Inductive transformer system for transmitting electrical energy into an excitation winding of a rotor

Abstract

The invention relates to a stator (2) of an electrically excited synchronous machine (1), comprising a multiphase stator winding (7) having a plurality of phase conductors (8) and comprising a primary part (10p) of an inductive transformer system (10) for transmitting electrical energy into an excitation winding (13) of a rotor (3) of the synchronous machine (1), wherein a primary transformer winding (14) of the primary part (10p) is formed by multiple hybrid phase conductors (8) of the stator winding (7) which, as hybrid conductors (9), serve both to generate a rotating field of a three-phase system for driving the rotor (3) and to generate a transformer field of the transformer system (10), characterised in that each hybrid conductor (9) of the stator winding (7) has two hybrid partial conductors (9.1, 9.2), which are located in two different stator partial windings (7.1, 7.2) and belong to the same phase (U, V, W), and in that each stator partial winding (7.1, 7.2) has multiple hybrid partial conductors (9.1, 9.2) of different phases (U, V, W), which are connected to a star point (15) in a star connection.

Description

[0001] Description

[0002] title

[0003] Inductive transformer system for transmitting electrical energy into an excitation winding of a rotor

[0004] State of the art

[0005] The invention is based on a stator and a rotor of an electrically excited synchronous machine and on an electrically excited synchronous machine.

[0006] A stator of an electrically excited synchronous machine is already known from JP H04 347566 A, with a multi-phase stator winding comprising a plurality of phase strands and with a primary part of an inductive transformer system for transmitting electrical energy into an excitation winding of a rotor of the synchronous machine, wherein the primary part of the inductive transformer system has a primary transformer winding, wherein the primary transformer winding is formed by a plurality of hybrid strands of the stator winding, which each serve both to generate a rotating field of a three-phase system for driving the rotor and to generate a transformer field of the transformer system and into which both a phase current of the three-phase system and a primary transformer current of the transformer system can be fed.

[0007] In the transformer system of JP H04 347566 A, comparatively high ohmic losses occur because a resistor network with reference number 8 is provided for feeding the excitation current. As a result, a portion of the three-phase current of the three-phase system flows through the resistors of the resistor network with high ohmic losses, whereby this portion of the three-phase current disadvantageously cannot contribute to torque generation. The excitation current of the transformer system also flows through the resistors of the resistor network, causing a large portion of the input power to be lost in the resistors of the resistor network. The requirements of the three-phase system and the transformer system are contradictory because a high conductivity of the resistors improves the efficiency of feeding the excitation current but reduces the efficiency of feeding the three-phase current.An excitation current source, designated 7, is galvanically isolated from the three-phase system, which requires considerable effort. In JP H04 347566 A, the excitation current is fed into the star point of the stator winding. The excitation current then flows through the hybrid phases and then, via corresponding nodes, through the resistor network 8 back to the excitation current source 7. The number of poles of the rotating field (2-pole) is smaller than the number of poles of the transformer field (6-pole). This can lead to higher stray inductance in the transformer system. From the perspective of the transformer current, the hybrid phases are connected in parallel.

[0008] An electrically excited synchronous machine is already known from US20050218740 A1. This machine comprises a stator with a multiphase stator winding with multiple phase strands and a primary part of an inductive transformer system for transmitting electrical energy to an excitation winding of a rotor of the synchronous machine. The primary part of the inductive transformer system comprises a primary transformer winding.Furthermore, the electrically excited synchronous machine of US20050218740 A1 comprises a rotor having an excitation winding for generating a rotor field for exciting the synchronous machine and a secondary part of an inductive transformer system for transmitting electrical energy to the excitation winding of the rotor, wherein the secondary part of the inductive transformer system comprises at least one secondary transformer winding for providing a transformer AC voltage and at least one rectifier circuit acting as a rectifier for rectifying the transformer AC voltage into a secondary DC voltage for the excitation winding. A disadvantage is that the primary and secondary parts of the inductive transformer system are arranged as a transformer unit in a cavity of the rotor. The transformer unit requires a comparatively large installation space and, as an additional component, generates additional costs.The transformer unit comprises an excitation stator and an excitation rotor, which interact inductively as a transformer. When using a transformer as an additional component for power transmission, the transformer must be as small as possible to reduce costs and space requirements. This typically leads to an increase in electrical frequency, reduced efficiency, and increased system complexity.

[0009] Advantages of the invention

[0010] The stator according to the invention of an electrically excited synchronous machine with the characterizing features of claim 1 has the advantage over the prior art that the ohmic losses in the transformer system are reduced because the low-impedance stator winding is used as the primary transformer winding. The primary transformer winding is formed by a hybrid phase of the stator winding, which serves both to generate a rotating field of a three-phase system for driving the rotor and to generate a transformer field of the transformer system. In other words, the primary transformer winding is part of the stator winding or is integrated into the stator winding. Since the stator winding acts as the primary transformer winding, no additional winding is required in the stator. Compared to a transformer unit designed as an additional component, installation space is saved for the primary part of the inductive transformer system.In addition, the manufacturing costs of the transmission system, especially for the primary and / or secondary part, are reduced compared to a non-integrated, separate transmission system.

[0011] This is achieved according to the invention in that each hybrid phase of the stator winding has two hybrid sub-phases which are located in two different stator sub-windings and belong to the same phase, and in that each stator sub-winding has several, in particular three, hybrid sub-phases of different phases which are connected in a star connection with a star point.

[0012] Since the magnetic circuit of the machine is mostly only partially magnetically utilized or saturated during real operation and the excitation power to be transmitted is low compared to the three-phase power, the transformer field can be superimposed on the rotating field.

[0013] In particular, all phases of the stator winding are designed as hybrid phases. The interconnection of the hybrid subphases of the stator winding includes both a series connection of hybrid subphases and a parallel connection of hybrid subphases.

[0014] With the design of the stator, a 6-pole machine can be implemented in addition to an 8-pole synchronous machine.

[0015] The measures listed in subclaims 2 to 10 enable advantageous further developments and improvements of the stator of the electrically excited synchronous machine specified in claim 1. It is advantageous if the hybrid sub-phases of the respective hybrid phase are arranged offset from one another in the stator by a first offset angle, in particular by 90° mechanically in the case of eight stator poles and by 180° mechanically in the case of six stator poles, and in particular with respect to the partial assignment pattern in the pole group assignment pattern described below. In this way, each hybrid phase can generate a rotating field component with the number of poles of the rotating field from the DC current component of two in-phase hybrid sub-phases, and a transformer field with the number of poles of the transformer field from the current difference between two in-phase hybrid sub-phases.

[0016] According to an advantageous first embodiment, the hybrid sub-phases belonging to the same phase of different stator sub-windings for two of the three phases can each be electrically connected via a sub-winding connection. Each sub-winding connection has a coupling connection for the common current and voltage supply of the connected hybrid sub-phases and for connection to an inverter. The two hybrid sub-phases belonging to the same phase of the third phase each have an individual connection for connection to an inverter. A transformer current component can flow from one stator sub-winding to the other stator sub-winding through the coupling connection.

[0017] According to an advantageous second embodiment, the hybrid sub-strands of each stator sub-winding can each have an individual connection for connection to an inverter.

[0018] According to the first embodiment, the hybrid phases of different phases are connected in parallel from the perspective of the excitation current between the two star points. Within this parallel connection, a larger proportion of the excitation current flows through the path with the lower impedance. The hybrid phase with lower impedance therefore carries more current, reducing the negative effects of the stray inductance dependent on the rotor position. The poles of the hybrid phases active in the transformer field together form wider poles with a higher number of turns, thereby reducing the stray inductance and increasing the magnetic field. The hybrid phases with coupling connections carry half the excitation current on average over time, thus creating a less sharp flux pattern in the air gap, which reduces unwanted vibrations, noise, and torque ripples.According to the advantageous second embodiment, the hybrid sub-phases of each stator sub-winding can each have an individual connection for connection to an inverter. The current of each hybrid sub-phase is fed by the inverter, for example, such that the sum of all currents at the star points is zero, in particular, both the sum of the three-phase current components and the sum of the transformer current components are zero, in particular such that the amplitudes of the transformer current components of the first and second phases correspond to half the amplitude of the transformer current of the third phase.

