Induction winding field type synchronous machine

Abstract

The present invention relates to an inductive field type synchronous machine (1) having a rotor (2) with rotor coils (5) generating a rotor magnetic field and transformer secondary coils (6) supplying electrical energy to the rotor coils (5), and a stator (3) with stator coils (9) generating a stator magnetic field and transformer primary coils (10) inductively transmitting electrical energy to each of the transformer secondary coils (6). Demagnetization of the rotor coils (5) can be improved with a demagnetization circuit (19), the demagnetization circuit (19) being electrically connected to the stator coils (9) and comprising a switching device (20) for activating and deactivating the demagnetization circuit (19) and an electrical energy load (22) and / or an electrical energy storage device (23), the switching device (20) deactivating the demagnetization circuit (19) during normal operation of the synchronous machine (1) and activating the demagnetization circuit (19) in the event of an equipment fault.

Description

[Technical field]

[0001] The invention relates to an inductive field synchronous machine according to the preamble of claim 1. [Background technology]

[0002] A synchronous machine is a rotating electrical machine, in which the rotor rotates, i.e. runs, in synchronism with the rotating magnetic field of the stator during operation. Synchronous machines can generally be operated as electric motors or as generators. In the case of electrically excited, i.e. separately excited, synchronous machines, the magnetic field is additionally generated electrically in the rotor. Since electrical energy, in particular direct current, must be supplied to generate the magnetic field on the rotor side, at least one rotor coil is used here. In the case of an induction field synchronous machine, the supply of electrical energy to the respective rotor coil can be performed brushlessly, i.e. by induction. An induction field synchronous machine thus corresponds to a brushless separately excited electric synchronous machine.

[0003] A typical synchronous machine is known, for example from DE 10 2016 207 392 A1. This typical synchronous machine comprises a rotor with at least one rotor coil generating a rotor magnetic field. This synchronous machine additionally comprises a stator, which is rotatably attached to the stator about a rotation axis and which comprises at least one stator coil generating a stator magnetic field. This synchronous machine is further provided with a rotary transformer, which comprises at least one transformer primary coil fixedly arranged on the stator and at least one transformer secondary coil fixedly arranged on the rotor. During operation of the rotary transformer, each transformer secondary coil serves to supply electrical energy to each rotor coil. During operation of the rotary transformer, each transformer primary coil serves to perform an inductive transfer of electrical energy to each transformer secondary coil. For this purpose, there is usually also a rectifier fixed to the rotor, the rectifier being electrically arranged between each transformer secondary coil and each rotor coil to convert the AC in each transformer secondary coil into DC for each rotor coil.

[0004] Typically, a synchronous machine may include a synchronous machine controller connected or coupled to each stator coil and each transformer primary coil for operating the synchronous machine as a motor and / or as a generator. In practice, the synchronous machine controller may be further configured to demagnetize each rotor coil in the event of an equipment fault of the synchronous machine. Summary of the Invention

[0005] In case of an equipment fault, which may occur in one of the components of the synchronous machine, for example in the rotor and stator coils or in the electronic circuit of the synchronous machine controller including the inverter, the synchronous machine is switched off or stopped from operating. This is done, for example, by stopping the supply of electrical energy to each stator coil and each transformer primary coil. In order to avoid in the process a sudden interruption of the rotor in the stator or very dangerous currents and voltages in the coils, in case of an equipment fault, it is necessary to demagnetize each rotor coil.

[0006] In the above-mentioned known DE 10 2016 207 392 A1, it is proposed to provide a brake circuit on the rotor side, which circuit includes a switching element, a start circuit and a load element. As soon as an equipment fault occurs, for example due to a stop of the stator coil, the voltage on the rotor side exceeds a certain limit value, the switching element opens and directs the electrical energy to the load element, where it is converted into heat. In such a rotor-side brake circuit, it can be problematic in any case, that a powerful synchronous machine is subjected to a high thermal load, as a result of which the further heat generated in the load element of the brake circuit cannot be dissipated and the electrical elements of the brake circuit can easily overheat.

