Selectively combinable electric machine and electric drive with deselectable components

Abstract

An electrical machine (EM) is provided with a first and a second multiphase winding system (W1, W2). Each winding system (W1, W2) has a first end (FE1, FE2) adapted to be connected to an inverter output (IF1, IF2) and second end (SE1, SE2) with a plurality of phases (U, V, W). A first switch (SW1) is connected between the second ends (FE1, FE2), a second switch (SW2) is connected between the second end (SE1) of the first winding (W1) and a first star point (S1) and a third switch (SW3) is connected between the second end (SE2) of the second winding (W2) and a second star point (S2). The first switch (SW1) is positioned between the second and the third switch (SW2, SW3). Further, an electrical drive (ED) is provided comprising the electrical machine (EM).

Description

[0001] Description

[0002] Selectively combinable electric machine and electric drive with deselectable components

[0003] Vehicles with an electric drive usually have a accumulator (battery) supplying, a multiphase inverter, as well as an multiphase electrical machine, which is driven by the multiphase inverter. The inverter and the electrical machine have a plurality of phases in order to provide a rotating magnetic field for driving the rotor of the electrical machine.

[0004] Usually, these components are supervised and are shut down in case of a failure. Thus, the availability of the drive depends on the availability of all phases of all components. It would be advantageous to have an increased availability. Further, the optimum efficiency of an electric drive is usually met in a narrow window of operating parameters. However, electric drives are operated in a plurality of different operating situations, including a maximum power range for fast driving and acceleration and a reduced power range for cruising or low speed driving. It is an object of the invention to provide a drive providing a high efficiency for such distinct operating situations.

[0005] This object is met by the subject matter of claim 1 . Further properties, features, embodiments and advantages are given with the dependent claims, the description and the figure.

[0006] It is proposed to provide an electrical machine with at least two multiphase winding systems, the open ends of which can be connected in series by a first switch, or which can be separated from each other in order to form an individual star point for each of the winding systems. Depending on the operating parameters, the most effective configuration can be provided. In addition, in case of a failure in one of the winding systems (or in one of the connected inverters), the individual winding system configuration can be provided, which allows to deactivate the defective winding system while the other winding system can be used for driving. This enables a limp home function. Further embodiments and their advantages are given below. An electrical machine is described, having (at least) a first and a second multiphase winding system. Each winding system comprises a plurality of phases (3, 5, 6, ... ). The number of phases of the first winding system is equal to the number of phases of the second winding system. Preferably, there are two winding systems, each of which has three phases. Each winding system has a first end adapted to be connected to an inverter output and second end with a plurality of phases. Each winding system is an open end winding system, ie. has open ends. Star points could be switchable connected to the second ends. A first switch is connected between the second ends, ie. between the second end of the first winding system and the second end of the second winding system. The first switch is a multiphase switch. The number of phases of the switch corresponds to the number of phases of each of the winding systems. The first switch can be provided to open / close all phases synchronously. Further, the first switch can be provided to open / close the phases individually (e.g. by having at least one individual switching element per phase). The first switch is adapted to controllably connect the open ends of the winding with each other. This results in a series connection of the winding systems, ie. of the windings of the distinct systems. Thereby, the phases of the distinct winding systems are individually connected with each other, phase by phase. The first switch allows to controllably provide a connection between the phases in series (and to controllably break this connection). The first switch is connected to the ends of the winding systems, which are opposed to the ends of the winding systems located at an inverter connection interface (in order to be connected to the inverter output I AC side of the inverter or being connected to the inverter output I AC side of the inverter). The first switch can be denoted as serial connecting switch.

[0007] There are a second a third switch. These switches are provided to controllably connect the second ends of the winding systems with a pertaining star point. The second switch connects the first winding system with a first star point. The third switch connects the second winding system with a second star point. In other words, the second and third switches connect controllably the phases of the pertaining winding system among each other, resulting in a star point. The star point can be provided by an inner connection within the second and / or third switch, ie. between the switching elements of each of the second and the third switch. The second switch is connected between the second end of the first winding and a first star point. The third switch is connected between the second end of the second winding and a second star point. Since the electrical function is the same, this wording encompasses the second and the third switch selectively (by switching) providing a star point at the second ends connected thereto. The second and / or the third switch can be provided to open / close all phases synchronously. Further, the second and / or the third switch can be provided to open / close the phases individually (by having at least one individual switching element per phase), thus providing a partial star point. The second and the third switch can be denoted as star point switches (since they connect the open ends of the winding systems with a star point or provide a star point, if desired)

[0008] The first switch is positioned between the second and the third switch. The second switch is connected to the third switch by the first switch. The ends of the second switch opposed to the first star point are connected to the first switch. The ends of the third switch opposed to the second star point are connected to the first switch. These ends of the second and the third switch are connected to opposite ends of the first switch. The second switch and the third switch are positioned symmetrically to the first switch. The first winding system and the second winding system are positioned symmetrically to the first switch.