[0019] It is particularly advantageous if, for the eight-pole stator version, the hybrid sub-phases of each hybrid phase are connected with the same polarity to the star point of the respective stator sub-winding, and if, for the six-pole version, the hybrid sub-phases of each hybrid phase are connected with opposite polarity to the star point of the respective stator sub-winding. In this way, each hybrid phase generates a rotating field component with the same number of poles as the rotating field from the DC current component of two in-phase hybrid sub-phases toward the star point, and a transformer field with the same number of poles as the transformer field from the current difference between two in-phase hybrid sub-phases toward the star point.

[0020] It is furthermore advantageous if, in the same stator partial winding, a second hybrid partial strand is arranged offset relative to a first hybrid partial strand by a second offset angle and a third hybrid partial strand is arranged offset relative to the first hybrid partial strand by a third offset angle in the stator which is equal in magnitude to the second offset angle and opposite to the second offset angle, in particular by + / -15° mechanically in the case of eight stator poles and by + / -80° mechanically in the case of six stator poles. 0 mechanically, with the first hybrid sub-phase of the respective stator sub-winding having, in particular, a single connection. In this way, the angular offset of the transformer fields generated by the hybrid phases from the excitation currents is small, whereby they primarily superimpose themselves additively and together generate a stronger transformer field.

[0021] It is very advantageous if, for designs with eight stator poles in each stator sub-winding, the first hybrid sub-phase is connected to the star point with opposite polarity to the second and third hybrid sub-phases. The second and third hybrid sub-phases are thus connected to the star point in the same direction. In this way, electrical phase angles of 120 degrees are achieved between the magnetic fields generated by the three-phase current components in the hybrid phases, whereby a rotating magnetic field can be generated. The electrical phase angle between the magnetic fields generated by the transformer current components in the hybrid phases is small, in particular 30 degrees electrically in the 4-pole field, so that the magnetic fields generated by the hybrid phases predominantly superimpose themselves additively and thus together form a stronger transformer field.

[0022] For the version with six stator poles, all hybrid sub-phases in each stator sub-winding are connected to the star point with the same polarity.

[0023] In this way, electrical phase angles of 120 degrees are achieved between the magnetic fields generated by the hybrid phases through the three-phase current components, allowing the generation of a rotating magnetic field. The electrical phase angle between the magnetic fields generated by the hybrid phases through the transformer current components is small, particularly 40 degrees in the 4-pole field, so that the magnetic fields generated by the hybrid phases predominantly superimpose additively, thus forming a stronger transformer field.

[0024] According to advantageous embodiments, it is provided that the respective hybrid strand occupies a slot group of stator slots per pole, each according to an identical pole assignment pattern, forming a pole group with conductors of the same phase. The pole assignment pattern of an unstretched pole group comprises full occupancy of all conductor positions of the slot group, and the pole assignment pattern of a stretched pole group comprises incomplete occupancy, with the gaps being occupied by conductors of a different phase. The slot group of an unstretched pole group comprises, in particular, two or three adjacent stator slots, and the slot group of a stretched pole group comprises, in particular, three or four adjacent stator slots. In this way, a number of turns suitable for the machine design can be implemented to achieve power and torque requirements.A limitation of the air gap harmonics and a lower torque ripple can be achieved by chording the pole groups.

[0025] It is advantageous if, in the pole assignment pattern of a chorded pole group, the two outer stator slots have half conductors of the respective hybrid phase and the other half gaps. One outer stator slot has the opposite assignment and gap configuration compared to the other outer stator slot of the same chorded pole group, and at least one inner stator slot of the chorded pole group has only conductors of the respective hybrid phase in the pole assignment pattern. This makes the magnetic field profile more consistent at the transition from hybrid phase to hybrid phase, thereby reducing adverse harmonics.

[0026] According to advantageous embodiments, conductors of both hybrid sub-strands or conductors of only one of the two hybrid sub-strands are provided in the pole assignment pattern of the respective pole group.

[0027] The pole assignment patterns of several, in particular four, pole groups, which are spaced apart by the angle of one pole, form a pole group assignment pattern. The two hybrid sub-strands of the respective hybrid strand advantageously each have an identical partial assignment pattern in the pole group assignment pattern. The partial assignment pattern of one hybrid sub-strand is offset by the first offset angle from the identical partial assignment pattern of the other hybrid sub-strand in the stator. In this way, it is possible to simultaneously generate a rotating field and a transformer field through the hybrid strands.

[0028] The rotor according to the invention with the characterizing features of claim 11 has the advantage over the prior art that the secondary transformer winding of the rotor is integrated or formed in a part of the excitation winding. The partial phase of the respective excitation phase with the hybrid coil arrangement serves both the electrical excitation of the synchronous machine and the secondary transmission of the transformer system. The hybrid coil arrangements are thus traversed by both the excitation direct current and the transformer alternating current, whereby the conductor cross-section is better utilized over time. Thus, with the same total rotor excitation, lower power loss occurs at the rotor, which leads to less heating of the rotor and thus to higher system efficiency and higher continuous power.In addition, space is saved on the rotor for the secondary transformer winding, which can be used, for example, to increase the number of turns or the conductor cross-section of the other windings.

[0029] With the design of the rotor, in addition to an 8-pole synchronous machine, a 6-pole machine can also be realized.

[0030] This is achieved according to the invention in that - the excitation winding has at least one, in particular a single, excitation strand,

[0031] - the respective excitation strand has two series-connected excitation coil groups, each comprising a plurality of excitation coils, wherein the two excitation coil groups each have a number, in particular an even or odd number, of excitation coils corresponding to half the number of rotor teeth, in particular the value three or four,

[0032] - the secondary transformer winding is formed by a hybrid sub-strand provided in the respective excitation strand, which is interposed between the two excitation coil groups of the respective excitation strand and comprises a secondary hybrid coil arrangement,

[0033] - the hybrid coil arrangement comprises a plurality of parallel-connected transformer coil pairs, each formed by two series-connected transformer coils and each intended to generate a transformer AC voltage by inductive interaction with a primary part of the transformer system, as well as a DC input for connection to one of the two excitation coil groups and a DC output for connection to the other excitation coil group.

[0034] The measures listed in subclaims 12 to 19 enable advantageous further developments and improvements of the rotor of the electrically excited synchronous machine specified in claim 11.

[0035] It is also advantageous if one of the excitation coils and one of the transformer coils is provided on each of the rotor teeth, wherein the number of turns of the respective transformer coil is in particular smaller than the number of turns of the respective excitation coil, in particular such that a required transformer AC voltage can be generated. In this way, the ohmic resistance of the winding arrangement and the transformer voltage present on the rotor can be coordinated and optimized, in particular taking into account the rectifying semiconductor elements of the rectifier circuit, with an optimum between current and voltage being sought. The rotor coils are arranged on the rotor in such a way that as many rotor coils as possible can be wound one after the other with the same wire and without wire interruption, thereby reducing the cycle time during production.

[0036] Furthermore, it is advantageous if the excitation coils, in the case of an even-numbered excitation coil group, are electrically connected in series in pairs, with the excitation coil pairs of the even-numbered excitation coil group being electrically connected in series and / or parallel. In the case of an odd-numbered excitation coil group, the excitation coils are advantageously electrically connected in series.

[0037] Furthermore, it is advantageous if the rotor has an even number of rotor teeth, in particular six or eight rotor teeth, wherein the rotor teeth can be numbered with a counting number in the circumferential direction starting from one of the rotor teeth, wherein the excitation coils of one of the two excitation coil groups are arranged only on rotor teeth with an even counting number and the excitation coils of the other excitation coil group are arranged only on rotor teeth with an odd counting number, in particular in the case of odd-numbered excitation coil groups. In the case of even-numbered excitation coil groups, the excitation coils of the respective excitation coil pair are arranged on different rotor teeth, between which there is a certain partial number of rotor slots that is smaller than the number of rotor slots of the rotor and corresponds to the value of a doubled odd natural number.In this way, the electrical voltage between the terminals of the excitation coil group is not influenced by the transformer field, allowing for a uniform feed of the excitation current. The electrical voltage between the terminals of the excitation coil group results from the sum of the voltages of the excitation coils connected in series within the excitation coil group.