[0007] The present invention addresses the problem of providing an improved, or at least alternative, embodiment for an inductively wound field synchronous machine, in which demagnetization of each rotor coil can be accomplished quickly and without overheating in the event of a machine fault.

[0008] According to the invention, this problem is solved through the subject matter of claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0009] The invention is based on the general idea of ​​providing a demagnetization circuit on the stator side of a synchronous machine, which in the event of a fault dissipates electrical energy that is induced by the rotor magnetic field into each stator coil, so that a demagnetization of each rotor coil can be effected by each stator coil. In the demagnetization circuit, energy can be dissipated directly from each stator coil. Overheating of the rotor and stator can thus be avoided.

[0010] In practice, this demagnetization circuit may be internally controlled, for example by a control unit or control circuit, which monitors a parameter that correlates with an undesired fault event, such as the voltage in the stator coil or parts of the stator coil, and activates the demagnetization circuit when a certain threshold is exceeded.

[0011] Additionally or alternatively, the demagnetizing circuit can be configured to be externally controllable, in particular so that it can be activated and deactivated from outside, preferably from a synchronous machine controller. In particular, in the event of a fault, the demagnetizing circuit can be activated synchronously with the shutdown of the synchronous machine, thus achieving very short response times. Therefore, in order to reduce the rotor magnetic field in the event of a fault and to dissipate the electrical energy converted in the process, the stator coils that are present anyway are utilized in the present invention.

[0012] In particular, the invention proposes to provide a synchronous machine or a synchronous machine controller with a demagnetization circuit, the demagnetization circuit comprising a switching device electrically interconnected with each stator coil and adapted to activate and deactivate the demagnetization circuit, at least one electric energy load and at least one electric energy store. Furthermore, each switching device is configured and / or controlled to deactivate the associated demagnetization circuit during normal operation of the synchronous machine and to activate the associated demagnetization circuit in the event of an equipment fault. In the simplest case, the demagnetization circuit is designed as a brake circuit and comprises a switching device, a load and a control unit or control circuit.

[0013] In particular, the switching device can be realized by a chopper, which is used in the process like a brake chopper. The chopper can be controlled, for example, depending on the voltage currently applied to the respective stator coil. For this purpose, a control unit integrated in the respective switching device, not shown here, or a corresponding control circuit, can monitor the respective voltage and control the chopper, preferably by pulse width modulation. As soon as a predefined voltage threshold is exceeded, the chopper is controlled to activate the demagnetizing circuit, so that the chopper conducts and the load or the reservoir can draw current from the respective stator coil. When the monitored voltage falls below the threshold again, the chopper is controlled to deactivate the demagnetizing circuit, so that the chopper cuts off again and the load or the reservoir can no longer draw current from the respective stator coil.

[0014] In fact, each switching device may be configured to activate the demagnetization circuit depending on the voltage that can be drawn on the respective stator coil. In the process, one of the draw-off points may be arranged between the coil end and the respective stator coil, so that the drawn voltage is only generated by the corresponding part of the coil voltage. In a further preferred development, each switching device may be configured to activate the demagnetization circuit when the voltage drawn on the respective stator coil exceeds a predefined threshold. This can be particularly easily realized with power transistors or choppers. A further development is particularly advantageous, in which the threshold is selected such that the voltage applied to the respective stator coil or the coil voltage is kept lower than the voltage or the supply voltage that the electrical energy source provides to power the synchronous machine.

[0015] Additionally or alternatively, a synchronous machine controller may be connected or coupled to each switching device and configured to control each switching device to deactivate the demagnetization circuit during normal operation of the synchronous machine and to control each switching device to activate the demagnetization circuit during equipment fault.