[0009] A fourth switch and a fifth switch can be provided. The fourth switch is connected between the second end of the first winding on the one hand and the first switch as well as the second switch on the other hand. There can be a multiphase connection point which connects the first switch (in particular the end of the first switch facing to the first winding system) to the second switch (in particular the end of the second switch facing to the first winding system). The fourth switch connects the second ends of the first winding system to this multiphase connection point.

[0010] The fifth switch is preferably connected between the second end of the second winding on the one hand, and the first switch as well as the third switch on the other hand. Further, there can be an additional multiphase connection point which connects the first switch (in particular the end of the first switch facing to the second winding system) to the third switch (in particular the end of the third switch facing to the second winding system). The fifth switch connects the second ends of the second winding system to this additional multiphase connection point.

[0011] The fourth switch connects the second end of the first winding system (in series) to the first switch. The fifth switch connects the second end of the second winding system (in series) to the first switch (but at the opposite end of the first switch). The first switch connects the fourth switch to the fifth switch. The fourth switch, the first switch and fifth switch form a series connection (in this order). The second switch is connected to the connecting point between the first and the fourth switch. The third switch is connected to the connecting point between the first and the fifth switch. The fourth and the fifth switch can be denoted as breaking switches providing a (switchable) disconnect of the second ends (open ends) of the winding systems from the first switch and / or the second and third switch and / or the star points.

[0012] The fourths and the fifths switch can be provided to open / close all phases synchronously. Further, the fourths and the fifths switch can be provided to open / close the phases individually (e.g. by having at least one individual switching element per phase).

[0013] A control device can be provided controlling the switches. The control device can be a part of the electrical machine or of the electrical drive. The switches are controllably connected to the control device. The control inputs of the switches can be connected to pertaining control outputs of the control device. The control device can be provided as a single entity, or can be provided by control elements, which are arranged hierarchically. The control device is adapted to provide a combined drive mode. In the combined drive mode, the control device provides the first switch in a closed state and provides the second switch as well as the third switch in an open state. The control device is adapted to control the switches in this way. In the combined drive mode, the control device is adapted to connect the winding system in series, i.e. is adapted to connect the open ends (second ends) of the winding systems. In the combined drive mode, the control device is adapted to disconnect or suppress the star points. In the combined drive mode, the control device provides the fourth and the fifth switch (if present) in a closed state. In this way, the control device provides a phase-individual connection of the first switch to the second ends of the winding systems. The control device is preferably adapted to provide an individual drive mode. In the individual drive mode, the control device provides the first switch in an open state and provides the second switch as well as the third switch in a closed state. In the individual drive mode, the control device provides the first star point for the first winding system at the second end of the first winding system (or connects the first star point to the second (open) end of the first winding system). In the individual drive mode, the control device provides the second star point for the second winding system at the second (open) end of the second winding system (or connects the second star point to the second end of the second winding system). In the individual drive mode, the control device provides an electrical separation of the first winding system from the second winding system. In the individual drive mode, the fourth and fifth switches are closed, which connects the pertaining second ends to the second / third switch, or, in other words, to the star points.

[0014] Preferably, the control device has an emergency drive mode. In the emergency drive mode, the control device provides the first switch in an open state, and preferably provides one of the second and third switch in an open state, while the other one of these two switches (second, third switch) is provided in a closed state by the control device. In the emergency drive mode, the control device provides a separation of the winding systems (by having an open first switch), in particular to be able to separate a faulty winding system or inverter attached thereto from the residual drive or machine. In case the emergency drive mode reflects an error in the first winding system (or in the inverter attached thereto), the third switch is closed, which allows to activate the second winding system (and the inverter attached thereto). The second switch can be opened in this case. In case the emergency drive mode reflects an error in the second winding system (or in the inverter attached thereto), the second switch is closed, which allows to activate the first winding system (and the inverter attached thereto). The third switch can be opened in this case.