[0038] It is advantageous if the number of transformer coil pairs per hybrid coil arrangement corresponds to half the number of rotor teeth of the rotor, in particular the value three or four, wherein the transformer coils of the respective transformer coil pair are arranged on two different rotor teeth, between which there is a certain partial number of rotor slots, which in the case of an even number of transformer coil pairs per hybrid coil arrangement is smaller than the number of rotor slots and corresponds to the value of a doubled odd natural number and in the case of an odd number of transformer coil pairs per hybrid coil arrangement corresponds to half the number of rotor slots of the rotor.In this way, the voltage between the terminals of the transformer coil pairs is not influenced by the transformer field, allowing the transformer coil pairs to be connected in parallel and the excitation current to be fed evenly into the transformer coil pairs. Furthermore, a voltage induced by the transformer field can be tapped at the center node of the transformer coil pairs for feeding into a rectifier.

[0039] The transformer coils of the respective transformer coil pair can be connected in series in the same direction in the case of an even number of transformer coil pairs per hybrid coil arrangement, so that when the transformer coil pair is energized from the DC input to the DC output, the corresponding rotor teeth are magnetized in the same radial direction. The transformer coils of the respective transformer coil pair can be connected in series in opposite directions in the case of an odd number of transformer coil pairs per hybrid coil arrangement, so that when the transformer coil pair is energized from the DC input to the DC output, the corresponding rotor teeth are magnetized in the opposite radial direction.In this way, the excitation coils can generate a rotor-side excitation field with a magnetization direction alternating from tooth to tooth to generate a torque in interaction with a synchronous stator rotating field.

[0040] The transformer coils of the hybrid coil arrangement can, in the case of an even number of transformer coil pairs per hybrid coil arrangement, be connected to the DC input or DC output in such a way that, when the transformer coil pairs are energized, the rotor teeth with odd numbers are magnetized in the opposite radial direction to the rotor teeth with even numbers, while the magnetization direction of the respective transformer coil and the excitation coil arranged on the same rotor tooth coincides. The transformer coils arranged on rotor teeth with even numbers can, in the case of an odd number of transformer coil pairs per hybrid coil arrangement, all be connected to the DC input or all to the DC output.In this way, the transformer coils can generate a rotor-side excitation field to generate a torque in interaction with a synchronous stator rotating field. Furthermore, the transformer coils act as the secondary winding of a transformer arrangement for receiving electrical energy from the stator to supply power to the rotor.

[0041] It is further advantageous if, in the case of an even number of transformer coil pairs per hybrid coil arrangement, each transformer coil connected to the DC input forms a connection pair with another of the transformer coils connected to the DC input, the transformer coils being arranged on two different rotor teeth, between which there is a certain partial number of rotor slots that is smaller than the number of rotor slots and corresponds to the value of a doubled odd natural number. In this way, the sum of the currents fed through a connection pair at the DC input and DC output is zero, since the voltages and currents at the intermediate nodes are equal in magnitude but have different signs. Thus, the current in the excitation coils is not influenced by the transformer current, even though the transformer coils are arranged in series with the excitation coils.

[0042] It is also advantageous if the hybrid coil arrangement has a plurality of AC voltage outputs, each for connection to an AC voltage input of one of the rectifier circuits, wherein the number of AC voltage outputs corresponds in particular to the number of transformer coil pairs per hybrid coil arrangement, wherein the respective AC voltage output is formed by an intermediate node between the transformer coils of the respective transformer coil pair, wherein the AC voltage outputs are each electrically connected to an AC voltage input of one of the rectifier circuits. In this way, the AC voltages and alternating currents provided by the transformer field at the intermediate nodes of the transformer coil pairs can be rectified by a rectifier, and the excitation coils can thereby be supplied to excite the rotor.

[0043] Advantageously, in addition to the excitation coils and transformer coils arranged on the rotor, a short-circuited wave winding can be provided on the rotor, which runs with a short-circuited conductor strand in a wave shape through in particular all of the rotor slots. In this way, voltage peaks in the excitation and transformer coils can be suppressed or reduced to protect the rectifier circuits.

[0044] The electrically excited synchronous machine according to the invention has the advantage over the prior art that the costs and installation space for the inductive transformer system are reduced, as well as the manufacturing costs of the synchronous machine. Furthermore, a large portion of the unwanted voltage harmonics and current ripple generated during pulse-width modulation operation can be utilized for stator-side excitation, allowing the machine to be excited with the same inverter chip area as a three-phase inverter without an excitation function. An increase in the inverter chip area for integrating the excitation function can thus be reduced or even eliminated entirely.

[0045] The number of poles of the transformer system corresponds to half the number of poles of the three-phase system if the number of poles of the three-phase system is a multiple of four. The number of poles of the transformer system is four if the three-phase system has six poles.

[0046] The invention also relates to a control device for controlling the synchronous machine according to the invention. The control device comprises an inverter and a control unit for controlling the inverter. The inverter has inverter outputs for providing phase voltages to supply power to the stator winding, with one of the inverter outputs being provided for each coupling or individual connection of the stator winding.

[0047] The invention also relates to a method for operating the synchronous machine according to the invention with a control device, wherein the control device controls the inverter for operating the synchronous machine in such a way that a total current is fed into the individual connections of the stator partial windings, which total current is formed from a portion of a phase current of the three-phase system, in particular with half the amplitude, and a portion of an excitation current of the transformer system, wherein the excitation current is an alternating current or direct current.

[0048] In a stator winding design with coupling terminals, a phase current of the three-phase system is fed into each of the coupling terminals at full amplitude, with the excitation current component having different signs at the two individual terminals belonging to the same phase. This allows the machine to be operated with four inverter outputs. The two inverter outputs for the individual terminals can have a reduced current carrying capacity, in particular half the current carrying capacity, compared to the two inverter outputs for the coupling terminals, thus enabling the machine to be excited without changing the total chip area of ​​the inverter. This can reduce manufacturing and development costs.

[0049] drawing

[0050] Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description

[0051] They show:

[0052] Fig.1 A is a system view of an electrically excited synchronous machine according to the invention according to a first embodiment,

[0053] Fig.1 B is a system view of an electrically excited synchronous machine according to the invention according to a second embodiment,

[0054] Fig.2A shows a circuit of the stator winding according to the invention of the stator according to Fig.1 A for a stator with eight stator poles,

[0055] Fig.2B shows a circuit of the stator winding according to the invention of the stator according to Fig.1 B for a stator with eight stator poles,

[0056] Fig.3A shows a circuit of the stator winding according to the invention of the stator according to Fig.1 A for a stator with six stator poles,

[0057] Fig.3B shows a circuit of the stator winding according to the invention of the stator according to Fig.1 B for a stator with six stator poles,

[0058] Fig.4 shows an unstretched arrangement of a hybrid strand according to the invention for a

[0059] 8-pole three-phase system,

[0060] Fig.5 shows an unstretched arrangement of a hybrid strand according to the invention for a

[0061] 6-pole three-phase system,

[0062] Fig.6 shows a first variant of a desired arrangement of an inventive

[0063] Hybrid string for an 8-pole three-phase system, Fig.7 a second variant of a desired arrangement of an inventive

[0064] Hybrid string for an 8-pole three-phase system,

[0065] Fig.8 shows a first variant of a desired arrangement of an inventive

[0066] Hybrid string for a 6-pole three-phase system,

[0067] Fig.9 shows a second variant of a desired arrangement of an inventive

[0068] Hybrid string for a 6-pole three-phase system,

[0069] Fig.lOA a rotor excitation circuit according to the invention for an 8-pole three-phase system,

[0070] Fig.10B shows a rotor according to the invention with the coils of the rotor excitation circuit according to Fig.10A for an 8-pole three-phase system,

[0071] Fig.11 A shows a rotor excitation circuit according to the invention for a 6-pole three-phase system and

[0072] Fig.11 B shows a rotor according to the invention with the coils of the rotor excitation circuit according to Fig.11 A for a 6-pole three-phase system.

