Machine system and method for operating machine system

Abstract

The invention relates to a machine system (1) comprising an electric machine (2) and a plurality of half-bridges (3) for controlling the electric machine (2), the electric machine (2) having a stator winding (4) comprising two winding parts (4.1, 4.2), each winding part (4.1, 4.2) having a winding branch (14) and a winding connection (10), the winding connections (10) of the winding parts (4.1) being electrically connected to phase connections (8) of the half-bridges (3) of a first group (13.1), and the phase connections (8) of the half-bridges (3) of a second group (13.1) being electrically connected to phase connections (8) of the half-bridges (3) of the second group (13.1). The winding connection (10) of the first winding part (4.1) is electrically connected to the phase connection (8) of the half-bridge (3) of the first group (13.1), and the winding connection (10) of the other winding part (4.2) is electrically connected to the phase connection (8) of the half-bridge (3) of the second group (13.2), the phase connection (8) of the half-bridge (3) of the first group (13.1) being electrically connectable in each case via a bridge connection (11) to one of the phase connections (8) of the half-bridge (3) of the second group (13.2) for electrically connecting two winding connections (10) of the different winding parts (4.1, 4.2), a switchable switching device (12) is arranged in the respective bridge connection (11), characterized in that-the half-bridge (3) of the machine system (1) is a regulated half-bridge,-each winding branch (14) of one of the two winding parts (4.1, 4.2) forms a branch pair (15) with one of the winding branches (14) of the respective other winding part (4.1, 4.2), the winding branches (14) of each branch pair (15) are phase-shifted by 180 degrees relative to one another, and-the respective bridge connection (11) can be switched by means of the respective switching device (12) so as to be conductive continuously in both current directions.

Description

Technical Field

[0001] The invention relates to a machine system according to the preamble of the main claim. Background Art

[0002] DE 3227602 A1 discloses a machine system comprising a generator as an electric machine and a plurality of unregulated half-bridges of an uncontrolled two-way rectifier circuit, wherein the electric machine has a stator with a stator winding, wherein the half-bridges each have two input nodes for connection to a DC voltage source, each have two switching elements connected in series between the input nodes, and each have a phase connection between the switching elements, wherein the stator winding comprises two multi-phase winding parts, in particular two three-phase winding parts, with the same number of phases, wherein each winding part has a number of winding branches corresponding to the number of phases and a number of winding branches corresponding to the number of phases. Group connections, wherein the winding connections of one winding part are electrically connected to the phase connections of the half-bridges of the first group, and the winding connections of the other winding part are electrically connected to the phase connections of the half-bridges of the second group, wherein each group of half-bridges has a number of half-bridges corresponding to the number of phases of the respective winding part, wherein the phase connections of the half-bridges of the first group can be electrically connected to one of the phase connections of the half-bridges of the second group via a bridge connection to form a half-bridge pair for electrically connecting two winding connections of different winding parts, wherein in the respective bridge connection, a thyristor is provided as a switchable switching device for interrupting the bridge connection. However, the respective bridge connection can only be switched to conduct continuously in one current direction.

[0003] In series operation, below a certain speed of the internal combustion engine, the two winding parts of the stator winding are connected in series with respect to each other and correspond to a single winding with a correspondingly high number of turns. In parallel operation, above a certain speed of the internal combustion engine, the two winding parts of the stator winding are connected in parallel with respect to each other and correspond to a single winding with a smaller number of turns than in series operation. In both system operations, all switching devices of the bridge connection are always either open or closed together. The unregulated half-bridge of the rectifier circuit only includes diodes. The phase current is determined by the phase voltage induced in the stator winding in a generator-like manner. The so-called "opposite-name" connection is achieved by the bridge connection, resulting in a phase offset of 60 degrees (=180°-120°) of the phase branches of the branch pairs connected by the corresponding bridge connection. The two winding parts of the winding are said to be "anti-phase" with respect to each other, which should mean that the phases of the two winding parts have oppositely set circulation directions. This can be understood as according to DE 3227601 A1. Figure 3 The winding branches of the winding parts are arranged in the stator along opposite directions of rotation.

[0004] The machine system comprises a phase system with a plurality of phase subsystems, wherein the respective phase subsystem is formed by one of the half-bridge pairs, a bridge connection of the respective half-bridge pair and two winding connections connectable by the respective half-bridge pair. Summary of the invention

[0005] Advantages of the present invention.

[0006] The machine system according to the invention having the features of the characterizing part of the main claim has the advantage over the prior art that the line losses and switching losses in the semiconductors of the half-bridge can be reduced in a time-averaged sense, which allows an increase in the phase current and / or a thermal load reduction of the half-bridge. Furthermore, an operating point-dependent adaptation of the impedance of the electric machine can be achieved by the series connection of the winding components. By reducing the current fluctuations, the losses in the electric machine can be reduced. Furthermore, the torque fluctuations of the electric machine can be reduced and the efficiency of the electric machine can be increased.

