Surface-mounted permanent magnet synchronous motor sensorless direct torque control method

Abstract

The invention discloses a surface-mounted permanent magnet synchronous motor sensorless direct torque control method. The method comprises a direct torque control method based on SVPWM and a flux linkage self-adaptive method, a novel method for estimating the positions and the rotating speed of rotors by a sliding mode observer and a novel compound control method which is suitable for self-detecting the positions of the rotors within a full speed range. According to the surface-mounted permanent magnet synchronous motor sensorless direct torque control method, the problem that in traditional SVPWM direct torque control, straight-axis currents are large when a motor is operated in a no-load state or under the condition that the heavy load is suddenly applied is fundamentally solved, the buffeting problem of a traditional sliding mode observer is solved, the phase delay problem of the traditional sliding mode observer caused by a low pass filter is solved, and estimation accuracy of the positions of the rotors when the motor is operated is improved. In addition, the problem that the positions of the rotors are inaccurately estimated when the motor is operated in a low speed and standstill mode is further solved, and the sensorless self-starting function can be achieved.

Description

technical field [0001] The invention relates to the field of permanent magnet motor control, in particular to a direct torque control method for a surface-mounted permanent magnet synchronous motor without a position sensor. Background technique [0002] Surface-mounted permanent magnet synchronous motors have the advantages of high power density, high efficiency and easy maintenance, and are widely used in the fields of electric vehicle drive and ship propulsion. These fields have high requirements on the dynamic performance of motor drive technology, hoping to get a response in the shortest time. Compared with vector control, direct torque control has the advantages of fast torque response, simple system structure and strong robustness to parameter changes. However, compared with vector control, the traditional direct torque control has larger torque and flux linkage fluctuations and the switching frequency of the inverter is not constant; since SVPWM can provide unlimite...

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Problems solved by technology

[0004] In view of the above existing technologies, a position sensorless direct torque control method for surface-mounted permanent magnet synchronous motors is proposed, which solves the problem of direct-axis current when the motor is running at no load or suddenly loaded with heavy loads in the traditional SVPWM direct torque control. Big problem; improved the chattering problem existing in the traditional sliding mode observer, and solved the phase delay problem caused by the low-pass filter in the traditional sliding mode observer, and improved the estimation accuracy of the rotor position when the motor is running; In addition, it also solves the problem of inaccurate rotor position estimation when the motor is running at zero and low speed, and can realize the self-starting function without position sensor

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