Electric machine and vehicle

Abstract

The present invention relates to an electric machine (20) comprising a rotor arrangement (40), a stator arrangement (50) and an inverter arrangement (30), wherein the stator arrangement (50) has a winding arrangement (60) with six phases (61-66) and with six phase terminals (U, V, W, X, Y, Z) associated with the phases (61-66), wherein the phases (61-66) comprise three first phases (61-63) and three second phases (64-66), wherein the first phases (61-63) have an electrical phase shift of 120° from each other, and wherein the second phases (64-66) have an electrical phase shift of 120° from each other, wherein the first phases (61-63) and the second phases (64-66) have an electrical phase shift of 30° to each other, wherein the inverter arrangement (30) includes a control device (35) and has half-bridges (34), wherein each phase terminal (U, V, W, X, Y, Z) is assigned one of the half-bridges (34), wherein the inverter arrangement (30) comprises a six-phase inverter or two three-phase inverters (31, 32), wherein each phase (61-66) has at least two windings (611, 612) and a connection arrangement (71-76), wherein the circuit arrangement (71-76) comprises semiconductor switches (711, 712, 713), and wherein the control device (35) is configured to control the semiconductor switches (711, 712, 713) accordingly - to effect a parallel connection of the at least two windings (611, 612) in a first state (Z1), and - to effect a series connection of at least two windings (611, 612) in a second state (Z2).

Description

[0001] The invention relates to an electric machine and a vehicle.

[0002] EP 4 366 155 A1 shows a six-phase electric machine.

[0003] The CN 104 953 743 A shows an electric machine which can be operated in six-phase or three-phase mode.

[0004] DE 10 2007 040 725 A1 shows a changeable winding configuration.

[0005] US 10 566 922 B2 shows a drive system with multiple inverters.

[0006] The CN 202 856 582 U shows a three-phase electric machine for an electric vehicle.

[0007] The EP 3 008 814 B1 shows an electric machine with two sets of three phases and with two inverters.

[0008] The CN 107 994 710 A shows a three-phase electric machine in which the windings can be connected in series and in parallel.

[0009] DE 10 2022 212 946 A1 shows an inverter to whose terminals a stator winding of a first stator and a stator winding of a second stator are connected, which can be connected in series or in parallel.

[0010] DE 10 2017 209 479 A1 discloses a method for operating an electric machine which has several phases, wherein each phase has at least two windings.

[0011] DE 10 2011 053 572 A1 discloses an electrical machine system comprising an electrical machine with switched stator windings.

[0012] US 2004 / 0 164 636 A1 shows an electric motor with two separate windings.

[0013] The CN 1 05 553 345 A shows a permanent magnet motor with a control for switching and speed.

[0014] The CN 1 06 685 305 A shows a motor with three operating states.

[0015] Wang, Shensheng; Zhu, Ziqiang; Pride, Adam; Shi, Juntao; Deodhar, Rajesh; Umemura, Chiaki: Comparison of Different Winding Configurations for Dual Three-Phase Interior PM Machines in Electric Vehicles. In: World Electric Vehicle Journal, 13, 2022, pp. 1-51 show a comparison of different winding configurations.

[0016] It is therefore an object of the invention to provide a new electric machine and a new vehicle.

[0017] An electric machine comprises a rotor arrangement, a stator arrangement, and an inverter arrangement, wherein the stator arrangement has a winding arrangement with six phases and with six phase terminals assigned to the phases, wherein the inverter arrangement has a control device and half-bridges, with each phase terminal being assigned one of the half-bridges, wherein each phase has at least two windings and a connection arrangement, wherein the connection arrangement has semiconductor switches, and wherein the control device is configured to control the semiconductor switches accordingly. - to effect a parallel connection of at least two windings in a first state, and - to effect a series connection of at least two windings in a second state.

[0018] The efficiency of the electric machine can be improved by reconfiguring the phase windings. Depending on the application, either the first or second state can be selected.