[0007] This is achieved according to the invention by:

[0008] According to a first inventive feature, the half-bridge of the machine system is a regulated half-bridge for feeding a phase current or a phase voltage into the stator winding,

[0009] - according to a second inventive feature, each winding branch of one of the two winding parts forms a branch pair with one of the winding branches of the respective other winding part, wherein the winding branches of each branch pair are phase-shifted by 180 degrees with respect to each other, and

[0010] According to a third inventive feature, the respective bridge connection can be switched by means of a respective switching device to conduct electricity continuously in both current directions.

[0011] By means of the second inventive feature, the winding branches of each branch pair generate a magnetomotive force in the stator when energized in the same direction, and the contributions of the magnetomotive force to the fundamental wave are 180 degrees phase-shifted relative to each other. According to the third inventive feature, the bridge connection can be electrically interrupted by opening the switching device, or continuously conductive by closing the switching device.

[0012] Advantageous developments and improvements of the machine system specified in the main claim are made possible by the measures listed in the dependent claims.

[0013] According to an advantageous embodiment, the switching elements of the respective half-bridge are semiconductor switches, in particular IGBT transistors or MOSFET transistors, wherein the respective semiconductor switch is in particular assigned a freewheeling diode as a separate component connected in parallel, or wherein the respective semiconductor switch inherently includes the function of the freewheeling diode. In this way, the current of the half-bridge can be adjusted by pulse width modulation in interaction with an inductance, in particular the inductance of the stator.

[0014] The switching device of the corresponding bridge connection can advantageously include at least one semiconductor switch, which is in particular an IGBT transistor, a MOSFET transistor or a thyristor. According to an advantageous embodiment, the switching device can be formed by connecting two transistors in series in an anti-series manner, in particular an IGBT transistor or a MOSFET transistor, or by connecting two thyristors in anti-parallel, in particular a triac.

[0015] Since the switching device needs to be switched less frequently than the switching elements of the half-bridge, low-cost semiconductor components can be used for the switching device, wherein higher switching losses can be tolerated. When high phase currents flow, the switching device of the bridge connection is preferably connected to relieve the half-bridge to the greatest extent. Therefore, the switching device must have a high current carrying capacity. The ability of the switching device to switch quickly and efficiently is not required, because the switching device only switches cyclically in series operation. Since the series operation is only used at low to medium speeds, the necessary switching frequency is small.

[0016] It is particularly advantageous if the winding branches of each branch pair have the same number of turns for voltage retention (with respect to the fundamental frequency) and / or the same conductor cross section and / or the same inductance. In this way, a uniform distribution of power to the winding parts is achieved during operation, thereby making optimal use of the winding parts and thus achieving a high efficiency.

[0017] It is very advantageous if the half bridges of the two groups and in particular the bridge connection including the switching devices are part of the inverter. In this way, a space-saving design can be achieved. The arrangement of the components on the heat sink allows for a cost-effective, highly integrated design, wherein the wiring effort is low due to the small spacing of the components relative to one another. The control circuit can be integrated in the controller.

[0018] The winding branches of the respective winding parts can advantageously be connected in a star connection or in a delta connection, wherein in the case of a star connection a branch pair can be connected via corresponding bridge connections and in the case of a delta connection two branch pairs can be connected to one another.

[0019] The machine system comprises a control unit for actuating the switching elements of the half bridge and for actuating the switching devices of the bridge connection.

[0020] The invention further relates to a method for operating a machine system according to the invention, wherein the machine system comprises a phase system with a plurality of phase subsystems, wherein the respective phase subsystem is formed by a half-bridge pair of half-bridge pairs, a bridge connection of the respective half-bridge pair and two winding connections which can be connected by the respective bridge connection, wherein the machine system can be operated in one of a plurality of operating states, in particular in series operation, individual operation, emergency operation or active short-circuit operation, as a function of one or more system operating parameters, in particular the speed, torque and / or efficiency of the electric machine and / or disturbance parameters of the machine system. The operating state can be selected, for example, by means of a lookup table. Series operation is particularly suitable for low and medium speeds and individual operation is suitable for high speeds.

[0021] In the series operation, it is provided that, as a function of at least one subsystem operating parameter, a respective one of the phase subsystems is operated alternately in passive subsystem operation and the respective remaining phase subsystem is operated in active subsystem operation.

[0022] In passive subsystem operation, the two half-bridges of the respective phase subsystem are deactivated to form the passive phase subsystem. Furthermore, the bridge connection of the passive phase subsystem is continuously conducting in passive subsystem operation via the corresponding switching position in order to enable a current flow in two directions from one of the two winding connections via the bridge connection of the passive phase subsystem to the respective other of the two winding connections.

