Correction method for output torque of permanent magnet synchronous motor affected by temperature

Abstract

The invention discloses a method for correcting the output torque of a permanent magnet synchronous motor affected by temperature. The method respectively calibrates the motor at the normal temperature and the lowest and highest working temperature of the motor, and obtains the shaft currents of the motor under the three temperature conditions respectively. According to the expected value of the output torque of the motor, the unique combination of the shaft current of the motor that falls on the MTPA curve of the motor is obtained by looking up the table, and is output as the expected value of the DQ axis current of the motor vector control system, thereby correcting the output torque of the motor. The method corrects the flux linkage of the permanent magnet of the motor rotor affected by temperature to achieve the purpose of compensating the output torque of the motor. The algorithm is simple and does not need to increase the load rate of the single-chip microcomputer of the on-board controller to ensure the control performance of the whole vehicle.

Description

technical field [0001] The invention relates to a method for correcting the output torque of a permanent magnet synchronous motor affected by temperature. Background technique [0002] With the gradual popularization of new energy vehicles on a global scale, permanent magnet synchronous motors are widely used in the transmission of new energy vehicles due to their high power density, high efficiency, small size and light weight. system. [0003] But because the permanent magnet material in the rotor is made of magnetic steel, permanent magnet synchronous motors also have some disadvantages. For example, under the condition of the whole vehicle, the car must be able to operate normally in various extreme weathers, and the range of the working environment temperature of the motor is often designed to be very wide (for example, from -40°C to 120°C), but according to the hysteresis loop, it can be seen that , The magnetic flux density of the rotor permanent magnet magnet steel...

AI Technical Summary

Problems solved by technology

However, the mature and available algorithms are often more complicated. Considering the limited computing power of the single-chip microcomputer used by the vehicle-mounted controller, most algorithms increase the load rate of the single-chip microcomputer and affect the computing efficiency of the single-chip microcomputer of the vehicle-mounted controller.

Images