals, optionally including a neutral connection. If the first switching module is configured to supply or receive both DC and AC voltages, it may be selectively controlled to transition between supplying or receiving a DC voltage and supplying or receiving an AC voltage, for example depending on operational requirements, in which case the first mechanical terminal and the first mechanical conductor or conductor assembly may carry either the AC voltage or the DC voltage, as appropriate.

[0048] The second switching module can be controlled to supply a fixed or variable DC voltage or can receive a DC voltage. In this case, the second machine terminal can include a positive DC machine terminal and a negative DC machine terminal. The electric machine can optionally include a positive DC machine conductor electrically connected to the positive DC machine terminal and a negative DC machine conductor electrically connected to the negative DC machine terminal.

[0049] When suitably configured, the second switching module is controlled to supply an AC voltage or to receive an AC voltage. For example, the AC voltage can be selected from two or more different voltages (e.g., 440 VAC and 690 VAC) depending on the operational requirements. The AC voltage can have any suitable frequency (e.g., 50 or 60 Hz). The second machine terminals can include two or more AC machine terminals defining respective AC phases or neutrals. The electric machine can also include two or more AC machine conductors electrically connected to corresponding phase AC machine terminals or neutral terminals. In an arrangement, the electric machine may include three or four AC machine terminals and three or four AC machine conductors, thereby facilitating electrical connection of one or more three-phase AC loads or sources to the second machine terminals. When the second switching module is configured to supply or receive both DC and AC voltages, it can be selectively controlled to transition between supplying or receiving a DC voltage and supplying or receiving an AC voltage depending on, for example, the operational requirements. In this case, the second mechanical terminal and the second mechanical conductor or conductor assembly may carry an AC voltage or a DC voltage, as appropriate.

[0050] The first switching module may be controlled independently or substantially independently from the second switching module. For example, the first switching module may be controlled to provide a variable DC voltage and the second switching module may be controlled to provide a fixed DC voltage or current or a fixed or variable AC voltage. Control strategies may be used to minimize the effects of mutual coupling between the respective portions of the stator windings, i.e., between the first stator coil electrically connected to the first switching module and the second stator coil electrically connected to the second stator module. The skilled person will understand that an electrical machine according to the present invention may experience mutual coupling between the first and second stator coil groups and that armature reaction resulting from current flowing in the stator coil groups may cause local perturbation of the air gap flux density.The combined effects of mutual coupling and armature reaction may be such that the coil open circuit voltages within the first stator coils are affected by the currents that flow in the second stator coils (and vice versa) in a manner that is well understood. Independent closed loop control may be provided for each switching module and under steady state conditions, the mean voltage and current at the first machine terminals are controlled independently of the mean voltage and current at the second machine terminals.Closed loop controllers have finite gain and bandwidth and the term “substantially independently” is used herein to reflect the abnormal transient conditions at the second machine terminals that may transiently influence the voltage and current at the first machine terminals. The duration and magnitude of this transient effect can be minimized by optimizing each closed loop controller, for example by incorporating pre-emptive cross linking between each controller.

[0051] The first switching module can be controlled to supply power to a first mechanical terminal, while the second switching module can receive power from, for example, a second mechanical terminal. In particular, it can receive power from one or more second power sources electrically connected to the second mechanical terminal. In one aspect, if the electric machine is a rotating electric machine and the rotor is mechanically connected to a prime mover, such as, for example, a diesel engine or a gas turbine engine, the power received at the second mechanical terminal can be used to assist the prime mover by controlling the second switching module to drive the rotor in conjunction with the prime mover while the first switching module is controlled to supply power to the first mechanical terminal. The power received at the second mechanical terminal can also be recirculated to the first mechanical terminal.

[0052] The first and second machine terminals may be selectively electrically connected by a first switch. When the electric machine includes first and second machine conductors or conductor assemblies, they may be electrically connected by the first switch. When the first switch is controlled to an open state, the first and second machine terminals and the electrically connected load or power source are electrically isolated (or substantially electrically isolated) from each other. Thus, the first switching module can be controlled independently (or substantially independently) from the second switching module. When the first switch is controlled to be closed, the first and second machine terminals are electrically connected to form a "common" machine terminal. The first and second machine conductors or conductor assemblies are also electrically connected to form a "common" machine conductor or a "common" conductor assembly. The first and second switching modules are electrically connected to or between the "common" machine terminals, e.g., to a "common" machine conductor or conductor assembly. Thus, the control of the first and second switching modules should be coordinated and may include controls to minimize or accommodate the above mutual coupling effects. When the electric machine is operated as a generator, the first and / or second switching modules may be operated in a coordinated manner to supply the same power to one or more first loads and / or one or more second loads through a "common" machine terminal. When the electric machine is operated as a motor, the first and / or second switching modules may receive power from one or more first power sources and / or one or more second power sources through a "common" machine terminal. The first and second switching modules may be operated in concert, for example, to drive the rotation of a rotor of a rotating electric machine. It will be readily understood that one or both of the first and second switching modules may be operated depending on the operating requirements. Similarly, one or both of the first and second switching modules may also supply power to one or both of the first and second loads and / or receive power from one or both of the first and second power sources depending on the operating requirements.

[0053] The first switch is an electric switch and may include one or more controllable semiconductor switches, such as thyristors. For example, an electric switch designed to pass an AC voltage may include anti-parallel thyristors to allow bidirectional current flow. Anti-parallel thyristors may also be used when the respective switching modules are configured as voltage source converters with reversible current at their DC terminals. Simple thyristors may also be used when the respective switching modules are configured as current source converters with unidirectional current at their DC terminals. The electric switch may further include snubbers, gate drivers, a cooling system, etc. The one or more controllable switches may be controlled to be switched on / off by a suitable controller. When thyristors are employed, the commutation of the electrical switches must usually be coordinated with the control of the respective switching module assembly, as the current through the thyristor must be interrupted so that the thyristor goes into the blocking state. Instead of thyristors, one or more fully controllable semiconductor switches can be used. The electrical switches can be in a series redundant configuration.

[0054] The electrical connections between the first machine terminal and one or more first loads or power sources and between the second machine terminal and one or more second loads or power sources can be made, for example, using suitable cabling or buses. The cabling or buses may be electrically connected to the first machine terminal of the electric machine and / or to one or more first loads or power sources by isolation switches and / or fuses. The cabling or buses may be electrically connected to the second machine terminal of the electric machine and / or to one or more second loads or power sources by isolation switches and / or fuses. The isolation switches may be electric switches and may include one or more controllable semiconductor switches, for example thyristors. For example, an electric switch designed to pass an AC voltage may include anti-parallel thyristors to allow bidirectional current flow. Anti-parallel thyristors can also be used when the respective switching modules are configured as voltage source converters with reversible current at their DC terminals. Simple thyristors can also be used if the respective switching modules are configured as current source converters with unidirectional current at their DC terminals. The electrical switches can further include snubbers, gate drivers, cooling systems, etc. The one or more controllable switches can be controlled to switch on / off by a suitable controller. Commutation of the electrical switches must usually be coordinated with the control of the respective switching module assembly if thyristors are employed. Instead of thyristors, one or more fully controllable semiconductor switches can also be used. The electrical switches can be configured in a series redundant configuration.The isolation switches may be mechanical isolators, or in fact any suitable isolation switches, removable links, or fuses, for example, may be inserted anywhere in the power system to provide electrical isolation as required.

[0055] Isolation switches can be used to electrically isolate (or substantially isolate) cables or buses from electrical machines and / or loads or power sources. Mechanical isolators in conventional power systems have an off state that is substantially open circuit and the ability to withstand open circuit voltages that are several times the normal operating voltage. Isolation switches constructed of controllable semiconductor switches may have a lower off state impedance and voltage withstand. However, with properly designed voltage margins and redundancy, each isolation switch can have an off state sufficient to substantially isolate the electrical circuit to which it is electrically connected, hence the term "substantially isolating" used herein. If the switching module controlled to provide power is configured as a current source converter, it is possible to interrupt the current and open the isolation switch when the current through the cable or bus has already been interrupted. If the electrical connection is configured as a current source connection, the electrical connection may include one or more inductors and some degree of regulation may be required between the electrical machine and one or more connected loads or power sources. If the electrical connection is configured as a voltage source connection, the electrical connection may include one or more capacitors. In some arrangements, the one or more inductors and / or capacitors may be provided at the first and / or second machine terminals of the electric machine, or on any machine conductor or conductor assembly to which the switching module is electrically connected.

[0056] The present invention further provides a power system including a first electric machine as described above and a second electric machine, the second electric machine comprising: A first mechanical terminal; a stator including a plurality of first stator coil groups defining respective stator phases, each first stator coil group including one or more interconnected first stator coils; a power electronics switching assembly including a plurality of first switching module assemblies electrically connected to or between the first mechanical terminals; Each first switching module assembly includes one or more interconnected first switching modules, each first switching module electrically connected to a respective first stator coil group; The first mechanical terminal of the second electric machine is electrically connected to the first mechanical terminal of the first electric machine. In other words, the second electric machine is the first load mentioned above, which is electrically connected to the first mechanical terminal of the first electric machine.

[0057] The second electric machine may be as described above for the first electric machine, in particular the first machine terminals, the first stator coil group, and the first switching module assembly and the first switching module of the power electronics switching assembly of the second electric machine may be configured and controlled as described above.

[0058] The second electric machine may be a rotating electric machine. In this case, the second electric machine may include a rotor that rotates relative to a stationary stator and is radially spaced from the stator by an air gap. The rotor may have any suitable configuration. The rotor may include rotor windings or may be a permanent magnet rotor including a plurality of permanent magnets circumferentially spaced around the rotor. The permanent magnets may be located on the rotor surface, for example, using a magnet carrier assembly fixed to the rotor surface, or may be held in place using a sleeve or band. The permanent magnets may also be embedded within the rotor.

[0059] The second electric machine may be a linear electric machine, in which case it may include a mover that moves relative to a stationary stator, and the mover may have any suitable configuration.

[0060] The first machine terminals of each of the first and second electric machines may be electrically connected by a suitable cable or bus.

[0061] The cabling or buses may be electrically connected to a first machine terminal of the first electric machine by isolation switches and / or fuses. The cabling or buses may be electrically connected to a first machine terminal of the second electric machine by isolation switches and / or fuses. As mentioned above, the isolation switches may be electrical switches and may include one or more controllable semiconductor switches, e.g., thyristors. The one or more controllable switches may be controlled to be on / off by a suitable controller. The isolation switches may be mechanical isolators.

[0062] The isolation switch can be used to electrically isolate (or substantially isolate) a wire or bus from a first electric machine and / or a second electric machine. If the switching module controlled to provide power is configured as a current source converter, the isolation switch can interrupt the current and can open when the current through the wire or bus is already interrupted.

[0063] The direct electrical connection between the first and second electric machines eliminates the need for power converters, switchboards, etc., which are often standalone or remotely located as part of the power system, resulting in significant cost and space savings. In particular, the power system of the present invention eliminates the need for the electric machines to be electrically connected to the AC bus by a suitable power converter. The power converter is effectively replaced by a power electronics switching assembly of the electric machine. The machine conductors or conductor assemblies replace the bus sections of a conventional linear switchboard. A switch between a set of machine terminals (or between machine conductors or conductor assemblies) effectively replaces the conventional bus ties that electrically connect the bus sections of the conventional linear switchboard. As a result, the power system is physically compact and more flexible. For example, it can be configured to provide maximum resilience / redundancy or efficiency. It is also possible to have two independent system voltages, but with only one prime mover and no energy storage devices. Power systems also benefit from reduced size of interconnecting conductors because large fault currents are not experienced. DC transmission increases power throughput for a given conductor size and insulation thickness. Interconnecting cables and buses for DC transmission can be significantly smaller.

[0064] When the first electric machine is operated as a generator and the second electric machine is operated as a motor, the first electric machine can supply power to the second electric machine through an electrical connection between the respective first machine terminals provided by a cable or a bus. At the same time, the first electric machine can independently supply power to one or more second loads through the second machine terminals by controlling the second switching module independently from the first switching module. When the power system is used on a ship, the one or more second loads may be, for example, service loads of a ship or hotel electrically connected to a DC or AC power network. When the first electric machine includes the optional first switch described above, the first and second switching modules can independently supply power through the first and second machine terminals of the first electric machine if the first switch is controlled to an open state. When the first switch is controlled to be closed, the first and / or second switching modules of the first electric machine can be controlled in a coordinated manner to supply the same power to the second electric machine and / or the electrically-connected second load through the "common" machine terminal. The first electric machine may also stop supplying power to one or more second loads, which are optionally electrically isolated (or substantially isolated) from the first electric machine by opening the above-mentioned isolation switch. All power generated by the first electric machine by controlling the first and second switching modules is then supplied to the second electric machine through the "common" machine terminal.

[0065] When the first electric machine is operated as a generator and the second electric machine is operated as a motor, at least the first switching module can be controlled to supply a variable DC voltage to the first machine terminals. The variable DC voltage is supplied to the first switching module of the second electric machine via its first machine terminals and optionally any first machine conductors or conductor assemblies. The rotational speed of the second electric machine can be varied by varying the DC voltage supplied to the second electric machine and controlling the first switching module of the second electric machine to drive the rotation of the rotor. When the first switching module of the first electric machine is configured as a current source converter, for example, the amplitude of the DC voltage supplied by the first electric machine can be proportional to the rotational speed with a polarity determined by the power flow direction, and the amplitude of the direct current can be proportional to the torque. The first switching module can be used to vary the applied coil voltages of the connected stator coil groups when the first electric machine is operated as a generator. By delaying the firing of the controllable semiconductor switches in each first switching module of the first electric machine, a variable DC voltage can be derived and supplied to the first machine terminals of the first electric machine.

[0066] When the first and second mechanical terminals of the first electric machine are electrically connected, i.e. the optional first switch is controlled to be closed, the second switching module may also be controlled to supply a variable DC voltage, the first and second switching modules being preferably controlled in a coordinated manner. When the first and second mechanical terminals of the first electric machine are electrically isolated, i.e. the optional first switch is omitted or controlled to be open, the second switching module may be independently controlled to supply a variable or fixed DC voltage or a variable or fixed AC voltage to the second mechanical terminal. A variable DC voltage is suitable when a third electric machine is electrically connected to the second mechanical terminal of the first electric machine and operates as a motor. Thus, the first electric machine may be configured to independently supply power to the two electric machines operated as motors through the first and second mechanical terminals. The second and third electric machines are separately electrically connected to the first and second machine terminals of the first electric machine so that they can be operated at different rotational speeds or torques and can be rotated in different directions (e.g., for counter-rotating applications). A fixed DC voltage may be suitable for one or more loads, such as ship or hotel service loads, for example if the power system is used on a marine vessel, or more generally for loads that prefer to operate with a fixed DC input voltage. This also includes AC loads electrically connected to the second machine terminals by respective power converters, for which a fixed DC input voltage is preferred. A fixed AC voltage may be suitable for similar reasons, allowing AC loads to be directly electrically connected to the second machine terminals without the need for a respective power converter. The one or more second loads may include a power network, such as a DC or AC power network, to which the one or more loads are in turn electrically connected.

[0067] When the first electric machine is operated as a motor and the second electric machine is operated as a generator, the first electric machine can receive power from the second electric machine through an electrical connection between the respective first machine terminals. The first electric machine can also receive power from one or more second power sources through the second machine terminals. More specifically, the first switching module of the first electric machine can receive power from the first switching module of the second electric machine through the electrically connected first machine terminals, and the second switching module of the first electric machine can receive power from one or more second power sources electrically connected to the second machine terminals. When the first electric machine includes the optional first switch described above, when the first switch is controlled to an open state, the first switching module and the second switching module can independently receive power through the first and second machine terminals of the first electric machine. When the first switch is controlled to be closed, the first and / or second switching modules of the first electric machine can receive power from the second electric machine and / or the electrically connected second power source through the “common” machine terminal.

[0068] When the first electric machine is operated as a motor and the second electric machine is operated as a generator, at least a first switching module of the first electric machine typically receives a variable DC voltage from the first machine terminal and an optional intervening first machine conductor or conductor assembly. The variable DC voltage is supplied from the first machine terminal of the second electric machine and controlled accordingly. The supplied DC voltage can be varied by the second electric machine and the first switching module of the first electric machine can be operated to vary the rotational speed of the first electric machine when operating as a motor, i.e. to reproduce the function of a conventional variable speed drive. When the first and second machine terminals of the first electric machine are electrically connected, i.e. the optional first switch is controlled to be closed, the second switching module can also receive a variable DC voltage and can be operated to drive the rotor of the first electric machine in a coordinated manner. If the first and second machine terminals of the first electric machine are electrically isolated, i.e. the optional first switch is omitted or controlled to be open, the second switching module can receive a variable DC voltage, a fixed DC voltage, a variable AC voltage or a fixed AC voltage from the second machine terminal and any intervening second machine conductor or conductor assembly. The one or more second power sources electrically connected to the second machine terminals may include one or more AC power sources, optionally with suitable power converters, and may include, for example, one or more DC power networks. A variable DC voltage is suitable if a third electric machine similar to the second electric machine is electrically connected to the second machine terminals, i.e. the one or more second power sources include a third electric machine operating as a generator. Thus, the first electric machine may be configured to receive power from two electric machines operated as generators.The first electric machine may be configured to receive power from both the second and third electric machines simultaneously in a coordinated manner, or may be configured to normally receive power from only one of the electric machines but have the option to receive power from the other electric machine in some circumstances, for example in the event of a fault or if the electric machine that normally supplies power is not operational for some reason, such as during scheduled maintenance. When receiving power from only one of the second and third electric machines, an optional switch may be closed such that the first and second switching modules of the first electric machine receive power from a "common" machine terminal and any intervening "common" machine conductors or "common" conductor assemblies. The first and second switching modules receive the same power from either the second or third electric machine and are preferably coordinated to drive the rotor of the first electric machine.