[0023] In the active subsystem operation, the two half-bridges of the corresponding phase subsystem are controlled to provide two regulated phase currents when forming an active phase subsystem, which are phase-shifted by 180 degrees relative to each other, especially in terms of value and form, but with different signs. In addition, the bridge connection of the active phase subsystem is electrically interrupted by means of a corresponding switching device through a corresponding switching position during the active subsystem operation. It is particularly advantageous that the half-bridges of the corresponding active phase subsystem are controlled in anti-phase with respect to pulse width modulation. Since the half-bridge provides anti-phase phase currents in the active state, the switching duration (duty cycle) to be set by the half-bridge is also anti-phase. In the anti-phase pulse width modulation of the half-bridges of the half-bridge pair (phase shift of 180° with respect to the PWM frequency between the midpoints of the switching cycle), it is therefore possible to achieve a nearly anti-phase voltage variation curve at the winding connection. As a result, the phase current (offset current) flowing through the coupling capacitance of the winding component is also anti-phase with respect to the rotor and compensated. The voltage of the rotor caused by the coupling via the capacitor can be reduced, whereby leakage currents that damage the ball bearings can be avoided. Possibly necessary rotor grounding measures or insulating ceramic bearings can be omitted.

[0024] The method according to the invention makes it possible to set an indirectly regulated phase current in the series connection of two winding parts in response to the provision of a regulated phase current in the active phase subsystem, which phase current flows in one of two directions through the bridge connection of the passive phase subsystem depending on its sign. In this way, the correct phase current is respectively available at the corresponding winding connection of the respectively inactive phase subsystem for feeding.

[0025] Furthermore, it is advantageous if, in the series operation, all phase subsystems are switched successively into the passive subsystem operation in a continuous sequence as a function of the subsystem operating parameters.

[0026] In this way, the thermal relief of the half bridge is evenly distributed over time.

[0027] It is very advantageous if the subsystem operating parameter is the value of the phase current in the phase subsystem, wherein the phase current of each of the following phase subsystems is operated in passive subsystem operation and is above a threshold value in terms of value, in particular in a time interval of one twelfth of the electrical cycle of the phase current around a peak value of the phase current, i.e. from one twelfth of the electrical cycle before the peak to one twelfth of the electrical cycle after the peak, respectively in the positive and negative current half-waves.

[0028] In this way, the phase current is transferred from one winding part to the other winding part at the maximum phase current of the bridge connection in the time interval, so that the phase current does not have to be regulated by the half-bridge of the passive phase subsystem. Since the power loss in the half-bridge is proportional to the current-time plane in which the half-bridge carries the current, the setting of the passive subsystem operation leads to the maximum possible load reduction of the half-bridge in the mentioned interval.

[0029] Furthermore, it is advantageous, however, to control the two winding sections individually in separate operation by interrupting all bridge connections by means of the switching device and actuating the first and second group of half-bridges to provide regulated phase currents at the winding connections of the two winding sections.

[0030] In this way, the supply voltage can be optimally utilized in stand-alone operation for generating high powers at high rotational speeds with a reduced requirement for field weakening current.

[0031] It is also advantageous if, in emergency operation, only one of the two winding parts is energized by only the first or second group of half-bridges being controlled to provide a regulated phase current at the winding connections of only one of the two winding parts. In emergency operation, all bridge connections are interrupted by means of the switching device. In this way, for example, in the event of an insulation fault in one of the two winding parts, the other of the two winding parts can also be energized in order to achieve a limp home mode.

[0032] It is also advantageous if, in active short-circuit operation, all half-bridges of all phase subsystems are deactivated and all bridge connections are continuously conducting in order to produce an active short circuit of the electric machine via the bridge connections. Since all half-bridges are deactivated in interference operation, the two winding parts have no electrical connection to the voltage supply. The winding parts are thus in a potential-free active short circuit (particularly when the system is fed by a battery), which creates a reliable state even in the event of an insulation fault in one of the two winding parts.

[0033] It is also advantageous that, in series operation and in individual operation, the phase currents at the winding connections of the first winding part form a first alternating current and the phase currents at the winding connections of the second winding part form a second alternating current, wherein the two alternating currents have a phase shift of 180° relative to one another. Magnetomotive forces are generated in the stator by the two winding branches of each branch pair being phase-shifted by 180 degrees relative to one another by a corresponding configuration and the phase currents of each individual active phase subsystem being phase-shifted by 180 degrees relative to one another, in particular being identical in value and form, but having different signs, which magnetomotive forces are added in an additive manner to generate a torque. The first and second alternating currents act in the machine similarly to an alternating current whose amplitude corresponds to the sum of the amplitudes of the two alternating currents.

[0034] The method according to the present invention realizes that the power loss in the half-bridge due to the inactive phase of the half-bridge is reduced in the time average sense, so that the half-bridge has a lower temperature under the same cooling. At the same maximum semiconductor temperature, the phase current in the machine system can therefore be increased. The possible increase in the phase current in the machine system can also achieve a reduction in the number of turns for voltage maintenance in the motor under the same maximum torque, which reduces the necessity for field weakening current under higher speeds. In single operation, the following operating point can then be operated under higher speeds, which requires a field weakening current with a lower proportion of the phase current, so that a larger proportion of the phase current contributes to torque generation. Therefore, the electrical power and efficiency of the motor can be significantly improved under high speeds. For the half-bridge that performs current regulation of the active phase subsystem, the winding component is a load with a larger inductance, a larger ohmic resistance and a larger inductor voltage in the passive phase subsystem due to the conductive bridge connection, so that the duty cycle to be set becomes larger. As a result, the current fluctuation or current distortion factor and torque fluctuation are reduced. In addition, the iron loss in the motor is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Exemplary embodiments of the invention are illustrated in simplified form in the drawings and are explained in more detail in the following description.