[0016] In the event of an equipment fault, the synchronous machine controller acts to demagnetize, preferably without short-circuiting the stator coils, so that they remain active and can be used for dissipation by induction of the rotor magnetic field. In relation to the embodiment as a brake circuit or brake chopper described above, this means that the inverter does not need to be and is not short-circuited in the event of a fault. Instead, the inverter is simply switched off or opened so as to reflect the vehicle electrical system voltage or the battery voltage, in particular as a square wave voltage, to each stator coil. The chopper then rapidly increases the current and reduces or holds the voltage at each stator coil at a low level, preferably the vehicle electrical system voltage or the battery voltage, and draws the current from the battery.

[0017] In one particular embodiment, the demagnetization circuit includes a storage device and further includes at least one rectifier, which converts the AC voltage applied to each stator coil into a DC voltage and supplies the DC voltage to a respective load or to a respective storage device. Thus, the electrical energy induced in each stator coil during demagnetization of the respective rotor coil can be particularly easily and efficiently dissipated. Such a rectifier is used in particular when a storage device is used. Depending on the configuration of the load, a rectifier may also be advantageous.

[0018] In a usual manner, the synchronous machine controller may comprise an inverter for supplying electrical energy to each stator coil, which may be connected to each stator coil via a first inverter line and a second inverter line. The first inverter line is electrically connected to a first coil end of each stator coil, and the second inverter line is electrically connected to a second coil end of each stator coil. Via the inverter, each stator coil is energized for normal operation of the synchronous machine to generate the stator magnetic field. In a multi-phase synchronous machine, a number of stator coils are provided, which are in fact arranged as a star connection. The first inverter line may be connected to each stator coil at each first coil end, and the second inverter line is connected to a so-called star point of the star connection, which in this case corresponds to each second coil end. In this case, each stator coil is assigned its own first inverter line, while the stator coils are assigned a common second inverter line.

[0019] In an advantageous further development, the demagnetization circuit for electrical interconnection with each stator coil may comprise a circuit line pair having two circuit lines, i.e. a first circuit line and a second circuit line, which may be utilized to electrically connect each stator coil to the demagnetization circuit.

[0020] According to an advantageous embodiment, the first circuit line may be electrically connected to a first inverter line, in particular to a first coil end, and the second circuit line may be electrically connected to a second inverter line, in particular to a second coil end. As a result, the demagnetizing circuit is connected in parallel to each stator coil. This makes it easy to integrate the demagnetizing circuit in the stator.

[0021] In an alternative embodiment, the first circuit line may be electrically connected to the first inverter line, in particular to the first coil end, and the second circuit line is electrically connected to a coil tap of each stator coil, the coil tap being electrically arranged between the first coil end and the second coil end of the stator coil. Thus, the demagnetizing circuit utilizes only a part of the stator coil, rather than the entire stator coil. As a result, the voltage drawn by the demagnetizing circuit at each stator coil in case of a fault is also reduced proportionately. Thus, the demagnetizing circuit may be realized with relatively low-cost components. With an internally controlled demagnetizing circuit, it may also be achieved through a corresponding control circuit that the switching device is operated even at a relatively low voltage threshold, so that demagnetization is performed relatively quickly.

[0022] A further development is practical in which the coil tap is located off-center between the first coil end and the second coil end within each stator coil. In particular, the coil tap can be located closer to the first coil end than to the second coil end within each stator coil. As a result, the voltage between the circuit lines, or between the coil tap and the second coil end, is less than half the voltage between the two inverter lines, or between the two coil ends.

[0023] In an advantageous embodiment, the synchronous machine may have a multi-phase, preferably three-phase, configuration, with at least one stator coil assigned to each phase, so that in the event of a fault it is possible to dissipate as much energy as possible as quickly as possible, and the demagnetizing circuit is therefore electrically interconnected with several, preferably all, of the stator coils.

[0024] Other embodiments propose that the synchronous machine is of single-phase or multi-phase configuration, with each phase being assigned a coil group or multiple stator coils. If such a coil group comprises exactly two stator coils, the coil group may form a coil pair, in which the two associated stator coils are preferably arranged diametrically opposite each other. Thus, multiple stator coils are also present here. In this case too, the demagnetizing circuit is electrically interconnected with multiple, preferably all, stator coils in order to be able to dissipate energy effectively and as quickly as possible in the event of a fault.