[0069] The first and second electric machines can both be operated as generators or as motors, in other words, it is not necessary for one of the first and second electric machines to be operated as a generator and the other of the first and second electric machines to be operated as a motor.

[0070] The second electric machine may further include second machine terminals electrically connectable to one or more second loads or power sources. The stator of the second electric machine may further include a plurality of second stator coil groups defining respective stator phases. Each second stator coil group may include one or more interconnected second stator coils. The power electronics switching assembly of the second electric machine may further include a plurality of second switching module assemblies electrically connected to or between the second machine terminals. Each second switching module assembly may include one or more interconnected second switching modules, each second switching module electrically connected to a respective second stator coil group.

[0071] The second mechanical terminal, the second stator coil group, and the second switching module assembly and the second switching module of the power electronics switching assembly may be configured and controlled as described above.

[0072] The first switching module of the second electric machine may be adapted to be selectively controlled independently (or substantially independently) from the second switching module of the second electric machine.

[0073] The first and second machine terminals of the second electric machine can be selectively electrically connected by a second switch. When the second switch is controlled to open, the load or power source connected with the first and second machine terminals are electrically isolated (or substantially isolated), and when the second switch is controlled to close, the first and second machine terminals are electrically connected. It will thus be readily appreciated that the second electric machine can be configured similarly to the first electric machine when operated as a generator or a motor.

[0074] The second switch may be an electrical switch and may include one or more controllable semiconductor switches, such as thyristors. For example, an electrical switch designed to pass an AC voltage may be configured with anti-parallel thyristors to allow bidirectional current flow. Anti-parallel thyristors may also be used when the respective switching modules are configured as voltage source converters with reversible current flow at the DC terminals. Simple thyristors may also be used when the respective switching modules are configured as current source converters with unidirectional current flow at the DC terminals. The electrical switch may further include snubbers, gate drivers, a cooling system, etc. The one or more controllable switches may be controlled to switch on and off by a suitable controller. Commutation of the electrical switch must typically be coordinated with the control of the respective switching module assembly if thyristors are employed. Instead of thyristors, one or more fully controllable semiconductor switches may also be used. The electrical switches may be in a series redundant configuration.

[0075] The first electric machine may further include third machine terminals electrically connectable to one or more third loads or power sources. The stator of the first electric machine may further include a plurality of third stator coil groups defining respective stator phases. Each third stator coil group may be comprised of one or more interconnected third stator coils. The power electronics switching assembly of the first electric machine may further include a plurality of third switching module assemblies electrically connected to or between the third machine terminals. Each third switching module assembly may include one or more interconnected third switching modules, each third switching module electrically connected to a respective third stator coil group.

[0076] The third mechanical terminal, the third stator coil group, and the third switching module assembly and the third switching module of the power electronics switching assembly may be configured and controlled as described above.

[0077] The third switching module of the first electric machine may be adapted to be selectively controlled independently (or substantially independently) from the first and second switching modules of the first electric machine. Control strategies may be used to minimise any effects of mutual coupling between the respective parts of the stator winding - i.e., between the first stator coils that are electrically connected to the first switching modules, the second stator coils that are electrically connected to the second stator modules, and the third stator coils that are electrically connected to the third switching modules.

[0078] In general terms, each electric machine in a power system may include two or more sets of machine terminals. Each set of machine terminals may be electrically connected to multiple switching module assemblies. Each set of machine terminals may be electrically connected to a set of machine conductors or conductor assemblies. The number of sets of machine terminals, machine conductors, etc. depends on the requirements of a particular power system. Each set of machine terminals may include any suitable number of individual machine terminals (e.g., a positive DC mechanical terminal and a negative DC mechanical terminal, or two or more AC mechanical terminals).

[0079] The second and third mechanical terminals of the first electric machine may be selectively electrically connected by a third switch. When the third switch is controlled to open, the second and third mechanical terminals and the connected load or power source are electrically isolated (or substantially isolated), and when the third switch is controlled to close, the second and third mechanical terminals are electrically connected. The first and third mechanical terminals of the first electric machine may be electrically connected by a fourth switch. When the fourth switch is controlled to open, the first and third mechanical terminals and the connected load or power source are electrically isolated (or substantially isolated), and when the fourth switch is controlled to close, the first and third mechanical terminals are electrically connected. Thus, the first, third and fourth switches may electrically connect or isolate any two or all three of the first, second and third mechanical terminals of the first electric machine as required. The third and fourth switches may be electrical switches and may include one or more controllable semiconductor switches, e.g., thyristors. For example, an electrical switch designed to pass an AC voltage can be constructed with anti-parallel thyristors to allow bidirectional current flow. Anti-parallel thyristors can also be used when the respective switching modules are configured as voltage source converters with reversible current flow at the DC terminals. Simple thyristors can also be used when the respective switching modules are configured as current source converters with unidirectional current flow at the DC terminals. The electrical switch can further include snubbers, gate drivers, cooling systems, etc. The controllable switches or switches can be controlled to switch on and off by a suitable controller. The controllable switches or switches can be controlled to switch on and off by a suitable controller. If thyristors are used, the commutation of the electrical switch usually needs to be coordinated with the control of the respective switching module assembly. Instead of thyristors, one or more fully controllable semiconductor switches can also be used. The electrical switches can be configured in a series redundant configuration.

[0080] The third (and additional) machine terminals may supply or receive a variable or fixed DC voltage, or a variable or fixed AC voltage, as required.

[0081] In addition to the first and second electric machines, the power system may further include a third electric machine. The third electric machine may be A first mechanical terminal; a stator including a plurality of first stator coil groups defining respective stator phases, each first stator coil group including one or more interconnected first stator coils; a power electronics switching assembly including a plurality of first switching module assemblies electrically connected to or between the first mechanical terminals; Each first switching module assembly includes one or more interconnected first switching modules, each first switching module electrically connected to a respective first stator coil group; The first mechanical terminal of the third electric machine is electrically connected to the first mechanical terminal or the second mechanical terminal of the first electric machine. In other words, the third electric machine is the first or second load mentioned above.

[0082] The third electric machine may be as described above for the first and second electric machines, in particular the first machine terminals, the first stator coil group, and the first switching module assembly and first switching module of the power electronics switching assembly of the third electric machine may be configured and controlled as described above.

[0083] The third electric machine may be a rotating electric machine. In this case, the third electric machine may include a rotor that rotates relative to a stationary stator and is radially spaced from the stator by an air gap. The rotor may have any suitable configuration. The rotor may include rotor windings or may be a permanent magnet rotor including a plurality of permanent magnets circumferentially spaced around the rotor. The permanent magnets may be located on the rotor surface, for example, using a magnet carrier assembly fixed to the rotor surface, or may be held in place using a sleeve or band. The permanent magnets may also be embedded within the rotor.

[0084] The third electric machine may be a linear electric machine, in which case it may include a mover that moves relative to a stationary stator, and the mover may have any suitable configuration.

[0085] The first machine terminal of the third electric machine may be electrically connected to the first or second machine terminal of the first electric machine by a suitable cable or bus.

[0086] The wiring or bus may be electrically connected to the first or second machine terminal of the first electric machine by an isolation switch and / or fuse. The wiring or bus may be electrically connected to the first terminal of the third electric machine by an isolation switch and / or fuse. As mentioned above, the isolation switch may be an electrical switch and may include one or more controllable semiconductor switches, for example thyristors. The one or more controllable switches may be controlled to be on / off by a suitable controller. The isolation switch may be a mechanical isolator.

[0087] The isolation switch can be used to electrically isolate (or substantially isolate) a wire or bus from the first electric machine and / or the third electric machine. If the switching module controlled to provide power is configured as a current source converter, the isolation switch can interrupt the current and can open when the current through the wire or bus is already interrupted.

[0088] It may be preferred that the first mechanical terminal of the first electric machine is electrically connected to the first mechanical terminal of the second electric machine, and the second mechanical terminal of the first electric machine is electrically connected to the first mechanical terminal of the third electric machine. This allows the second electric machine and the third electric machine to be electrically isolated (or substantially isolated) from each other. However, it is also possible that the first mechanical terminals of the second and third electric machines are both electrically connected in parallel to the first mechanical terminal of the first electric machine. When the first electric machine is operated as a generator and the second and third electric machines are operated as motors, for example, the first electric machine can supply power to the second electric machine via an electrical connection between the respective first mechanical terminals of the first and second electric machines, and can supply power to the third electric machine via an electrical connection between the second mechanical terminal of the first electric machine and the first mechanical terminal of the third electric machine. Such power is supplied independently to the second and third electric machines when the first and second mechanical terminals of the first electric machine are electrically isolated, and is supplied in a coordinated manner when the first and second mechanical terminals of the first electric machine are electrically connected, i.e., the first switch is controlled to be closed. When the first switch is controlled to be closed, the first electric machine can supply the same power to one or both of the second and third electric machines from a "common" mechanical terminal. In this case, the second and third electric machines are substantially electrically connected in parallel with respect to the "common" mechanical terminal. When the first mechanical terminals of the second and third electric machines are electrically connected in parallel to the first mechanical terminal of the first electric machine, the second mechanical terminal of the first electric machine may be electrically connected to one or more other second loads or power sources. The second and third electric machines may also be electrically connected in series to the first mechanical terminal of the first electric machine, as will be described in more detail below.

[0089] When the first electric machine is operated as a motor and the second and third electric machines are operated as generators, the first electric machine can receive power from the second electric machine through an electrical connection between the first machine terminals of the first and second electric machines, and can receive power from the third electric machine through an electrical connection between the second machine terminal of the first electric machine and the first machine terminal of the third electric machine. Such power can be received independently from the second and third electric machines if the first and second machine terminals of the first electric machine are electrically isolated, or in a coordinated manner if the first and second machine terminals of the first electric machine are electrically connected, i.e. the first switch is controlled to be closed. If the first switch is controlled to be closed, the first electric machine can receive power from one or both of the second and third electric machines through a "common" machine terminal. The first and second switching modules are preferably controlled in a coordinated manner to drive the rotor of the first electric machine.

[0090] The machine terminals of any electrical machine may be used to transfer or re direct power even if the respective electrical machine is not operating, i.e., if the switching modules associated with a particular set of machine terminals are turned off. For example, the machine terminals of a first electric machine may be used to transfer or redirect power between a second electric machine and a third electric machine when the first electric machine is not operating. This is done by optionally closing the first switch to electrically connect the second and third electrical machines to the “common” machine terminals of the first electrical machine (For example, the machine terminals of the first electrical machine may be used to transfer or re direct power between the second and third electrical machines if the first electrical machine is not operating - optionally by closing the first switch so that the second and third electrical machines are electrically connected to “common” machine terminals of the first electrical machine). Such functionality may resemble a bus section of a conventional linear switchboard that is not electrically connected to the generator.Thus, the interconnected machine terminals may be used as needed to direct power to an electric power system. The machine terminals of two or more electric machines may be interconnected as needed to facilitate the transfer or redirection of power throughout an electric power system. This includes, for example, the interconnection between the machine terminals of two or more electric machines that normally operate as generators or that normally operate as motors.

[0091] It will be apparent to one skilled in the art that the above example can be extended in several different ways to create many different power systems. Each power system can include any suitable number of electric machines having any suitable number of machine terminal sets and machine conductors or conductor assemblies (e.g., one set, two sets, three sets or more) that are electrically connected in different ways between the electric machines and, optionally, to other loads or power sources. The different sets of machine terminals are electrically connected by switches that can be opened or closed as needed. A particular power system having a particular number of electric machines, each electric machine having a particular number of machine terminal sets, and in which the machine terminals are electrically connected in a particular way, can thus be reconfigured as needed (e.g., for different operating conditions) by opening or closing switches to electrically isolate or connect the respective machine terminal sets and associated machine conductors or conductor assemblies. Also, the switching modules of each electric machine can be controlled in any suitable manner, independently or in a coordinated manner, depending on the operating conditions and whether the machine terminals to which the switching modules are electrically connected are isolated or electrically connected to other machine terminals. For example, at one operating condition of the power system, a particular switching module may be controlled to provide a fixed DC voltage and at another operating condition, a variable DC voltage, or vice versa. At one operating condition of the power system, a switching module may be controlled to provide a DC voltage and at another operating condition, a single-phase or multi-phase AC voltage. This can be achieved by simply adjusting the way in which the switching modules are controlled to commutate the coil currents of the stator coil groups when the power system is reconfigured for different operating conditions. The switching modules and their respective machine terminals and conductors can be configured according to the operational flexibility required. This power system is flexible and can be easily adapted to different operating conditions, for example, on a ship. This power system also provides important redundancy with the ability to accommodate faults and component failures.Most importantly, it eliminates the need for separate, physically separate power converters and power distribution boards that are typically required in conventional power systems.

[0092] The rotor of the electric machine, which typically operates as a generator, may be configured to be driven by a prime mover, such as a diesel engine or a gas turbine engine, or other suitable rotary power source or drive, such as a wind turbine assembly or a hydro turbine assembly. The rotor of the electric machine, which typically runs a motor, may be configured to drive a load, such as a propulsion load, for example, if the power system is used on a marine vessel. It will be appreciated that if the electric machine is not a rotating electric machine (e.g., if it is a linear electric machine having a mover), other sources of power and / or loads are used as part of the power system.

[0093] An electric machine that normally operates as a motor may operate as a generator, such as during regenerative braking, and vice versa. In such a situation, the switching module of the electric machine operating as a generator may be controlled to supply power instead of being controlled to drive the rotor. The generated power may be supplied to machine terminals of a second electric machine or to a different machine terminal of the same electric machine (i.e., the power is recirculated within the machine). In some arrangements, the generated or received power may be re directed to another part of the power system. For example, if the second electric machine includes another set of machine terminals that may be electrically connected, for example, to a power network, an optional switch between the sets of machine terminals may be closed so that the received power is supplied to the power network. The power generated by the electric machine is sent to an energy storage device (e.g., a battery, a supercapacitor, a flywheel energy storage system, etc.) or to a dynamic braking system, where it is dissipated as heat. The energy storage device may be electrically connected to the machine terminals of an electric machine operating as a generator, for example during regenerative braking, or to the machine terminals of another electric machine in the power system to which power may be redirected. An electric machine may operate simultaneously as a motor and a generator, with power being received at a first machine terminal and supplied to a second machine terminal, or vice versa. For example, for a rotating electric machine, the input torque on the rotor shaft may be different from its internal torque.In the case of a rotating electrical machine, for example, the input torque on the rotor shaft may be different from its internal torque, i.e. with the exception of power losses associated with electrical machines and power converters having less than 100% efficiency in practice, the air gap torque associated with power delivery to the second machine terminals may be the sum of the input torque on the rotor shaft and the air gap torque associated with power received at the first machine terminals. Recirculating power may be useful in certain operating conditions such as when a prime mover is compromised or where a transient overload occurs.

[0094] In one embodiment, the power system may be implemented as a marine power distribution system, and the present invention may further provide a marine vessel including the power system described above. Prime movers in such a marine power distribution system may be of different types, power ratings, etc. Suitable propulsion loads that may be driven by one or more electric machines when operated as motors may include propellors, thrusters, etc. By eliminating the conventional fixed frequency power distribution network, the shaft speed of the prime movers does not need to be constrained or limited to a particular distribution frequency. Thus, the prime movers and electric machines may be operated at any ideal shaft speed for a given operating condition of the power system.

[0095] As mentioned above, the power system is not limited to offshore applications, but can be used in any land or air based application. [Brief description of the drawings]

[0096] [Figure 1] 1 is a schematic diagram of a known power system for a marine vessel; [Diagram 2] 1 is a schematic diagram of a known electric machine including a power electronics switching assembly with a plurality of switching modules, each switching module electrically connected to a respective stator coil. [Diagram 3] 1 is a schematic diagram of a known switching module; [Figure 4] 1 is a schematic diagram of an electric machine according to the present invention, including a pair of first machine conductors and a pair of second machine conductors, each stator coil group including a single stator coil, and each switching module assembly including a single switching module. [Diagram 5]FIG. 5 is a schematic diagram of the power electronics switching assembly and stator coils of the electric machine of FIG. [Figure 6] 1 is a schematic diagram of a power electronic switching assembly and stator coils of an electric machine according to the present invention, where each stator coil group includes a pair of stator coils connected in series; [Figure 7] FIG. 2 is a schematic diagram of a power electronic switching assembly and stator coil of an electric machine according to the present invention, where each switching module assembly includes a plurality of switching modules connected in series and the switching module assemblies are connected in parallel to the machine conductors. [Figure 8] 1 is a schematic diagram of an electric machine according to the present invention, in which switching module assemblies are interconnected in a chain link configuration; [Figure 9] FIG. 9 is a schematic diagram of the power electronics switching assembly and stator coils of the electric machine of FIG. [Figure 10] FIG. 10 is a schematic diagram of a power electro-switching assembly and a stator coil of an electric machine according to the present invention, in which the switching module assemblies are arranged in parallel-connected groups interconnected in a chain link configuration. [Figure 11] 1 is a schematic diagram of a switching module according to the invention configured as a current source converter; [Figure 12] 1 is a schematic diagram of a switching module according to the invention configured as a voltage source converter; [Figure 13] 2 is a schematic diagram of an electric machine according to the present invention including three sets of first mechanical conductors and three sets of second mechanical conductors; [Figure 14] FIG. 14 is a schematic diagram of the power electronics switching assembly and stator coils of the electric machine of FIG. [Figure 15] 2 is a schematic diagram of a switching module according to the invention configured as a back-to-back current source converter and voltage source converter; [Figure 16]FIG. 5 is a schematic diagram of the electric machine of FIG. 4 including a first switch. [Figure 17] 2 is a schematic diagram of an electric machine according to the present invention including a pair of third machine conductors. [Figure 18] FIG. 18 is a schematic diagram of the power electronics switching assembly and stator coils of the electric machine of FIG. [Figure 19] FIG. 18 is a schematic diagram of the electric machine of FIG. 17 with first, second and third switches. [Figure 20] 1 is a schematic diagram of a first embodiment of a power system according to the present invention; [Figure 21] FIG. 4 is a schematic diagram of a second embodiment of a power system according to the present invention. [Figure 22] FIG. 4 is a schematic diagram of a third embodiment of a power system according to the present invention. [Figure 23] FIG. 11 is a schematic diagram of a fourth embodiment of a power system according to the present invention. [Figure 24] 24 is a schematic diagram illustrating different operating conditions of the third example of the power system shown in FIG. 23. [Diagram 25] 24 is a schematic diagram illustrating different operating conditions of the third example of the power system shown in FIG. 23. [Figure 26] 24 is a schematic diagram illustrating different operating conditions of the third example of the power system shown in FIG. 23. [Figure 27] FIG. 27 is a detailed view of FIGS. 23 to 26 showing the interconnections between the four electric machines. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0097] 4 and 5 are schematic diagrams of an electric machine 100 according to the present invention. The electric machine 100 includes a rotor 102 and a stator 104 separated from the rotor by an air gap. The stator 104 includes a plurality of first stator coils 1061, 1062, ..., 106 n (n is any suitable integer, e.g., 60), and a plurality of second stator coils 1081, 1082, . . . , 108 p(p may be any suitable integer, e.g., 60). In this example, n and p are the same, but may be different. The stator 104 includes a total of 120 stator coils. The stator coils may be single layer coils so that only one coil side is received in a corresponding stator slot or two layer coils so that two coil sides are received in the same stator slot one on top of the other, for example. In Figs. 4 and 5, first and second stator coils 1061, 1062, ..., 106 n , and 1081, 1082, ~, 108 p are shown as being arranged alternately around the circumference of the stator 104, they may be arranged in different ways, for example in groups.