[0073] Description of the embodiments

[0074] Fig.1 A shows a system view of an electrically excited synchronous machine according to the invention according to a first embodiment.

[0075] The electrically excited synchronous machine 1 comprises a stator 2 according to the invention and a rotor 3 according to the invention.

[0076] The stator 2 has a multi-phase, in particular three-phase, stator winding 7 with several phase strands 8 running in stator slots 6 of a stator body 5. The stator 2 also comprises a primary part 10p of an inductive transformer system 10 for transmitting electrical energy to an excitation winding 13 of the rotor 3 of the synchronous machine 1.

[0077] The primary part 10p of the inductive transformer system 10 has a primary transformer winding 14 formed by several hybrid phase strands 8 of the stator winding 7. The hybrid phase strands 8 serve as hybrid strands 9, each for generating a rotating field of a three-phase system for driving the rotor 3 and for generating a transformer field of the transformer system 10. Both a phase current of the three-phase system and a primary transformer current of the transformer system 10 can be fed into the hybrid strands 9, each of which is assigned to one of the phases U, V, and W. For example, each of the phase strands 8 of the stator winding 7 is a hybrid strand 9.

[0078] According to the invention, each hybrid strand 9 of the stator winding 7 has two hybrid partial strands 9.1, 9.2, which are arranged in two different stator partial windings

[0079] 7.1,7.2 and belong to the same phase U,V,W. Each stator partial winding

[0080] According to the invention, 7.1,7.2 comprises several, in particular three, hybrid sub-strings 9.1,9.2 of different phases U,V,W, which are connected in a star connection with a star point 15.

[0081] According to the first embodiment in Fig.lA, the hybrid sub-strands 9.1, 9.2 belonging to the same phase V,W are made of different stator sub-windings

[0082] 7.1, 7.2 for two of the three phases V.W are each electrically connected via a partial winding connection 16, wherein each partial winding connection 16 has a coupling connection 17 for the common current and voltage supply of the connected partial strands 9.1, 9.2 and for connection to an inverter output 51 of an inverter 50. The two hybrid partial strands 9.1, 9.2 of the third phase U belonging to the same phase U each have an individual connection 18 for connection to one of the inverter outputs 51 of the inverter 50.

[0083] The three-phase system of synchronous machine 1 has a first number of poles, and the inductive transformer system has a second number of poles. The (second) number of poles of the transformer system corresponds, for example, to half the (first) number of poles of the three-phase system if the number of poles of the three-phase system is a multiple of four. The number of poles of the transformer system has, for example, the value four if the three-phase system has six poles.

[0084] The overall system also includes a control device 60 for controlling the electrically excited synchronous machine 1. The control device 60 has the inverter 50 with inverter outputs 51 and a control unit 61 for controlling the inverter 50. Phase voltages for supplying energy to the stator winding 7 of the stator 2 are provided at the inverter outputs 51. One of the inverter outputs 51 is provided for each connection of the two stator partial windings 7.1, 7.2. The control unit 61 controls the inverter 50 to operate the synchronous machine 1 in such a way that a total current is fed into the individual connections 18 of the stator partial windings 7.1, 7.2, which total current is formed from a portion of a phase current of the three-phase system, in particular with half the amplitude, and a portion of an excitation current of the transformer system 10, wherein the excitation current is an alternating or direct current.

[0085] A phase current of the three-phase system with full amplitude is fed into the coupling connections 17 according to the first embodiment. At the individual connections 18 belonging to the same phase, the component of the excitation current has different signs.

[0086] Fig.1 B shows a system view of an electrically excited synchronous machine according to the invention according to a second embodiment.

[0087] The second embodiment according to Fig.1 B differs from Fig.1A in that the hybrid partial strands 9.1, 9.2 of each stator partial winding 7.1, 7.2 each have an individual connection 18 for connection to one of the inverter outputs 51 of the inverter 50.

[0088] The hybrid sub-strands 9.1, 9.2 of the respective hybrid strand 9 are arranged offset from one another by a first offset angle in the stator body 5 for both embodiments according to Fig.lA and Fig.lB, in particular in the case of eight stator poles by 90° mechanically and in the case of six stator poles by 180° mechanically (Table 1 for the first embodiment and Table 2 for the second embodiment, in each case second column “Position mech”).

[0089] Table 1 shows the angular positions in the stator for the individual hybrid sub-phases for the 8-pole three-phase system according to Fig. 2A or Fig. 2B. Column 2 of Table 1 shows the mechanical angular position of the hybrid sub-phases, column 3 shows the magnetic phase angular position of the hybrid sub-phases with respect to the rotating field (8-pole), column 4 shows the magnetic phase angular position of the hybrid sub-phases with respect to the transformer field (4-pole), column 5 shows the resulting magnetic phase angular position of the generated rotating field components of the hybrid sub-phases with respect to the rotating field (8-pole) taking into account the current direction of the three-phase components, and column 6 shows the resulting magnetic phase angular position of the generated transformer field components of the hybrid sub-phases with respect to the transformer field (4-pole) taking into account the current direction of the transformer current components.

[0090] Table 2 shows the angular positions in the stator for the individual hybrid sub-phases for the 6-pole three-phase system according to Fig. 3A or Fig. 3B. Column 2 of Table 2 shows the mechanical angular position of the hybrid sub-phases, column 3 shows the magnetic phase angular position of the hybrid sub-phases with respect to the rotating field (6-pole), column 4 shows the magnetic phase angular position of the hybrid sub-phases with respect to the transformer field (4-pole), column 5 shows the resulting magnetic phase angular position of the generated rotating field components of the hybrid sub-phases with respect to the rotating field (6-pole) taking into account the current direction of the three-phase components, and column 6 shows the resulting magnetic phase angular position of the generated transformer field components of the hybrid sub-phases with respect to the transformer field (4-pole) taking into account the current direction of the transformer current components.

[0091] In the same stator partial winding 7.1, 7.2, for both embodiments according to Fig. 1A and Fig. 1B, a second hybrid partial strand 9.1, 9.2 (for example, phase V) is arranged offset relative to a first hybrid partial strand 9.1, 9.2 (for example, phase II) by a second offset angle and a third hybrid partial strand 9.1, 9.2 (for example, phase W) is arranged offset relative to the first hybrid partial strand 9.1, 9.2 (for example, phase U) by a third offset angle in the stator body 5 which is equal in magnitude to the second offset angle and opposite to the second offset angle, in particular in the case of eight stator poles by + / -15° mechanically and in the case of six stator poles by + / -80 0 mechanically. In particular, the first hybrid sub-phase 9.1, 9.2 of the respective stator sub-winding 7.1, 7.2 has a single connection 18 (Table 1 for an 8-pole three-phase system and Table 2 for a 6-pole three-phase system, second column "Mech. Position").

[0092] Table 1

[0093] Table 2 Fig.2A shows a circuit of the stator winding according to the invention of the stator according to Fig.1A for a stator with eight stator poles. In Fig.2A to Fig.3B, the ends of the hybrid sub-phases 9.1, 9.2 are marked with a dot and the beginnings of the hybrid sub-phases 9.1, 9.2 are marked without a dot. In the case of eight stator poles, the hybrid sub-phases 9.1, 9.2 of the respective hybrid phase 9 are connected with the same polarity to the star point 15 of the respective stator sub-winding 7.1, 7.2. For the hybrid phase 9 of phase U, the hybrid sub-phases 9.1 (U1) and 9.2 (U2) are therefore connected with the same polarity to the star point 15 of the respective stator sub-winding 7.1, 7.2. The same applies to the hybrid sub-strands 9.1 (V1) and 9.2 (V2) as well as to the hybrid sub-strands 9.1 (W1) and 9.2 (W2).

[0094] In the case of eight stator poles, according to Fig. 2A, in each stator partial winding 7.1, 7.2, the first hybrid partial phase 9.1, 9.2 (for example, phase II) is connected to the star point 15 with opposite polarity to the second and third hybrid partial phase 9.1, 9.2 (for example, phases V and W). The first hybrid partial phases 9.1, 9.2 form a first hybrid phase, the second hybrid partial phases 9.1, 9.2 form a second hybrid phase, and the third hybrid partial phases 9.1, 9.2 form a third hybrid phase.