[0036] in:

[0037] Figure 1 The equivalent circuit diagram of the machine system according to the invention is shown, which comprises the electric machine according to the first embodiment, the motor according to the invention, which operates in series operation according to the invention and is located according to Figure 2A-2C At the time point Y,

[0038] Figure 1A Shown according to Figure 1 One of the half bridges of

[0039] Figure 2A According to Figure 1 The phase subsystem 21V shows the variation curve of the phase current in the active and passive subsystem operation in the series operation,

[0040] Figure 2B According to Figure 1 The phase subsystem 21U shows the variation curve of the phase current during the operation of the active and passive subsystems in series operation.

[0041] Figure 2C according to Figure 1 , for the phase subsystem 21W, shows the variation curve of the phase current in the active and passive subsystem operation in the series operation,

[0042] Figure 3 Shown according to Figure 1 an equivalent circuit diagram of a machine system according to the invention, which is operated in a single operation according to the invention,

[0043] Figure 4 According to Figure 3 Each phase subsystem of the machine system operated in individual operation shows the variation of the phase current at the phase connection of the corresponding half bridge,

[0044] Figure 5 Shown according to Figure 1 an equivalent circuit diagram of a machine system according to the invention, which is operated in an emergency mode according to the invention,

[0045] Figure 6 Shown according to Figure 1 An equivalent circuit diagram of a machine system according to the invention, which is operated in active short-circuit operation according to the invention, and

[0046] Figure 7 An equivalent circuit diagram of a machine system according to the invention is shown, which comprises an electric machine according to a second exemplary embodiment and is operated in series operation according to the invention. DETAILED DESCRIPTION

[0047] Figure 1 An equivalent circuit diagram of a machine system according to the invention is shown, which comprises an electric machine according to a first exemplary embodiment and is operated in series operation according to the invention.

[0048] The machine system 1 according to the invention comprises an electric motor 2 and a plurality of half-bridges 3 arranged in a circuit for controlling the electric motor 2. The electric motor 2 has a stator with a stator winding 4. Each half-bridge 3 of the machine system 1 according to the invention is arranged according to Figure 1ATwo input nodes 5 are provided for connection to a DC voltage source 6 , for example a battery of a vehicle, with two switching elements 7 connected in series between the input nodes 5 and a phase connection 8 between the two switching elements 7 .

[0049] The stator winding 4 comprises two multi-phase, in particular three-phase winding parts 4.1, 4.2, which have the same number of phases, wherein each winding part 4.1, 4.2 has a number of winding branches 14 corresponding to the number of phases and a number of winding connections 10 corresponding to the number of phases. The winding branches 14 can each have parallel-connected sub-branches.

[0050] The winding connections 10 of one winding part 4.1 of the stator winding 4 are electrically connected to the phase connections 8 of the half-bridges 3 of the first group 13.1, and the winding connections 10 of the other winding part 4.2 are electrically connected to the phase connections 8 of the half-bridges 3 of the second group 13.2. The half-bridges 3 of the first group 13.1 include a number of half-bridges 3 corresponding to the number of phases of the winding part 4.1. Similarly, the half-bridges 3 of the second group 13.2 include a number of half-bridges 3 corresponding to the number of phases of the winding part 4.2. Each winding connection 10 of each winding part 4.1, 4.2 is electrically connected to another half-bridge 3 of the half-bridge 3 of the corresponding group 13.1, 13.2.

[0051] The phase connections 8 of the half-bridges 3 of the first group 13.1 can each be electrically connected to one of the phase connections 8 of the half-bridges 3 of the second group 13.2 via a bridge connection 11 to form a half-bridge pair 23 for the (direct) electrical connection of two winding connections 10 of different winding parts 4.1, 4.2 of the stator winding 4. A switchable switching device 12 is provided in each bridge connection 11 for interrupting the respective bridge connection 11.

[0052] According to the invention, it is provided that the half-bridge 3 of the machine system 1 is a regulated half-bridge for respectively converting the phase current I u ,I v ,I w In other words, the phase voltage is fed into the stator winding 4 .

[0053] Furthermore, according to the invention, it is provided that each winding branch 14 of one of the two winding parts 4.1, 4.2 forms a branch pair 15 with one of the winding branches 14 of the respective other winding part 4.1, 4.2, wherein the winding branches 14 of each branch pair 15 are phase-shifted by 180 degrees relative to one another.

[0054] In addition, it is provided according to the invention that the respective bridge connection 11 can be switched to conduct electricity continuously in two current directions by means of the respective switching device 12. The respective bridge connection 11 can then be switched to a continuously conducting state for both current directions in the respective bridge connection 11. Depending on the respective switching position of the switching device 12, the respective bridge connection 11 is then either continuously conducting or electrically interrupted.