[0015] In the emergency drive mode, the control device provides the second and / or the fourth switch (if present) in an open state, while the third and / or the fifth switch (if present) is provided in a closed state by the control device. In case the emergency drive mode reflects an error in the first winding system (or in the inverter attached thereto), the control device is adapted to provide the fourth switch (if present) in an open state (while the fifth switch, if present, is preferably provided in a closed state by the control device). In case the emergency drive mode reflects an error in the second winding system (or the inverter attached thereto), the control device is adapted to provide the fifth switch (if present) in an open state (while the fourth switch - if present - is preferably provided in a closed state by the control device). In case the emergency drive mode reflects an error in the first winding system (or the inverter attached thereto), the inverter attached thereto is deactivated by the control device, by a control entity upstream the control device, or by an entity downstream a control entity, which is upstream the control device. In case the emergency drive mode reflects an error in the second winding system (or the inverter attached thereto), the inverter attached thereto is deactivated by the control device, by a control entity upstream the control device, or by an entity downstream a control entity, which is upstream the control device.

[0016] The control device is adapted to control the first switch on one hand and the second and the third switch on the other hand, in an inverted or complementary way. If the first switch is open, the second and the third switch are closed and vice versa. This relates to several modes of the control device, apart from a shutdown mode, in which all switches a provided in an open state. In the combined drive mode, the first, the fourth and the fifth switch are controlled synchronously and are provided in the same switching state. When switching from this mode to another mode, e.g. the individual drive mode, the first switch opens before the second and third switch are closed.

[0017] Advantageously, the control device has a reduced mode. In the reduced mode, the control device provides at least one switch in a closed state for at least one of the phases all switches and in an open state for the other phase(s). In this mode, only a part of all phases are connected, while the other phase(s) are disrupted. In case of an error in one phase, the switch is provided in an open state for this phase and is provided in a closed state for all but the mentioned phase. The pertaining switch is adapted to allow phase-individual switching. This also holds true for the control device controlling the pertaining switch. In this way, only a part (but not all) phases can be activated in the combined drive mode or the individual drive mode. In the individual drive mode, one of the winding systems can be fully activated and connected (by the switches), while the other winding system is only partly activated and comprises at least one phase, which is isolated by the pertaining switch (fourth or fifth switch / / second or third switch).

[0018] The control device can also comprise a safety mode or failure mode, in which the control device provides all switches in an open state, in particular in order to avoid damages.

[0019] Preferably, the windings are positioned in the same stator of the electrical machine. The windings can be positioned in distinct stators, both stators exerting force on the same drive shaft. In particular, the windings have the same dimensioning, in particular in view of winding pattern, layers, conductor diameter, winding numbers etc. The phases of the distinct winding systems can be provided with an angle offset.

[0020] The electrical machine can be used in an electric drive. Such an electrical drive can comprise the electrical machine as described in here. The electrical drive comprises a first inverter. The first inverter is connected the first winding system, in particular to the first end thereof. The electrical drive comprises a second inverter. The second inverter is connected the second winding system, in particular to the first end thereof. Each of the inverters has a DC-side (for direct current, DC) and an AC-side (for alternating current, AC). The AC-sides of the inverters can comprise an inverter connection interface. The first winding systems is connected to the inverter connection interface of the first inverter. The second winding systems is connected to the inverter connection interface of the second inverter. The status (active / inactive) of each of the inverters can be controlled by the control device, by a control entity upstream the control device, or by a (lower ranked) control entity downstream a control entity, which also controls the control device.

[0021] In the combined drive mode, both inverters are active, e.g. together providing a joint switching pattern to the inverters. In the individual drive mode, both inverters are active, e.g. each providing a switching pattern to the inverters, which can be synchronized or interleaved between the inverters. In the emergency drive mode, one of the inverters is active (for all or only a part of the phases) while the other inverter is inactive (for all or of the phases). In the emergency drive mode, the active inverter is the one attached to the winding system, which is connected to a closed second I third switch, ie. which has a star point. The first inverter connected to the first winding system via the fourth switch is active, if the fourth switch is at least partly closed. The first inverter connected to the first winding system via the fourth switch is inactive, if the fourth switch is open. The second inverter connected to the second winding system via the fifth switch is active, if the fifth switch is at least partly closed. The second inverter connected to the second winding system via the fourth switch is inactive, if the fifth switch is open. In a reduced mode, the inverter connected to the at least one switch, which is in a closed state for at least one of the phases and is open state for the other phase(s), is active in a reduced phase mode. In a reduced phase mode, only the phases of the inverter are active, which are connected to the phases of the winding system, for which the pertaining switch is in a closed state. The reduced mode can relate to both winding systems I inverters or only to one of the winding systems I inverters, while the other winding system I inverter is active for all phases. In the shutdown mode, the inverters are inactive (for all inverter phases).

