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DE-102024133135-A1 - Electric machine, motor vehicle and method for operating the electric machine

DE102024133135A1DE 102024133135 A1DE102024133135 A1DE 102024133135A1DE-102024133135-A1

Abstract

The invention relates to an electric machine (1) with a pulse inverter device (2), wherein the electric machine (1) is designed as an N x M-phase machine with N times M phases (4), wherein for N: N >= 2 and for M: M >= 3, such that M has N-fold parallel-connected phases (4), wherein the pulse inverter device (2) has a half-bridge (3) per phase (4), wherein the half-bridge (3) has semiconductor switches (5), wherein the N-fold interconnection of the phases (4) has N parallel-connected half-bridges (3), wherein at least one of the parallel-connected half-bridges (3) is or are switchable.

Inventors

  • Robin Lehner

Assignees

  • DR. ING. H.C. F. PORSCHE AKTIENGESELLSCHAFT

Dates

Publication Date
20260513
Application Date
20241113

Claims (9)

  1. An electrical machine (1) with a pulse inverter device (2), wherein the electrical machine (1) is designed as an N x M-phase machine with N times M phases (4), wherein for N: N >= 2 and for M: M >= 3, such that M has N-fold parallel connected phases (4), wherein the pulse inverter device (2) has a half-bridge (3) per phase (4), wherein the half-bridge (3) has semiconductor switches (5), wherein the N-fold interconnection of the phases (4) has N parallel connected half-bridges (3), wherein at least one of the parallel connected half-bridges (3) is or are switchable.
  2. Electric machine (1) according to Claim 1 , characterized in that the parallel connected half-bridges (3) are switched off in partial load operation for each phase (4).
  3. Electric machine (1) according to Claim 1 or 2 , characterized in that when the half-bridge (3) is switched off, the semiconductor switches (5) of the half-bridge (3) are open.
  4. Electric machine (1) according to Claim 1 , 2 or 3 , characterized in that the partial load operation of the electric machine (1) is in a power range below the maximum power of the electric machine (1) and/or in a torque range below the maximum torque of the electric machine (1), in particular the partial load operation of the electric machine (1) is in a power range below 90% of the maximum power of the electric machine (1) and/or in a torque range below 90% of the maximum torque of the electric machine (1), furthermore in particular the partial load operation of the electric machine (1) is in a power range below 80% of the maximum power of the electric machine (1) and/or in a torque range below 80% of the maximum torque of the electric machine (1).
  5. Electric machine (1) according to one of the preceding claims, characterized in that the electric machine (1) is designed such that: N = 2 and M = 3 or N = 3 and M = 3 or N > 3 and M = 3 or N = 2 and M = 4 or N = 3 and M = 4.
  6. Motor vehicle comprising an electric machine (1) for driving the motor vehicle and a pulse inverter device (2) for supplying and controlling the electric machine (1), wherein the electric machine (1) and the pulse inverter device (2) are designed according to one of the preceding claims.
  7. Method for operating an electric machine (1) with a pulse inverter device (2), wherein the electric machine (1) is designed as an N x M-phase machine with N times M phases (4), wherein for N: N >= 2 and for M: M >= 3, such that M has N-fold parallel connected phases (4), wherein the pulse inverter device (2) has a half-bridge (3) per phase (4), wherein the half-bridge (3) has semiconductor switches (5), wherein the N-fold interconnection of the phases (4) has N parallel connected half-bridges (3), wherein at least one of the parallel connected half-bridges (3) per phase (4) is or are switched off in a partial load operation.
  8. Procedure according to Claim 7 , characterized in that when the half-bridge (3) is switched off, the semiconductor switches (5) of the half-bridge (3) are switched open.
  9. Procedure according to Claim 7 or 8 , characterized in that the partial load operation of the electric machine (1) is in a power range below the maximum power of the electric machine (1) and/or in a torque range below the maximum torque of the electric machine (1), in particular the partial load operation of the electric machine (1) is in a power range below 90% of the maximum power of the electric machine (1) and/or in a torque range below 90% of the maximum torque of the electric machine (1), furthermore in particular the partial load operation of the electric machine (1) is in a power range below 80% of the maximum power of the electric machine (1) and/or in a torque range below is 80% of the maximum torque of the electric machine (1).