[0098] The power electronics switching assembly of the electric machine 100 includes a plurality of first switching module assemblies 1091, 1092, ..., 109 n and a plurality of second switching module assemblies 1111, 1112, ..., 111 p First switching module assembly 1091, 1092, ~, 109 n Each of the first switching modules 1101, 1102, ..., 110 n and a second switching module assembly 1111, 1112, ~, 111 p Each of the second switching modules 1121, 1122, ..., 112p Includes.

[0099] First stator coils 1061, 1062, ~, 106 n Each of the first switching modules 1101, 1102, ..., 110 n The second stator coils 1081, 1082, . . . , 108 p Each of the second switching modules 1121, 1122, . . . 112 p The first and second switching modules 1101, 1102, . . . , 110 n , 1121, 1122, ~, 112 p are typically arranged on the circumference of the stator 104. (i.e., 60 first switching modules 1101, 1102, . . . , 110 n , and 60 second switching modules 1121, 1122, ~, 112 p ).

[0100] Each stator coil defines a respective stator phase. The electric machine 100 shown in FIGS. 4 and 5 includes n first stator coils 1061, 1062, . . . , 1063, 1064, 1065, 1066, 1067, 1068, 1069, 1070, 1071, 1072, 1073, 1074, 1075, 1076, 1077, 1078, 1079, 1080, 1081, 1082, 1083, 1084, 1085, 1086, 1087, 1088, 1089, 1090, 1091, 1092, 1093, 1094, 1095, n and p second stator coils 1081, 1082, . . . , 1083 that define p second stator phases. p When the electric machine 100 is in operation, the first stator coils 1061, 1062, ..., 106 n defines a plurality of phase-shifted first coil voltages that are rectified by the first switching modules 1101, 1102, ~, 110, and 110. ~, 110 n , second stator coils 1081, 1082, ~, 108 p , the second switching modules 1121, 1122, ~, 112 p defines a plurality of phase-shifted second coil voltages commutated by

[0101] The electric machine 100 includes a pair of first machine conductors 114a, 114b and a pair of second machine conductors 116a, 116b. The machine conductors 114a, 114b and 116a, 116b may be formed as separate annular rings (or "end rings") of a conductive material, for example copper. The end rings may be axially spaced apart so as to be electrically isolated. For the avoidance of any doubt, although in Figure 4 the first and second machine conductors 114a, 114b and 116a, 116b are conveniently represented as pairs of concentric rings around the rotor 102 and the stator 104, in practice they may be formed as axially spaced endrings at an axial end of the stator 104. In particular, a pair of end rings defining the first mechanical conductors 114a, 114b may be positioned at a first axial end of the stator 104, and a pair of end rings defining the second mechanical conductors 116a, 116b may be positioned at the first axial end of the stator 104 or at the second axial end of the stator.

[0102] The first and second mechanical conductors 114a, 114b and 116a, 116b are electrically insulated from each other.

[0103] Each of the first switching modules 1101, 1102, ..., 110n , a pair of module terminals 118a and 118b, i.e., module terminals 118a1, 118b1, 118a2, 118b2, . . . , 118a shown in FIG. n , 118b n The module terminals 118a, 118b are electrically connected to the first mechanical conductors 114a, 114b as shown. In particular, each of the first switching modules 1101, 1102, ..., 110 n The module terminals 118a are electrically connected to the mechanical conductors 114a, and each of the first switching modules 1101, 1102, . . . , 110 n The module terminal 118b is electrically connected to the machine conductor 114b.

[0104] Each of the second switching modules 1121, 1122, ~, 112 p 4 and 5. p , 120b p The module terminals 120a, 120b are electrically connected to the second mechanical conductors 116a, 116b as shown. In particular, each of the second switching modules 1121, 1122, ..., 112 p The module terminals 120a are electrically connected to the mechanical conductors 116a, and each of the second switching modules 1121, 1122, . . . , 112 p The module terminal 120b is electrically connected to the machine conductor 116b.

[0105] In this manner, the first switching modules 1101, 1102, ..., 110 n are electrically connected to the first mechanical conductors 114a, 114b, and the second switching modules 1121, 1122, . . . , 112 p Each of the first stator coils 1061, 1062, . . . , 106 n , and the first switching modules 1101, 1102, ~, 110 nThe second stator coils 1081, 1082, ~, 108 can be arranged circumferentially around the stator 104 and electrically connected to the first machine conductors 114a, 114b at a first axial end of the stator. p and second switching modules 1121, 1122, ~, 112 p may also be circumferentially disposed around the stator 104 and electrically connected to the second machine conductors 116a, 116b at the first or second axial ends of the stator. Alternatively, the first switching modules 1101, 1102, . . . 1101 may be electrically connected to the second machine conductors 116a, 116b at the first or second axial ends of the stator, as shown in FIGS. 8-10 and described below. n are electrically connected using appropriate cables or buses, and the second switching modules 1121, 1122, ~, 112 p can be electrically connected using an appropriate cable or bus.

[0106] The electric machine 100 has a pair of first mechanical terminals 122a, 122b and a pair of second mechanical terminals 124a, 124b, as shown in Figures 4 and 5. The mechanical terminal 122a is electrically connected to the mechanical conductor 114a, and the mechanical terminal 122b is electrically connected to the mechanical conductor 114b. The mechanical terminal 124a is electrically connected to the mechanical conductor 116a, and the mechanical terminal 124b is electrically connected to the mechanical conductor 116b. The first and second mechanical terminals 122a, 122b and 124a, 124b allow external electrical connections to be made to the electric machine 100, for example by means of a suitable cable or bus, as will be described in more detail below. The first and second mechanical terminals 122a, 122b and 124a, 124b can be arranged in a terminal box 125 of the electric machine 100.

[0107] FIG. 6 shows the first switching modules 1101, 1102, . . . 110 n are electrically connected to the two series-connected first stator coils, and each of the second switching modules 1121, 1122, ~, 112 p1 is a schematic diagram of a portion of an alternative electric machine 100 according to the present invention in which a first one of the first switching modules 1101 is electrically connected to two series-connected first stator coils 106-11, 106-21, a second one of the first switching modules 1102 is electrically connected to two series-connected first stator coils 106-12, 106-22, etc. A first one of the second switching modules 1121 is electrically connected to two series-connected second stator coils 108-11, 108-21, and a second one of the second switching modules 1122 is electrically connected to two series-connected second stator coils 108-12, 108-22, etc. Each set of series-connected stator coils (e.g., stator coils 106-11, 106-21) is a stator coil group that defines a respective stator phase, i.e., a position where the coil voltages of the series-connected stator coils are in phase. The electric machine 100 shown in FIG. 6 has n first stator coil groups, each defined by a respective pair of series-connected first stator coils, and p second stator coil groups, each defined by a respective pair of series-connected second stator coils. When the electric machine 100 is operating, the first stator coil groups are switched by first switching modules 1101, 1102, ..., 110 n The second stator coil group defines a plurality of phase-shifted first coil voltages rectified by the second switching modules 1121, 1122, ~, 112 p Each of the first switching modules 1101, 1102, ~, 110 defines a plurality of phase-shifted second coil voltages that are rectified by n may be electrically connected to three or more series-connected first stator coils, and each of the second switching modules 1121, 1122, ~, 112 pIt will be apparent that the first stator coil may be electrically connected to three or more series-connected second stator coils. In all other respects, the electric machine 100 shown in Figure 6 is the same as the electric machines shown in Figures 4 and 5.

[0108] FIG. 7 shows each of the first switching module assemblies 1091, 1092, . . . 109 n / 3 , and each of the second switching module assemblies 1111, 1112, ~, 111 p / 3 1 is a schematic diagram of a portion of an alternative electric machine 100 including three switching modules. It will be apparent that each switching module assembly may include two or more than three switching modules, as desired.

[0109] Each of the first switching module assemblies 1091, 1092, ..., 109 n / 3 The switching modules are arranged in a "chain link" configuration as shown. n / 3 7. The pair of module terminals 118a and 118b, i.e., the module terminals 118a1, 118b1, 118a2, 118b2, . . . , 118a n / 3 , 118b n / 3 which are electrically connected in parallel to a pair of first mechanical conductors 114a, 114b.

[0110] Each of the second switching module assemblies 1111, 1112, ~, 111 p / 3 The switching modules of each second switching module assembly 1111, 1112, . . . , 1111 are arranged in a "chain link" configuration as shown. p / 3 7. The pair of module terminals 120a and 120b, i.e., the module terminals 120a1, 120b1, 120a2, 120b2, . . . , 120a p / 3 , 120b p / 3 and electrically connected in parallel to a pair of second mechanical conductors 116a, 116b.

[0111] In all other respects, the electric machine 100 shown in FIG. 7 is the same as the electric machine shown in FIG. 4 and FIG. 5. Each of the first and second switching modules 1101, 1102, . . . , 110 n and 1121, 1122, ~, 112 p It will be apparent that the can be electrically connected to two or more stator coils as shown in FIG.

[0112] 8 and 9 are schematic diagrams of an alternative electric machine 100 in accordance with the present invention. The electric machine 100 includes a rotor 102 and a stator 104 spaced from the rotor by an air gap. The stator 104 includes a plurality of first stator coils 1061, 1062, ..., 106 n (n is any suitable integer (e.g., 60)), and a plurality of second stator coils 1081, 1082, . . . , 108 p (p may include any suitable integer, e.g., 60). In this example, n and p are the same, but may be different. Stator 104 includes a total of 120 stator coils. The stator coils may be, for example, single layer coils, with only one coil side received in a corresponding stator slot, or double layer coils, with two coil sides received in the same stator slot one above the other. In Figs. 8 and 9, first and second stator coils 1061, 1062, ..., 106 n , 1081, 1082, ~, 108 p Although shown arranged in two groups, the first and second stator coils may be arranged in a different manner, for example, with individual first and second stator coils interleaved or with groups of first and second stator coils interleaved around the stator.

[0113] The power electronics switching assembly of the electric machine 100 includes a plurality of first switching module assemblies 1091, 1092, ..., 109 n and a plurality of second switching module assemblies 1111, 1112, ~, 111 pFirst switching module assembly 1091, 1092, ~, 109 n Each of the first switching modules 1101, 1102, ..., 110 n and a second switching module assembly 1111, 1112, ~, 111 p Each of the second switching modules 1121, 1122, ..., 112 p Includes.

[0114] First stator coils 1061, 1062, ~, 106 n Each of the first switching modules 1101, 1102, ..., 110 n The second stator coils 1081, 1082, . . . , 108 p Each of the second switching modules 1121, 1122, . . . 112 p Each of the first and second switching modules 1101, 1102, . . . , 110 n , 1121, 1122, ~, 112 p It will be apparent that the first and second switching modules 1101, 1102, . . . , 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1200, 1210, 1220, 1230, 1240, 1250, 1260, 1270, 1280, n and 1121, 1122, ~, 112 p are typically arranged on the circumference of the stator 104 and are divided into two groups as shown in the figure. That is, 60 first switching modules 1101, 1102, ..., 110 n and 60 second switching modules 1121, 1122, ~, 112 p It is.

[0115] Each stator coil defines a respective stator phase. When the electric machine 100 is in operation, the first stator coils 1061, 1062, ..., 106 n The first switching module 1101, 1102, ..., 110 n, and a plurality of phase-shifted first coil voltages are defined, which are commutated by the second stator coils 1081, 1082, ~, 108 p , the second switching modules 1121, 1122, ~, 112 p The phase shifted second coil voltages are defined as being commutated by

[0116] Each of the first switching modules 1101, 1102, ..., 110 n 8 and 9, a pair of module terminals 118a and 118b, i.e., module terminals 118a1, 118b1, 118a2, 118b2, . . . , 118a n , 118b n Each of the second switching modules 1121, 1122, ~, 112 p 8 and 9. p , 120b p has.

[0117] The electric machine 100 has a pair of first mechanical terminals 122a, 122b and a pair of second mechanical terminals 124a, 124b. The first and second mechanical terminals 122a, 122b and 124a, 124b may be disposed in a terminal box 125 of the electric machine 100.

[0118] First switching module 1101, 1102, ~, 110 n and second switching modules 1121, 1122, ~, 112 pare arranged in a "chain link" configuration. More specifically, a module terminal 118a1 of a first one of the first switching modules 1101 is electrically connected to one of the first mechanical terminals 122a. A module terminal 118b1 of a first one of the first switching modules 1101 is electrically connected to a module terminal 118a2 of a second one of the first switching modules 1102. A module terminal 118b2 of a second one of the first switching modules 1102 is electrically connected to a module terminal 118a3 of a third one of the first switching modules 1103. n The nth module terminal 118b n is electrically connected to the other one of the first mechanical terminals 122b. Therefore, the first switching modules 1101, 1102, . . . , 110 n The module terminals 118a, 118b are electrically connected in series between the first mechanical terminals 122a, 122b.

[0119] The module terminal 120a1 of a first one of the second switching modules 1121 is electrically connected to one of the second mechanical terminals 124a. The module terminal 120b1 of the first one of the second switching modules 1121 is electrically connected to a module terminal 120a2 of a second one of the second switching modules 1122. The module terminal 120b2 of the second one of the second switching modules 1122 is electrically connected to a module terminal 120a3 of a third one of the second switching modules 1123. p The first module terminal 120b n is electrically connected to another one of the second mechanical terminals 124b. Therefore, the second switching modules 1121, 1122, . . . , 112 p The module terminals 120a, 120b are electrically connected in series between the second mechanical terminals 124a, 124b.

[0120] First and second switching modules 1101, 1102, ~, 110 n , 1121, 1122, ~, 112 p are electrically connected to each other and to their respective machine terminals, for example by suitable cabling or a bus.

[0121] 10 is a schematic diagram of a portion of an alternative electric machine 100 in which the first switching modules are arranged in two separate groups and the second switching modules are arranged in two separate groups. In particular, the first switching modules are arranged in first groups 110-11, 110-12, ..., 110-14, such that half of the first switching modules are in the first group and half of the first switching modules are in the second group. n / 2 and the second group 110-21, 110-22, ~, 110-2 n / 2 The second switching modules are arranged in the first group 112-11, 112-12, . . . , 112-1 such that half of the second switching modules are in the first group and half of the second switching modules are in the second group. p / 2 and the second group 112-21, 112-22, ~, 112-2 p / 2 will be placed in.

[0122] The switching modules of each group are arranged in a "chain link" configuration. More specifically, a module terminal 118a-11 of a first one of the first switching modules 110-11 is electrically connected to one of the first mechanical terminals 122a. A module terminal 118b-11 of a first one of the first switching modules 110-11 is electrically connected to a module terminal 118a-12 of a second one of the first switching modules 110-12. A module terminal 118b-12 of a second one of the first switching modules 110-12 is electrically connected to a module terminal 118a-13 of a third one of the first switching modules 110-13. n / 2 n / 2nd 1 module terminal 118b-1n / 2 is electrically connected to another one of the first mechanical terminals 122b. Therefore, the first switching modules 110-11, 110-12, . . . , 110-1 n / 2 The module terminals 118a-1, 118b-1 (ie, the first group of switching modules) are electrically connected in series between the first mechanical terminals 122a, 122b.