[0095] Into the individual terminals 18 of the first hybrid strand 9.1, 9.2 (for example phase U) of the circuit according to Fig.2A and Fig.3A, sum currents are fed formed from half a phase current of the three-phase current and an excitation current component l err . The excitation current component l errhas the same amplitude at the two individual terminals 18 of the circuit shown in Fig. 2A and Fig. 3A, but a different sign. A full three-phase current component is fed into the coupling terminals 17 of the second and third hybrid sub-phases 9.1, 9.2 (for example, phases V and W). The excitation current component l err , which is fed into the first hybrid sub-string 9.1, 9.2, flows at star point 15 into the second and third hybrid sub-string 9.1, 9.2, which represents a parallel connection for the excitation current component. Depending on the instantaneous impedances of the second and third hybrid sub-string 9.1, 9.2, the excitation current component at star point 15 is divided into two partial excitation current components, the sum of which corresponds to the excitation current component, indicated in Fig. 2A by the excitation current component l err * K and the excitation current component l err* (1 - K), with K greater than or equal to zero and K less than or equal to one. The coupling connections 17 enable the current flow of the partial excitation current components from one stator partial winding 7.1, 7.2 into the other stator partial winding 7.1, 7.2.

[0096] Fig.2B shows a circuit of the stator winding according to the invention of the stator according to Fig.1 B for a stator with eight stator poles.

[0097] In a winding with six individual terminals 18 according to Fig.2B and Fig.3B, a total current is fed into each individual terminal 18, formed from half a phase current of the three-phase current and an excitation current component l err . The excitation current component l errhas the same amplitude at the two individual terminals 18 of the circuit shown in Fig. 2B, but a different sign. The phase currents and excitation current components are adjusted by current control, so that at the star points 15, both the sum of the phase currents of the three-phase current and the sum of the excitation current components l err is zero. The magnitudes of the excitation current components of the second and third hybrid sub-strings 9.1, 9.2 are set to the values ​​of excitation current component l err * K and excitation current component l err* (1 - K) set by control (with K greater than or equal to zero and K less than or equal to one), whereby the value 1 / 2 can be selected for the parameter K, which corresponds to an equal distribution of the transformer current between the respective second and third hybrid strings. The parameter K can also be time-variable, so that it is selected depending on the instantaneous phase currents in the second and third hybrid strings. The parameter K can be set to a value other than 0.5 to an unequal distribution of the excitation current between the second and third hybrid strings, so that the one of the two hybrid strings which carries the lower phase current of the three-phase system receives a higher excitation current from the transformer system to generate a more uniform current density in the conductors and reduce ohmic losses.The amount of the excitation current component in the second or third hybrid string, which currently carries the lower phase current of the two, is increased.

[0098] Fig.3A shows a circuit of the stator winding according to the invention of the stator according to Fig.1 A for a stator with six stator poles.

[0099] In the case of six stator poles, the hybrid sub-phases 9.1, 9.2 of the respective hybrid phase 9 are connected with opposite polarity to the star point 15 of the respective stator sub-winding 7.1, 7.2. As a result, the hybrid sub-phases 9.1, 9.2 of one stator sub-winding 7.1 are connected with opposite polarity to the respective star point 15 of the other stator sub-winding 7.2.

[0100] In the case of six stator poles, according to Fig.3A, in each stator partial winding 7.1, 7.2 all hybrid partial phases 9.1, 9.2 are connected with the same polarity to the star point 15.

[0101] Fig. 3B shows a circuit configuration of the stator winding according to the invention of the stator shown in Fig. 1B for a stator with six stator poles. Fig. 4 shows an unstrung arrangement of a hybrid phase according to the invention for an 8-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2 or a phase W hybrid phase comprising the hybrid subphases W1 and W2.

[0102] Fig. 5 shows an unstrung arrangement of a hybrid phase according to the invention for a 6-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2 or a phase W hybrid phase comprising the hybrid subphases W1 and W2.

[0103] The respective hybrid strand 9 occupies a slot group 20 of adjacent stator slots 6 per stator pole, each according to an identical pole occupancy pattern, forming a pole group 21 of electrical conductors 22 of the same phase U, V, W.

[0104] The pole assignment pattern of an unstretched pole group 21 comprises a full assignment of all conductor positions of the slot group 20 with conductors of the respective hybrid strand 9. The slot group 20 of an unstretched pole group 21 comprises, for example, two (Fig. 4) or three (Fig. 5) adjacent stator slots 6.

[0105] In the pole assignment pattern PP of the respective unstretched pole group 21, conductors 22 of both hybrid sub-strands 9.1, 9.2 or conductors 22 of only one of the two hybrid sub-strands 9.1, 9.2 can be provided.

[0106] Fig. 6 shows a first variant of a chorded arrangement of a hybrid phase according to the invention for an 8-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2, or a phase W hybrid phase comprising the hybrid subphases W1 and W2. - TI -

[0107] Fig. 7 shows a second variant of a chorded arrangement of a hybrid phase according to the invention for an 8-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2 or a phase W hybrid phase comprising the hybrid subphases W1 and W2.

[0108] Fig. 8 shows a first variant of a chorded arrangement of a hybrid phase according to the invention for a 6-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2 or a phase W hybrid phase comprising the hybrid subphases W1 and W2.

[0109] Fig. 9 shows a second variant of a chorded arrangement of a hybrid phase according to the invention for a 6-pole three-phase system. The hybrid phase shown is, for example, a phase U hybrid phase and thus comprises the hybrid subphases U1 and U2, but could also be a phase V hybrid phase comprising the hybrid subphases V1 and V2 or a phase W hybrid phase comprising the hybrid subphases W1 and W2.

[0110] The pole assignment pattern PP of a chorded pole group 21 according to one of the embodiments in Fig. 6 to Fig. 9 comprises a patchy assignment with respect to an assignment with conductors 22 of the same hybrid phase 9, wherein the gaps 23 in the assignment are occupied by conductors 22 of a different phase. The slot group 20 of a chorded pole group 21 comprises, in particular, three (Fig. 6, Fig. 7) or four (Fig. 8, Fig. 9) adjacent stator slots 6.

[0111] In the pole assignment pattern PP of the respective chorded pole group 21, conductors 22 of both hybrid sub-strands 9.1, 9.2 or conductors 22 of only one of the two hybrid sub-strands 9.1, 9.2 of the respective hybrid strand 9 can be provided.

[0112] In the pole assignment pattern PP of a chorded pole group 21 according to Fig.6 to Fig.9, the two outer stator slots 6a have half conductors 22 of the respective hybrid strand 9 and the other half gaps 23, i.e. conductors of a different phase, wherein one outer stator slot 6a is inversely occupied with respect to the other outer stator slot 6a of the same chorded respective pole group 21 with regard to assignment with conductors 22 of the same hybrid strand 9 and gap 23. In the pole assignment pattern PP of the respective chorded pole group 21 according to Fig.6 to Fig.9, the at least one inner stator slot 6i of the chorded pole group 21 has only conductors 22 of the respective hybrid strand 9, wherein in the pole assignment pattern PP the at least one inner stator slot 6i of the chorded pole group 21 according to Fig.6 to Fig.9 has both a portion of conductors 22 of the one hybrid sub-strand 9.1, 9.2 and a portion of conductors 22 of the other hybrid sub-strand 9.1, 9.2 of the respective hybrid strand 9 or alternatively only conductor 22 of one of the two hybrid sub-strands 9.1, 9.2.

[0113] The pole assignment patterns PP of several, in particular four, chorded pole groups 21 according to Fig.6 to Fig.9 (these are spaced from each other by the angle of one stator pole) together form a pole group assignment pattern PG. The two hybrid sub-strands 9.1, 9.2 of the respective hybrid strand 9 each have an identical partial assignment pattern PG1.PG2 in the pole group assignment pattern PG, wherein the partial assignment pattern PG1 of one hybrid sub-strand 9.1 is offset from the identical partial assignment pattern PG2 of the other hybrid sub-strand 9.2 in the stator body 5 by the first offset angle <|J1, in particular in the case of eight stator poles (Fig.6 and Fig.7) by 90° mechanically and in the case of six stator poles (Fig.8 and Fig.9) by 180° mechanically.