[0022] The first inverter has preferably a DC-side, which is connected to a first traction accumulator. The first traction accumulator can be a part of the electric drive or can be connected to a first supply port of the drive, which is in turn connected to the first inverter of the drive. The second inverter has preferably a DC-side, which is connected to a second traction accumulator. The second traction accumulator can be a part of the electric drive or can be connected to a second supply port of the drive, which is in turn connected to the second inverter of the drive. The accumulators and / or the supply ports are high voltage I high power components adapted for traction of a vehicle.

[0023] The first traction accumulator and the second traction accumulator can be connected in parallel via an accumulator switch. In absence of an error, in particular in the combined drive mode and in the individual drive mode, the accumulator switch is in a closed state. Also in the reduced mode (at least one of the inverters I winding systems are active only for a reduced number of phases), the accumulator switch can be closed. In the emergency mode (one of the inverters I winding systems has a failure), the accumulator switch is preferably open. In the shutdown mode, the the accumulator switch is preferably open. The control device is adapted to control the accumulator switch. Alternatively, a control entity upstream or downstream the control device or a control entity downstream a control entity upstream the control device is adapted to control the accumulator switch.

[0024] A control device can be provided for controlling the accumulator switch, in particular one of the control devices given above. The control device has preferably a combined mode, in which the control device provides the accumulator switch in a closed state, and a separate mode, in which the control device provides the accumulator switch in an open state. In the combined drive mode and in the individual drive mode, the combined mode applies. Also in the reduced mode, the combined mode can be applied. In the emergency mode and in the shutdown mode, the separate mode applies.

[0025] All or a part of the switches can be provided in a switching unit connected to the winding systems. The switching unit and the winding systems (and the pertaining stators) can be positioned at distinct positions.

[0026] Figure 1 shows an embodiment of an electric drive useful for describing embodiments of the invention.

[0027] The electric drive ED of Figure 1 shows an electrical machine EM with a first and a second winding system W1 , W2 as well as switches SW1 - SW5 connected thereto. Further, the electric drive ED of Figure 1 comprises a first and a second inverter 11 , I2, each inverter comprises a DC link capacitor C1 , C2 and a power module PM1 , PM2, each exemplarily shown as controllable 3-phase bridge circuit (B6C). A first and a second accumulator (traction batterie) A1 , A2 is provided. The first accumulator is connected to the first inverter 11 comprising the first DC link capacitor C1 and the first power module PM1. The second accumulator is connected to the second inverter I2 comprising the second DC link capacitor C2 and the second power module PM2. The accumulators are connected in parallel by an accumulator switch AS, which comprises a first switching element E1 (for the negative voltage potential) and a second switching element E2 (for the negative voltage potential). Elements E1 and E2 are switched synchronously. The first inverter 11 has a first inverter interface IF1 . The second inverter I2 has a second inverter interface IF2. An electrical machine EM of the electric drive ED is connected to the inverters 11 , I2, in particular to their interfaces IF1 , IF2. The electrical machine EM comprises two winding systems W1 , W2. The first end FE1 of the first winding system W1 is connected to the first inverter 11 via the first inverter interface IF1 . The first end FE2 of the second winding system W2 is connected to the second inverter I2 via the second inverter interface IF2. The first end FE1 of the first winding system W1 has three phases U, V, W. This applies also to the first end FE12 of the second winding system W2. Also the second ends SE1 , SE2 of the first and the second winding system W1 , W2 have three phases. The second end SE1 of the first winding system W1 is opposite to the first end FE1 of the first winding system W1 as regards the windings. The second end SE2 of the second winding system W2 is opposite to the first end FE2 of the second winding system W2 as regards the windings. Switches are connected to the second ends SE1 , SE2.