[0123] The module terminal 118a-21 of a first one of the first switching modules 110-21 is electrically connected to one of the first mechanical terminals 122a. The module terminal 118b-21 of a first one of the first switching modules 110-21 is electrically connected to a module terminal 118a-22 of a second one of the first switching modules 110-22. The module terminal 118b-22 of a second one of the first switching modules 110-22 is electrically connected to a module terminal 118a-23 of a third one of the first switching modules 110-23. The module terminal 118b-2 of the n / 2th one of the first switching modules 110-2 is electrically connected to a module terminal 118a-24 of a third one of the first switching modules 110-24. n / 2n / 2 is electrically connected to the other one of the first mechanical terminals 122b. Therefore, the first switching modules 110-21, 110-22, . . . , 110-2 n / 2 The module terminals 118a-2, 118b-2 of the switching modules (i.e., the second group of switching modules) are electrically connected in series between the first mechanical terminals 122a, 122b, and the first group of switching modules 110-11, 110-12, ..., 110-1 n / 2 is electrically connected in parallel with the

[0124] The module terminal 120a-11 of the first one of the second switching modules 112-11 is electrically connected to one of the second mechanical terminals 124a. The module terminal 120b-11 of the first one of the second switching modules 112-11 is electrically connected to a module terminal 120a-12 of a second one of the second switching modules 112-12. The module terminal 120b-12 of the second one of the second switching modules 112-12 is electrically connected to a module terminal 120a-13 of a third one of the second switching modules 112-13. p / 2 p / 2 module terminal 120b-1 p / 2 is electrically connected to the other one of the second mechanical terminals 124b. Therefore, the second switching modules 112-11, 112-12, . . . , 112-1 p / 2 The module terminals 120a-1, 120b-1 (ie, of the first group of switching modules) are electrically connected in series between the second mechanical terminals 124a, 124b.

[0125] The module terminal 120a-21 of the first one of the second switching modules 112-21 is electrically connected to one of the second mechanical terminals 124a. The module terminal 120b-21 of the first one of the second switching modules 112-21 is electrically connected to a module terminal 120a-22 of a second one of the second switching modules 112-22. The module terminal 120b-22 of the second one of the second switching modules 112-22 is electrically connected to a module terminal 120a-23 of a third one of the second switching modules 112-23. The module terminal 120b-2 of the p / 2nd one of the second switching modules 112-2 is electrically connected to a module terminal 120a-24 of a third one of the second switching modules 112-24. p / 2p / 2 is electrically connected to the other one of the second mechanical terminals 124b. Therefore, the second switching modules 112-21, 112-22, . . . , 112-2 p / 2The module terminals 120a-2, 120-2 of the first group of switching modules (i.e., the second group of switching modules) are connected in series between the second mechanical terminals 124a, 124b of the first group of switching modules 112-11, 112-12, ..., 112-1 p / 2 is electrically connected in parallel with the

[0126] In other respects, the electric machine 100 shown in FIG. 10 is the same as the electric machine shown in FIGS.

[0127] 11 shows an individual switching module, i.e., the first switching module 110 or the second switching module 112 (or the third switching module 134, described below). Each switching module includes an H-bridge circuit configured as a current source converter having a pair of AC bridge terminals 126a, 126b electrically connected to a respective stator coil, i.e., the first stator coil 106 or the second stator coil 108 (or the third stator coil 132, described below). Each H-bridge circuit also includes a pair of DC bridge terminals 128a, 128b electrically connected to the module terminals of the switching module, i.e., the module terminals 118a, 118b or 120a, 120b (or 138a, 138b, described below). The DC bridge terminals 128a, 128b may be electrically connected to a mechanical terminal of the electric machine, i.e., for example, one of the pair of first mechanical terminals 122a, 122b or one of the pair of second mechanical terminals 124a, 124b.

[0128] Each H-bridge circuit includes four bidirectional bridge switches S1, S2, S3, S4. Each bridge switch S1, S2, ~, S4 includes a pair of MOSFETs connected in anti series (or back to back), although it will be understood that other possible switch arrangements are described above or known to those skilled in the art. Although an anti parallel diode is shown for each MOSFET in each bridge switch S1, S2, ~, S4, it will be understood that in practice this is provided by the body diode of each MOSFET. For each bridge switch S1, S2, ~, S4, the reverse blocking function is provided by the lower one of the series connected pair of MOSFETs, and the forward blocking function is provided by the upper one of the series connected pair of MOSFETs.

[0129] The bridge switches S1, S2, ..., S4 are controlled on / off by gate drive signals generated by a gate drive controller (not shown). When back-to-back MOSFETs or other back-to-back semiconductor switches are used, the gate drive signal for each switch is routed to both of the semiconductor switches simultaneously. For example, the first gate drive signal is routed to both MOSFETs of bridge switch S1 simultaneously. This means that both MOSFETs of each bridge switch are turned on / off simultaneously by their respective gate drive signals.

[0130] FIG. 12 shows an individual switching module, i.e. the first switching module 110 or the second switching module 112 (or the third switching module 134 described below). Each switching module includes an H-bridge circuit configured as a voltage source converter with a pair of AC bridge terminals 126a, 126b electrically connected to a respective stator coil, i.e. the first stator coil 106 or the second stator coil 108 (or the third stator coil 132 described below). Each H-bridge circuit also includes a pair of DC bridge terminals 128a, 128b electrically connected to the module terminals of the switching module, i.e. the module terminals 118a, 118b or 120a, 120b (or 138a, 138b described below). The DC bridge terminals 128a, 128b may also be electrically connected to the mechanical terminals of the electric machine, i.e. for example one of the pair of first mechanical terminals 122a, 122b or one of the pair of second mechanical terminals 124a, 124b.

[0131] Each H-bridge circuit includes four unidirectional bridge switches S1, S2, S3, and S4. Each bridge switch S1, S2, ..., S4 includes an IGBT and is connected to an anti-parallel diode. The bridge switches S1, S2, ..., S4 are controlled to be turned on and off by a gate drive signal generated by a gate drive controller (not shown).

[0132] The electric machine 100 shown in FIGS. 4 to 10 includes first switching modules 1101, 1102, . . . 110 n The second switching modules 1121, 1122, ~, 1123, ~, 1124, ~, 1125, ~, 1126, ~, 1127, ~, 1128, ~, 1129, ~, 1210, ~, 1211, ~, 1212, ~, 1213, ~, 1214, ~, 1215, ~, 1216, ~, 1217, ~, 1218, ~, 1219, ~, 1220, ~, 1221, ~, 1222, ~, 1223, ~, 1224, ~, 1225, ~, 1226, ~, 1227, ~, 1228, ~, 1229, ~, 1230, ~, 1231, ~, 1232, ~, 1233, ~, 1234, ~, 1235, ~, 1236, ~, 1237, ~, 1238, ~, 1239 ... pcan be controlled or receive a variable or fixed DC voltage via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b. More specifically, one of the second mechanical conductors 116a is a positive DC conductor and one of the second mechanical terminals 124a is a positive DC terminal. The other of the second mechanical conductors 116b is a negative DC conductor and the other of the second mechanical terminals 124b is a negative DC terminal.

[0133] 13 and 14 are schematic diagrams of an alternative electric machine 100 according to the present invention. The electric machine 100 includes a rotor 102 and a stator 104 separated from the rotor by an air gap. The stator 104 includes a plurality of first stator coils 1061, 1062, ..., 106 n (n is any suitable integer (e.g., 60)), and a plurality of second stator coils 1081, 1082, . . . , 108 p (p may include any suitable integer, e.g., 60). In this example, n and p are the same, but may be different. Stator 104 includes a total of 120 stator coils. The stator coils may be, for example, single layer coils, such that only one coil side is received in a corresponding stator slot, or double layer coils, such that two coil sides are received in the same stator slot above the other one. In Figs. 13 and 14, first and second stator coils 1061, 1062, ..., 106 n , and 1081, 1082, ~, 108 p are shown as being arranged alternately around the circumference of the stator 104, but may be arranged in a different manner, for example in groups.

[0134] The power electronics switching assembly of the electric machine 100 includes a plurality of first switching module assemblies 1091, 1092, ..., 109 n and a plurality of second switching module assemblies 1111, 1112, ~, 111 p First switching module assembly 1091, 1092, ~, 109 nEach of the first switching modules 1101, 1102, ..., 110 n and a second switching module assembly 1111, 1112, ~, 111 p Each of the second switching modules 1121, 1122, ..., 112 p Includes.

[0135] First stator coils 1061, 1062, ~, 106 n Each of the first switching modules 1101, 1102, ..., 110 n The second stator coils 1081, 1082, . . . , 108 p Each of the second switching modules 1121, 1122, . . . 112 p The first and second switching modules 1101, 1102, . . . , 110 n , 1121, 1122, ~, 112 p are typically arranged on the circumference of the stator 104. (i.e., 60 first switching modules 1101, 1102, . . . , 110 n , and 60 second switching modules 1121, 1122, ~, 112 p ).

[0136] Each stator coil defines a respective stator phase. The electric machine 100 shown in FIGS. 13 and 14 includes n first stator coils 1061, 1062, . . . , 1063, 1064, 1065, 1066, 1067, 1068, 1069, 1070, 1071, 1072, 1073, 1074, 1075, 1076, 1077, 1078, 1079, 1080, 1081, 1082, 1083, 1084, 1085, 1086, 1087, 1088, 1089, 1090, 1091, 1092, 1093, 1094, 109 n and p second stator coils 1081, 1082, . . . , 1083 that define p second stator phases. p When the electric machine 100 is in operation, the first stator coils 1061, 1062, ..., 106 n The first switching module 1101, 1102, ..., 110 n , and a plurality of phase-shifted first coil voltages are rectified by 110, and the second stator coils 1081, 1082, ~, 108 p, the second switching modules 1121, 1122, ~, 112 p When the electrical machine 100 is operating, the first stator coils 1061, 1062, ..., 106n define a plurality of phase shifted first coil voltages that are commutated by the first switching modules 1101, 1102, ..., 110n, and the second stator coils 1081, 1082, ..., 108p define a plurality of phase-shifted second coil voltages that are commutated by the second switching modules 1121, 1122, ..., 112p.

[0137] The electric machine 100 includes a triplet of first mechanical conductors 114a, 114b, and 114c and a triplet of second mechanical conductors 116a, 116b, and 116c. The mechanical conductors 114a, 114b, 114c and 116a, 116b, and 116c may be formed as separate annular rings (or "end rings") of a conductive material, for example copper. The end rings may be axially spaced apart so as to be electrically isolated. For the avoidance of doubt, in FIG. 13 the first and second mechanical conductors 114a, 114b, and 114c and 116a, 116b, and 116c are conveniently represented as pairs of concentric rings around the rotor 102 and stator 104, but in practice may be formed as axially spaced apart end rings at the axial ends of the stator 104. In particular, the three sets of end rings defining the first mechanical conductors 114a, 114b, 114c may be positioned at a first axial end of the stator 104, and the three sets of end rings defining the second mechanical conductors 116a, 116b, 116c may be positioned at the first axial end of the stator 104 or at the second axial end of the stator.

[0138] The first and second mechanical conductors 114a, 114b and 114c, and 116a, 116b and 116c are electrically insulated from one another.

[0139] Each of the first switching modules 1101, 1102, ..., 110 n , three sets of module terminals 118a, 118b, and 118c, that is, module terminals 118a1, 118b1, 118c1, 118a2, 118b2, 118c2, . . . , 118a shown in FIG. 13 and FIG. 14. n , 118b n , 118c n The module terminals 118a, 118b, 118c are electrically connected to the first mechanical conductors 114a, 114b, 114c as shown. In particular, each of the first switching modules 1101, 1102, ..., 110 nThe module terminals 118a are electrically connected to the mechanical conductors 114a, and each of the first switching modules 1101, 1102, . . . , 110 n The module terminals 118b are electrically connected to the mechanical conductors 114b, and each of the first switching modules 1101, 1102, . . . , 110 n The module terminal 118c is electrically connected to the machine conductor 114c.

[0140] Each of the second switching modules 1121, 1122, ~, 112 p 13 and 14, the three sets of module terminals 120a, 120b, and 120c, that is, the module terminals 120a1, 120b1, 120c1, 120a2, 120b2, 120c2, . . . , 120a p , 120b p , 120c p The module terminals 120a, 120b, 120c are electrically connected to the second mechanical conductors 116a, 116b, 116c as shown. In particular, each of the second switching modules 1121, 1122, ..., 112 p The module terminals 120a are electrically connected to the mechanical conductors 116a, and each of the second switching modules 1121, 1122, . . . , 112 p The module terminal 120b is electrically connected to the mechanical conductor 116b, and each of the second switching modules 1121, 1122, . . . , 112 p The module terminal 120c is electrically connected to the machine conductor 116c.

[0141] In this manner, the first switching modules 1101, 1102, ..., 110 n are electrically connected to the first mechanical conductors 114a, 114b, 114c, and the second switching modules 1121, 1122, . . . , 112 p Each of the first stator coils 1061, 1062, . . . , 106 n , first switching module 1101, 1102, ~, 110 nThe second stator coils 1081, 1082, . . . , 1083, 1084, 1085, 1086, 1087, 1088, 1089, 1090, 1091, 1092, 1093, 1094, 1095, 1096, 1097, 1098, 1099, 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1008, 1009, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, p and second switching modules 1121, 1122, ~, 112 p may likewise be circumferentially disposed about the stator 104 and electrically connected to second machine conductors 116a, 116b, 116c at the first or second axial ends of the stator.

[0142] The electric machine 100 has three sets of first mechanical terminals 122a, 122b, and 122c and three sets of second mechanical terminals 124a, 124b, and 124c, as shown in Figures 13 and 14. The mechanical terminals 122a are electrically connected to the mechanical conductors 114a, the mechanical terminals 122b are electrically connected to the mechanical conductors 114b, and the mechanical terminals 122c are electrically connected to the mechanical conductors 114c. The mechanical terminals 124a are electrically connected to the mechanical conductors 116a, the mechanical terminals 124b are electrically connected to the mechanical conductors 116b, and the mechanical terminals 124c are electrically connected to the mechanical conductors 116c. The first and second mechanical terminals 122a, 122b, and 122c, as well as 124a, 124b, and 124c, allow external electrical connections to be made to the electric machine 100, for example, using a suitable cable or bus, as will be described in more detail below. The first and second machine terminals 122 a , 122 b and 122 c and 124 a , 124 b and 124 c may be disposed in a terminal box 125 of the electric machine 100 .

[0143] The electric machine 100 shown in FIGS. 13 and 14 includes first switching modules 1101, 1102, . . . , 110 nThe second switching modules 1121, 1122, . . . are configured to be controlled to supply or receive a variable or fixed three-phase AC voltage via the first mechanical conductors 114a, 114b, 114c and the first mechanical terminals 122a, 122b, 122c. More specifically, each of the first mechanical conductors 114a, 114b, 114c is an AC conductor, and each of the first mechanical terminals 122a, 122b, 122c is an AC terminal that defines a respective AC phase. p can be controlled to supply or receive a variable or fixed three-phase AC voltage via second machine conductors 116a, 116b, 116c and second machine terminals 124a, 124b, 124c. More specifically, each of the second machine conductors 116a, 116b, 116c is an AC conductor, and each of the second machine terminals 124a, 124b, 124c is an AC terminal that defines a respective phase. Additional machine terminals and conductors (not shown) can be included to define a neutral point.

[0144] 15 shows an individual switching module, i.e., first switching module 110 or second switching module 112. Each switching module includes an H-bridge circuit configured as a current source converter with a pair of AC bridge terminals electrically connected to a respective stator coil, i.e., first stator coil 106 or second stator coil 108. The H-bridge circuit also includes a pair of DC bridge terminals.

[0145] The H-bridge circuit includes four bidirectional bridge switches S1, S2, S3, S4. Each bridge switch S1, S2, ~, S4 includes a pair of MOSFETs connected in anti series (or back to back), although it will be understood that other possible switch arrangements are described above or known to those skilled in the art. Although an anti parallel diode is shown for each MOSFET in each bridge switch S1, S2, ~, S4, it will be understood that in practice this is provided by the body diode of each MOSFET. For each bridge switch S1, S2, ~, S4, the reverse blocking function is provided by the lower one of the pair of anti-parallel connected MOSFETs, and the forward blocking function is provided by the upper one of the pair of anti-parallel connected MOSFETs.

[0146] The bridge switches S1, S2, ..., S4 of the H-bridge circuit are controlled on / off by gate drive signals generated by a gate drive controller (not shown). When back-to-back MOSFETs or other back-to-back semiconductor switches are used, the gate drive signal of each switch is routed to both of the semiconductor switches simultaneously. For example, the first gate drive signal is routed to both MOSFETs of bridge switch S1 simultaneously. This means that both MOSFETs of each bridge switch are turned on / off simultaneously by the respective gate drive signal.

[0147] Each switching module includes a Graetz bridge circuit configured as a voltage source converter with a triplet of AC bridge terminals electrically connected to the module terminals of the switching module, i.e., module terminals 118a, 118b, 118c or 120a, 120b, 120c. The Graetz bridge circuit also includes a pair of DC bridge terminals electrically connected to the DC bridge terminals of the H-bridge circuit by a DC link. The DC link includes a capacitor and an inductor as shown.

[0148] The Gretz bridge circuit includes six unidirectional bridge switches S1, S2, ..., S6. Each bridge switch S1, S2, ..., S6 includes an IGBT and is connected to an anti-parallel diode. The bridge switches S1, S2, ..., S6 are controlled to be turned on and off by a gate drive signal generated by a gate drive controller (not shown).

[0149] Each switching module also includes an AC filter (not shown).

