An automatic calibration method for permanent magnet synchronous motor

Abstract

The present invention relates to the field of pure electric vehicle calibration test, in particular to an automatic calibration method for a permanent magnet synchronous motor, comprising the following steps: Step 1, the dynamometer drags the calibrated permanent magnet synchronous motor to run at a set speed; step 2. Record the maximum torque current point under the set current vector amplitude, i.e. the optimal operating point: step 3, the current vector amplitude increases step by step according to the preset current gradient; Reasonable planning, so that it gradually decreases from 90°, avoiding the current vector angle that is gradually increased from 0° to 90° in the existing method. When the current vector angle is above the base speed, the current vector angle is directly set to 0° and the voltage is insufficient. To adjust the size of the current problem and the problem of motor runaway.

Description

technical field [0001] The invention relates to the field of calibration testing of pure electric vehicles, in particular to an automatic calibration method for a permanent magnet synchronous motor. Background technique [0002] Compared with traditional fuel vehicles, new energy vehicles have outstanding advantages such as energy saving, environmental protection, and no pollution. The new energy vehicle industry has shown a rapid development momentum. The motor and its drive system are the core components of the new energy vehicle powertrain. The permanent magnet synchronous motor has become the first choice for domestic new energy vehicle motors due to its outstanding advantages such as high power factor, high efficiency, good control performance, and small moment of inertia. [0003] In order to give full play to the performance of the permanent magnet synchronous motor, it is necessary to calibrate the corresponding relationship between the torque and current of the moto...

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Problems solved by technology

[0005] 1. The torque measurement process is a necessary step in the current calibration method. The torque value needs to be obtained from external sources such as power analyzers and torque sensors, which puts higher requirements on the equipment required for calibration and increases the calibration cost;

[0006] 2. During the calibration process, the torque value obtained from the external equipment needs to be transmitted to the motor controller with the help of relevant data communication means. The process is complicated, and the torque value obtained by the motor controller inevitably has a delay problem;

[0007] 3. It is difficult to simultaneously consider the calibration of the maximum torque-current ratio below the base speed and the calibration of the maximum torque-voltage ratio above the base speed;

[0008] 4. During the calibration process, the change process of the current vector angle is not properly planned, which leads to the problem of system out of control. Most of the existing methods allow the current vector angle to gradually increase from 0 degrees to 90 degrees. When the current vector angle is above the base speed, the current vector angle Directly setting 0 degrees will cause the problem that the voltage is not enough to adjust the current, causing the motor to run out of control

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