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DE-102025121791-A1 - ENGINE DRIVE SYSTEM AND METHOD FOR ITS CONTROL

DE102025121791A1DE 102025121791 A1DE102025121791 A1DE 102025121791A1DE-102025121791-A1

Abstract

A motor drive system is provided. The motor drive system controls a drive mode of a motor such that the system switches between a first drive mode and a second drive mode, and if a first target operating point according to a required current output belongs to a second operating point range corresponding to the second drive mode, and a second target operating point according to a torque reduction of the motor belongs to a first operating point range corresponding to the first drive mode, the second target operating point is adjusted in the second drive mode.

Inventors

  • Byung Oh TAK
  • Seung Hyeon Bin
  • HEE WON AN
  • Joon Ha HWANG
  • Seong Min Kim
  • Ho Sun JANG

Assignees

  • HYUNDAI MOTOR COMPANY
  • KIA CORPORATION

Dates

Publication Date
20260513
Application Date
20250604
Priority Date
20241113

Claims (20)

  1. Motor drive system comprising: a motor with a plurality of windings; a first inverter connected to a first end of each of the plurality of windings; a second inverter connected to a second end of each of the plurality of windings; and a controller configured to control a drive mode of the motor to a first drive mode in which the motor is driven using the first inverter, or a second drive mode in which the motor is driven using both the first inverter and the second inverter, the controller further configured to track a second setpoint operating in the second drive mode if a first setpoint operating The point according to a currently required power belongs to a second operating point range, which corresponds to the second drive mode, and the second target operating point according to torque reduction of the motor belongs to a first operating point range, which corresponds to the first drive mode.
  2. Motor drive system according to Claim 1 , wherein the control system performs the torque reduction when the temperature of the first inverter and/or the second inverter is at or above a preset temperature condition.
  3. Motor drive system according to Claim 1 , wherein, if the torque reduction is not performed, the control unit controls the drive mode to the first drive mode if the first target operating point belongs to the first operating point range.
  4. Motor drive system according to Claim 3 , whereby if the torque reduction is not performed, the control switches the drive mode to the second drive mode if the first target operating point belongs to the second operating point range.
  5. Motor drive system according to Claim 1 , wherein the second operating point range includes a range which, at the same engine speeds, exhibits a torque greater than a torque of the first operating point range.
  6. Motor drive system according to Claim 1 , wherein the control unit tracks the second target operating point using the second drive mode if both the first target operating point and the second target operating point belong to the second operating point range.
  7. Motor drive system according to Claim 1 , wherein the control system tracks the second target operating point using the first drive mode if both the first target operating point and the second target operating point belong to the first operating point range.
  8. Motor drive system according to Claim 1 , which further comprises a plurality of switches, wherein a first end of each of the switches is connected to the second end of each of the plurality of windings.
  9. Motor drive system according to Claim 8 , wherein each of the multiple switches has a second end, the second ends of the switches being connected to each other to form a node.
  10. Motor drive system according to Claim 8 , whereby the control unit controls the drive mode of the motor by switching the multitude of switches on or off.
  11. A method for controlling a motor drive system comprising a motor with a plurality of windings, a first inverter connected to a first end of each of the plurality of windings, and a second inverter connected to a second end of each of the plurality of windings, wherein the method comprises: controlling a drive mode of the motor to a first drive mode in which the motor is driven using the first inverter, and a second drive mode in which the motor is driven using both the first inverter and the second inverter; and tracking a second target operating point in the second drive mode, where a first target operating point, according to a required current torque, belongs to a second operating point range corresponding to the second drive mode, and the second target operating point, according to a torque reduction of the motor, belongs to a first operating point range corresponding to the first drive mode.
  12. Procedure according to Claim 11 , which further includes performing torque reduction when the temperature of the first inverter and/or the second inverter is at or above a preset temperature condition.
  13. Procedure according to Claim 11 , wherein controlling a drive mode includes controlling the drive mode to the first drive mode if the first target operating point belongs to the first operating point range.
  14. Procedure according to Claim 13 , furthermore encompassing the control of the drive mode to the second drive mode if the first target operating point belongs to the second operating point range, if the torque reduction is not carried out.
  15. Procedure according to Claim 11 , wherein the second operating point range includes a range which, at the same engine speeds, exhibits a torque greater than a torque of the first operating point range.
  16. Procedure according to Claim 11 , which further includes tracking the second target operating point by the second drive mode when both the first target operating point and the second The target operating point belongs to the second operating point area.
  17. Procedure according to Claim 11 , which further includes tracking the second target operating point by the first drive mode if both the first target operating point and the second target operating point belong to the first operating point range.
  18. Procedure according to Claim 11 , wherein the motor drive system further includes a plurality of switches, wherein a first end of each of the switches is connected to the second end of each of the plurality of windings.
  19. Procedure according to Claim 18 , wherein each of the multiple switches has a second end, the second ends of the switches being connected to each other to form a node.
  20. Procedure according to Claim 18 , whereby controlling the drive mode of the motor involves turning several switches on or off.