[0019] The inverter arrangement comprises either a six-phase inverter or two three-phase inverters. Both options allow for control of the winding arrangement.

[0020] According to a preferred embodiment, the six phases are connected in a star connection with one neutral point, in two star connections with two neutral points, in a delta connection with two phases connected in series, or in two delta connections. These variants benefit from the possibility of different connection configurations.

[0021] According to a preferred embodiment, the control device is configured to select either the first or the second state depending on the operating point of the electric machine. The efficiency of the electric machine in the two states depends on the operating point. Therefore, selecting the state based on the operating point is advantageous.

[0022] According to a preferred embodiment, the control device is configured to determine the current operating point as a function of at least one parameter from a parameter group consisting of: - Rotational speed of the rotor assembly, - Current strength of the current through at least one of the phases, - Voltage between two of the phase terminals, and - Torque of the electric machine.

[0023] These parameters, both individually and especially in combination, make it advantageous to determine the operating point.

[0024] According to a preferred embodiment, the semiconductor switches comprise at least one semiconductor switch type from a group of semiconductor switch types consisting of: - Metal-oxide-semiconductor field-effect transistors (MOSFETs), - Insulated gate bipolar transistors (IGBTs), - Silicon carbide MOSFETs, and - Gallium nitride transistors.

[0025] These semiconductor switch types have particularly low power loss.

[0026] According to a preferred embodiment, the interconnection arrangements each have at least three semiconductor switches. Different phase configurations can be achieved with at least three semiconductor switches.

[0027] According to a preferred embodiment, the phases are each connected on a first side to a first point and on a second side to a second point, the windings of each phase comprise a first winding and a second winding, the interconnection arrangements each have a first semiconductor switch, a second semiconductor switch and a third semiconductor switch, wherein the first winding is connected on a first winding side to a third point and on a second winding side to the second point, the third point being connected to the first point via the first semiconductor switch, wherein the second winding is connected on a first winding side to the first point and on a second winding side to a fourth point, the fourth point being connected to the second point via the second semiconductor switch.and wherein the third point is connected to the fourth point via the third semiconductor switch.

[0028] This configuration allows for parallel and series connections using a small number of semiconductor switches.

[0029] According to a preferred embodiment, the stator assembly has a stator core with slots, and the windings extend through the slots. This increases the magnetic flux towards the rotor assembly and also gives the windings a predetermined spatial offset from each other.

[0030] According to a preferred embodiment, the phases each have a predetermined first number of windings, wherein the predetermined first number lies in at least one predetermined first region consisting of a region group comprising: - Range between 2 and 10, - Range between 2 and 8, - Range between 2 and 6, - range between 2 and 4, and - Range between 4 and 8.

[0031] These areas allow for smooth switching between different configurations and are well-suited for various operating points. The technology can be scaled by increasing the number of parallel windings.

[0032] The phases comprise three first phases and three second phases, wherein the first phases have an electrical phase shift of 120° from each other, and wherein the second phases have an electrical phase shift of 120° from each other. The first phases and the second phases can thus preferably each be operated in three-phase mode, generating maximum torque at a phase interval of 120°.

[0033] The first and second phases have an electrical phase shift of 30° relative to each other. This ensures an even distribution of the rotor assembly positions with maximum torque.

[0034] A vehicle has such an electric motor. This allows the vehicle to be operated with good efficiency, and the range is increased.

[0035] According to a preferred embodiment, the electric machine serves as a drive for the vehicle.

[0036] Further details and advantageous embodiments of the invention will become apparent from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. It shows: Fig. 1 in a schematic representation a vehicle with an electric motor, Fig. 2 in a schematic representation the electric machine of Fig. 1 in a first interconnection state of a winding arrangement and in a second interconnection state of the winding arrangement, Fig. 3. The winding arrangement is shown schematically. Fig. 1 with a wiring arrangement, Fig. 4 in schematic representation the winding arrangement of Fig. 3 with parallel connected windings, Fig. 5 in schematic representation the winding arrangement of Fig. 3 with windings connected in series, and Fig. 6 in a schematic top view a stator arrangement of the electric machine of Fig. 1. Fig. 7 in a schematic representation the complete winding system with the six phase connections U, V, W, X, Y, Z

[0037] In the following, identical or similarly functioning parts are designated with the same reference symbols and are usually described only once. The description builds upon itself across figures to avoid unnecessary repetition.

