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

Abstract

A correction method of the output torque of a permanent magnet synchronous motor affected by temperature is disclosed. The method calibrates the motor at the normal temperature and the lowest and highest working temperatures of motor operation, the dq-axis currents of the motor under the three temperature conditions are obtained, and the unique combination of dq-axis current i<d> and i<q> of the motor falling on a motor MTPA curve is obtained by looking up a table according to the expected value of the motor output torque as the expected value of the DQ-axis current of the motor vector controlsystem, thereby correcting the motor output torque. The method corrects the permanent magnet flux linkage of the motor rotor affected by temperature so as to achieve the purpose of compensating the motor output torque, the algorithm is simple and the load rate of a vehicle-mounted controller single-chip microcomputer does not need to be improved, and the control performance of the whole vehicle is ensured.

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.

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