Hybrid excitation synchronous motor sensorless direct torque control method

Abstract

The invention discloses a hybrid excitation synchronous motor sensorless direct torque control method. A sliding film observer is used for estimating the rotating speed and the initial position of a hybrid excitation synchronous motor, and the general control idea is based on the direct torque control method. The motor operation area is judged according to the rotating speed, the motor runs in a low-speed area, id=0 is adopted for control, and when the load torque is smaller than or equal to the rated torque, magnetism increasing control is not needed; when the load torque is larger than the rated torque, magnetism increasing control is conducted. When the motor runs in a high-speed area, magnetism weakening control is adopted, id=0 is kept firstly, magnetism weakening is conducted through excitation current if, and when the magnetism weakening if reaches the rated value, the d-axis current id is used for magnetism weakening. According to the hybrid excitation synchronous motor sensorless direct torque control method, cost is reduced, and the reliability and the fast torque responding capability of a driving system are improved.

Description

technical field [0001] The invention belongs to the technical field of electric transmission, and relates to a direct torque strategy without a position sensor, in particular to a control method for a hybrid excitation synchronous motor. Background technique [0002] Hybrid excitation synchronous motor is a kind of wide speed regulation motor developed on the basis of permanent magnet synchronous motor and electric excitation synchronous motor. Its main purpose is to solve the problem that the air gap magnetic field of permanent magnet synchronous motor is difficult to adjust. The hybrid excitation synchronous motor has two excitation sources, one is permanent magnet and the other is electric excitation. The magnetic potential generated by the permanent magnet is the main magnetic potential, and the magnetic potential generated by the excitation winding is the auxiliary magnetic potential. This motor combines the advantages of permanent magnet synchronous and electric excita...

AI Technical Summary

Problems solved by technology

The advantage of the above control strategy is continuous control, which is relatively smooth; the disadvantage is that the torque dynamic response is not fast enough, and the rotation coordinate transformation is required, which is more complicated

Due to the presence of sensors, the control system is more expensive, prone to failure, and less reliable

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