[0038] Fig. Figure 1 shows a schematically indicated vehicle 10.

[0039] The vehicle 10 has an electric machine 20 and a traction battery (not shown) to power the electric machine 20.

[0040] The electric machine 20 is preferably used as a drive for the vehicle 10.

[0041] The electric machine 20 has a rotor arrangement 40, a stator arrangement 50 and an inverter arrangement 30.

[0042] The stator arrangement 50 has a winding arrangement 60 with six phases 61-66 and with six phase terminals U, V, W, X, Y, Z assigned to the phases 61-66.

[0043] The stator arrangement 50 has a stator core 52. The stator core 52 can, for example, be designed as a laminated core.

[0044] The inverter arrangement 30 has a control device 35 and half-bridges 34, wherein each phase terminal U, V, W, X, Y, Z is assigned one of the half-bridges 34.

[0045] The inverter arrangement 30 serves to provide an alternating voltage suitable for the stator arrangement 50. The inverter arrangement 30 is supplied, for example, via a high-voltage network and is preferably connected to a traction battery.

[0046] The inverter arrangement 30 preferably comprises a six-phase inverter or two three-phase inverters 31, 32.

[0047] Fig. Figure 2 shows a schematic representation of the electric motor 20A in state Z2 and the electric motor 20B in state Z1.

[0048] Only three of the six phases are shown.

[0049] Each half-bridge 34 is connected to the phase terminal U.

[0050] The half-bridge 34 has a point 343, which is connected via a semiconductor switch 341 to an upper DC voltage terminal HV+ and via a semiconductor switch 342 to a lower DC voltage terminal HV-. HV stands for high-voltage terminal.

[0051] High voltage is a term from automotive engineering for systems that are operated with an alternating voltage between 30 V and approximately 1 kV or with a direct voltage in the range between 60 V and approximately 1.5 kV.

[0052] Point 343 is connected to phase terminal U.

[0053] Phases 61 to 63 each have two windings 611, 612.

[0054] In the left state Z2, the windings 611 and 612 are connected in series.

[0055] Series connection increases torque and is particularly advantageous at low speeds.

[0056] In the right-hand state Z1, windings 611 and 612 are connected in parallel.

[0057] Parallel connection increases power at higher speeds.

[0058] By selecting the first state Z1 or the second state Z2 with the appropriate winding configuration for the corresponding operating point, the efficiency of the electrical machine 20 can be improved.

[0059] The control device 35 (see Fig. 1) is preferably configured to select the first state Z1 or the second state Z2 depending on the operating point of the electrical machine 20.

[0060] The control device 35 is preferably configured to determine the current operating point as a function of at least one parameter from a parameter group consisting of: - Rotational speed of the rotor assembly 40, - Current strength of the current through at least one of the phases 61-66, - Voltage between any two of the phase terminals U, V, W, X, Y, Z, and - Torque of the electric machine 20.

[0061] These parameters, individually and especially in combination, are well suited for determining the operating point.

[0062] Fig. Figure 3 shows the winding arrangement 60 with the six phases 61-66, each of which is assigned a connection arrangement 71-76.

[0063] In the exemplary embodiment, the six phases 61-66 are connected in a star connection with a common star point 69.

[0064] Alternatively, phases 61-66 can be connected in two star connections with two star points, in a delta connection with two phases connected in series, or in two delta connections.

[0065] The interconnection arrangements 71-76 feature semiconductor switches 711, 712, 713.

[0066] The control device 35 (see Fig. 1) is designed to control the semiconductor switches 711, 712, 713 accordingly. - in the first state Z1 to effect a parallel connection of at least two windings 611, 612, and - in the second state Z2 to effect a series connection of at least two windings 611, 612.

