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CN-114915215-B - Battery heating control device and method and electric vehicle

CN114915215BCN 114915215 BCN114915215 BCN 114915215BCN-114915215-B

Abstract

The application provides a battery heating control device, a battery heating control method and an electric vehicle, which comprise a motor controller and a motor, the motor controller and the motor are connected with the battery to form a heating loop, and the motor controller comprises an inverter and a controller. The inverter comprises a three-phase bridge arm and a bus capacitor, the bus capacitor is connected with the three-phase bridge arm in parallel, the control ends of six switch modules of the three-phase bridge arm are respectively connected with the controller, and the midpoints of the three-phase bridge arm are respectively electrically connected with three-phase stator windings of the motor. The controller is used for detecting the rotor position angle of the motor. And confirming the angle range of the rotor position angle according to the detected rotor position angle. And adjusting the switching frequency or the duty ratio of a switching module in the inverter according to the angle range of the rotor position angle. The embodiment of the application can avoid the problem of demagnetizing the magnetic steel of the motor in the heating process of the battery, ensure the safety of the motor and improve the heating efficiency of the battery.

Inventors

  • LI YING
  • FU FANGYUAN

Assignees

  • 华为数字能源技术有限公司

Dates

Publication Date
20260508
Application Date
20220421

Claims (15)

  1. 1. A battery heating control device, characterized by comprising a motor controller and a motor, wherein the motor controller and the motor are connected with a battery to form a heating loop, and the motor controller comprises an inverter and a controller; the inverter comprises a three-phase bridge arm and a bus capacitor, the bus capacitor is connected with the three-phase bridge arm in parallel, the control ends of six switch modules of the three-phase bridge arm are respectively connected with the controller, and the midpoints of the three-phase bridge arm are respectively electrically connected with a three-phase stator winding of the motor; The controller is used for: detecting a rotor position angle of the motor; confirming the angle range of the rotor position angle; And adjusting the switching frequency or the duty ratio of a switching module in the inverter according to the angle range of the rotor position angle so as to control the ripple current of the motor under the rotor position angle.
  2. 2. The battery heating control device according to claim 1, wherein the controller is configured to: when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the switching frequency of the switching module is increased; and when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, reducing the switching frequency of the switching module, wherein the second threshold value is smaller than the first threshold value.
  3. 3. The battery heating control device according to claim 1 or 2, wherein the controller is further configured to: when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the duty ratio of the switch module is reduced; And when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, the duty ratio of the switch module is increased, wherein the second threshold value is smaller than the first threshold value.
  4. 4. The battery heating control device of claim 1, wherein the controller is further configured to: when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the switching frequency of the switching module is increased, and the duty ratio of the switching module is reduced; And when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, reducing the switching frequency of the switching module and improving the duty ratio of the switching module, wherein the second threshold value is smaller than the first threshold value.
  5. 5. The battery heating control device of claim 1, wherein the controller is further configured to: when the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the switching frequency of the switching module is increased; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, reducing the switching frequency of the switching module, wherein the fourth threshold value is smaller than the third threshold value.
  6. 6. The battery heating control device according to claim 1 or 5, wherein the controller is further configured to: When the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the duty ratio of the switch module is reduced; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, the duty ratio of the switch module is increased, wherein the fourth threshold value is smaller than the third threshold value.
  7. 7. The battery heating control device of claim 1, wherein the controller is further configured to: When the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the switching frequency of the switch module is increased, and the duty ratio of the switch module is reduced; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, reducing the switching frequency of the switching module and improving the duty ratio of the switching module, wherein the fourth threshold value is smaller than the third threshold value.
  8. 8. The battery heating control method is applied to a battery heating control device, the battery heating control device comprises a motor controller and a motor, the motor controller and the motor are connected with a battery to form a heating loop, the motor controller comprises an inverter and a controller, the inverter comprises a three-phase bridge arm and a bus capacitor, the bus capacitor is connected with the three-phase bridge arm in parallel, control ends of six switch modules of the three-phase bridge arm are respectively connected with the controller, and midpoints of the three-phase bridge arm are respectively electrically connected with a three-phase stator winding of the motor, and the method is characterized by comprising the following steps: detecting a rotor position angle of the motor; confirming the angle range of the rotor position angle; And adjusting the switching frequency or the duty ratio of a switching module in the inverter according to the angle range of the rotor position angle so as to control the ripple current of the motor under the rotor position angle.
  9. 9. The battery heating control method according to claim 8, wherein, When the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the switching frequency of the switching module is increased; and when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, reducing the switching frequency of the switching module, wherein the second threshold value is smaller than the first threshold value.
  10. 10. The battery heating control method according to claim 8 or 9, wherein, When the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the duty ratio of the switch module is reduced; And when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, the duty ratio of the switch module is increased, wherein the second threshold value is smaller than the first threshold value.
  11. 11. The battery heating control method according to claim 8, wherein, When the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, the switching frequency of the switching module is increased, and the duty ratio of the switching module is reduced; And when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, reducing the switching frequency of the switching module and improving the duty ratio of the switching module, wherein the second threshold value is smaller than the first threshold value.
  12. 12. The battery heating control method according to claim 8, wherein, When the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the switching frequency of the switching module is increased; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, reducing the switching frequency of the switching module, wherein the fourth threshold value is smaller than the third threshold value.
  13. 13. The battery heating control method according to claim 8 or 12, wherein, When the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the duty ratio of the switch module is reduced; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, the duty ratio of the switch module is increased, wherein the fourth threshold value is smaller than the third threshold value.
  14. 14. The battery heating control method according to claim 8, wherein, When the motor torque corresponding to the rotor position angle of the motor reaches a third threshold value, the switching frequency of the switch module is increased, and the duty ratio of the switch module is reduced; And when the motor torque corresponding to the rotor position angle of the motor reaches a fourth threshold value, reducing the switching frequency of the switching module and improving the duty ratio of the switching module, wherein the fourth threshold value is smaller than the third threshold value.
  15. 15. An electric vehicle, characterized in that the electric vehicle includes the battery heating control device according to any one of claims 1 to 7.

