Nine-state control strategy for three-phase electrically excited doubly salient pole motor

Abstract

The invention provides a nine-state control strategy for a three-phase electro-magnetic doubly-salient motor. According to the nine-state control strategy, counter emf of the motor is fully utilized, the positive onset interval of each phase of the motor is prolonged, the electrical angles of the positive onset intervals of all phases exceed 120 degrees, nine working states are formed in one electrification period, the electric current change rate of a phase winding is increased when commutation of the motor is conducted, the up-down power tube dead-time is eliminated while the positive onset intervals of all the phases are prolonged, and a torque gap generated by excitation reluctance is offset through the generated phase torque; for the problem that the three-phase electromagnetic property of the electro-magnetic doubly-salient motor is not symmetrical, the positive onset intervals of all phases are optimized, so that the motor torque peak is restrained, the motor torque valley value is increased, and the torque pulses are reduced.

Description

technical field [0001] The invention relates to a starting system for a three-phase electric excitation double salient pole motor, which belongs to the technical field of special motors and motor control. Background technique [0002] Three-phase electrically excited double salient pole motor (hereinafter referred to as double salient pole motor) has a simple and reliable structure, high power density and flexible control, and is suitable for use in high-demand fields such as aerospace. When a doubly salient motor operates as a motor, its control system is similar to that of a brushless DC motor. Compared with other types of motors, doubly salient motors have a larger torque-to-current ratio, but due to their own structural characteristics, their torque ripple rate is also larger than other types of motors, resulting in loud noise, severe vibration, and Problems such as large speed fluctuations limit its application range to a certain extent. [0003] At present, the main ...

AI Technical Summary

Problems solved by technology

However, in the current on-off control strategy, for the sake of convenient operation, system simplification, and the difficulty of writing control programs, and based on the assumption that the motor structure is symmetrical, the three-phase on-off and off angles are all set to the same size , which will make the peak torque of each phase different, and a more obvious torque peak will appear

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