[0055] The switching element 7 of the respective half bridge 3 is an electronic semiconductor switch, in particular an IGBT transistor or a MOSFET transistor. The respective semiconductor switch 7 can be assigned a freewheeling diode 9 as a separate component connected in parallel. Alternatively, the respective semiconductor switch 7 can inherently include the function of the freewheeling diode.

[0056] The half-bridges 3 of the two groups 13.1, 13.2 are part of an inverter 16. According to this embodiment, the bridge connection 11, including the switching device 12, is also part of the inverter 16, for example.

[0057] The winding branches 14 of each branch pair 15 are designed in such a way that, when energized, they generate a magnetomotive force in the machine, the fundamental components of which have a phase shift of 180 degrees relative to one another.

[0058] For example, the winding branches 14 of each branch pair 15 can be offset relative to each other by a certain sub-polar angle. Alternatively, the winding branches 14 of each branch pair 15 can be identically functioning branches, wherein, however, the winding start and end are swapped relative to each other. Nearly the same voltage is induced in the winding branches 14 of each branch pair 15.

[0059] The switching device 12 of the respective bridge connection 11 comprises, for example, at least one semiconductor switching element, in particular an IGBT transistor, a MOSFET transistor or a thyristor.

[0060] The winding branches 14 of each branch pair 15 can have the same number of voltage-maintaining turns and / or the same conductor cross section and / or the same inductance.

[0061] The winding branches 14 of the respective winding parts 4.1, 4.2 are arranged according to Figures 1 to 6 The first embodiment is connected in a star circuit and according to Figure 7The second embodiment of the invention is connected in a delta circuit. Two specific winding connections 10 from different winding parts 4.1, 4.2 can be electrically connected via corresponding bridge connections 11, wherein the two specific winding connections 10 form a connection pair of winding connections 10. By means of the connection pair of winding connections 10, one branch pair 15 can be connected in the case of a star circuit, and two branch pairs 15 can be connected to each other in the case of a delta circuit.

[0062] The machine system 1 additionally has a control unit 17 for actuating the switching elements 7 of the half bridge 3 and for actuating the switching devices 12 of the bridge connection 11 .

[0063] The machine system 1 includes a phase system 20 having a plurality of phase subsystems 21, such as 21 u ,twenty one v ,twenty one w The number of phase subsystems 21 corresponds to the number of phases of one of the winding parts 4 . 1 , 4 . 2 of the stator winding 4 .

[0064] Each phase subsystem 21 is formed by one of the half-bridge pairs 23 , the bridge connection 11 of the respective half-bridge pair 23 and two winding connections 10 of the two winding sections 4 . 1 , 4 . 2 which can be (directly) connected via the respective bridge connection 11 .

[0065] The machine system 1 can be operated in one of a plurality of operating states, in particular in series operation, individual operation, emergency operation or active short-circuit operation, depending on one or more system operating parameters, in particular the speed, torque and / or efficiency of the electric machine 2 and / or disturbance parameters of the machine system 1 .

[0066] according to Figure 1 , the machine system 1 is in series operation, wherein the machine system 1 is Figure 1 The state in is exemplarily for FIG. 2A to FIG. 2C The time point Y is shown.

[0067] In series operation, depending on at least one subsystem operating parameter, a respective one of the phase subsystems 21 is alternately made “passive” in passive subsystem operation and the respective remaining phase subsystem is made “active” in active subsystem operation.

[0068] During passive subsystem operation, the two half-bridges 3 of the corresponding phase subsystem 21 are deactivated or switched to inactivity when forming the passive phase subsystem 21, and the bridge connection 11 of the passive phase subsystem 21 is continuously conductive via the corresponding switching position of the switching device 12 so as to enable current flow in two directions from one of the two winding connections 10 through the bridge connection 11 of the passive phase subsystem 21 to the corresponding other winding connection of the two winding connections 10.

[0069] In active subsystem operation, the two half-bridges 3 of the respective phase subsystem 21 are controlled to provide two regulated phase currents I u ,I v ,I w , which are phase-shifted by 180 degrees relative to one another, are identical in value and form, but have different signs. The bridge connection 11 of the active phase subsystem 21 is electrically interrupted or interrupted by means of corresponding switching devices 12 via corresponding switching positions.

[0070] Figure 2A According to Figure 1 Phase subsystem 21V shows the profile of the phase currents with respect to the electrical phase angle in the active and passive subsystem operation in series operation.

[0071] In particular,

[0072] Figure 2A a shows the phase current I at the winding connection 10 of the phase subsystem 21V v The change curve of

[0073] Figure 2A b shows the phase current I at the phase connection 8 of the two half-bridges 3 of the phase subsystem 21V. v The change curve of

[0074] Figure 2A c shows the phase current I in the bridge connection 11 of the phase subsystem 21V br The change curve of

[0075] Figure 2A d shows the switching of the phase subsystem 21V between the active subsystem operation “active” and the passive subsystem operation “passive” with respect to the electrical phase angle.