[0028] A first switch SW 1 is provided in a switchable series connection between the second ends SE1 , SE2. A first star point S1 is connected via a second switch SW2 to (one end of) the first switch SW1 . A second star point S2 is connected via a third switch SW3 to (an opposite end of) the first switch SW1 . A fourth switch SW4 connects (in a switchable manner) the second end SE1 of the first winding system W1 to the first switch as well as to the second switch. The fourth switch SW4 connects the second end SE1 of the first winding system W1 to the side of the first switch SW1 facing the second end SE1 as well as to the side of the second switch SW2, which is opposed to the end of the second switch SW2 providing or connected to the first star point S1 . A fifth switch SW5 connects (in a switchable manner) the second end SE2 of the second winding system W2 to the first switch SW1 as well as to the third switch SW3. The fifth switch SW5 connects the second end SE2 of the second winding system W2 to the side of the first switch SW1 facing the second end SE2 as well as to the side of the third switch SW3, which is opposed to the end of the third switch SW3 providing or connected to the second star point S2. Star point S1 can be a part of the second switch SW2. Star point S2 can be a part of the third switch SW3. The switchable series connection between the second ends SE1 , SE2 is provided by the fourth switch SW4 connected between the second end SE1 and the first switch SW1 . The first switch SW1 connects the fourth switch SW4 and the fifth switch SW5. The fifth switch SW5 connects the second end SE2 to the first switch. The series connection between SE1 and SE2 is provided by the switches SW4, SW1 and SW5 (in this order).

[0029] A control device C controls the switches AS, SW1 , SW2, SW3, SW4 and SW5. In a combined drive mode, the control device C provides SW1 , SW4 and SW5 in closed state. The inverters jointly drive the first and the second winding systems, which are connected together. Switches SW2 and SW3 are open, no star point is given for the winding systems W1 , W2. Rather, the winding systems W1 , W2 are in an open end mode. The combined drive mode is comparable to the operation of a dual inverter.

[0030] In the individual drive mode, SW1 is open in order to have separated winding systems W1 , W2. In order to provide a connection between the winding systems W1 , W2 and inverters 11 , I2, SW4 and SW5 are closed. Thus, SW4 and 5 provide a phase-individual connection. In the individual drive mode, the winding systems W1 and W2 are provided in star configuration by closing switches SW2 and SW3. The phases of the second ends of each of the winding systems W1 , W2 are connected thereby, leading to a star point configuration with star points S1 , S2.

[0031] In case of a failure F in one of the inverters or in one of the winding systems (in Fig. 1 : failure in inverter 11 as an example), an emergency drive mode is provided. In the emergency mode, switch SW1 is open in order to suppress the propagation of failure F to the second inverter I2 or the second winding system W2. Further, the star point of the winding system having the failure or connected to the inverter 11 having the failure F is cancelled. This is provided by switch SW2 being in an open state. The other inverter (error free) and the winding system connected thereto (ie. the winding system neither having a failure nor connected to an inverter having a failure) are active. This means that the other inverter I2 is operating and that the winding system connected thereto (the error free winding system) is in a star point configuration by having the switch SW3 in a closed state. Thus, the second winding system W2 in the example of Fig. 1 has a star point in form of the second star point S2. In the emergency drive mode, the drive can be operated by one of the winding systems and the inverter connected thereto, while the other winding system and the inverter connected thereto is deactivated (by having the deactivated inverter in an open state, non-pulsing or not supplied, and by having a deactivated winding system resulting from an opened star point, ie. open switch SW2).

[0032] In a reduced mode, only one phase is deactivated and the residual phases are active. In case of a failure F in the first phase U of the first inverter 11 , this phase of the inverter is deactivated. If the reduced mode is combined with the combined drive mode, the same phase of the second inverter (generally: of the other inverter) is deactivated. Further, in particular if combined with the combined drive mode, the switches SW2 and SW3 are closed only for the phases, which are error-free and are open for the phase(s) having a failure. If the reduced mode is combined with the individual drive mode, only the phase of the inverter or winding system having the failure is deactivated. This is done by providing the pertaining phase of the pertaining inverter in an open state (non-pulsed) and by closing the pertaining star switch only for the phases, which are not affected. The phases of the inverter and the winding system not affected by or connected to a winding or inverter (rsp.) having a failure are activated. In this context, an activated inverter provides a pulsed signal for all phases and an activated winding system has all phases connected in star configuration (by having the pertaining star switch in a closed state for all phases). The first switch SW1 is in an open state for allowing the winding systems to be operated with a distinct number of active phases.

[0033] In shutdown mode, the inverters 11 , I2 are inactive and the switches are open (at least SW1 , SW4 and SW5, or SW1 , SW2 and SW3, or SW1 - SW5).

[0034] In combined mode of the accumulators, the traction accumulators A1 , A2 are connected in parallel by switch AS. In separate mode, switch AS is open, by which the traction accumulators A1 , A2 individually supply the inverters 11 , I2.

[0035] This allows a high number of distinct modes, since the accumulator modes and the electric drive modes can be broadly combined.

