Control strategy applied to high speed motor

Abstract

A traditional three-phase bridge type inverter circuit in control manners of a high speed motor has high switch frequency, large loss and large possibility of device failure. The invention provides an optimized control strategy for a high speed motor, which settles the loss problem caused by high switch frequency and enhances the efficiency and the reliability of a system. The circuit of the highspeed motor is characterized in that a chopping tube and a follow current tube are additionally arranged in front of a three-phase inverter circuit of a conventional motor. The chopping tube adopts a power switch tube with high switch frequency, and the control for the rotating speed of the motor is realized by performing high frequency chopping on the power switch tube; and the follow current tube adopts a diode with short backward recovery time to realize follow current. As to the control method, the power tube adopts high frequency modulation, the turn-on interval of all the power tubes of the three-phase circuit is an electrical angle of 120 degrees, the power tubes are turned on and off once upon every electrical angle of 360 degrees, and phase conversion is performed on the state of follow current.

Description

technical field [0001] The invention relates to a control strategy of a high-speed motor, which belongs to the motor control technology. Background technique [0002] With the demand for high-speed motors in military industry and civilian use, high-speed motors have become one of the research hotspots in the field of electrical engineering at home and abroad. High-speed motors usually refer to motors with a speed exceeding 10,000r / min. Their main features are high speed, small size, and high power density. They are widely used in many fields, such as high-speed grinding machines, high-speed gyroscopes, high-speed flywheel energy storage systems, high-speed centrifuges compressor etc. [0003] Since the end of the last century, developed countries such as the United Kingdom and the United States have carried out research on high-speed motors. The 5MW high-speed induction generator researched by the Electromagnetic and Electronic Systems Laboratory of the Massachusetts Instit...

AI Technical Summary

Problems solved by technology

However, high-speed motors work at high speeds, and the corresponding switching tubes have high operating frequencies and large losses.

In the freewheeling stage under high-frequency modulation mode, the current is realized through the body diode or integrated diode of the power switch tube, and the loss is large. The usual power tube body diode has the disadvantage of long reverse recovery time.

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