A control method and drive system for a three-phase double salient pole brushless DC motor

Abstract

The present invention discloses a control method of a three-phase doubly salient brushless DC motor. The control method is characterized in that a power converter adopts a three-phase full-bridge inverter, the three phase armature windings of the motor are connected with the midpoints of the three phase bridge arms of the three-phase full-bridge inverter respectively and correspondingly, and the three phase armature windings are in star connection. The control method comprises the steps of making a commutation position ahead of an ahead commutation angle than a standard commutation position, lagging a phase current turn-off position a lagging turn-off angle than a standard phase current turn-off position, utilizing a PWM chopped wave to realize the current closed loop control, defining a phase reference current value, defining the positive direction of an excitation current as that the exciting current flows from a power supply to an exciting winding, and defining the positive direction of a rotor as that the rotator rotates along a counter-clockwise direction; obtaining four sets of control logic according to the direction of the exciting current, the rotor rotation direction, the ahead commutation angle and the lagging turn-off angle. The control method enables the output power and the working power of a doubly salient motor to be improved. The present invention also provides a driving system of the three-phase doubly salient brushless DC motor for realizing the above control method.

Description

technical field [0001] The invention belongs to the technical field of reluctance synchronous motor drive, and in particular relates to an asymmetric current control method of a three-phase double-salient pole brushless DC motor and a drive system thereof. Background technique [0002] Double salient pole motor is a novel variable reluctance motor. Its stator and rotor are salient pole structures. There are no windings and permanent magnets on the rotor. Because of its simple and firm structure, reliable operation, low cost, and good robustness, it has many The advantages have attracted widespread attention in the industry, especially in harsh environments and high-speed occasions with broad application prospects. According to different excitation methods, doubly salient pole motors can be divided into permanent magnet doubly salient pole motors, electric excitation doubly salient pole motors and hybrid excitation doubly salient pole motors. The permanent magnet double sali...

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Problems solved by technology

Therefore, after the advance angle control is adopted, the output torque and motor performance can be effectively improved, especially when the speed is high, but this also makes the mechanical characteristics of the motor soft; 3. The three-phase nine-state control method can effectively suppress commutation Torque pulsation generated during the time, increase the output torque, reduce the reverse current of the bus, but the output of the motor still has room for improvement

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