Description

Battery heating control device and method and electric vehicle Technical Field The present application relates to the field of power electronics, and in particular, to a battery heating control device and method, and an electric vehicle. Background The lithium precipitation phenomenon easily occurs when the battery is discharged at a low temperature, and the capacity attenuation of the battery and the potential safety hazard of the battery can be caused. Therefore, under the condition of low air temperature, the electric automobile can start running only when the battery needs to be heated to be above the preset temperature. The existing heating control method is to control the duty ratio of a switch module of an inverter in a battery heating system to be fixed (for example, d=0.5), so that the battery can be in a rapid charge and discharge alternating state, and the internal resistance of the battery causes a large amount of heat in the battery to rapidly raise the temperature. In order to ensure the heating power, the magnetic steel loss of the motor is increased, so that the magnetic steel of the motor is demagnetized, the motor is greatly damaged, and the heating safety of the motor is low. Disclosure of Invention In view of this, the present application provides a battery heating control device and method, and an electric vehicle, which can avoid the problem of demagnetization of the magnetic steel of the motor during the battery heating process, ensure the safety of the motor, and also can improve the heating efficiency of the battery. In a first aspect, an embodiment of the application provides a battery heating control device, which comprises a motor controller and a motor, wherein the motor controller is connected with the motor and a battery to form a heating loop, the motor controller comprises an inverter and a controller, the inverter comprises a three-phase bridge arm and a bus capacitor, the bus capacitor is connected with the three-phase bridge arm in parallel, control ends of six switch modules of the three-phase bridge arm are respectively connected with the controller, midpoints of the three-phase bridge arm are respectively and electrically connected with a three-phase stator winding of the motor, the controller is used for detecting a rotor position angle of the motor, confirming an angle range of the rotor position angle, and adjusting a switching frequency or a duty ratio of the switch modules in the inverter according to the angle range of the rotor position angle. By adopting the embodiment of the application, the angular range of the motor rotor position can be confirmed by detecting the rotor position of the motor, so that the embodiment of the application can correspondingly adjust the switching frequency or the duty ratio of the switching module according to the angular range of the motor rotor position. Therefore, the problem of demagnetization of the magnetic steel of the motor in the battery heating process can be avoided, the safety of the motor can be ensured, and the heating efficiency of the battery can be improved. As an optional implementation manner, the controller is further configured to increase the switching frequency of the switching module when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, and decrease the switching frequency of the switching module when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, where the second threshold value is smaller than the first threshold value. Based on such design, the switching frequency is improved at the angle of small motor loss, the switching frequency is reduced at the angle of large motor loss, the thermal safety of the motor under the heating condition is ensured, and the heating efficiency of the internal resistance heating of the battery is improved. As an optional implementation manner, the controller is further configured to reduce the duty cycle of the switch module when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold value, and increase the duty cycle of the switch module when the motor loss corresponding to the rotor position angle of the motor reaches a second threshold value, where the second threshold value is smaller than the first threshold value. Based on the design, the duty ratio is improved under the angle of small motor loss, the duty ratio is reduced under the angle of large motor loss, the thermal safety of the motor under the heating condition is ensured, and the heating efficiency of the internal resistance heating of the battery is improved. As an alternative implementation manner, the controller is further configured to increase the switching frequency of the switching module and decrease the duty cycle of the switching module when the motor loss corresponding to the rotor position angle of the motor reaches a first threshold, and decrease th