[0076] Figure 2B According to Figure 1 Phase subsystem 21U shows the profile of the phase currents with respect to the electrical phase angle in the operation of the active and passive subsystems in series operation.

[0077] In particular,

[0078] Figure 2B a shows the phase current I at the winding connection 10 of the phase subsystem 21U u The change curve of

[0079] Figure 2B b shows the phase current I at the phase connection 8 of the two half-bridges 3 of the phase subsystem 21U. u The change curve of

[0080] Figure 2B c shows the phase current I in the bridge connection 11 of the phase subsystem 21U br The change curve of

[0081] Figure 2B d shows the changeover of the phase subsystem 21U between the active subsystem operation “active” and the passive subsystem operation “passive” with respect to the electrical phase angle.

[0082] Figure 2C According to Figure 1 Phase subsystem 21W shows the profile of the phase currents with respect to the electrical phase angle in the active and passive subsystem operation in series operation.

[0083] In particular,

[0084] Figure 2C a shows the phase current I at the winding connection 10 of the phase subsystem 21W w The change curve of

[0085] Figure 2C b shows the phase current I at the phase connection 8 of the two half-bridges 3 of the phase subsystem 21W. w The change curve of

[0086] Figure 2C c shows the phase current I in the bridge connection 11 of the phase subsystem 21W. br The change curve of

[0087] Figure 2C d shows the changeover of the phase subsystem 21W between the active subsystem operation “active” and the passive subsystem operation “passive” with respect to the electrical phase angle.

[0088] Depend on Figure 2A a to Figure 2CIt is apparent that in series operation, depending on at least one subsystem operating parameter, a respective one of the phase subsystems 21 is operated alternately in passive subsystem operation “passive” and the respective remaining phase subsystem is operated in active subsystem operation “active”.

[0089] The course I of the phase current at the phase connection 8 of the half bridge 3 u ,I v ,I w In the time interval dt, Figure 2A b. Figure 2B b and Figure 2C b shows a sudden change to the value zero.

[0090] In series operation and in individual operation, the phase current I at the winding connection 10 of the first winding part 4 . 1 is u ,I v ,I w At each time point or in each state, a first alternating current is formed. Furthermore, the phase current at the winding connection 10 of the second winding part 4.2 forms a second alternating current at each time point, wherein the two alternating currents at the two winding parts 4.1, 4.2 have a phase shift of 180° relative to each other. The phase current I of each of the two alternating currents u ,I v ,I w They are each phase-shifted by 120 degrees relative to one another and are, for example, wave-shaped or sinusoidal.

[0091] In response to Figure 2A b. Figure 2B b and Figure 2C b Provides a regulated phase current I in the active phase subsystem 21 u ,I v ,I w , when the bridge connection 11 of the passive phase subsystem 21 is continuously conducting via the corresponding switching position of the switching device 12, the corresponding remaining phase current (not directly regulated by means of the half-bridge 3) is used as the indirectly regulated phase current I u ,I v ,I w In the series connection of the two winding parts 4.1, 4.2, it is set autonomously, whereby the phase current I br Depending on its sign, the current flows in one of two directions through the bridge connection 11 of the passive phase subsystem 21 .

[0092] according to FIG. 2A to FIG. 2C At time point Y of machine system 1, for example, phase subsystem 21 v ,twenty onew In active subsystem operation and phase subsystem 21 u In the passive subsystem operation. In the active phase subsystem 21 v ,twenty one w The middle half-bridge 3 is then actively operated, so that a phase current I v , I w In the passive phase subsystem 21 u The middle half-bridge 3 is inactive, so that no phase current I is provided at the phase connection 8 of the half-bridge 3. u In response to the two active phase subsystems 21 v ,twenty one w The regulated phase current I v , I w , indirectly regulating the phase current I u In the series connection of the two winding parts 4 . 1 , 4 . 2 , each phase current I br Depending on its sign it flows in one of two directions through the passive phase subsystem 21 u The bridge connection 11 and thus the phase subsystem 21 u Therefore, despite the temporary deactivation of the half-bridge 3 in the passive subsystem operation, the phase current I at the winding connection 10 of the phase subsystem 21U u It has a wave-shaped, for example sinusoidal, variation curve.

[0093] The autonomous setting of the phase currents in the respectively passive phase subsystems 21 is achieved by virtue of the fact that the regulation of the first Kirchhoff's law (the sum of all phase currents equals zero) is applied to each winding section 4.1, 4.2 in each case. Thus, one of the phase currents of the winding sections 4.1, 4.2 is determined by the respective remaining phase current, so that one of the phase currents does not have to be actively regulated.

[0094] In the series operation, all phase subsystems 21 are switched successively into the passive subsystem operation in a continuous sequence as a function of the subsystem operating parameters.