[0150] 13 and 14 may supply or receive DC voltages and may also supply or receive AC voltages. For example, two of the first and / or second machine conductors may be configured as positive and negative DC conductors and two of the first and / or second machine terminals may be configured as positive and negative DC terminals. The first and / or second switching modules 1101, 1102, ..., 110 n , and 1121, 1122, ~, 112 p When the switching modules 1101, 1102, ..., 1103 are configured as shown in FIG. 15, the Gratz bridge circuit of each switching module is bypassed or placed in a suitable operating state, so that the first and / or second switching modules 1101, 1102, ..., 1103 are not n , 1121, 1122, ~, 112 p, may be operated to supply or receive a DC voltage. (If the first and / or second switching modules 1101, 1102, ... 110n and 1121, 1122, ... 112p are configured as shown in Figure 15, the Graetz bridge circuit of each switching module may be bypassed or placed in a suitable operating state so that the first and / or second switching modules 1101, 1102, ... 110n and 1121, 1122, ... 112p may be operated to supply or may receive a DC voltage.) In other words, the first and / or second switching modules 1101, 1102, ... 110 n , 1121, 1122, ~112. 112 p Depending on how the first and / or second switching modules 1101, 1102, 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1200, 1210, 1220, 1230, 1240, 1250, 1260, 1270, 1280, 1290, 1300, 1310, 1320, 1330, 1340, 1350, 1360, 1370, 1380, 1390, 1400, 1410, 1420, 1430, 1440, 1450, 1460, 1470, 1480, 1490, 1500, 1510, 1520, 1530, 1540, 1550, 1560, 1570, 1580, 1590, 1600, 1610, 1620, 1630, 1640, 1650, 1660, 1670, 1680, 1690, 1700, 1710, 1720, 1730, 1740, 1750, 1760, 1770, 1780, 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880, 1890, 1900, 1910, 1920, 1930, 1 n , 1121, 1122, ~112. 112 pDepending on how the first and / or second switching modules 1101, 1102, ... 110n and 1121, 1122, ... 112p are configured, an electrical machine configured as shown in Figures 4 to 10 - i.e., with a pair of first and second machine conductors 114a, 114b and 116a, 116b that are normally configured as positive and negative DC conductors and a pair of first and second machine terminals 122a, 122b and 124a, 124b that are normally configured as positive and negative DC conductors, may also be used to supply or receive a single-phase AC voltage. 122a, 122b and 124a, 124b that are normally configured as positive and negative DC conductors - may also be used to supply or receive a single-phase AC voltage, for example). A particular set of machine conductors and machine terminals may be designed for flexible use, for example with the option to transmit DC or AC voltages as required. In this case, each switching module is normally configured to be able to supply or receive DC and AC voltages. A particular machine conductor and machine terminal may be used inflexibly, for example designed to transmit only a variable or fixed DC voltage, and each switching module may be configured accordingly, for example as shown in FIGS. 11 and 12.

[0151] When the electric machine 100 shown in any of FIGS. 4 to 10 is operated as a generator, the first switching modules 1101, 1102, ..., 110 n The second switching modules 1121, 1122, . . . , 1123 can supply power to one or more first loads (not shown) via the first machine conductors 114a, 114b and the first machine terminals 122a, 122b. p 13 and 14 can supply power to one or more second loads (not shown) via second machine conductors 116a, 116b and second machine terminals 124a, 124b. When the electric machine shown in FIG. 13 and FIG. 14 is operated as a generator, the first switching modules 1101, 1102, . . . , 110 n The second switching modules 1121, 1122, . . . , 1123 can supply power to one or more first loads (not shown) via the first mechanical conductors 114a, 114b, 114c and the first mechanical terminals 122a, 122b, 122c. p , power may be supplied to one or more second loads (not shown) via second machine conductors 116a, 116b, 116c and second machine terminals 124a, 124b, 124c.

[0152] When the electric machine 100 shown in any one of FIGS. 4 to 10 is operated as a motor, the first switching modules 1101, 1102, ..., 110 n can receive power from one or more first power sources (not shown) via the first mechanical terminals 122a, 122b and the first mechanical conductors 114a, 114b. p can receive power from one or more second power sources (not shown) via second machine terminals 124a, 124b and second machine conductors 116a, 116b. When the electric machine 100 shown in FIGS. 13 and 14 is operated as a motor, the first switching modules 1101, 1102, . . . , 110 ncan receive power from one or more first power sources (not shown) via the first mechanical terminals 122a, 122b, 122c and the first mechanical conductors 114a, 114b, 114c. p can receive power from one or more second power sources (not shown) via second mechanical terminals 124a, 124b, 124c and second mechanical conductors 116a, 116b, 116c. n , 1121, 1122, ~, 112 p may be controlled in unison to drive the rotation of the rotor 102.

[0153] One or more first loads or power sources (not shown) may be electrically connected to the pair of first mechanical terminals 122a, 122b (or three sets of first mechanical terminals 122a, 122b and 122c), for example, using a suitable cable or bus.

[0154] One or more second loads or power sources (not shown) may be electrically connected to the pair of second mechanical terminals 124a, 124b (or to the triplet of first mechanical terminals 124a, 124b, 124c), for example, using a suitable cable or bus.

[0155] First switching module 1101, 1102, ~, 110 n , the second switching modules 1121, 1122, ~, 112 p For example, the first switching modules 1101, 1102, ..., 110 n , the second switching modules 1121, 1122, ~, 112 p , may be controlled to supply different variable DC voltages, fixed DC voltages, or fixed or variable AC voltages. n, the second switching module 1121, 1122, ~, 112 p , for example, can receive different variable DC voltages, fixed DC voltages, or fixed or variable AC voltages because the first mechanical conductors 114a, 114b are electrically isolated from the second mechanical conductors 116a, 116b and the first mechanical terminals 122a, 122b are electrically isolated from the second mechanical terminals 124a, 124b.

[0156] Figure 16 shows the electric machine 100 of Figures 4 and 5 with a first switch 130 electrically connected between the first mechanical conductors 114a, 114b and the second mechanical conductors 116a, 116b. The first switch 130 may also be electrically connected between the first mechanical terminals 122a, 122b and the second mechanical terminals 124a, 124b and may be located in the terminal box 125, for example.

[0157] The first switch 130 may be an electrical switch and may include one or more controllable semiconductor switches, for example thyristors. When the first switch 130 is controlled to an open state, for example by a suitable controller (not shown), the first and second mechanical conductors 114a, 114b and 116a, 116b are electrically isolated from each other. This is because the first switching modules 1101, 1102, ..., 110 n As described above, the second switching modules 1121, 1122, . . . , 112 pThis means that the first and second machine conductors 114a, 114b and 116a, 116b can be controlled independently from each other. However, when the first switch 130 is controlled to be closed, for example, by the controller, the first and second machine conductors 114a, 114b and 116a, 116b are electrically connected to form a "common" machine conductor and a "common" machine terminal. In particular, the machine conductor 114a is electrically connected to the machine conductor 116a, and the machine conductor 114b is electrically connected to the machine conductor 116b by the first switch 130. The electrically connected machine conductors 114a and 116a can form a "common" positive DC conductor, and the electrically connected machine conductors 114b and 116b can form a "common" negative DC conductor. Alternatively, the electrically connected machine conductors 114a and 116a can form a "common" first AC conductor for a first AC phase, and the electrically connected machine conductors 114b and 116b can form a "common" second AC conductor for a neutral or vice versa. (For the electric machines shown in Figures 13 and 14, similar switches can be used to form a "common" second AC conductor for the second AC phase and a "common" third AC conductor for the third AC phase). The electrically connected machine terminals 122a and 124a can form a "common" positive DC terminal and the electrically connected machine terminals 122b and 124b can form a "common" negative DC terminal. Alternatively, the electrically connected machine terminals 122a and 124a can form a "common" first AC conductor for the first AC phase and the electrically connected machine terminals 122b and 124b can form a "common" second AC conductor for the neutral or vice versa. (For the electric machines shown in Figures 13 and 14, similar switches can be used to form a "common" second AC terminal for the second AC phase and a "common" third AC terminal for the third AC phase).

[0158] First and second switching modules 1101, 1102, ~, 110 n , 1121, 1122, ~, 112 p are electrically connected to a "common" pair of machine conductors and their control can be coordinated.

[0159] When the electric machine 100 is operated as a generator, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p can supply power to one or more first loads (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or supply power to one or more second loads (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b. Depending on requirements, the first and second switching modules 1101, 1102, ~, 110 n and 1121, 1122, ~, 112 p It will be readily appreciated that the power supply may operate either or both of the first and second loads (not shown) depending on requirements.

[0160] When the electric machine 100 operates as a motor, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p can receive power from one or more first power sources (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or from one or more second power sources (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b. Depending on requirements, the first and second switching modules 1101, 1102, ~, 110 n and 1121, 1122, ~, 112 p It will be readily understood that one or both of the first and second switching modules 1101, 1102, . . . may be operated. Also, depending on requirements, power may be provided from one or both of the first and second power sources (not shown). n , 1121, 1122, ~, 112 pcan be controlled cooperatively to drive the rotation of the rotor 102.

[0161] FIG. 16 also shows how the cabling or bus 150 is electrically connected to the first machine terminals 122a, 122b by the isolation switches 127a, 127b, and how the cabling or bus 160 is electrically connected to the second machine terminals 124a, 124b by the isolation switches 129a, 129b. The isolation switches 127a, 127b and 129a, 129b may be electrical switches and may include one or more controllable semiconductor switches, for example thyristors. The one or more controllable switches may be controlled to be switched on and off by a suitable controller. The isolation switches 127a, 127b and 129a, 129b may also be mechanical isolators.

[0162] In other respects, the electric machine 100 shown in FIG. 16 is the same as the electric machine shown in FIGS.

[0163] 17 and 18 show a plurality of third stator coils 1321, 1322, . . . 132 q 13 is a schematic diagram of an alternative electric machine 100 including a power electronics switching assembly 1331, 1332, . . . , 1333, where q is any suitable integer (e.g., forty (40)). q The third switching module assembly 1331, 1332, ~, 133 q Each of the third switching modules 1341, 1342, ..., 134 q Includes.

[0164] Third stator coils 1321, 1322, ~, 132 q Each of the third switching modules 1341, 1342, ..., 134 q As described above, the first stator coils 1061, 1062, . . . , 106 nEach of the first switching modules 1101, 1102, ..., 110 n The second stator coils 1081, 1082, . . . , 108 p Each of the second switching modules 1121, 1122, . . . 112 p In this example, n and p are also 40, so the stator 104 includes a total of 120 stator coils. The first, second and third switching modules 1101, 1102, . . . , 110, n 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 q are typically arranged on the circumference of the stator 104. That is, 40 first switching modules 1101, 1102, . . . , 110 n , 40 second switching modules 1121, 1122, ~, 112 p , and 40 third switching modules 1341, 1342, ~, 134 q Therefore, it can be seen that the inclusion of multiple third switching modules does not increase the total number of switching modules in the power electronic switching assembly overall. However, the total number of switching modules can be increased if there is sufficient space to accommodate the switching modules.

[0165] Each stator coil defines a respective stator phase. The electric machine 100 shown in FIGS. 17 and 18 includes n first stator coils 1061, 1062, . . . , 1063, which define n first stator phases. n and p second stator coils 1081, 1082, . . . , 1083 that define p second stator phases. p and q third stator coils 1321, 1322, . . . , 1323 defining q third stator phases. q When the electric machine 100 is in operation, the first stator coils 1061, 1062, ..., 106 n The first switching module 1101, 1102, ..., 110n defines a plurality of phase-shifted first coil voltages that are rectified by the second stator coils 1081, 1082, ~, 108 defines a plurality of phase-shifted second coil voltages. p , the second switching modules 1121, 1122, ~, 112 p , and a third stator coil 1321, 1322, ~, 132 q , the third switching module 1341, 1342, ~, 134 q defines a plurality of phase-shifted third coil voltages commutated by

[0166] The electric machine 100 includes a pair of first mechanical conductors 114a, 114b and a pair of second mechanical conductors 116a, 116b. The electric machine 100 also includes a pair of third mechanical conductors 136a, 136b, which may be formed as separate annular rings (or "end rings") of a conductive material, such as copper. The pair of end rings that define the third mechanical conductors 136a, 136b may be located at either the first or second axial ends of the stator 104.

[0167] Each of the third switching modules 1341, 1342, ..., 134 q 17 and 18. q , 138b q The module terminals 138a, 138b are electrically connected to the third mechanical conductors 136a, 136b as shown. In particular, each of the third switching modules 1341, 1342, ..., 134 q The module terminals 138a are electrically connected to the machine conductors 136a, and each of the third switching modules 1341, 1342, . . . , 134 q The module terminal 138b of the third switching module 1341, 1342, . . . , 1343 is electrically connected to the mechanical conductor 136b. qEach of the third stator coils 1321, 1322, . . . , 132 is electrically connected to a third mechanical conductor 136a, 136b. q , and the third switching modules 1341, 1342, ~, 134 q are arranged circumferentially around the stator 104, and electrical connections can be made to third mechanical conductors 136a, 136b at the first or second axial ends of the stator. Alternatively, the first, second and third switching modules 1101, 1102, ..., 1103 can be connected to a first axial end of the stator 104, as shown in Figures 8-10 and described above. n , 1121, 1122, ~, 112 p , and 1341, 1342, ~, 134 q may be electrically connected using a suitable cable or bus.

[0168] The electric machine 100 has a pair of third mechanical terminals 140a, 140b, as shown in Figures 17 and 18. The mechanical terminal 140a is electrically connected to the mechanical conductor 136a, and the mechanical terminal 140b is electrically connected to the mechanical conductor 136b. The third mechanical terminals 140a, 140b allow additional external electrical connections to be made to the electric machine 100, for example, using a suitable cable or bus. The third mechanical terminals 140a, 140b can be arranged in the terminal box 125 together with the first and second mechanical terminals 122a, 122b and 124a, 124b.

[0169] In other respects, the electric machine 100 shown in FIGS. 17 and 18 is the same as the electric machine shown in FIGS.

[0170] When the electric machine 100 is operated as a generator, the third switching modules 1341, 1342, ..., 134 q can supply power to one or more third loads (not shown) via third machine conductors 136a, 136b and third machine terminals 140a, 140b. When the electric machine 100 operates as a motor, the third switching modules 1341, 1342, ..., 134 qmay receive power from one or more third power sources (not shown) via third mechanical terminals 136a, 136b and third mechanical conductors 140a, 140b. One or more third loads or power sources (not shown) may be electrically connected to the pair of third mechanical terminals 140a, 140b.

[0171] The third switching module 1341, 1342, ~, 134 q can be controlled to supply or receive a variable or fixed DC voltage via the third mechanical conductors 136a, 136b and the third mechanical terminals 140a, 140b. In this case, the third mechanical conductors can include a positive DC conductor (e.g., mechanical conductor 136a) and a negative DC conductor (e.g., mechanical conductor 136b). Also, the third mechanical terminals can include a positive DC terminal (e.g., mechanical terminal 140a) and a negative DC terminal (e.g., mechanical terminal 140b). The third switching modules 1341, 1342, ~, 134 q The first and second switching modules 1101, 1102, . . . , 110 n and 1121, 1122, ~, 112 p can be controlled in the same manner.

[0172] The third switching module 1341, 1342, ~, 134 qcan be controlled to supply or receive a variable or fixed AC voltage via the third machine conductors 136a, 136b and the third machine terminals 140a, 140b. In this case, the third machine conductors can include a first AC conductor for a first AC phase (e.g., machine conductor 136a) and a second AC conductor for a neutral (e.g., machine conductor 136b) or vice versa. The third machine terminals can also include a first AC terminal for a first AC phase (e.g., machine terminal 140a) and a second AC terminal for a neutral or vice versa (e.g., machine terminal 140b). If the electric machine includes three sets of third machine conductors and three sets of third machine terminals, it can supply or receive a three-phase AC voltage - see, for example, the electric machine shown in Figures 13 and 14.

[0173] The third switching module 1341, 1342, ~, 134 q The first and second switching modules 1101, 1102, . . . , 110 n and 1121, 1122, ~, 112 p can be controlled in the same manner.

[0174] The third switching module 1341, 1342, ~, 134 q The first switching module 1101, 1102, ..., 110 n and second switching modules 1121, 1122, ~, 112 p For example, the first and second switching modules 1101, 1102, ..., 110 n , and 1121, 1122, ~, 112 p can be controlled to supply a variable DC voltage, and the third switching module 1341, 1342, ~, 134 qcan be controlled to supply a fixed DC voltage, or a fixed or variable AC voltage, because the third mechanical conductors 136a, 136b are electrically isolated from the first and second mechanical conductors 114a, 114b and 116a, 116b, and the third mechanical terminals 140a, 140b are electrically isolated from the first and second mechanical terminals 122a, 122b and 124a, 124b.

[0175] 19 shows an electric machine 100 having a first switch 130 electrically connected between the first mechanical conductors 114a, 114b and the second mechanical conductors 116a, 116b. A second switch 142 is electrically connected between the second mechanical conductors 116a, 116b and the third mechanical conductors 136a, 136b. A third switch 144 is electrically connected between the first mechanical conductors 114a, 114b and the third mechanical conductors 136a, 136b. The first, second and third switches 130, 142 and 144 may be electrically connected between their respective mechanical terminals and may be located in a terminal box 125.

[0176] The first, second and third switches 130, 142 and 144 may be electrical switches and may include one or more controllable semiconductor switches, such as thyristors.

[0177] When the first, second and third switches 130, 140 and 142 are controlled to an open state, for example by a suitable controller (not shown), the first, second and third mechanical conductors 114a, 114b, 116a, 116b and 136a, 136b are electrically isolated from each other. This is because the first, second and third switching modules 1101, 1102, ..., 110 n , 1121, 1122, ~, 112 p , 1341, 1342, ~, 134 q This means that the two can be controlled independently.

[0178] When the first switch 130 is controlled to be closed, for example, by the controller, the first and second machine conductors 114a, 114b and 116a, 116b are electrically connected to form a "common" pair of machine conductors. In particular, the machine conductor 114a is electrically connected to the machine conductor 116a, and the machine conductor 114b is electrically connected to the machine conductor 116b. For example, the machine conductors 114a and 116a can form a "common" positive DC conductor, and the machine conductors 114b and 116b can form a "common" negative DC conductor. Alternatively, the machine conductors 114a and 116a can form a "common" first AC conductor for the first AC phase, and the machine conductors 114b and 116b can form a "common" second AC conductor for the neutral or vice versa. The mechanical terminals 122a and 124a may form a “common” positive DC terminal or a “common” first AC terminal for a first AC phase, and the mechanical terminals 122b and 124b may form a “common” negative DC terminal or a “common” second AC terminal for a neutral point. n , 1121, 1122, ~, 112 p are electrically connected to a "common" pair of machine conductors and their control can be coordinated.