[0025] The two above-mentioned variants can also be combined with each other, so that the synchronous machine is of a multi-phase, preferably three-phase, configuration, with each phase being assigned to at least one coil pair of two diametrically opposed stator coils. In a three-phase synchronous machine, at least six stator coils are provided. Here too, the demagnetizing circuit is electrically connected to a number of, preferably all, stator coils.

[0026] Preferably, each load or each reservoir is disposed on the outer surface of the stator or outside the stator, so that overheating of the rotor can be effectively avoided.

[0027] Each load may comprise at least one thermoelectric element, which converts electrical energy into heat, which may be, for example, a load element, which may be an electrical resistor, a suppressor diode, or a Zener diode.

[0028] The synchronous machines considered here can preferably be designed as drive or traction motors for motor vehicles and / or with an output of 100 kW-200 kW, preferably 120 kW-160 kW, in particular approximately 140 kW.

[0029] Further important features and advantages of the invention can be derived from the dependent claims, the drawings and the associated figure description via the drawings.

[0030] The features mentioned above and still further below can be used not only in each of the presented combinations, but also in other combinations or only with those features, without departing from the scope of the invention. The above-mentioned and still further named parts of a higher-level unit, such as a facility, equipment or device, which are individually referred to, may be areas or parts constituting individual parts or components of this unit or forming part of this unit, even if they are represented in the drawings. [Brief description of the drawings]

[0031] Preferred exemplary embodiments of the invention are illustrated in the drawings and described in more detail in the following description, where like reference numbers indicate identical or similar or functionally identical elements. [Figure 1] FIG. 1 is a highly simplified circuit diagram of a first embodiment of an induction field type synchronous machine. [Diagram 2] FIG. 2 is a highly simplified circuit schematic diagram of a second embodiment of an induction field type synchronous machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] 1 and 2, the induction-winding-field synchronous machine 1 includes a rotor 2, a stator 3, and a synchronous machine controller 4. The rotor 2 includes at least one rotor coil 5 for generating a rotor magnetic field and at least one transformer secondary coil 6 for supplying electrical energy to each rotor coil 5. In practice, the rotor 2 may include a rectifier 7, which converts AC supplied from the transformer secondary coil 6 into DC and supplies the DC to the rotor coil 5. The rotor 2 is attached to the stator 3 so as to be rotatable around a rotation axis 8. The stator 3 includes at least one stator coil 9 for generating a stator magnetic field and a transformer primary coil 10 for inductively transmitting electrical energy to each transformer secondary coil 6. Each transformer primary coil 10 and each transformer secondary coil 6 constitute a rotary transformer 33, which in operation inductively transfers electrical energy between the transformer coils 6 and 10. The representation of the rotary transformer 33 in Figures 1 and 2 should be understood only diagrammatically. In particular, the transformer coils 6, 10 in a specific rotary transformer or in a specific synchronous machine 1 are located opposite each other with respect to the axis of rotation 8.

[0033] To operate the synchronous machine 1 as a motor and / or as a generator, the synchronous machine controller 4 is connected to each stator coil 9 and each transformer primary coil 10. For this purpose, the synchronous machine controller 4 may comprise at least one inverter 11, which is connected to each stator coil 9 via a first inverter line 13 and a second inverter line 14. In Figs. 1 and 2, the inverter lines 13 and 14 are shown in simplified form as inverter line pairs 12. It is clear that in a multi-phase synchronous machine 1, a star connection is usually adopted. To energize each transformer primary coil 10, the synchronous machine controller 4 may comprise a transformer controller 15 connected to each transformer primary coil 10 via a corresponding transformer line 16. The transformer controller 15 may in particular be integrated in the inverter 11. In addition, the synchronous machine controller 4 may comprise a control device 17, which may include at least one CPU and is connected to the inverter 11 via a control line 18. The control device 17 can likewise be structurally integrated in the inverter 11 .