[0067] The semiconductor switches 711, 712, 713 preferably have at least one semiconductor switch type from a semiconductor switch type group consisting of: - Metal-oxide-semiconductor field-effect transistors (MOSFETs), - Insulated gate bipolar transistors (IGBTs), - Silicon carbide MOSFETs, and - Gallium nitride transistors.

[0068] These types have low power loss and increase the efficiency of the electric machine 20.

[0069] The circuit arrangements 71-76 preferably each have at least three semiconductor switches 711, 712, 713. For phases 61-66 with a larger number of windings 611, 612, more than three semiconductor switches 711, 712, 713 are preferably used.

[0070] Phases 61-66 are each linked on a first page with a first point 715 and on a second page with a second point 716.

[0071] The first point 715 and the second point 716 can be one of the phase connections, a star point or a point of another phase.

[0072] In the exemplary embodiment, the winding 611 is connected to a point 717 on a first winding side, and on a second winding side it is connected to the point 716.

[0073] Point 717 is connected to point 715 via semiconductor switch 711.

[0074] The winding 612 is connected to point 715 on a first winding side and to point 718 on a second winding side.

[0075] Point 718 is connected to point 716 via semiconductor switch 712.

[0076] Point 717 is connected to point 718 via semiconductor switch 713.

[0077] Phases 61-66 each have a predetermined first number of windings 711, 712, wherein the predetermined first number lies in at least one predetermined first area from an area group consisting of: - Range between 2 and 10, - Range between 2 and 8, - Range between 2 and 6, - range between 2 and 4, and - Range between 4 and 8.

[0078] Fig. Figure 4 shows the winding arrangement 60 in state Z1. In the circuit arrangement 71, the semiconductor switch 711 and the semiconductor switch 712 are connected. The semiconductor switch 713 (see Figure 4) is also connected. Fig. 3) is non-conductive and therefore not shown.

[0079] Phase 61 thus has two windings 611, 612, which are connected in parallel between the phase terminal U and the star point 69.

[0080] The interconnection arrangements 72 to 76 of the remaining phases 62 to 66 are preferably connected accordingly.

[0081] Fig. Figure 5 shows the winding arrangement 60 in state Z2. In the circuit arrangement 71, the semiconductor switch 713 is switched on. The semiconductor switches 711 and 712 (see Figure 5) are switched on. Fig. 3) are non-conductive and therefore not shown.

[0082] Phase 61 thus has two windings 611, 612, which are connected in series between the phase terminal U and the star point 69.

[0083] The interconnection arrangements 72 to 76 of the remaining phases 62 to 66 are preferably connected accordingly.

[0084] Fig. Figure 6 shows a section of the stator arrangement 50 with the stator core 52. The stator core 52 has slots 54, and the windings 611, 612 extend through the slots 54.

[0085] In each slot 54, six winding wires are arranged in the exemplary embodiment. This is, for example, a hairpin winding.

[0086] From left to right, two slots 54 are each filled with winding wires of phases 66, 62, 65, 63, 64, 61.

[0087] The section shown can be described as a stator pole of the stator arrangement 50.

[0088] Fig.Figure 7 schematically shows the complete winding system with the six phase connections U, V, W, X, Y, Z.

[0089] Phases 61 to 66 are shown schematically with one winding each, which serves as a schematic replacement for the majority of windings.

[0090] Phases 61 to 66 comprise three first phases 61 to 63 with winding terminals U, V, W and three second phases 64 to 66 with winding terminals X, Y, Z.

[0091] The first phases 61 to 63 have an electrical phase shift of 120° between them.

[0092] The second phases 64 to 66 have an electrical phase shift of 120° between them.

[0093] The first and second phases are therefore each structured in three phases.

[0094] Preferably, the first phases 61 to 63 and the second phases 64 to 66 have an electrical phase shift of 30° to each other.

[0095] Naturally, various variations and modifications are possible within the scope of the present invention.