[0179] When the electric machine 100 is operated as a generator, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p can supply power to one or more first loads (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or supply power to one or more second loads (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b. Depending on requirements, the first and second switching modules 1101, 1102, ~, 110 n and 1121, 1122, ~, 112 pIt will be readily understood that the third switching module 1341, 1342, . . . may be operated in the same manner as ...2, . . . may be operated in the same manner as the third switching module 1343, 1344, . . . may be operated in the same manner as the third switching module 1344, 1345, . . . may be operated in the same manner as the third switching module 1345, 1346, . . . may be operated in the same manner as the third switching module 1346, 1347, . . . may be operated in the same manner as the third switching module 1347, 1348, . . . may be operated in the same manner as the third switching module 1349, 1349 q may also be used to independently power one or more third loads (not shown).

[0180] When the electric machine 100 operates as a motor, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p can receive power from one or more first power sources (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or from one or more second power sources (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b. Depending on requirements, the first and second switching modules 1101, 1102, ~, 110 n and 1121, 1122, ~, 112 p It will be readily understood that one or both of the first and second power sources may be operated. Depending on requirements, power may be provided from one or both of the first and second power sources (not shown). Power may also be provided from one or more third power sources (not shown) via third machine conductors 136a, 136b and third machine terminals 140a, 140b to the third switching modules 1341, 1342, ..., 1343. q The first and second switching modules 1101, 1102, ..., 110 n , 1121, 1122, ~, 112 p can be coordinately controlled to drive the rotation of the rotor 102.

[0181] When the second switch 142 is controlled to be closed, for example, by the controller, the second and third machine conductors 116a, 116b and 136a, 136b are electrically connected to form a "common" pair of machine conductors. In particular, the machine conductor 116a is electrically connected to the machine conductor 136a, and the machine conductor 116b is electrically connected to the machine conductor 136b. For example, the machine conductors 116a and 136a can form a "common" positive DC conductor, and the machine conductors 116b and 136b can form a "common" negative DC conductor. Alternatively, the machine conductors 116a and 136a can form a "common" first AC conductor for the first AC phase, and the machine conductors 116b and 136b can form a "common" second AC conductor for the neutral or vice versa. The mechanical terminals 124a and 140a may form a “common” positive DC terminal or a “common” first AC terminal for the first AC phase, and the mechanical terminals 124b and 140b may form a “common” negative DC terminal or a “common” second AC terminal for the neutral. p , 1341, 1342, ~, 134 q may be electrically connected to a single (or "common") set of machine conductors and their control coordinated.

[0182] When the electric machine 100 is operated as a generator, the second switching modules 1121, 1122, ..., 112 p and / or a third switching module 1341, 1342, ~, 134 q can supply power to one or more second loads (not shown) via second machine conductors 116a, 116b and second machine terminals 124a, 124b, and / or supply power to one or more third loads (not shown) via third machine conductors 136a, 136b and third machine terminals 140a, 140b. Depending on requirements, the second and third switching modules 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 qIt will be readily understood that the power supply 1101 may operate either or both of the first and second loads (not shown). Depending on requirements, the power may also be supplied to either or both of the second and third loads (not shown). The power is also supplied to the first switching modules 1101, 1102, ~, 1103, ~, 1104, ~, 1105, ~, 1106, ~, 1107, ~, 1108, ~, 1109, ~, 1200, ~, 1201, ~, 1202, ~, 1203, ~, 1204, ~, 1205, ~, 1206, ~, 1207, ~, 1208, ~, 1209, ~, 1300, ~, 1301, ~, 1302, ~, 1303, ~, 1304, ~, 1305, ~, 1306, ~, 1307, ~, 1308, ~, 1309, ~, 1401, ~, 1401, ~, 1402, ~, 1403, ~, 1404, ~, 1405, ~, 1406, ~, 1407, ~, 1408, ~, 1409, ~, 1501, ~, 1509, ~, 1510, ~, 1511, ~, 1512, ~, 1513, ~, 1514, ~, 1515, ~, 1516, ~, 1517, ~, 1518, ~, 1519, ~, 1520, ~, 1521, ~, 1522, ~, 1523, ~, 1524, ~, n may be independently supplied to one or more first loads (not shown).

[0183] When the electric machine 100 is operated as a motor, the second switching modules 1121, 1122, ..., 112 p , and / or the third switching module 1341, 1342, ~, 134 q can receive power from one or more second power sources (not shown) via second mechanical conductors 116a, 116b and second mechanical terminals 124a, 124b, and / or from one or more third power sources (not shown) via third mechanical conductors 136a, 136b and third mechanical terminals 140a, 140b. Depending on requirements, the second and third switching modules 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 q It will be readily understood that the first switching modules 1101, 1102, ..., 1103 can be operated with either or both of the first and second power sources (not shown). Depending on requirements, power can also be provided from either or both of the second and third power sources (not shown). Power can also be provided from one or more first power sources (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b to the first switching modules 1101, 1102, ..., 1103. n The second and third switching modules 1121, 1122, . . . , 112 p , 1341, 1342, ~, 134 q can be coordinately controlled to drive the rotation of the rotor 102.

[0184] When the third switch 144 is controlled to be closed, for example, by the controller, the first and third machine conductors 114a, 114b and 136a, 136b are electrically connected to form a "common" pair of machine conductors. In particular, the machine conductor 114a is electrically connected to the machine conductor 136a, and the machine conductor 114b is electrically connected to the machine conductor 136b. For example, the machine conductors 114a and 136a can form a "common" positive DC conductor, and the machine conductors 114b and 136b can form a "common" negative DC conductor. Alternatively, the machine conductors 114a and 136a can form a "common" first AC conductor for a first AC phase, and the machine conductors 114b and 136b can form a "common" second AC conductor for a neutral or vice versa. The mechanical terminals 122a and 140a may form a "common" positive DC terminal or a "common" first AC terminal for a first AC phase, and the mechanical terminals 122b and 140b may form a "common" negative DC terminal or a "common" second AC terminal for a neutral point, or vice versa. n , 1341, 1342, ~, 134 q are electrically connected to a single (or "common") pair of machine conductors and their control may be coordinated.

[0185] When the electric machine 100 is operated as a generator, the first switching modules 1101, 1102, ..., 110 n and / or a third switching module 1341, 1342, ~, 134 q can supply power to one or more first loads (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or supply power to one or more third loads (not shown) via the third mechanical conductors 136a, 136b and the third mechanical terminals 140a, 140b. n and 1341, 1342, ~, 134 qIt will be readily understood that one or both of the first and third power sources may be operated. Depending on requirements, power may also be provided to one or both of the first and third power sources (not shown). Power may also be provided to the second switching modules 1121, 1122, ~, 1123 via second mechanical conductors 116a, 116b and second mechanical terminals 124a, 124b. p may be independently supplied to one or more secondary loads (not shown).

[0186] When the electric machine 100 is operated as a motor, the first switching modules 1101, 1102, ..., 110 n and / or a third switching module 1341, 1342, ~, 134 q can receive power from one or more first power sources (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or from one or more third power sources (not shown) via the third mechanical conductors 136a, 136b and the second mechanical terminals 140a, 140b. Depending on requirements, the first and third switching modules 1101, 1102, ..., 110 n and 1341, 1342, ~, 134 q It will be readily understood that one or both of the first and second switching modules 1121, 1122, ~, 1123 can be operated. Depending on requirements, power can also be provided from one or both of the first and third power sources (not shown). Power is provided to the second switching modules 1121, 1122, ~, 1123 via the second mechanical conductors 116a, 116b and the first mechanical terminals 124a, 124b. p The first and third switching modules 1101, 1102, . . . , 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1209 n and 1341, 1342, ~, 134 q can be controlled in unison to drive the rotation of the rotor 102.

[0187] When any two of the first, second and third switches 130, 140 and 142 are closed, for example by a controller, the first, second and third mechanical conductors 114a, 114b, 116a, 116b and 136a, 136b are electrically connected to form a "common" pair of mechanical conductors. In particular, the mechanical conductors 114a, 116a and 136a are electrically connected and the mechanical conductors 114b, 116b and 136b are electrically connected. For example, the mechanical conductors 114a, 116a and 136a can form a "common" positive DC conductor and the mechanical conductors 114b, 116b and 136b can form a "common" negative DC conductor. Alternatively, the machine conductors 114a, 116a, 136a may form a "common" first AC conductor for the first AC phase, and the machine conductors 114b, 116b, 136b may form a "common" second AC conductor for the neutral or vice versa. The machine terminals 122a, 124a, 140a may form a "common" positive DC terminal or a "common" first AC terminal for the first AC phase, and the machine terminals 122b, 124b, 140b may form a "common" negative DC terminal or a "common" second AC terminal for the neutral. The first, second and third switching modules 1101, 1102, ~, 110 n , 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 q are electrically connected to a "common" pair of machine conductors and their control can be coordinated.

[0188] When the electric machine 100 is operated as a generator, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p and / or a third switching module 1341, 1342, ~, 134 qcan supply power to one or more first loads (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or to one or more second loads (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b, and / or to one or more third loads (not shown) via the third mechanical conductors 136a, 136b and the third mechanical terminals 140a, 140b. Depending on requirements, the first, second and third switching modules 1101, 1102, ~, 110 n , 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 q It will be readily appreciated that the power supply may operate one or more of the first, second and third loads (not shown) as well, depending on requirements.

[0189] When the electric machine 100 operates as a motor, the first switching modules 1101, 1102, ..., 110 n and / or the second switching module 1121, 1122, ~, 112 p and / or a third switching module 1341, 1342, ~, 134 q can receive power from one or more first power sources (not shown) via the first mechanical conductors 114a, 114b and the first mechanical terminals 122a, 122b, and / or from one or more second power sources (not shown) via the second mechanical conductors 116a, 116b and the second mechanical terminals 124a, 124b, and / or from one or more third power sources (not shown) via the third mechanical conductors 136a, 136b and the third mechanical terminals 140a, 140b. Depending on requirements, the first, second and third switching modules 1101, 1102, ~, 110 n , 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 qIt will be readily understood that the first, second and third switching modules 1101, 1102, . . . may be operated in one or more of the following modes. Also, depending on requirements, power may be provided from one or more of the first, second and third power sources (not shown). n , 1121, 1122, ~, 112 p and 1341, 1342, ~, 134 q may be controlled in unison to drive the rotation of the rotor 102.

[0190] FIG. 19 also shows how the cable wiring or bus 150 is electrically connected to the first mechanical terminal 122a, 122b by the isolation switches 127a, 127b, how the cable wiring or bus 160 is electrically connected to the second mechanical terminal 124a, 124b by the isolation switches 129a, 129b, and how the cable wiring or bus 170 is electrically connected to the third mechanical terminal 140a, 140b by the isolation switches 141a, 141b. The isolation switches may be electrical switches and may include one or more controllable semiconductor switches, e.g., thyristors. The one or more controllable switches may be controlled to be on / off by a suitable controller. The isolation switches may also be mechanical isolators.

[0191] FIG. 20 shows a first example of a power system including the first electric machine 100 described above. The first electric machine 100 is as shown in FIGS. 4 and 5 , a rotor 102, a stator 104, said stator 104 comprising: A plurality of first stator coils (not shown for clarity, but the first stator coils 1061, 1062, . . . , 1063 shown in FIGS. 4 and 5 n ), and A plurality of second stator coils (not shown for clarity, but the second stator coils 1081, 1082, . . . , 1083 shown in FIGS. 4 and 5 p the stator 104 including a a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (first switching modules 1101, 1102, . . . , 110 shown in FIG. 4 and FIG. 5) n a plurality of first switching modules, each of the first switching modules being electrically connected to a respective first stator coil; A plurality of second switching modules (second switching modules 1121, 1122, . . . , 112 shown in FIGS. 4 and 5) p and a plurality of second switching modules, each of the second switching modules being electrically connected to a respective second stator coil; a pair of first mechanical conductors 114a, 114b; a pair of second mechanical conductors 116a, 116b; a pair of first mechanical terminals 122a, 122b; a pair of second mechanical terminals 124a, 124b.

[0192] The first electric machine 100 is typically operated as a generator, with the rotor 102 driven by a suitable prime mover, for example a diesel engine or a gas turbine engine (not shown).

[0193] The second electric machine 200 typically operates as a motor; a rotor 202 driving a suitable load, e.g. a propulsion load (not shown); - A plurality of stator coils (not shown for clarity, but stator coils 341, 342, . . . , 34 shown in FIG. 3) n 204 including a stator 205 (corresponding to A power electronic switching assembly (not shown for clarity) comprising a plurality of switching modules (switching modules 301, 302, ..., 303 shown in FIG. 3). na power electronics switching assembly including: a pair of mechanical conductors 206a, 206b; a pair of mechanical terminals 208a, 208b.

[0194] The first machine terminals 122a, 122b of the first electric machine 100 are electrically connected to the machine terminals 208a, 208b of the second electric machine 200 using suitable wiring or a bus 150 as shown.

[0195] First switching modules 1101, 1102, ..., 110 of the first electric machine 100 n are controlled to supply a variable DC voltage to the second electric machine 200. n By varying the DC voltage supplied by the first switching modules 1101, 1102, ~, 1103 of the first electric machine 100, the rotational speed of the rotor 202 of the second electric machine 200 can be selectively varied. n to the first machine conductors 114a, 114b via the first machine terminals 122a, 122b, the wiring or bus 150, and the machine terminals 208a, 208b to the machine conductors 206a, 206b of the second electric machine 200. The switching modules of the second electric machine 200 are then controlled to drive the rotation of the rotor 202.

[0196] The power network 300 includes a positive DC network conductor 302a and a negative DC network conductor 302b. The power network 300 also includes a positive DC network terminal 304a and a negative DC network terminal 304b. The second machine terminals 124a, 124b of the first electric machine 100 are electrically connected to the terminals 304a, 304b of the power network 300 using suitable cabling or a bus 160 as shown. The power network 300 can be used to supply ship or hotel services, for example, if the power system is used on a marine vessel. The second switching modules 1121, 1122, ~, 1123 of the first electric machine 100 are electrically connected to the terminals 304a, 304b of the power network 300 using suitable cabling or a bus 160 as shown. p can be independently controlled to supply a fixed DC voltage to the power network 300. The fixed DC voltage is supplied to the second switching modules 1121, 1122, ~, 1123 of the first electric machine 100. p to the second machine conductors 116a, 116b via the second machine terminals 124a, 124b, the wiring or bus 160, and the network terminals 304a, 304b to the power network 300. One or more loads (not shown) are electrically connected to the power network 300 either directly or indirectly by respective power converters, such as when the loads require an AC voltage. pAlternatively, the power network 300 may be controlled to supply a fixed single-phase AC voltage (e.g., 440 or 690V AC at 50 or 60 Hz) to the power network 300. In this case, the power network 300 may include a first AC conductor (e.g., network conductor 302a) for a first AC phase and a second AC conductor (e.g., network conductor 302b) for a neutral or vice versa. The power network 300 also includes a first AC terminal (e.g., network terminal 304a) for the first AC phase and a second AC terminal (e.g., network terminal 304b) for a neutral or vice versa. In another arrangement, the power network may include first, second and third AC conductors and first, second and third AC terminals to facilitate electrical connection to one or more three-phase AC loads, and the second switching module may be configured to supply a three-phase AC voltage as described above.

[0197] FIG. 21 shows a second embodiment of a power system including the first electric machine 100 described above. The first electric machine 100 is as shown in FIGS. 4 and 5 , a rotor 102, a stator 104, A plurality of first stator coils (not shown for clarity, but the first stator coils 1061, 1062, . . . , 1063 shown in FIGS. 4 and 5 n ), and A plurality of second stator coils (not shown for clarity, but the second stator coils 1081, 1082, . . . , 1083 shown in FIGS. 4 and 5 p (corresponding to a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (first switching modules 1101, 1102, . . . , 110 shown in FIG. 4 and FIG. 5) n each of the first switching modules is electrically connected to a respective first stator coil; A plurality of second switching modules (second switching modules 1121, 1122, . . . , 112 shown in FIGS. 4 and 5) p and a power electronics switching assembly including: a first switching module, the first switching module corresponding to the first stator coil; and a second switching module, the first switching module corresponding to the second stator coil; a pair of first mechanical conductors 114a, 114b; a pair of second mechanical conductors 116a, 116b; a pair of first mechanical terminals 122a, 122b; - A pair of second mechanical terminals 124a, 124b.

[0198] The first electric machine 100 is typically operated as a generator, with the rotor 102 driven by a suitable prime mover, for example a diesel engine or a gas turbine engine (not shown).

[0199] The second electric machine 200-1 operates normally as a motor; - a rotor 202-1 driving a suitable load, e.g. a propulsion load (not shown); A plurality of stator coils (not shown for clarity, but stator coils 341, 342, ..., 34 shown in FIG. 3) n ) and A power electronic switching assembly (not shown for clarity) including a plurality of switching modules (switching modules 301, 302, ..., 303 shown in FIG. 3). n a power electronics switching assembly including: a pair of mechanical conductors 206a-1, 206b-1; - a pair of mechanical terminals 208a-1, 208b-1.

[0200] One of the first machine terminals 122a of the first electric machine 100 is electrically connected to one of the machine terminals 208a-1 of the second electric machine 200-1 using a suitable cable or bus 150-1 as shown.

[0201] The third electric machine 200-2 normally operates as a motor; - a rotor 202-2 driving a suitable load, e.g. a propulsion load (not shown); - a plurality of stator coils (not shown for clarity, but stator coils 341, 342, ..., 34 shown in FIG. 3) n ) and A power electronic switching assembly (not shown for clarity) comprising a plurality of switching modules (switching modules 301, 302, ..., 303 shown in FIG. 3). n a power electronics switching assembly including: a pair of mechanical conductors 206a-2, 206b-2; a pair of mechanical terminals 208a-2, 208b-2.