[0034] Although only one and three stator coils 9 are shown in FIGS. 1 and 2, respectively, the stator 3 may also comprise two or more stator coils 9 or four or more stator coils 9 .

[0035] The inverter 11 may be connected to an electrical energy source 34, such as a battery or a vehicle electrical system. In Fig. 2, the energy source 34 is omitted for simplicity. The energy source 34 preferably provides a predetermined voltage or a mains voltage as a DC voltage.

[0036] The synchronous machine controller 4 or its control device 17 may be configured to monitor the synchronous machine 1 in particular with regard to certain equipment faults, such as for example excessive values ​​of temperature, rotation speed, voltage and / or current. As soon as an equipment fault is identified, the synchronous machine controller 4 stops the supply of electrical energy to each stator coil 9 and / or each transformer primary coil 10. Here, this is in fact achieved by controlling the inverter 11 to be switched off or stopped, i.e. to no longer operate. The active inverter 11 operates as a converter, which converts the DC voltage coming from the energy source 34 into an AC voltage to supply to each stator coil 9, while the inactive inverter 11 operates as a rectifier, which converts the AC voltage coming from each stator coil 9 into a DC voltage to supply to the energy source 34. Preferably, no short circuit of each stator coil 9 should occur during the process. In other words, the synchronous machine controller 4 preferably operates without short circuits of the stator coils.

[0037] Furthermore, the synchronous machine controller 4 or its control device 17 may be configured to specifically cause demagnetization of each rotor coil 5 in the event of a fault.

[0038] In order to demagnetize the rotor coils 5, the synchronous machine 1 or its synchronous machine controller 4 comprises a demagnetization circuit 19, which is electrically interconnected with each stator coil 9. In case of a plurality of stator coils 9, the demagnetization circuit 19 is in fact interconnected with a plurality of stator coils 9, preferably with all of them. The demagnetization circuit 19 comprises a switching device 20, which is configured so that it can be used to activate and deactivate the demagnetization circuit 19. The switching device 20 can be configured to be internally controlled and operate quasi-independently. This is done, for example, through a corresponding control circuit or control unit, not shown here. For example, the voltage applied to each stator coil 9 can be monitored. In order to control or operate the switching device 20 externally, the synchronous machine controller 4 or its control device 17 can be connected to the switching device 20 via a corresponding control line 21. The demagnetization circuit 19 further comprises at least one consumer 22 of electrical energy and / or at least one store 23 of electrical energy. If there are several stator coils 9 and a demagnetizing circuit 19 is interconnected with several or all of the stator coils 9, the demagnetizing circuit 19 may comprise a common switching device 20 and at least one common consumer 22 or at least one common reservoir 23, which is assigned to all the stator coils 9 interconnected with the demagnetizing circuit 19. The switching device 20 is preferably an electronic switch, which may be realized for example by a diode, a transistor, a MOSFET, an IGBT or a chopper. In particular, the switching device 20 may be realized by a chopper interconnected as a brake chopper, which is controlled for example depending on the voltage currently applied to the respective stator coil 9. For this purpose, a control circuit or a control unit integrated in each switching device 20 (not shown here) may monitor the respective voltage and may control the chopper, preferably by pulse width modulation. As soon as a certain voltage threshold is exceeded, the chopper is controlled to activate the demagnetizing circuit 19 , so that the chopper conducts and the consumer 22 or reservoir 23 can draw current from the respective stator coil 9 .When the monitored voltage falls below the threshold again, the chopper is controlled to stop the demagnetization circuit 19, so that the chopper cuts off again and so that the consumer 22 or the reservoir 23 cannot draw current from the respective stator coil 9.

