Current control method for automatically judging current state of switch reluctance motor

Abstract

The invention discloses a current control method for automatically judging the current state of a switch reluctance motor. The method comprises the following steps: judging whether the reluctance motor is in an electric state or a generating state by judging the relation between the actual current of a phase coil winding and upper and lower given currents; then controlling the on / off of switch tubes inside a power switching circuit according to the result of the judgment, alternately turning off a single switch tube to limit current when the reluctance motor is in the electric operation state,and turning off two switch tubes when the reluctance motor is in the generating state to feed back energy to a bus capacitor, so that overcurrent faults caused by the fact that the off of the switchtubes is not controlled in time are avoided. The judgments for the electric and generating states depend on current signals, and external signals are not needed, so that the circuit structure is simplified, and the operation efficiency is improved.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a current control method for automatically judging the current state of a switched reluctance motor. Background technique [0002] The switched reluctance motor has a simple structure and a large starting torque, and is widely used in presses and other fields. The torque of the switched reluctance motor is realized by controlling the current of the winding, and the control of the winding current is realized by controlling the opening and closing of the switching element connected to the winding. The current control method can be PWM voltage chopping control or current feedback control. Commonly used switched reluctance motors have two switching devices per phase winding. When the two switches are closed at the same time, a positive voltage is applied to both ends of the winding, and electric energy flows from the power supply to the motor; when both switches are turned off, a negati...

AI Technical Summary

Problems solved by technology

In actual work, the switched reluctance motor will change from the motoring state to the power generation state, and the controller does not judge and deal with it in time. Because the current chopping method is still in the motoring state, the winding current is out of control, resulting in an overcurrent fault.

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