[0114] Fig.lOA shows a rotor excitation circuit according to the invention for an 8-pole three-phase system.

[0115] Fig.10B shows a rotor according to the invention with the coils of the rotor excitation circuit according to Fig.1 OA for an 8-pole three-phase system.

[0116] In addition to the excitation coils 34 and transformer coils 37 arranged on the rotor 3, a short-circuited wave winding 45 can be provided on the rotor 3. This short-circuited wave winding 45 runs, in particular, through all rotor slots 31 with a short-circuited strand 46 and serves to suppress voltage peaks in the excitation coils 34 and the transformer coils 37. The wave winding 45 is marked with the letter "C" in Fig. 10B. Furthermore, the axial current direction in the respective coil sides of the coils 34, 37 is indicated in Fig. 10B.

[0117] Fig. 11 A shows a rotor excitation circuit according to the invention for a 6-pole three-phase system. Fig. 11 B shows a rotor according to the invention with the coils of the rotor excitation circuit according to Fig. 11 A for a 6-pole three-phase system.

[0118] In addition to the excitation coils 34 and transformer coils 37 arranged on the rotor 3, the short-circuited wave winding 45 can be provided on the rotor 3, which, with the short-circuited conductor strand 46, runs in a wave-like manner through in particular all of the rotor slots 31 and serves to suppress voltage peaks in the excitation coils 34 and in the transformer coils 37. The wave winding 45 is marked with the letter "C" in Fig. 11 B. The beginning and end of the conductor strand 46 are directly connected to one another and thus electrically short-circuited. The conductor strand 46 is formed from a series connection of electrical conductors, with at least one conductor of the conductor strand 46 being provided for each rotor slot 31 and the current direction from the rotor slot 31 to the respectively adjacent rotor slot 31 being opposite.

[0119] Furthermore, in Fig.11 B the current direction in the respective coil sides of the coils 34,37 is indicated in the usual way.

[0120] The rotor 3 of the electrically excited synchronous machine 1 has the excitation winding 13 for generating a rotor field for exciting the synchronous machine 1 and a secondary part 10s of the inductive transformer system 10 for transmitting electrical energy into the excitation winding 13 of the rotor 3. The secondary part 10s of the inductive transformer system 10 comprises at least one secondary transformer winding 28 for providing a transformer AC voltage and at least one rectifier circuit 29 acting as a rectifier, in particular a bridge circuit, for rectifying the transformer AC voltage into a secondary DC voltage for the excitation winding 13.

[0121] The rotor 3 has rotor teeth 30, wherein rotor slots 31 are formed between the rotor teeth 30, which are designed to receive the excitation winding 13 and to receive the secondary transformer winding 28. The rotor teeth 30 of the rotor 3 are numbered with a counting number in ascending order starting from one of the rotor teeth 30 in the circumferential direction with respect to a rotor axis 32 of the rotor 3. The rotor 3 has, for example, an even number of rotor teeth 30, in particular six rotor teeth according to Fig. 11B or eight rotor teeth 30 according to Fig. 10B. According to the invention, it is provided that the excitation winding 13 has at least one, in particular a single, excitation strand 13s, wherein the respective excitation strand 13s has two series-connected excitation coil groups 33, each comprising a plurality of excitation coils 34, which are designed, for example, as single-tooth coils.The two excitation coil groups 33 each have a number, in particular an even or an odd number, of excitation coils 34 that corresponds to half the number of rotor teeth 30, in particular the value three or four. The excitation coils 34 are identified in Fig. 10A, Fig. 10B, Fig. 11A, and Fig. 11B by a "B" and subsequently by the number of the rotor tooth 30 on which the respective excitation coil 34 is arranged.

[0122] Furthermore, it is provided according to the invention that the secondary transformer winding 28 according to Fig.10 A and Fig.11A is formed by a hybrid sub-strand 13h provided in the respective excitation strand 13s, which is interposed between the two excitation coil groups 33 of the respective excitation strand 13s and comprises a secondary hybrid coil arrangement 35.

[0123] The hybrid coil arrangement 35 comprises several parallel-connected transformer coil pairs 36, each formed by two series-connected transformer coils 37, each intended to generate a transformer AC voltage through inductive interaction with the primary part 10p of the transformer system 10. The transformer coils 37 are designed, for example, as single-tooth coils and are identified in Fig. 10A, Fig. 10B, Fig. 11A, and Fig. 11B by an "A" and subsequently by the number of the rotor tooth 30 on which the respective transformer coil 37 is arranged.

[0124] Furthermore, the hybrid coil arrangement 35 comprises a DC input 38 for connection to one of the two excitation coil groups 33 of the excitation strand 13s and a DC output 39 for connection to the other excitation coil group 33 of the excitation strand 13s.

[0125] According to Fig. 10B and Fig. 11B, one of the excitation coils 34 and one of the transformer coils 37 is provided on each of the rotor teeth 30, wherein the number of turns of the respective transformer coil 37 is in particular smaller than the number of turns of the respective excitation coil 34, in particular such that a required transformer AC voltage can be generated. The respective excitation coil group 33 can, according to Fig. 10A, be an even-numbered excitation coil group 33 comprising an even number of excitation coils 34. Alternatively, the respective excitation coil group 33 according to Fig. 11A can be an odd-numbered excitation coil group 33 comprising an odd number of excitation coils 34.

[0126] The excitation coils 34 of an even-numbered excitation coil group 33 are electrically connected in series in pairs to form excitation coil pairs 34p. The excitation coil pairs 34p of the even-numbered excitation coil group 33 can be electrically connected in series and / or in parallel. The excitation coils 34 of an odd-numbered excitation coil group 33 are electrically connected in series.

[0127] According to Fig.10A and Fig.11A, the excitation coils 34 of one of the two excitation coil groups 33 can, for example, only be arranged on rotor teeth 30 with an even number, and the excitation coils 34 of the other excitation coil group 33 can, for example, only be arranged on rotor teeth 30 with an odd number, in particular in the case of odd-numbered excitation coil groups 33 according to Fig.11A.

[0128] In the case of even-numbered excitation coil groups (Fig. 10A), the excitation coils 34 of the respective excitation coil pair 34p are arranged on such different rotor teeth 30, between which a certain partial number of rotor slots 31 lies, which is smaller than the number of rotor slots 31 of the rotor 3 and corresponds to the value of a doubled odd natural number, according to Fig. 10A and Fig. 11A, for example, the value two.

[0129] The number of transformer coil pairs 36 per hybrid coil arrangement 35 corresponds to half the number of rotor teeth 30 of the rotor 3, for example the value three according to Fig.11A or the value four according to Fig.10A, wherein the transformer coils 37 of the respective transformer coil pair 36 are arranged on two such different rotor teeth 30, between which there is a certain partial number of rotor slots 31, which in the case of an even number of transformer coil pairs 36 (Fig.10A) per hybrid coil arrangement 35 is smaller than the number of rotor slots 31 and corresponds to the value of a doubled odd natural number, for example the value two according to Fig.10A.

[0130] In the case of an odd number of transformer coil pairs 36 per hybrid coil arrangement 35, the specific partial number of rotor slots 31 corresponds to half the number of rotor slots 31 of the rotor 3 or half the number of rotor teeth 30, according to Fig.11 A the value three.

[0131] The transformer coils 37 of the respective transformer coil pair 36 are connected in series with one another in the same direction according to Fig. 10A in the case of an even number of transformer coil pairs 36 per hybrid coil arrangement 35, so that when the transformer coil pair 36 is energized from the direct current input 38 to the direct current output 39, the associated rotor teeth 30 are magnetized in the same radial direction with respect to the rotor axis 32.

[0132] The transformer coils 37 of the respective transformer coil pair 36 are connected in series in opposite directions to one another according to Fig.11 A in the case of an odd number of transformer coil pairs 36 per hybrid coil arrangement 35, so that when the transformer coil pair 36 is energized from the DC input 38 to the DC output 39, the associated rotor teeth 30 are magnetized in the opposite radial direction with respect to the rotor axis 32.