[0039] In addition, the synchronous machine controller 4 may be optionally designed to control the switching device 20 to deactivate the demagnetization circuit 19 during normal operation of the synchronous machine 1. However, as soon as there is an equipment fault, the synchronous machine controller 4 controls the switching device 20 to activate the demagnetization circuit 19. When the current supply to the stator coil 9 and each transformer primary coil 10 is turned off, a residual stator magnetic field still exists. In addition, a rotor magnetic field still exists. Thus, electrical energy is induced in the stator coil 9. Then, the electrical energy is dissipated by the demagnetization circuit 19 and can be consumed in each consumer 22 or stored in each storage 23. By connecting the demagnetization circuit 19 to each stator coil 9, the demagnetization circuit 19 can be utilized to loosen the coupling of the rotor magnetic field, so that the equipment cost for realizing the demagnetization circuit 19 is relatively low. In the process, it is worth noting that the demagnetization circuit 19 is arranged on the stator side, i.e., outside the rotor 2. The energy dissipated during demagnetization of the rotor coils 5 therefore cannot serve to heat the rotor 2. It is further noteworthy that by controlling the switching devices 20 by the synchronous machine controller 4, the rotor magnetic field can be reduced before it induces excessive voltages in the stator coils 9 in the event of a fault.

[0040] At least in the case where the demagnetization circuit 19 includes a reservoir 23, the demagnetization circuit 19 comprises a rectifier 24, which in the representations of Figures 1 and 2 is formed in an assembly 25 together with the switching device 20. However, the rectifier 24 can also be constructed separately. When the demagnetization circuit 19 is in operation, the rectifier 24 converts the AC voltage applied to each stator coil 9 into a DC voltage which is then supplied to each consumer 22 or each reservoir 23.

[0041] The inverter 11 is connected to the stator coils 9 via inverter lines 13, 14. For electrical coupling of the inverter 11 to each stator coil 9, the first inverter line 13 is electrically connected to a first coil end 29 of each stator coil 9, and the second inverter line 14 is electrically connected to a second coil end 30 of each stator coil 9. For electrical interconnection with each stator coil 9, the demagnetization circuits 19 each include a circuit line pair 26, and the circuit line pair 26 includes two circuit lines, namely a first circuit line 27 and a second circuit line 28.

[0042] 1, each first circuit line 27 is electrically connected to a first inverter line 13 and each second circuit line 28 is electrically connected to a second inverter line 14. Thus, a circuit line pair 26 is electrically connected to the inverter lines 13, 14 such that a demagnetizing circuit 19 is connected in parallel to each stator coil 9. In this case, the electrical energy induced in each stator coil 9 when the synchronous machine 1 is switched off is dissipated by the demagnetizing circuit 19 at full voltage.

[0043] In the second embodiment shown in FIG. 2, in contrast, it is described that the first circuit line 27 is electrically connected to the first inverter line 13, for example via the first coil end 29. In contrast to this, the second circuit line 28 in this second embodiment is electrically connected to a coil tap 31, which is additionally present at each stator coil 9 and is arranged between the first coil end 29 and the second coil end 30. It is thus achieved that when the synchronous machine 1 is switched off, the electrical energy induced in each stator coil 9 does not have to be dissipated by the demagnetizing circuit 19 at full voltage, but at a proportional voltage depending on the position of the coil tap 31. This is particularly advantageous for an automatic operation of the switching device 20, when it monitors the connection of the circuit lines 27, 28, i.e. the voltage at the tap points 29, 30. In this case, the voltage threshold, on the basis of which the switching device 20 activates the demagnetizing circuit 19, can be selected relatively low. In particular it can thus be achieved that the voltage induced in each stator coil 9 is kept lower than the supply voltage provided by the energy source 34 .

[0044] In the example of Fig. 2, the coil tap 31 is located off-centre between the two coil ends. "Off-centre" should be understood in an electrical sense and refers to the number of turns in the stator coil 9. In that respect, a configuration in which the coil tap 31 is located within the stator coil 9 closer to the first coil end 29 than to the second coil end 30 is preferred. The stator coil 9 therefore has fewer turns between the coil tap 31 and the first coil end 29 than between the coil tap 31 and the second coil end 30. The voltage that can be drawn by the circuit lines 27, 28 is therefore less than half the voltage applied to the coil ends 29, 30.