[0095] The subsystem operating parameter can be, for example, the phase current I in the phase subsystem 21 u ,I v ,I w , wherein the following phase subsystems 21 are respectively operated in passive subsystem operation, and the phase current I u ,I v ,I wIn terms of value, it is above the threshold value X, in particular, when the phase current I u ,I v ,I w The phase current I of the electrical cycle is from one twelfth of the electrical cycle before the peak value S to the end of the electrical cycle. u ,I v ,I w The time interval dt is one twelfth of the peak value S.

[0096] For each phase current I u ,I v ,I w In each electrical cycle of , the bridge connection 11 of the associated phase subsystem 21 conducts electricity continuously in two time intervals dt, for which purpose two switching operations and two switching operations are provided at the corresponding switching device 12 , which can be achieved by suitable activation.

[0097] Figure 3 Shown according to Figure 1 An equivalent circuit diagram of a machine system according to the invention, which is operated in a separate operation according to the invention.

[0098] In separate operation, the two winding parts 4.1, 4.2 are controlled separately in that all bridge connections 11 of the machine system are interrupted or interrupted by means of the switching device 12 and all half-bridges 3 of the first and second groups 13.1, 13.2 are active, i.e., controlled to provide a regulated phase current I at all winding connections 10 of the two winding parts 4.1, 4.2. u ,I v ,I w .

[0099] Figure 4 Shown according to Figure 3 The curve of the phase current of all phase subsystems of a machine system operated in single operation with respect to the electrical phase angle.

[0100] Figure 5 Shown according to Figure 1 An equivalent circuit diagram of a machine system according to the invention, which is operated in the emergency mode according to the invention.

[0101] In emergency operation, only one of the two winding parts 4.1, 4.2 is energized by only the half-bridges 3 of the first or second group 13.1, 13.2 being actuated to provide a regulated phase current I at the winding connection 10 of one of the two winding parts 4.1, 4.2. u ,I v ,I wIn this case, all bridge connections 11 are interrupted by means of the switching device 12 via the corresponding switching position. In emergency operation, the phase subsystem 21 is in the “semi-active” state, in which one half-bridge 3 of the half-bridge pair 23 is actively controlled and provides a regulated phase current I u ,I v ,I w , and the other half-bridge 3 is passive.

[0102] Figure 6 Shown according to Figure 1 FIG. 1 is an equivalent circuit diagram of a machine system according to the invention, which is operated in the active short-circuit operation according to the invention.

[0103] In active short-circuit operation, all half-bridges 3 of all phase subsystems 21 are passive or deactivated. Furthermore, all bridge connections 11 of machine system 1 are continuously made conductive by means of switching devices 12 via corresponding switching positions in order to produce an active short-circuit of electric machine 2 via bridge connections 11 .

Claims

1. A machine system (1) comprising a motor (2) and a plurality of half-bridges (3) for controlling the motor (2), wherein: The electric motor (2) has a stator with a stator winding (4), wherein the half bridge (3) has two input nodes (5) for connection to a DC voltage source (6), two switching elements (7) connected in series between the input nodes (5) and phase connections (8) between the switching elements (7), wherein the stator winding (4) comprises two multi-phase winding parts (4.1, 4.2) with the same number of phases, in particular two three-phase winding parts, wherein each winding part (4.1, 4.2) has a number of winding branches (14) corresponding to the number of phases and a number of winding connections (10) corresponding to the number of phases, wherein the winding connections (10) of one winding part (4.1) are electrically connected to the phase connections (8) of the first group (13.1) of half bridges (3), and The winding connection (10) of another winding part (4.2) is electrically connected to the phase connection (8) of the half bridge (3) of the second group (13.2), wherein the half bridge (3) of each group (13.1, 13.2) has a number of half bridges (3) corresponding to the number of phases of the corresponding winding part (4.1, 4.2), wherein the phase connection (8) of the half bridge (3) of the first group (13.1) can be electrically connected to one of the phase connections (8) of the half bridge (3) of the second group (13.2) through a bridge connection (11) to form a half bridge pair (23) for electrically connecting two winding connections (10) of different winding parts (4.1, 4.2), wherein a switchable switching device (12) is provided in the corresponding bridge connection (11) for interrupting the bridge connection (11), It is characterized in that The half-bridge (3) of the machine system (1) is a regulated half-bridge for respectively converting the phase current (I u ,I v ,I w ) or the phase voltage is fed into the stator winding (4), - each winding branch (14) of one of the two winding parts (4.1, 4.2) forms a branch pair (15) with one of the winding branches (14) of the respective other winding part (4.1, 4.2), wherein the winding branches (14) of each branch pair (15) are phase-shifted by 180 degrees relative to one another, and The respective bridge connection (11) can be switched by means of a respective switching device (12) so as to be continuously conductive in both current directions.

2. The machine system according to claim 1, characterized in that: The switching element (7) of the corresponding half bridge (3) is a semiconductor switch, in particular an IGBT transistor or a MOSFET transistor, wherein the corresponding semiconductor switch is in particular assigned a freewheeling diode (9) as a separate component connected in parallel, or wherein the corresponding semiconductor switch inherently includes the function of the freewheeling diode.

3. A machine system according to any one of the preceding claims, characterised in that The two groups (13.1, 13.2) of half bridges (3) and in particular the bridge connection (11) are part of an inverter (16).