[0202] The other one of the first machine terminals 122b of the first electric machine 100 is electrically connected to one of the machine terminals 208b-2 of the third electric machine 200-2 using a suitable cable or bus 150-2 as shown.

[0203] The other machine terminal 208b-1 of the second electric machine 200-1 is electrically connected to the other machine terminal 208a-2 of the third electric machine 202-2 using a suitable cable or bus 170. In this manner, the second and third electric machines 200-1, 200-2 are electrically connected in series to the first machine terminals 122a-1, 122b-1 of the first electric machine 100.

[0204] First switching modules 1101, 1102, ..., 110 of the first electric machine 100 nare controlled to supply a variable DC voltage to the second and third electric machines 200-1, 200-2. n By varying the DC voltage supplied by the switching modules of the second and third electric machines 200-1, 200-2, the rotational speed of the rotors 202-1, 202-2 of the second and third electric machines 200-1, 200-2 can be selectively varied. The switching modules of the second and third electric machines 200-1, 200-2 are controlled to drive the rotation of the respective rotors 202-1, 202-2.

[0205] The power network 300 includes a positive DC network conductor 302a and a negative DC network conductor 302b. The power network 300 also includes a positive DC network terminal 304a and a negative DC network terminal 304b. The second machine terminals 124a, 124b of the first electric machine 100 are electrically connected to the terminals 304a, 304b of the power network 300 using suitable cabling or a bus 160 as shown. The power network 300 can be used to supply ship or hotel services, for example, if the power system is used on a marine vessel. The second switching modules 1121, 1122, ~, 1123 of the first electric machine 100 are electrically connected to the terminals 304a, 304b of the power network 300 using suitable cabling or a bus 160 as shown. p can be independently controlled to supply a fixed DC voltage to the power network 300. The fixed DC voltage is supplied to the second switching modules 1121, 1122, ~, 1123 of the first electric machine 100. p to the second machine conductors 116a, 116b via the second machine terminals 124a, 124b, the wiring or bus 160, and the network terminals 304a, 304b to the power network 300. One or more loads (not shown) are electrically connected to the power network 300 either directly or indirectly by respective power converters, such as when the loads require an AC voltage. pAlternatively, the power network 300 may be controlled to supply a fixed single-phase AC voltage (e.g., 440 or 690V AC at 50 or 60 Hz) to the power network 300. In this case, the power network 300 may include a first AC conductor (e.g., network conductor 302a) for a first AC phase and a second AC conductor (e.g., network conductor 302b) for a neutral or vice versa. The power network 300 also includes a first AC terminal (e.g., network terminal 304a) for the first AC phase and a second AC terminal (e.g., network terminal 304b) for a neutral or vice versa. In another arrangement, the power network may include first, second and third AC conductors and first, second and third AC terminals to facilitate electrical connection to one or more three-phase AC loads, and the second switching module may be configured to supply a three-phase AC voltage as described above.

[0206] FIG. 22 shows a third embodiment of a power system including the first electric machine 100 described above. The first electric machine 100 is as shown in FIGS. 4 and 5 , a rotor 102, A plurality of first stator coils (not shown for clarity, but the first stator coils 1061, 1062, . . . , 106 shown in FIGS. 4 and 5 n 4 and 5 ) and a plurality of second stator coils (not shown for clarity, but corresponding to the second stator coils 1081, 1082, . . . , 108 p a stator 104 including a a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (first switching modules 1101, 1102, . . . , 110 shown in FIG. 4 and FIG. 5) n each of the first switching modules is electrically connected to a respective first stator coil; A plurality of second switching modules (second switching modules 1121, 1122, . . . , 112 shown in FIGS. 4 and 5)p and a power electronics switching assembly including: second switching modules, each of the second switching modules being electrically connected to a respective second stator coil; a pair of first mechanical conductors 114a, 114b; a pair of second mechanical conductors 116a, 116b; a pair of first mechanical terminals 122a, 122b; a pair of second mechanical terminals 124a, 124b.

[0207] The first electric machine 100 is typically operated as a motor, with the rotor 102 driving a suitable load, for example a propulsion load (not shown).

[0208] The second electric machine 200-1 is typically operated as a generator; a rotor 202-1 driven by a suitable prime mover, e.g. a diesel engine or a gas turbine engine (not shown); A plurality of stator coils (not shown for clarity, but stator coils 341, 342, ..., 34 shown in FIG. 3) n ) and A power electronic switching assembly (not shown for clarity) comprising a plurality of switching modules (switching modules 301, 302, ..., 303 shown in FIG. 3). n a power electronics switching assembly including: a pair of mechanical conductors 206a-1, 206b-1; - a pair of mechanical terminals 208a-1, 208b-1.

[0209] The first machine terminals 122a, 122b of the first electric machine 100 are electrically connected to the machine terminals 208a-1, 208b-1 of the second electric machine 200-1 using a suitable cable or bus 150-1 as shown.

[0210] The third electric machine 200-2 is typically operated as a generator; a rotor 202-2 driven by a suitable prime mover, e.g. a diesel engine or a gas turbine engine (not shown); A plurality of stator coils (not shown for clarity, but the stator coils 341, 342, . . . , 34 shown in FIG. 3) n ) and A power electronic switching assembly (not shown for clarity) comprising a plurality of switching modules (switching modules 301, 302, ..., 303 shown in FIG. 3). n a power electronics switching assembly including: A pair of mechanical conductors 206a-2, 206b-2; and a pair of mechanical terminals 208a-2, 208b-2.

[0211] The second machine terminals 124a, 124b of the first electric machine 100 are electrically connected to machine terminals 208a-2, 208b-2 of the third electric machine 200-2 using suitable wiring or bus 150-2 as shown.

[0212] First switching modules 1101, 1102, ..., 110 of the first electric machine 100 n The second switching modules 1121, 1122, ~, 1123 of the first electric machine 100 receive a variable DC voltage from the second electric machine 200-1 via the machine terminals 208a-1, 208a-1, the wiring or bus 150-1, the first machine terminals 122a, 122b, and the first machine conductors 114a, 114b. pThe first and second switching modules 1101, 1102, ~, 1103 of the first electric machine 100 receive a variable DC voltage from the third electric machine 200-2 via the machine terminals 208a-2, 208b-2, the wiring or bus 150-2, the second machine terminals 124a, 124b, and the second machine conductors 116a, 116b. n and 1121, 1122, ~, 112 p 1101, 1102, . . . , 1103 of the first electric machine 100. n , 1121, 1122, ~, 112 p Varying the DC voltage supplied to the first and second switching modules 1101, 1102, ..., 110n and 1121, 1122, ..., 112p of the first electrical machine 100 through the first and second machine terminals 122a, 122b and 124a, 124b, and controlling the first and second switching modules 1101, 1102, ..., 110n and 1121, 1122, ..., 112p of the first electrical machine 100 to commutate the coil currents, allows the rotational speed of the rotor 102 of the first electrical machine 100 to be selectively varied. The first and second switching modules 1101, 1102, ..., 110 of the first electric machine 100 n and 1121, 1122, ~, 112 pcan be controlled in a coordinated manner to drive the rotation of the rotor 102. As mentioned above, the first electric machine 100 may receive power from both the second and third electric machines 200-1, 200-2 simultaneously. Alternatively, the first electric machine 100 may normally receive power only from the second electric machine 200-1, but may be able to receive power from the third electric machine 200-2 when necessary (e.g., if the second electric machine 200-1 fails). If the first electric machine 100 includes a first switch 130 (shown in FIG. 16 ) between the first and second machine conductors 114a, 114b and 116a, 116b, it may be controlled by the first and second switching modules 1101, 1102, ..., 1104, ...). n and 1121, 1122, ~, 112 p can be closed to receive the same power from the second electric machine 200-1 during normal operation, and also from the third electric machine 200-2 in the event of a fault.

[0213] FIG. 23 shows a fourth embodiment of a power system including the first electric machine 100-1 described above. The first electric machine 100-1 is as shown in FIG. rotor 102-1; A stator 104-1, A plurality of first stator coils (not shown for clarity, but the first stator coils 1061, 1062, . . . , 106 shown in FIG. 19 ) n ), and A plurality of second stator coils (not shown for clarity, but the second stator coils 1081, 1082, . . . , 1083 shown in FIG. 19) p ), and A plurality of third stator coils (not shown for clarity, but the third stator coils 1321, 1322, . . . , 1323 shown in FIG. 19) q (corresponding to a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (first switching modules 1101, 1102, . . . , 110 shown in FIG. 19) n a plurality of first switching modules, each of which is electrically connected to a respective first stator coil; A plurality of second switching modules (second switching modules 1121, 1122, . . . , 112 shown in FIG. 19) p a plurality of second switching modules, each of which is electrically connected to a respective second stator coil; A plurality of third switching modules (second switching modules 1341, 1342, . . . , 134 q a power electronics switching assembly including: a plurality of third switching modules, each of the third switching modules being electrically connected to a respective third stator coil; a pair of first mechanical conductors 114a-1, 114b-1; a pair of second mechanical conductors 116a-1, 116b-1; a pair of third mechanical conductors 136a-1, 136b-1; a pair of first mechanical terminals 122a-1, 122b-1; a pair of second mechanical terminals 124a-1, 124b-1; a pair of third mechanical terminals 140a-1, 140b-1; a first switch 130-1 electrically connected between the first and second mechanical conductors 114a-1, 114b-1 and 116a-1, 116b-1; a second switch 142-1 electrically connected between the second and third mechanical conductors 116a-1, 116b-1 and 136a-1, 136b-1; a third switch 144-1 electrically connected between the first and third mechanical conductors 114a-1, 114b-1 and 136a-1, 136b-1.

[0214] The first electric machine 100-1 is typically operated as a generator, with the rotor 102-1 driven by a suitable prime mover, for example a diesel engine or a gas turbine engine (not shown).

[0215] The power system includes the second electric machine 100-2 described above. The second electric machine 100-2 is as shown in FIG. rotor 102-2; a stator 104-2, A plurality of first stator coils (not shown for clarity, but the first stator coils 1061, 1062, . . . , 106 shown in FIG. 19 ) n ), and A plurality of second stator coils (not shown for clarity, but the second stator coils 1081, 1082, . . . , 1083 shown in FIG. 19) p ), and A plurality of third stator coils (not shown for clarity, but the third stator coils 1321, 1322, . . . , 1323 shown in FIG. 19) q ) and a stator 104-2 including a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (first switching modules 1101, 1102, . . . , 110 shown in FIG. 19) n a plurality of first switching modules, each of which is electrically connected to a respective first stator coil; A plurality of second switching modules (second switching modules 1121, 1122, . . . , 112 shown in FIG. 19) p a plurality of second switching modules, each of which is electrically connected to a respective second stator coil; A plurality of third switching modules (second switching modules 1341, 1342, . . . , 134 qa power electronics switching assembly including a plurality of third switching modules, each of the third switching modules being electrically connected to a respective third stator coil; a pair of first mechanical conductors 114a-2, 114b-2; a pair of second mechanical conductors 116a-2, 116b-2; a pair of third mechanical conductors 136a-2, 136b-2; a pair of first mechanical terminals 122a-2, 122b-2; a pair of second mechanical terminals 124a-2, 124b-2; a pair of third mechanical terminals 140a-2, 140b-2; a first switch 130-2 electrically connected between the first and second mechanical conductors 114a-2, 114b-2 and 116a-2, 116b-2; a second switch 142-2 electrically connected between the second and third mechanical conductors 116a-2, 116b-2 and 136a-2, 136b-2; a third switch 144-2 electrically connected between the first and third mechanical conductors 114a-2, 114b-2 and 136a-2, 136b-2.

[0216] The second electric machine 100-2 is typically operated as a generator, with the rotor 102-2 driven by a suitable prime mover, for example a diesel engine or a gas turbine engine (not shown).

[0217] The power system includes the third electric machine 100-3 described above. The third electric machine 100-3 is as shown in FIG. rotor 102-3; a stator 104-3, A plurality of first stator coils (not shown for clarity, but stator coils 1061, 1062, . . . , 106 shown in FIG. 16 ) n ), and A plurality of second stator coils (not shown for clarity, but stator coils 1081, 1082, . . . , 1083 shown in FIG. 16 ) p stator 104-3 including a a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (switching modules 1101, 1102, . . . , 110 shown in FIG. 16) n a plurality of first switching modules, each of which is electrically connected to a respective first stator coil; A plurality of second switching modules (switching modules 1121, 1122, . . . , 112 shown in FIG. 16) p a power electronics switching assembly including: a pair of first mechanical conductors 114a-3, 114b-3; a pair of second mechanical conductors 116a-3, 116b-3; a pair of first mechanical terminals 122a-3, 122b-3; a pair of second mechanical terminals 124a-3, 124b-3; a first switch 130-3 electrically connected between the first and second mechanical conductors 114a-3, 114b-3 and 116a-3, 116b-3.

[0218] The third electric machine 100-3 is typically operated as a motor, with the rotor 102-3 driving a suitable load, for example a propulsion load (not shown).

[0219] The power system includes the fourth electric machine 100-4 described above. The fourth electric machine 100-4 is as shown in FIG. rotor 102-4; a stator 104-4, A plurality of first stator coils (not shown for clarity, but stator coils 1061, 1062, . . . , 106 shown in FIG. 16 ) n ), and A plurality of second stator coils (not shown for clarity, but stator coils 1081, 1082, . . . , 1083 shown in FIG. 16 ) p stator 104-4 including a a power electronics switching assembly (not shown for clarity), A plurality of first switching modules (switching modules 1101, 1102, . . . , 110 shown in FIG. 16) n a plurality of first switching modules, each of which is electrically connected to a respective first stator coil; A plurality of second switching modules (switching modules 1121, 1122, . . . , 112 shown in FIG. 16) p a power electronics switching assembly including: a pair of first mechanical conductors 114a-4, 114b-4; a pair of second mechanical conductors 116a-4, 116b-4; a pair of first mechanical terminals 122a-4, 122b-4; a pair of second mechanical terminals 124a-4, 124b-4; a first switch 130-4 electrically connected between the first and second mechanical conductors 114a-4, 114b-4 and 116a-4, 116b-4.

[0220] The fourth electric machine 100-4 is typically operated as a motor, with rotor 102-4 driving a suitable load, for example a propulsion load (not shown).

[0221] The first machine terminals 122a-1, 122b-1 of the first electric machine 100-1 are electrically connected to the first machine terminals 122a-3, 122b-3 of the third electric machine 100-3 using suitable wiring or bus 150-1 as shown. The second machine terminals 124a-1, 124b-1 of the first electric machine 100-1 are electrically connected to the second machine terminals 124a-4, 124b-4 of the fourth electric machine 100-4 using suitable wiring or bus 170-1 as shown.

[0222] The first machine terminals 122a-2, 122b-2 of the second electric machine 100 are electrically connected to the first machine terminals 122a-4, 122b-4 of the fourth electric machine 100-4 using suitable wiring or bus 150-2 as shown. The second machine terminals 124a-2, 124b-2 of the second electric machine 100-2 are electrically connected to the second machine terminals 124a-3, 124b-3 of the third electric machine 100-3 using suitable wiring or bus 170-2 as shown.

[0223] In this manner, the first electric machine 100-1 is electrically connected to the third and fourth electric machines 100-3, 100-4, and the second electric machine 100-2 is electrically connected to the third and fourth electric machines 100-3, 100-4. The interconnections between the electric machines 100-1, 100-2, ..., 100-4 are shown more clearly in Fig. 27. Fig. 27 also shows the isolation switches 129a-1, 129b-1, ..., 129a-4, 129b-4 between the second machine terminals 124a-1, 124b-1, ..., 124a-4, 124b-4 and the wiring or bus 170-1, 170-2. The isolation switches have been omitted from Figs. 23 to 26 for clarity. It will be appreciated that isolation switches are typically also provided between the first mechanical terminals 122a-1, 122b-1, ..., 122a-4, 122b-4 and the wires or buses 150-1, 150-2.

[0224] The third machine terminals 140a-1, 140b-1 of the first electric machine 100-1 are electrically connected to a first power network 300-1 using suitable cabling or bus 160-1 as shown. The third machine terminals 140a-2, 140b-2 of the second electric machine 100-2 are electrically connected to a second power network 300-2 using suitable cabling or bus 160-2 as shown. The first and second power networks 300-1, 300-2 are DC power networks and may be used to supply ship or hotel services if the power system is used on a ship, for example. The first and second power networks 300-1, 300-2 may be electrically connected by a bus tie 180. When the bus tie 180 is closed, the third switching modules of the first and second electric machines 100-1, 100-2 are typically coordinated to supply the same DC voltage to the electrically connected first and second power networks 300-1, 300-2. It will be appreciated that isolation switches are also typically provided between the third machine terminals 140a-1, 140b-1, ~, 140b-2 and the wiring or buses 160-1, 160-2.

[0225] In the first operating state (see FIG. 24 ), the first, second and third switches 130-1, 142-1 and 144-1 of the first electric machine 100-1 are open; the first, second and third switches 130-2, 142-2 and 144-2 of the second electric machine 100-1 are open; The first switch 130-3 of the third electric machine 100-3 is closed. The first switch 130-4 of the fourth electric machine 100-4 is closed.

[0226] The first switching module of the first electric machine 100-1 can be controlled to supply a variable DC voltage to the "common" machine terminal of the third electric machine 100-3, i.e., because the first switch 130-3 is closed. The first and second switching modules of the third electric machine 100-3 both receive the same power from the first electric machine 100-1 and can be coordinated to drive the rotor 102-3. By varying the DC voltage supplied to the third electric machine 100-3, the rotational speed of the rotor 102-3 of the third electric machine 100-3 can be selectively varied.