Claims

[1] Electric machine (20) comprising a rotor arrangement (40), a stator arrangement (50) and an inverter arrangement (30), wherein the stator arrangement (50) comprises a winding arrangement (60) with six phases (61-66) and with six phase terminals (U, V, W, X, Y, Z) associated with the phases (61-66), wherein the phases (61-66) comprise three first phases (61-63) and three second phases (64-66), wherein the first phases (61-63) have an electrical phase shift of 120° from each other, and wherein the second phases (64-66) have an electrical phase shift of 120° from each other, wherein the first phases (61-63) and the second phases (64-66) have an electrical phase shift of 30° to each other, wherein the inverter arrangement (30) comprises a control device (35) and half-bridges (34), wherein each phase terminal (U, V, W, X, Y, Z) is assigned one of the half-bridges (34), wherein the inverter arrangement (30) comprises a six-phase inverter or two three-phase inverters (31, 32), wherein each phase (61-66) has at least two windings (611, 612) and a connection arrangement (71-76), wherein the circuit arrangement (71-76) comprises semiconductor switches (711, 712, 713), and wherein the control device (35) is configured to control the semiconductor switches (711, 712, 713) accordingly - to effect a parallel connection of the at least two windings (611, 612) in a first state (Z1), and - to effect a series connection of at least two windings (611, 612) in a second state (Z2). [2] Electric machine (20) according to one of the preceding claims, in which the six phases (61-66) are connected in a star connection with one star point (69), in two star connections with two star points, in a delta connection with two phases connected in series or in two delta connections. [3] Electric machine (20) according to one of the preceding claims, wherein the control device (35) is configured to select the first state (Z1) or the second state (Z2) depending on the operating point of the electric machine (20). [4] Electric machine (20) according to claim 3, wherein the control device (35) is configured to determine the current operating point as a function of at least one parameter from a parameter group consisting of: - Rotational speed of the rotor assembly (40), - Current strength of the current through at least one of the phases (61-66), - Voltage between two of the phase terminals, and - Torque of the electric machine (20). [5] Electric machine (20) according to one of the preceding claims, wherein the semiconductor switches (711, 712, 713) comprise at least one semiconductor switch type from a group of semiconductor switch types consisting of: - Metal-oxide-semiconductor field-effect transistors (MOSFETs), - Insulated gate bipolar transistors (IGBTs), - Silicon carbide MOSFETs, and - Gallium nitride transistors. [6] Electric machine (20) according to one of the preceding claims, wherein the interconnection arrangements (71-76) each have at least three semiconductor switches (711, 712, 713). [7] Electric machine (20) according to one of the preceding claims, in which the phases (61-66) are each connected on a first side to a first point (715) and on a second side to a second point (716), in which the windings (611, 612) of the respective phase (61-66) comprise a first winding (611) and a second winding (612), in which the interconnection arrangements (71-76) each have a first semiconductor switch (711), a second semiconductor switch (712) and a third semiconductor switch (713), wherein the first winding (611) is connected on a first winding side to a third point (717) and on a second winding side to the second point (716), wherein the third point (717) is connected to the first point (715) via the first semiconductor switch (711), wherein the second winding (612) is connected on a first winding side to the first point (715) and on a second winding side to a fourth point (718), wherein the fourth point (718) is connected to the second point (716) via the second semiconductor switch (712), and where the third point (717) is connected to the fourth point (718) via the third semiconductor switch (713). [8] Electric machine (20) according to one of the preceding claims, wherein the stator arrangement (50) has a stator core (52) with slots (54) and wherein the windings (611, 612) extend through the slots (54). [9] Electrical machine (20) according to one of the preceding claims, in which the phases (61-66) each have a predetermined first number of windings (711, 712), wherein the predetermined first number lies in at least one predetermined first region consisting of a region group comprising: - Range between 2 and 10, - Range between 2 and 8, - Range between 2 and 6, - range between 2 and 4, and - Range between 4 and 8. [10] Vehicle (10) comprising an electric machine (20) according to any of the preceding claims.

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