Description

The invention relates to an electric machine, a motor vehicle with an electric machine and a method for operating an electric machine. In conventional electric vehicle drives, power modules of a pulse inverter are typically connected in parallel to a three-phase electric machine. The total chip area per phase determines the maximum current-carrying capacity of the pulse inverter. In some cases, the chip area is typically very large, which, however, leads to high switching losses in the pulse inverter under partial load, as the entire chip area must be recharged even under partial load. This is rather undesirable. The task is to create a method for operating an electric machine, an electric machine and a motor vehicle with an electric machine, whereby the aforementioned switching losses in the partial load range are reduced. The problem with the electric machine is solved by the features of claim 1. One embodiment of the invention relates to an electric machine with a pulse inverter device, wherein the electric machine is designed as an N x M phase machine with N times M phases, where N >= 2 and M >= 3, such that M has N parallel-connected phases, wherein the pulse inverter device has one half-bridge per phase, each half-bridge having semiconductor switches, and wherein the N-fold connection of the phases has N parallel-connected half-bridges, with at least one of the parallel-connected half-bridges being switchable. This makes it possible, for example, in partial load operation where maximum power is not required, to reduce switching losses and eliminate charging losses in the switched-off module or half-bridge by switching off an entire phase, with only slightly increased conduction losses in the activated power module or half-bridge. This results in an increase in the efficiency of the electric machine with the pulse inverter device and an increase in the range of the electrically powered vehicle. It is particularly advantageous if the parallel-connected half-bridges are switched off for each phase during partial load operation. This allows the advantages described above to be especially evident during partial load operation, whereas during full load operation, the phases are not switched off, so that the full power of the electric machine can be utilized by employing all available phases. It is also advantageous if the semiconductor switches of the half-bridge are open when the half-bridge is switched off. This prevents parasitic currents in the switched-off state. It is also advantageous if the partial load operation of the electric machine is in a power range below its maximum power and/or torque range below its maximum torque, in particular if the partial load operation is in a power range below 90% of its maximum power and/or torque range below 90% of its maximum torque, and furthermore, in particular if the partial load operation is in a power range below 80% of its maximum power and/or torque range below 80% of its maximum torque. This ensures that maximum power is available during full load operation. It is also advantageous if the electrical machine is designed such that: N = 2 and M = 3 or N = 3 and M = 3 or N > 3 and M = 3 or N = 2 and M = 4 or N = 3 and M = 4. The problem relating to the motor vehicle is solved by the features of claim 6. One embodiment of the invention relates to a motor vehicle with an electric machine for driving the motor vehicle and with a pulse inverter device for supplying and controlling the electric machine, wherein the electric machine and the pulse inverter device are designed according to the invention. The problem with the method is solved by the features of claim 7. One embodiment of the invention relates to a method for operating an electric machine with a pulse inverter device, wherein the electric machine is designed as an N x M-phase machine with N times M phases, where N >= 2 and M >= 3, such that M has N-fold parallel-connected phases, wherein the pulse inverter device has one half-bridge per phase, wherein the half-bridge has semiconductor switches, and wherein the N-fold connection of the phases is N-fold parallel-connected The system features half-bridges, with at least one of the parallel-connected half-bridges per phase being switched off, particularly during partial load operation. This ensures that, for example, during partial load operation where maximum power is not required, switching losses are reduced by switching off an entire phase, and there are no charging losses in the switched-off module or half-bridge, with only slightly increased conduction losses in the activated power module or half-bridge. This results in an increase in the efficiency of the electric machine with the pulse inverter and an increase in the range of the electric vehicle. It is also advantageous if the semiconductor switches of the half-bridge are switched open when the half-bridge is switched off. Furthermore, it is advantageous if the partial load operation of the elect