[0227] The second switching module of the first electric machine 100-1 is not operated (ie, turned off).

[0228] The third switching module of the first electric machine 100-1 can be controlled independently from the first switching module to supply a fixed DC voltage to the first power supply network 300-1.

[0229] The first switching module of the second electric machine 100-2 can be controlled (i.e., because the first switch 130-4 is closed) to supply a variable DC voltage to the "common" machine terminal of the fourth electric machine 100-4. The first and second switching modules of the fourth electric machine 100-4 both receive the same power from the second electric machine 100-2 and can be coordinated to drive the rotor 102-4. By varying the DC voltage supplied to the fourth electric machine 100-4, the rotational speed of the rotor 102-4 of the fourth electric machine 100-4 can be selectively varied.

[0230] The second switching module of the second electric machine 100-2 is not operated (ie, turned off).

[0231] The third switching module of the second electric machine 100-2 is controlled independently of the first switching module and can supply a fixed DC voltage to the second power grid 300-2, in which case the bus tie 180 is open.

[0232] Opening the first, second and third switches 130-1, 142-1 and 144-1 of the first electric machine 100-1 provides electrical resilience and provides three electrically isolated circuits. For example, an electrical fault in one of the circuits does not affect the other circuits. The same applies to the second electric machine 100-2. Closing the first switch 130-3 of the third electric machine 100-3 and the first switch 130-4 of the fourth electric machine 100-4 provides maximum availability of the stator coils and switching modules. In other words, during normal operation of the power system, both the first and second switching modules of the third electric machine 100-3 receive power from the first electric machine 100-1, and both the first and second switching modules of the fourth electric machine 100-4 receive power from the second electric machine 100-2. The first electric machine 100-1 may also independently supply power to a first power network 300-1, and the second electric machine 100-2 may also independently supply power to a second power network 300-2.

[0233] In a second operating state (see FIG. 25 ) in which the second electric machine 100-2 is not operating, for example due to a fault, The first, second and third switches 130-1, 142-1 and 144-1 of the first electric machine 100-1 are open. The first switch 130-3 of the third electric machine 100-3 is closed. The first switch 130-4 of the fourth electric machine 100-4 is closed.

[0234] The default state of an inoperative electric machine is for all switching modules to return to a high impedance (or "pulse suppressed") state. A protective strategy can quickly set the switching modules to this high impedance state whenever a failure mode occurs that is severe enough to require one or more of the switching modules to be pulse suppressed. An electric machine according to the invention preferably has sufficient design margins and / or redundancies to mitigate the risk of cascading failures after a first fault occurs. In practical terms, the protective strategy of the second electric machine 100-2 prevents backfeed of fault current from the third and fourth electric machines 100-3, 100-4.

[0235] The first switching module of the first electric machine 100-1 can be controlled to supply a variable DC voltage to the "common" machine terminal of the third electric machine 100-3, i.e., because the first switch 130-3 is closed. The first and second switching modules of the third electric machine 100-3 both receive the same power from the first electric machine 100-1 and can be coordinated to drive the rotor 102-3. By varying the DC voltage supplied to the third electric machine 100-3, the rotational speed of the rotor 102-3 of the third electric machine 100-3 can be selectively varied.

[0236] The second switching module of the first electric machine 100-1 is now activated (i.e., turned on) and controlled to supply a variable DC voltage to the "common" machine terminal of the fourth electric machine 100-4 (because the first switch 130-4 is closed). The first and second switching modules of the fourth electric machine 100-4 both receive the same power from the first electric machine 100-1 and may be coordinated controlled to drive the rotor 102-4. By varying the DC voltage supplied to the fourth electric machine 100-4, the rotational speed of the rotor 102-4 of the fourth electric machine 100-4 may be selectively varied. Since the first switch 130-1 of the first electric machine 100-1 remains open, the first and second switching modules of the first electric machine 100-1 can be controlled independently, for example to allow the third and fourth electric machines 100-3, 100-4 to be operated at different rotational speeds or with different power flows, and also to allow the rotors 102-3, 102-4 of the third and fourth electric machines 100-3, 100-4 to rotate in different directions.

[0237] The third switching module of the first electric machine 100-1 can be controlled independently from the first and second switching modules to supply a fixed DC voltage to the first power network 300-1.

[0238] In a third operating state (see FIG. 26), the second electric machine 100-2 is also inoperable, for example due to a fault. the first switch 130-1 of the first electric machine 100-1 is closed; the second and third switches 142-1 and 144-1 of the first electric machine 100-1 are open; The first switch 130-3 of the third electric machine 100-3 is closed. The first switch 130-4 of the fourth electric machine 100-4 is closed.

[0239] Closing the first switch 130-1 of the first electric machine 100-1 means that the first and second mechanical conductors 114a-1, 114b-1 and 116a-1, 116b-1 are electrically connected to form a pair of "common" mechanical conductors. The first and second mechanical terminals 122a-1, 122b-1 and 124a-1, 124b-1 are electrically connected to form a pair of "common" mechanical terminals. The first and second switching modules 1 of the first electric machine 100 are electrically connected to the "common" mechanical conductor. The third mechanical conductors 136a-1, 136b-1 of the first electric machine 100-1 remain electrically isolated.

[0240] The first and second switching modules of the first electric machine 100-1 may be coordinated to provide a variable DC voltage to the "common" machine terminals of the third and fourth electric machines 100-3, 100-4 - i.e. because the first switches 130-3, 130-4 are closed. The first and second switching modules of the third electric machine 100-3 may both receive the same power from the first electric machine 100-1 and be coordinated to drive the rotor 102-3. By varying the DC voltage provided to the third electric machine 100-3, the rotational speed of the rotor 102-3 of the third electric machine 100-3 may be selectively varied. Similarly, the first and second switching modules of the fourth electric machine 100-4 may both receive the same power from the first electric machine 100-1 and be coordinated to drive the rotor 102v4. By varying the DC voltage supplied to the fourth electric machine 100-4, the rotational speed of the rotor 102-4 of the fourth electric machine 100-4 can be selectively varied.

[0241] Because the first switch 130-1 is closed, the third and fourth electric machines 100-3, 100-4 receive the same DC voltage from the first electric machine 100-1 (i.e. from the “common” machine terminal formed by the electrically connected first and second machine terminals 122a-1, 122b-1 and 124a-1, 124b-1) and are therefore operated, for example, at the same rotational speed or with the same power flow.

[0242] The third switching module of the first electric machine 100-1 can be controlled independently from the first and second switching modules to supply a fixed DC voltage to the first power network 300-1.

[0243] It will be readily appreciated that in both the second and third operating conditions, the first electric machine 100-1 can supply power to both the third and fourth electric machines 100-3, 100-4 even though the second electric machine 100-2 is not operating.

[0244] Although the embodiments have been described above, it will be understood that various modifications can be made thereto without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described embodiments. In particular, the present invention is not limited to the first, second, third and fourth power systems described above with reference to the figures, and it will be readily understood that many other power systems are possible. Also, the power system according to the present invention can be configured in many different operating conditions, in particular by selectively controlling switching modules electrically connected to different sets of machine conductors, and by, for example, opening and closing optional switches. It will be understood that, although the first, second and third power systems described above use rotating electric machines, linear electric machines can also be used, for example including a mover instead of a rotor.

[0245] Unless otherwise indicated herein or clearly contradicted by context, all combinations of the above-described features in all possible variations thereof are encompassed in this specification.

[0246] Unless the context clearly requires otherwise, throughout this specification and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense rather than an exclusive or exhaustive sense. [Explanation of symbols]

[0247] 2a: 1st AC bus 2b: 2nd AC bus 4: bus tie 6, 8, 10, 12: AFE power converter 14, 16: active rectifier / inverter 18: DC link 20: harmonic filter 22a: 3rd AC bus 22b: 4th AC bus 24: 1st transformer 26: 2nd transformer 30: switching module 32a, 32b: AC terminals 34: stator coils 36a, 36b: DC terminals 38a, 38b: DC conductors / machine conductors 40a, 40b: DC machine terminals 100: electric machine 100-1: 1st electric machine 100-2: 2nd electric machine 100-3: 3rd electric machine 100-4: 4th electric machine 102: rotor 104: stator 106-1, 106-2, ~, 106-n: first stator coil 108-1, 108-2, ~, 108-p: second stator coil 109-1, 109-2, ~, 109-n: first switching module assembly 110-1, 110-2, ~, 110-n: first switching module 111-1, 111-2, ~, 111-p: second switching module assembly 112-1, 112-2, ~, 112-p: second switching module 114a, 114b, 114c: first mechanical conductor 116a, 116b, 116c: second mechanical conductor 118-a1, 118-b1, 118-a2, 118-b2, ~, 118-an, 118-bn: module terminals 120-a1, 120-b1, 120-a2, 120-b2, ~, 120-an, 120-bn: module terminals 122a, 122b, 122c: first mechanical terminals 124a, 124b, 124c: second mechanical terminals 125: terminal box 126a, 126b: AC bridge terminals 127a, 127b, 129a, 129b: isolation switches 128a, 128b: DC bridge terminals 130: first switches 132-1, 132-2, ~, 132-q: third stator coil 133-1, 133-2, ~, 133-q: third switching module assembly 134: third switching module 136a, 136b, 136c: mechanical conductors 138a, 138b: module terminals 140: second switch 140a, 140b, 140c: mechanical terminals 142: third switch 144: third switch 150, 160: cable wiring / bus200, 200-1: second electric machine; 200-2: third electric machine; 202: rotor; 204: stator; 206a, 206b: machine conductors; 208a, 208b: machine terminals; 300: power network; 302a: positive DC network conductors; 302b: negative DC network conductors; 304a: positive DC network terminals; 304b: negative DC network terminals; D1, D2, D3, D4: prime movers; G1, G2, G3, G4: alternators; M1, M2, M3, M4: motors; S1, S2, S3, S4: switches.

Claims

1. An electric machine (100), comprising: a first machine terminal (122a, 122b) electrically connectable to one or more first loads or power sources; second machine terminals (124a, 124b) electrically connectable to one or more second loads or power sources; A stator (104), a plurality of first stator coil groups, each of which defines a respective stator phase and includes one or more interconnected first stator coils (106 １ , 106 ２ , ~, 106 ｎ the first stator coil groups including a plurality of second stator coil groups, each second stator coil group defining a respective stator phase and including one or more interconnected second stator coils (108 １ , 108 ２ , ~, 108 ｐ the second stator coil groups including the first stator coil groups, 1. A power electronic switching assembly comprising: A plurality of first switching module assemblies (109) electrically connected to or between the first mechanical terminals (122a, 122b). １ , 109 ２ , ~, 109 ｎ ), each first switching module assembly (109 １ , 109, . . . , 109) include one or more interconnected first switching modules (110 １ , 110 ２ , ~, 110 ｎ ), each first switching module (110 １ , 110 ２ , ~, 110 ｎ ) electrically connected to each of the first stator coil groups, １ , 109 ２ , ~, 109 ｎ )and, A plurality of second switching module assemblies (111) electrically connected to or between the second mechanical terminals (124a, 124b). １ , 111 ２ , ~, 111 ｐ ), each second switching module assembly (111 １ , 111 ２ , ~, 111 ｐ ) includes one or more interconnected second switching modules (112 １ , 112 ２ , ~, 112 ｐ ), each second switching module (112 １ , 112 ２ , ~, 112 ｐ ) electrically connected to each of the second stator coil groups, １ , 111 ２ , ~, 111 ｐ ) the power electronic switching assembly; An electric machine (100).

2. 2. The electric machine (100) of claim 1, further comprising a first switch (130) electrically connected between the first and second machine terminals (122a, 122b and 124a, 124b), the first switch (130) being an electrical switch optionally including one or more controllable semiconductor switches.

3. The first switching module assembly (109 １ , 109 ２ , ~, 109 ｎ ) is electrically connected in parallel to the first electrical terminals (122a, 122b) and / or the second switching module assembly (111 １ , 111 ２ , ~, 111 ｐ 2. The electric machine (100) of claim 1, wherein the first and second electrical terminals (124a, 124b) are electrically connected in parallel to the second electrical terminals (124a, 124b).

4. The first switching module assembly (109 １ , 109 ２ , ~, 109 ｎ ) is electrically connected in series between the first mechanical terminals (122a, 122b) and / or the second switching module assembly (111 １ , 111 ２ , ~, 111 ｐ 2. The electric machine (100) of claim 1, wherein a first terminal (124a, 124b) is electrically connected in series between the second machine terminals (124a, 124b).

5. A power system comprising a first electric machine (100; 100-1) according to any one of claims 1 to 4 and a second electric machine (200; 200-1; 100-3), The second electric machine (200; 200-1; 100-3) comprises: A first mechanical terminal (208a, 208b; 208a-1, 208b-1; 122a-3, 122b-3); a stator (204; 204-1; 104-3) including a plurality of first stator coil groups, each first stator coil group defining a respective stator phase and including one or more interconnected first stator coils; a power electronics switching assembly including a plurality of first switching module assemblies electrically connected to or between the first mechanical terminals (208a, 208b; 208a-1, 208b-1; 122a-3, 122b-3), each first switching module assembly including one or more interconnected first switching modules, each first switching module electrically connected to a respective first stator coil group; a first machine terminal (208a, 208b; 208a-1, 208b-1; 122a-3, 122-b3) of the second electric machine (200; 200-1; 100-3) is electrically connected to a first machine terminal (122a, 122b; 122a-1, 122b-1) of the first electric machine (100; 100-1).

6. the second electric machine (100-3) further includes second machine terminals (124a-3, 124b-3) electrically connectable to one or more second loads or power sources; the stator (104-3) of the second electric machine (100-3) further includes a plurality of second stator coil groups, each second stator coil group defining a respective stator phase and comprising one or more interconnected second stator coils; 6. The power system of claim 5, wherein the power electronics switching assembly of the second electric machine (100-3) further includes a plurality of second switching module assemblies electrically connected to or between the second machine terminals (124a-3, 124b-3), each second switching module including one or more interconnected second switching modules, each second switching module electrically connected to a respective second stator group.

7. 7. The power system of claim 6, further comprising a second switch (130-3) electrically connected between the first and second machine terminals (122a-3, 122b-3, 124a-3, 124b-3) of the second electric machine (100-3), the second switch (130-3) being an electric switch optionally including one or more controllable semiconductor switches.

8. the first electric machine (100) further includes third machine terminals (140a, 140b) electrically connectable to one or more third loads or power sources; The stator (104) of the first electric machine (100) further includes a plurality of third stator coil groups, each third stator coil group defining a respective stator phase and including one or more interconnected third stator coils (132). １ , 132 ２ , ~, 132 ｑ ), The power electronics switching assembly of the first electric machine (100) includes a plurality of third switching module assemblies (133) electrically connected to or between the third machine terminals (140a, 140b). １ , 133 ２ , ~, 133 ｑ ), each third switching module assembly (133 １ , 133 ２ , ~, 133 ｑ ) includes one or more interconnected third switching modules (134 １ , 134 ２ , ~, 134 ｑ ), each third switching module (134 １ , 134 ２ , ~, 134 ｑ 6. The power system of claim 5, wherein a first stator coil group is electrically connected to each of the third stator coil groups.

9. 9. The power system of claim 8, further comprising a third switch (142) electrically connected between second and third mechanical terminals (124a, 124b and 140a, 140b) of the first electric machine (100) and a fourth switch (144) electrically connected between first and third mechanical terminals (122a, 122b and 140a, 140b) of the first electric machine (100), the third and fourth switches (142, 144) being electrical switches optionally including one or more controllable semiconductor switches.

10. Further comprising a third electric machine (200-2; 100-4), said third electric machine (200-2; 100-4) First mechanical terminals (208a-2, 208b-2; 124a-4, 124b-4) a stator (204-2; 104-4) including a plurality of first stator coil groups, each first stator coil group defining a respective stator phase and including one or more interconnected second stator coils; a power electronic switching assembly including a plurality of first switching module assemblies electrically connected to or between the first mechanical terminals (208a-2, 208b-2; 124a-4, 124b-4); Including, Each first switching module assembly includes one or more interconnected first switching modules, each first switching module electrically connected to a respective first stator coil group; 10. The power system of claim 9, wherein a first mechanical terminal (208a-2, 208b-2; 124a-4, 124b-4) of the third electric machine (200-2; 100-4) is electrically connected to a first or second mechanical terminal (122a, 122b or 124a, 124b; 122a-1, 122b-1 or 124a-1, 124b-1) of the first electric machine (100; 100-1).

11. 11. The power system of claim 10, wherein one of the first and second electric machines (100; 100-1) further includes a rotor (102; 102-1) configured to be driven by a prime mover or other rotary power source, and the other of the first and second electric machines (200; 100-3) includes a rotor (202; 102-3) configured to drive a load.

12. The power system of claim 11 , wherein the switching modules are circumferentially spaced about and mounted to a stator frame of each electric machine.

13. 13. The power system of claim 12, wherein the first machine terminals (208a, 208b; 122a-3, 122b-3) of the second electric machine (200; 100-3) are electrically connected to the first machine terminals (122a, 122b; 122a-1, 122b-1) of the first electric machine (100; 100-1) by a cable or bus (150; 150-1).

14. 14. The power system of claim 13, wherein the cable or bus (150; 150-1) is electrically connected to the first machine terminals (208a, 208b; 122a-3, 122b-3) of the second electric machine (200; 100-3) by an isolation switch and / or to the first machine terminals (122a, 122b; 122a-1, 122b-1) of the first electric machine (100; 100-1) by an isolation switch.

15. A method of operating a power system according to any of claims 5 to 14, comprising the step of supplying a variable DC voltage from the first machine terminals (122a, 122b; 122a-1, 122b-1) of the first electric machine (100; 100-1) to the first machine terminals (208a, 208b; 122a-3, 122b-3) of the second electric machine (200; 100-3).

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