4. A machine system according to any one of the preceding claims, characterised in that The switching device (12) of the respective bridge connection (11) comprises at least one semiconductor switch, which is in particular an IGBT transistor, a MOSFET transistor or a thyristor.

5. The machine system according to claim 4, characterized in that: The switching device (12) is formed by an anti-series connection of two transistors, in particular IGBT transistors or MOSFET transistors, or by an anti-parallel connection of two thyristors, in particular triacs.

6. A machine system according to any one of the preceding claims, characterised in that The winding branches (14) of each branch pair (15) have the same number of turns for voltage maintenance and / or the same conductor cross section and / or the same inductance.

7. A machine system according to any one of the preceding claims, characterised in that The winding branches (14) of the respective winding parts (4.1, 4.2) are connected in a star connection or in a delta connection, wherein in the case of a star connection a branch pair (15) can be connected via the respective bridge connection (11), and in the case of a delta connection two branch pairs (15) can be connected to one another.

8. A machine system according to any one of the preceding claims, characterised in that A control unit (17) is provided for actuating the switching element (7) of the half bridge (3) and for actuating the switching device (12) of the bridge connection (11).

9. Method for operating a machine system (1) according to any one of the preceding claims, wherein: The machine system (1) comprises a phase system (20) having a plurality of phase subsystems (21), wherein the respective phase subsystem (21) is formed by one of the half-bridge pairs (23), a bridge connection (11) of the respective half-bridge pair (23) and two winding connections (10) which can be connected via the respective bridge connection (11), wherein the machine system (1) can be operated in one of a plurality of operating states, in particular in series operation, individual operation, emergency operation or active short-circuit operation, depending on one or more system operating parameters, in particular the speed, torque and / or efficiency of the electric machine and / or disturbance parameters of the machine system.

10. The method according to claim 9, characterized in that In series operation, depending on at least one subsystem operating parameter, a respective one of the phase subsystems (21) is operated alternately in passive subsystem operation (passive) and the respective remaining phase subsystem (21) is operated in active subsystem operation (active), wherein: - in passive subsystem operation (passive), the two half-bridges (3) of the respective phase subsystem (21) are deactivated while forming a passive phase subsystem (21), and the bridge connection (11) of the passive phase subsystem (21) is continuously conductive, so as to enable a current flow in two directions from one of the two winding connections (10) through the bridge connection (11) of the passive phase subsystem (21) to the respective other of the two winding connections (10), wherein: In active subsystem operation (active), the two half-bridges (3) of the respective phase subsystem (21) are controlled to provide two regulated phase currents (I u ,I v ,I w ), which are phase-shifted by 180 degrees relative to each other, in particular are identical in value and form, but have different signs, and the bridge connection (11) of the active phase subsystem (21) is electrically interrupted by means of the corresponding switching device (12).

11. The method according to claim 10, characterized in that In response to providing a regulated phase current (I u ,I v ,I w ), autonomously setting an indirectly regulated phase current in the series connection of the two winding parts (4.1, 4.2), which phase current flows in one of two directions depending on its sign through the bridge connection (11) of the passive phase subsystem (21).

12. The method according to any one of claims 10 or 11, characterized in that In the series operation, all phase subsystems (21) are switched successively to passive subsystem operation (passive) in a continuous sequence as a function of subsystem operating parameters.

13. The method according to any one of claims 10 to 12, characterized in that The subsystem operating parameter is the phase current (I u ,I v ,I w ), wherein the following phase subsystem (21) is operated in passive subsystem operation (passive), the phase current (I u ,I v ,I w ) is above a threshold value (X) in terms of value, in particular at the point in time during which the phase current (I u ,I v ,I w ) in the one-twelfth time interval (dt) around the peak value (S).

14. The method according to claim 9, characterized in that In separate operation, two winding parts (4.1, 4.2) are controlled separately in that all bridge connections (11) are interrupted by means of the switching device (12) and all half-bridges (3) of the first and second groups (3.1, 3.2) are actuated to provide a regulated phase current (I u ,I v ,I w ).

15. The method according to claim 9, characterized in that In emergency operation, only one of the two winding parts (4.1, 4.2) is energized in that only the half-bridge (3) of the first group (3.1) or the second group (3.2) is actuated to provide a regulated phase current (I u ,I v ,I w ), wherein in emergency operation all bridge connections (11) are interrupted by means of the switching device (12).

16. The method according to claim 9, characterized in that In active short-circuit operation, all half-bridges (3) of all phase subsystems (21) are deactivated and all bridge connections (11) are continuously conducting in order to produce an active short-circuit of the electric machine (2) via the bridge connections (11).

17. The method according to any one of claims 10 to 14, characterized in that In series operation and in single operation, the phase current (I u ,I v ,I w ) forms a first alternating current, and a phase current (I u ,I v ,I w ) forms a second alternating current, wherein the two alternating currents at the two winding parts (4.1, 4.2) have a phase shift of 180° relative to each other.

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