[0133] In the case of an even number of transformer coil pairs 36 per hybrid coil arrangement 35 (Fig. 10A), the transformer coils 37 of the hybrid coil arrangement 35 are connected to the direct current input 38 or direct current output 39 in such a way that when the transformer coil pairs 36 are energized, the rotor teeth 30 with an odd number are magnetized in the opposite radial direction with respect to the rotor teeth 30 with an even number with respect to the rotor axis 32.

[0134] The transformer coils 37 of the hybrid coil arrangement 35, which are arranged on rotor teeth 30 with an even number, are all connected to the DC input 38 or all to the DC output 39 in the case of an odd number of transformer coil pairs 36 per hybrid coil arrangement 35 (Fig. 11 A).

[0135] In the case of an even number of transformer coil pairs 36 per hybrid coil arrangement 35 (Fig. 10A), each transformer coil 37 connected to the direct current input 38 forms a connection pair 40 with another of the transformer coils 37 connected to the direct current input 38, the transformer coils 37 of which are arranged on two different rotor teeth 30, between which there is a certain partial number of rotor slots 31 which is smaller than the number of rotor slots 31 and corresponds to the value of a doubled odd natural number, for example the value six according to Fig. 10A.

[0136] The hybrid coil arrangement 35 has a plurality of AC voltage outputs 41, each for connection to an AC voltage input 42 of one of the rectifier circuits 29. The number of AC voltage outputs 41 corresponds, for example, to the number of transformer coil pairs 36 per hybrid coil arrangement 35. The respective AC voltage output 41 is formed by an intermediate node between the transformer coils 37 of the respective transformer coil pair 36. The AC voltage outputs 41 are each electrically connected to an AC voltage input 42 of one of the rectifier circuits 29. The number of rectifier circuits 29 corresponds, for example, to the number of AC voltage outputs 41 of the hybrid coil arrangement 35. The respective rectifier circuit 29 has two DC voltage outputs 43 for generating a potential difference between the ends of the excitation phase 13s.

Claims

Claims 1 . Stator (2) of an electrically excited synchronous machine (1), with a multi-phase, in particular three-phase, stator winding (7) comprising a plurality of phase strands (8) and with a primary part (10p) of an inductive transformer system (10) for transmitting electrical energy into an excitation winding (13) of a rotor (3) of the synchronous machine (1), wherein the primary part (10p) of the inductive transformer system (10) has a primary transformer winding (14), wherein the primary transformer winding (14) is formed by a plurality of hybrid phase strands (8) of the stator winding (7), which, as hybrid strands (9), each serve both to generate a rotating field of a three-phase system for driving the rotor (3) and to generate a transformer field of the transformer system (10), and into each of which both a phase current of the three-phase system and a primary transformer current of the transformer system (10) can be fed, characterized in thatthat each hybrid strand (9) of the stator winding (7) has two hybrid sub-strands (9.1, 9.2) which are located in two different stator sub-windings (7.1, 7.2) and belong to the same phase (U, V, W) and that each stator sub-winding, (7.1.7.2) has several, in particular three, hybrid sub-strings (9.1, 9.2) of different phases (U, V, W) which are connected in a star connection with a star point (15).

2. Stator according to claim 1, characterized in that the hybrid partial strands (9.1.9.2) of the respective hybrid strand (9) in the stator (2) are arranged offset from one another by a first offset angle (4>1 ), in particular by 90° mechanically in the case of eight stator poles and by 180° mechanically in the case of six stator poles.

3. Stator according to one of the preceding claims, characterized in that a) the hybrid partial strands (9.1, 9.2) belonging to the same phase of different stator partial windings (7.1, 7.2) for two of the three phases are each electrically connected via a partial winding connection (16), wherein each partial winding connection (16) has a coupling connection (17) for the common current and voltage supply of the connected hybrid partial strands (9.1, 9.2) and for connection to an inverter (50) and wherein the two hybrid partial strands (9.1, 9.2) belonging to the same phase of the third phase each have an individual connection (18) for connection to an inverter (50), or b) the hybrid partial strands (9.1, 9.2) of each stator partial winding (7.1, 7.2) each have an individual connection (18) for connection to an inverter (50).

4. Stator according to one of the preceding claims, characterized in that a) in the case of eight stator poles, the hybrid partial strands (9.1, 9.2) of the respective hybrid strand (9) are connected with the same polarity to the star point (15) of the respective stator partial winding (7.1, 7.2), b) in the case of six stator poles, the hybrid partial strands (9.1, 9.2) of the respective hybrid strand (9) are connected with opposite polarity to the star point (15) of the respective stator partial winding (7.1, 7.2).

5. Stator according to one of the preceding claims, characterized in that in the same stator partial winding (7.1, 7.2), a second hybrid partial strand (9.1, 9.2) is arranged offset relative to a first hybrid partial strand (9.1, 9.2) by a second offset angle (θ2) and a third hybrid partial strand (9.1, 9.2) is arranged offset relative to the first hybrid partial strand (9.1, 9.2) by a third offset angle (θ3) which is equal in magnitude to the second offset angle (θ2) and opposite to the second offset angle (θ3), in particular in the case of eight stator poles by + / -15° mechanically and in the case of six stator poles by + / -80 0 mechanically, wherein the first hybrid partial strand (9.1, 9.2) of the respective stator partial winding (7.1, 7.2) has in particular an individual connection (18).

6. Stator according to claim 5, characterized in that a) in the case of eight stator poles in each stator partial winding (7.1, 7.2), the first hybrid partial strand (9.1, 9.2) is connected to the star point (15) with opposite polarity to the second and third hybrid partial strand (9.1, 9.2), b) in the case of six stator poles in each stator partial winding (7.1, 7.2), all hybrid partial strands (9.1, 9.2) are connected to the star point (15) with the same polarity.

7. Stator according to one of the preceding claims, characterized in that the respective hybrid strand (9) occupies a slot group (20) of stator slots (6) per pole, each according to a same pole assignment pattern (PP) to form a pole group (21) with conductors (22) of the same phase (U, V, W), wherein the pole Occupancy pattern (PP) of an unstretched pole group (21) comprises a full occupancy of all conductor positions of the slot group (20) and the pole occupancy pattern (PP) of a chorded pole group (21) comprises an incomplete occupancy, wherein the gaps (23) are occupied by conductors of a different phase, wherein the slot group (20) of an unstretched pole group (21) in particular comprises two or three adjacent stator slots (6) and the slot group (20) of a chorded pole group (21) in particular comprises three or four adjacent stator slots (6).

8. Stator according to claim 7, characterized in that in the pole assignment pattern (PP) of a chorded pole group (21), the two outer stator slots (6a) have half conductors (22) of the respective hybrid strand (9) and the other half gaps (23), wherein one outer stator slot (6a) is inversely occupied with respect to the other outer stator slot (6a) of the same chorded respective pole group (21) with regard to assignment and gap (23), wherein in the pole assignment pattern (PP) the at least one inner stator slot (6i) of the chorded pole group (21) has only conductors (22) of the respective hybrid strand (9).

9. Stator according to one of the preceding claims, characterized in that in the pole assignment pattern (PP) of the respective pole group (21) conductors (22) of both hybrid sub-strands (9.1, 9.2) or conductors (22) of only one of the two hybrid sub-strands (9.1, 9.2) are provided.

10. Stator according to one of claims 2 to 9, characterized in that the pole assignment patterns (PP) of several, in particular four, pole groups (21), which are spaced apart by the angle of a stator pole, form a pole group assignment pattern (PG), wherein the two hybrid partial strands (9.1, 9.2) of the respective hybrid strand (9) each have an identical partial assignment pattern (PG1) in the pole group assignment pattern (PG), wherein the partial assignment pattern (PG1) of the one hybrid partial strand (9.1, 9.2) is arranged offset by the first offset angle (θ1) from the partial assignment pattern (PG2) of the other hybrid partial strand (9.1, 9.2) in the stator (2).