[0045] In the example presented, the synchronous machine 1 has a polyphase, i.e. three-phase configuration. The individual phases are designated U, V and W in Figs. 1 and 2. At least one stator coil 9 is assigned to each phase U, V, W. In this case, each phase U, V, W is assigned a coil pair, which comprises two stator coils 9 and are arranged diametrically opposite each other. In Fig. 1, only one stator coil 9 is shown diagrammatically as representative of all stator coils 9. In Fig. 2, only one stator coil 9 for each of the three coil pairs is shown as representative for each phase U, V, W in Fig. 2.

[0046] If the stator 3 comprises several stator coils 9, the demagnetization circuit 19 is in fact connected to several, preferably all, of the stator coils 9, which can optionally be done in particular according to the embodiment shown in FIG. 1 or according to the embodiment shown in FIG. 2.

[0047] In practice, each consumer 22 or each reservoir 23 may be arranged on the outer surface of the stator 3 or outside the stator 3. In Fig. 2, the stator housing 32 is shown with a dashed line. Each consumer 22 or each reservoir 23 may be arranged on the outer surface of this stator housing 32. If each consumer 22 is equipped with at least one thermoelectric element, the energy dissipated during the demagnetization of the respective rotor coil 5 is converted into heat outside the rotor, so that overheating of the rotor 2 can be avoided.

[0048] In the case of the inverter 11 and the energy source 34, in particular a battery or the vehicle electrical system, it is not necessary to short-circuit the inverter 11 in the event of a fault. Rather, the inverter 11 can be switched off or open. The voltage reflected or returning from each stator coil 9 is passed by the inverter 11 to the energy source 34 as a square wave voltage. The demagnetizing circuit 19, which is activated in the event of a fault, directs the current away from each stator coil 9 towards the consumer 22 or towards the storage 23. The switching device 20 is controlled as a function of the voltage, for example as described above, and the voltage threshold is specifically selected so that the voltage at each stator coil 9 is always lower than a predefined limit value. Preferably, this limit value can be lower than the voltage of the energy source 34 provided by the energy source 34. Thus, an effective protection of the energy source 34, in particular of the battery or the vehicle electrical system, can be achieved.

Claims

1. An induction-wound field synchronous machine (1), wherein the induction-wound field synchronous machine (1) comprises a rotor (2) having at least one rotor coil (5) that generates a rotor magnetic field, the induction-wound field synchronous machine (1) comprises a stator (3), wherein the rotor (2) is rotatably mounted around a rotation axis (8) on the stator (3), and the stator (3) has at least one stator coil (9) that generates a stator magnetic field, the induction-wound field synchronous machine (1) comprises a rotary transformer (33), and the rotary transformer (33) has at least one transformer primary coil (10) fixed to the stator and at least one transformer secondary coil (6) fixed to the rotor and supplying electrical energy to each of the rotor coils (5), the induction-wound field synchronous machine (1) comprises a synchronous controller (4), and the synchronous controller (4) is connected to each of the stator coils (9) and each of the transformer primary coils (10) so as to operate the induction-wound field synchronous machine (1) as a motor and / or as a generator, each of the induction-wound field synchronous machines (1) has at least one field weakening circuit (19), the field weakening circuit (19) is electrically connected to each of the stator coils (9), and the field weakening circuit (19) has a switching device (20) for operating and stopping the field weakening circuit (19), and at least one electrical energy load (22) and / or at least one electrical energy storage device (23), each of the switching devices (20) is configured and / or controlled to stop the associated field weakening circuit (19) during normal operation of the induction-wound field synchronous machine (1) and to operate the associated field weakening circuit (19) in case of equipment failure, an induction-wound field synchronous machine (1).

2. Each of the switching devices (20) is configured as a braking circuit or a brake chopper, the induction-wound field synchronous machine (1) according to Claim 1.