Description

TECHNICAL AREA The present disclosure relates to a motor drive system with improved drive mode switching logic in a torque reduction situation and a method for controlling it. BACKGROUND Generally, one end of each winding of the phases contained in a motor is connected to an inverter, and the other ends of the windings are connected to form a Y-circuit. When the motor is driven, a switching element in the inverter is switched on and off by pulse width modulation control, applying a mains voltage to the Y-connected windings of the motor to generate alternating current, thereby producing torque. The fuel efficiency (e.g., or power efficiency) of an environmentally friendly vehicle, such as an electric vehicle that uses the torque generated by a motor as propulsion, is determined by the efficiency of the inverter and the motor, and therefore it makes sense to maximize the efficiency of the inverter and the efficiency of the motor to improve fuel efficiency. The efficiency of an inverter-motor system can be determined (e.g., mainly) by the voltage utilization rate of the inverter, and if an operating point of a vehicle, determined by the ratio between engine speed and torque, is formed in a range where the voltage utilization rate is high, the fuel efficiency of the vehicle can be improved. However, as the number of motor windings increases to raise the motor's maximum torque, the high-voltage utilization rate range moves further away from the low-torque range, which represents the vehicle's main operating range, potentially reducing fuel efficiency. Furthermore, if the main operating range is designed to fall within the high-voltage utilization rate range for optimal fuel efficiency, the motor's maximum torque is limited, which can reduce the vehicle's acceleration and starting performance. Since a motor drive technology that can improve the efficiency of the system while covering both the low-power and high-power ranges with just one motor is useful, a system was recently introduced in which a single motor is operated in two different modes with two inverters and a mode switch. The facts described above as background serve to better understand the background of the present disclosure and are not to be regarded as prior art. SUMMARY The present disclosure provides a motor drive system and a method for controlling it, which can prevent (e.g. minimize) damage to an inverter by improving a motor's drive mode switching logic in a torque reduction situation. The present disclosure is not limited to the items mentioned herein, and other, unmentioned items may be understood from the present description. In an exemplary embodiment, a motor drive system is provided, and the motor drive system includes a motor with a plurality of windings, a first inverter connected to one end (e.g., a first end) of each of the plurality of windings, a second inverter connected to the other end (e.g., a second end) of each of the plurality of windings, and a controller configured to control a drive mode of the motor such that it switches to a first drive mode in which the motor is driven using the first inverter, or to a second drive mode in which the motor is driven using both the first inverter and the second inverter. If a first target operating point, based on a current (e.g., a required current), belongs to a second operating point range corresponding to the second drive mode, and a second target operating point, according to the motor's torque reduction, belongs to a first operating point range corresponding to the first drive mode, the second target operating point is tracked in the second drive mode. In an exemplary embodiment, a method for controlling a motor drive system is provided. The motor drive system includes a motor with a plurality of windings, a a first inverter connected to one end of each of the plurality of windings, and a second inverter connected to the other end of each of the multiple windings, wherein the method comprises controlling a drive mode of the motor to switch between a first drive mode in which the motor is driven using the first inverter, and a second drive mode in which the motor is driven using both the first inverter and the second inverter, and if a first target operating point according to a current (e.g., a required) torque belongs to a second operating point range corresponding to the second drive mode, and if a second target operating point according to a torque reduction of the motor belongs to a first operating point range corresponding to the first drive mode, tracking the second target operating point in the second drive mode. BRIEF DESCRIPTION OF THE DRAWINGS The objectives and features of this disclosure can be understood with reference to the following description and the accompanying drawings, in which: 1 a circuit diagram of a motor drive system according to an embodiment of the present disclosure; 2 a diagram of the switching of a motor drive mode according to an exemplary embodime