Cooling system and control method for permanent magnet synchronous motor for electric vehicle

Abstract

The invention discloses a permanent magnet synchronous motor cooling system for an electric automobile and a control method thereof. The cooling system comprises a control unit, a motor winding ammeter, a cooling water pump, a cooling water jacket, a cooling water temperature sensor, a cooling liquid flow meter, a heat radiator and a cooling fan. The control method comprises the following steps: judging whether a permanent magnet synchronous motor has a temperature rising trend or a temperature lowering trend under the working condition through detecting current of a motor stator winding, and adjusting a cooling capability of the cooling system so as to realize active adjustment of the cooling system; meanwhile, introducing auxiliary feedback adjustment and inquiring a working point of a motor through a motor efficiency MAP graph, so as to obtain the efficiency of the motor under the corresponding working condition; calculating the heat productivity of the motor; then feeding a difference value of the heat productivity of the motor and a heat radiation amount of the heat radiator back to the control unit, so as to correct the adjustment of the cooling system. The cooling system is subjected to active cooling control before the temperature of the motor is changed; energy sources are saved while a sufficient heat dissipation capability of the motor is guaranteed.

Description

technical field [0001] The invention relates to the field of a permanent magnet synchronous motor cooling system for an electric vehicle, in particular to a permanent magnet synchronous motor cooling system for an electric vehicle and a control method thereof. Background technique [0002] The motor replaces the original internal combustion engine as the power source of the car, and has the advantages of zero emission, easy control, and low noise. Since permanent magnet synchronous electric motors have the advantages of large starting torque, strong overload resistance, and high energy conversion efficiency, electric vehicles generally use permanent magnet synchronous motors as drive motors. [0003] Permanent magnet synchronous motors are prone to high heat, and most of them adopt a fully enclosed structure. At this time, the heat dissipation conditions are even worse. The natural convection cooling of the external air of the motor cannot meet the heat dissipation needs of ...

AI Technical Summary

Problems solved by technology

But there is an obvious lag in this adjustment method, that is, only when the temperature of the motor has risen, the control unit will issue an instruction to increase the cooling capacity of the cooling system

In addition, if the motor continues to work or generates a large amount of heat, the temperature of the cooling water will continue to rise, and the increase in water temperature will reduce the cooling efficiency of the cooling system.

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