3. Each of the switching devices (20) is configured to operate the field weakening circuit (19) according to the voltage extractable in each of the stator coils (9), the induction-wound field synchronous machine (1) according to Claim 1 or 2.

4. Each of the switching devices (20) is configured to operate the demagnetization circuit (19) when the voltage induced in each of the stator coils (9) exceeds a predetermined threshold value. The induction winding field-excited synchronous machine (1) according to claim 3.

5. The threshold value is selected such that the voltage applied to each of the stator coils (9) remains lower than the voltage supplied by the electrical energy source (34) that powers the induction winding field-excited synchronous machine (1). The induction winding field-excited synchronous machine (1) according to claim 4.

6. The synchronous controller (4) is configured to control each of the switching devices (20) to stop the associated demagnetization circuit (19) during normal operation of the induction winding field-excited synchronous machine (1), and to control each of the switching devices (20) to operate the associated demagnetization circuit (19) in the event of a device failure. The induction winding field-excited synchronous machine (1) according to claim 1.

7. The demagnetization circuit (19) includes at least one rectifier (24), which, together with the activated demagnetization circuit (19), converts the alternating voltage applied to each of the stator coils (9) into a direct voltage and supplies the direct voltage to each of the electrical energy loads (22) and / or each of the electrical energy storage devices (23). The induction winding field-excited synchronous machine (1) according to claim 1.

8. The synchronous controller (4) includes an inverter (11) that supplies electrical energy to each of the stator coils (9). The inverter (11) is connected to each of the stator coils (9) via a first inverter line (13) and a second inverter line (14) for transmitting electrical energy. The first inverter line (13) is electrically connected to the first coil end (29) of each of the stator coils (9), and the second inverter line (14) is electrically connected to the second coil end (30) of each of the stator coils (9). The demagnetization circuit (19) for electrical connection to each of the stator coils (9) includes a pair of circuit lines (26) having two circuit lines, namely a first circuit line (27) and a second circuit line (28). The induction winding field-excited synchronous machine (1) according to claim 1.

9. The first circuit line (27) is electrically connected to the first inverter line (13), and the second circuit line (28) is electrically connected to the second inverter line (14). The induction winding field excitation synchronous machine (1) according to claim 8.

10. The first circuit line (27) is electrically connected to the first inverter line (13), and the second circuit line (28) is electrically connected to each coil tap (31) of the stator coil (9), and the coil tap (31) is arranged between the first coil end (29) and the second coil end (30). The induction winding field excitation synchronous machine (1) according to claim 8.

11. The coil tap (31) is arranged outside the center between the first coil end (29) and the second coil end (30) within each range of the stator coil (9). The induction winding field excitation synchronous machine (1) according to claim 10.

12. The coil tap (31) is arranged closer to the first coil end (29) than the second coil end (30) within each range of the stator coil (9). The induction winding field excitation synchronous machine (1) according to claim 10.

13. The induction winding field excitation synchronous machine (1) has a polyphase, preferably three-phase configuration, and at least one of the stator coils (9) is assigned to each phase (U, V, W). The induction winding field excitation synchronous machine (1) according to claim 1.

14. The induction winding field excitation synchronous machine (1) has a single-phase or polyphase configuration in which a coil group of a plurality of the stator coils (9) is assigned to each phase (U, V, W), or at least one coil pair of two of the stator coils (9) arranged at positions directly opposite to each other is assigned. The induction winding field excitation synchronous machine (1) according to claim 1.

15. Each of the electrical energy loads (22) and / or each of the electrical energy storage devices (23) is arranged on the outer surface of the stator (3) or outside the stator (3). The induction winding field excitation synchronous machine (1) according to claim 1.

16. Each of the electrical energy loads (22) includes at least one thermoelectric element that converts the electrical energy into heat. The induction winding field excitation synchronous machine (1) according to claim 1.

17. The synchronous controller (4) stops the supply of electrical energy to each of the stator coils (9) and / or each of the primary coils (10) of the transformer in the event of a device failure. The induction-wound field synchronous machine (1) according to claim 1.

Images