11. Rotor (3) of an electrically excited synchronous machine (1), with an excitation winding (13) for generating a rotor field for exciting the synchronous machine (1) and with a secondary part (10s) of an inductive transformer system (10) for transmitting electrical energy into the excitation winding (13) of the rotor (3), wherein the secondary part (10s) of the inductive transformer system (10) comprises at least one secondary transformer winding (28) for providing a transformer alternating voltage and at least one rectifier circuit (29), in particular a bridge circuit, acting as a rectifier for rectifying the transformer alternating voltage into a secondary direct voltage for the excitation winding (13), wherein the rotor (3) has rotor teeth (30) and wherein rotor slots (31) are formed between the rotor teeth (30), which are designed to receive the excitation winding (13) and to receive the secondary transformer winding (28). are characterized in that - the excitation winding (13) has at least one, in particular a single, excitation strand (13s), - the respective excitation strand (13s) has two series-connected excitation coil groups (33), each comprising a plurality of excitation coils (34), wherein the two excitation coil groups (33) each have a number, in particular an even or odd number, of excitation coils (34) corresponding to half the number of rotor teeth (30), in particular the value three or four, - the secondary transformer winding (28) is formed by a hybrid sub-strand (9.1, 9.2) provided in the respective excitation strand (13s), which is interposed between the two excitation coil groups (33) of the respective excitation strand (13s) and comprises a secondary hybrid coil arrangement (35), - the hybrid coil arrangement (35) comprises a plurality of parallel-connected transformer coil pairs (36), each formed by two series-connected transformer coils (37) and each provided for generating a transformer alternating voltage by inductive interaction with a primary part (10p) of the transformer system (10), as well as a direct current input (38) for connection to one of the two excitation coil groups (33) and a direct current output (39) for connection to the other excitation coil group (33).

12. Rotor according to claim 11, characterized in that one of the excitation coils (34) and one of the transformer coils (37) is provided on each of the rotor teeth (30), wherein a number of turns of the respective transformer coil (37) is in particular smaller than a number of turns of the respective excitation coil (34), in particular such that a required transformer alternating voltage can be generated.

13. Rotor according to one of claims 11 or 12, characterized in that a) the excitation coils (34) of an even-numbered excitation coil group (33) are electrically connected in series in pairs to form excitation coil pairs (34p), wherein the excitation coil pairs (34p) of the even-numbered excitation coil group (33) are electrically connected in series and / or in parallel or b) the excitation coils (34) of an odd-numbered excitation coil group (33) are electrically connected in series.

14. Rotor according to one of claims 11 to 13, characterized in that the rotor (3) has an even number of rotor teeth (30), in particular six or eight rotor teeth, wherein the rotor teeth (30) can be numbered with a counting number starting from one of the rotor teeth (30) in the circumferential direction, wherein - the excitation coils (34) of one of the two excitation coil groups (33) are arranged only on rotor teeth (30) with an even number and the excitation coils (34) of the other excitation coil group (33) are arranged only on rotor teeth (30) with an odd number, in particular in the case of odd-numbered excitation coil groups (33), and / or - in the case of even-numbered excitation coil groups (33), the excitation coils (34) of the respective excitation coil pair (34p) are arranged on different rotor teeth (30), between which there is a certain partial number of rotor slots (31) which is smaller than the number of rotor slots (31) of the rotor (3) and corresponds to the value of a doubled odd natural number.

15. Rotor according to one of claims 11 to 14, characterized in that the number of transformer coil pairs (36) per hybrid coil arrangement (35) corresponds to half the number of rotor teeth (30) of the rotor (3), in particular the value three or four, wherein the transformer coils (37) of the respective Transformer coil pairs (36) are arranged on two different rotor teeth (30), between which a certain partial number of rotor slots (31) lies, which a) in the case of an even number of transformer coil pairs (36) per hybrid coil arrangement (35) is smaller than the number of rotor slots (31) and corresponds to the value of a doubled odd natural number and b) in the case of an odd number of transformer coil pairs (36) per hybrid coil arrangement (35) corresponds to half the number of rotor slots (31) of the rotor (3).

16. Rotor according to claim 11 to 15, characterized in that the transformer coils (37) of the respective transformer coil pair (36) - are connected in series in the same direction in the case of an even number of transformer coil pairs (36) per hybrid coil arrangement (35), so that when the transformer coil pair (36) is energized from the direct current input (38) to the direct current output (39), the associated rotor teeth (30) are magnetized in the same radial direction, - are connected in series in opposite directions to one another in the case of an odd number of transformer coil pairs (36) per hybrid coil arrangement (35), so that when the transformer coil pair (36) is energized from the direct current input (38) to the direct current output (39), the associated rotor teeth (30) are magnetized in the opposite radial direction.

17. Rotor according to one of claims 11 to 16, characterized in that - the transformer coils (37) of the hybrid coil arrangement (35), in the case of an even number of transformer coil pairs (36) per hybrid coil arrangement (35), are connected to the direct current input (38) or direct current output (39) in such a way that when the transformer coil pairs (36) are energized, the rotor teeth (30) with an odd number are magnetized in the opposite radial direction to the rotor teeth (30) with an even number, - the transformer coils (37) arranged on rotor teeth (30) with an even number are all connected to the DC input (38) or all to the DC output (39) in the case of an odd number of transformer coil pairs (36) per hybrid coil arrangement (35).

18. Rotor according to one of claims 11 to 17, characterized in that in the case of an even number of transformer coil pairs (36) per hybrid coil arrangement (35), each transformer coil (37) connected to the direct current input (38) forms a connection pair (40) with another of the transformer coils (37) connected to the direct current input (38), the transformer coils (37) of which are arranged on two different rotor teeth (30), between which there is a certain partial number of rotor slots (31), which is smaller than the number of rotor slots (31) and corresponds to the value of a doubled odd natural number.

19. Rotor according to one of claims 11 to 18, characterized in that the hybrid coil arrangement (35) has a plurality of AC voltage outputs (41), each for connection to an AC voltage input (42) of one of the rectifier circuits (29), wherein the number of AC voltage outputs (41) corresponds in particular to the number of transformer coil pairs (36) per hybrid coil arrangement (35), wherein the respective AC voltage output (41) is formed by an intermediate node between the transformer coils (37) of the respective transformer coil pair (36), wherein the AC voltage outputs (41) are each electrically connected to an AC voltage input (42) of one of the rectifier circuits (29).

20. Rotor according to one of claims 11 to 19, characterized in that on the rotor (3), in addition to the excitation coils (34) and transformer coils (37) arranged on the rotor (3), a short-circuited wave winding (45) is provided, which runs with a short-circuited conductor strand (46) in a wave-like manner through in particular all the rotor slots (31).

21. Electrically excited synchronous machine (1) with a stator (2) according to one or more of claims 1 to 10 and with a rotor (3) according to one or more of claims 11 to 20, characterized in that a) the number of poles of the transformer system (10) is half the number of poles of the three-phase system if the number of poles of the three-phase system is a multiple of four, b) the number of poles of the transformer system (10) has the value four if the three-phase system has the number of poles six.

22. Control device (60) for controlling the electrically excited synchronous machine (1) according to claim 21, comprising a) an inverter (50) with inverter outputs (51) for providing phase voltages for supplying energy to the stator winding (7) of the stator (2), wherein for each connection (17, 18) of the two stator partial windings (7.1,7.2) an inverter output (51) is provided, and b) a control device (61) for controlling the inverter (5).

23. Method for operating an electrically excited synchronous machine (1) according to claim 21 with a control device (60) according to claim 22, characterized in that the control device (61) controls the inverter (5) for operating the synchronous machine (1) in such a way that a total current is fed into the individual connections (18) of the stator partial windings (7.1, 7.2), which total current is formed from a portion of a phase current of the three-phase system, in particular with half the amplitude, and a portion of an excitation current of the transformer system (10), wherein the excitation current is an alternating current or direct current.

24. Method according to claim 23, characterized in that in the case of coupling connections (17), a phase current of the three-phase system with full amplitude is fed into the coupling connections (17), wherein the component of the excitation current has different signs at the individual connections (18) belonging to the same phase.

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