[0036] An open-end winding machine concept can be realized, based on a dual inverter approach, by having SW 1 , 2, 3 closed, while SW4,5 are open. This corresponds to the combined drive mode. An open-end winding machine concept based on a dual inverter approach can be realized, however by using only 2 phases in case of one complete inverter leg (one phase of the inverter) is defect, see example failure F in Fig. 1 . This corresponds to the reduced mode, which can be defined as a mode with a reduced number of active phases - for both inverters I winding systems or for only one of the inverters I winding systems (the one being concerned by failure F). Further, a 6-phase machine with two star points can be realized with SW1 , 3, 4, 5 being closed, while SW2 is open. Generally, an n-phase machine with m star points can be realized, n being the number of phases of each inverter / winding system and m being the number of inverters I winding systems. In addition, a 3-phase machine (generally: n-phase machine) with reduced performance with the first set of phases (W1 ) can be provided by deactivating the second inverter I the second winding system by having SW1 , SW5 open (preferably SW3 as well). Finally, a 3-phase machine (generally: n-phase machine) with reduced performance with the second set of phases (W2) can be provided by deactivating the first inverter I the first winding system by having SW1 , SW4 open (preferably SW2 as well).

Claims

Patent Claims1 . Electrical machine (EM) with a first and a second multiphase winding system (W1 , W2), each winding system (W1 , W2) having a first end (FE1 , FE2) adapted to be connected to an inverter output (IF1 , IF2) and second end (SE1 , SE2) with a plurality of phases (U, V, W), wherein- a first switch (SW1 ) is connected between the second ends (FE1 , FE2),- a second switch (SW2) is connected between the second end (SE1) of the first winding (W1 ) and a first star point (S1 )- a third switch (SW3) is connected between the second end (SE2) of the second winding (W2) and a second star point (S2), wherein the first switch (SW1 ) is positioned between the second and the third switch (SW2, SW3).

2. Electrical machine (EM) according to claim 1 , wherein a fourth switch (SW4) is connected between the second end (SE1 ) of the first winding (W1 ) on the one hand and the first switch (SW1 ) as well as the second switch (SW2) on the other hand; and wherein a fifth switch (SW5) is connected between the second end (SE2) of the second winding (W2) on the one hand and the first switch (SW1 ) as well as the third switch (SW3) on the other hand.

3. Electrical machine (EM) according to claim 1 or 2, comprising a control device (C) controlling the switches (SW1 - SW5), the control device (C) having- a combined drive mode, in which the control device (C) provides the first switch (SW1 ) in a closed state and provides the second switch (SW2) as well as the third switch (SW3) in an open state; and- an individual drive mode, in which the control device (C) provides the first switch (SW1 ) in an open state and provides the second switch (SW2) as well as the third switch (SW3) in a closed state.

4. Electrical machine (EM) according to claim 3, the control device (C) having an emergency drive mode, in which the control device (C) provides the first switch (SW1 ) in an open state, and provides one of the second and thirdswitch (SW2) in an open state, while the other one (SW3) of these two switches (SW2, SW3) is provided in a closed state by the control device.

5. Electrical machine (EM) according to claim 3 or 4, the control device (C) having a reduced mode, in which the control device (C) provides at least one switch in a closed state for at least one of the phases all switches and in an open state for the other phase(s).

6. Electrical machine (EM) according to one of the proceeding claims, wherein the windings (W1 , W2) are positioned in the same stator of the electrical machine (EM) and have the same dimensioning.

7. Electrical drive (ED) with an electrical machine according to one of claims 1 - 6, the electrical drive (ED) having a first inverter (11 ) connected to the first end (FE1 ) of the first winding system (W1 ), and having a second inverter (I2) connected to the first end (FE2) of the second winding system (W2).

8. Electrical drive (ED) according to claim 7, the first inverter (11 ) having a DC- side connected to a first traction accumulator (A1 ) of the electrical drive (ED) and the second inverter (I2) having a DC-side connected to a second traction accumulator (A1 ) of the electrical drive (ED).

9. Electrical drive (ED) according to claim 8, wherein the first traction accumulator (A1 ) and the second traction accumulator (A2) are connected in parallel via an accumulator switch (AS).

10. Electrical drive (ED) according to claim 9, comprising a control device (C) controlling the accumulator switch (AS), the control device (C) having- a combined mode, in which the control device (C) provides the accumulator switch (AS) in a closed state, and- a separate mode, in which the control device (C) provides the accumulator switch (AS) in an open state.

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