Digital controller of single-phase alternating current motor

Abstract

The invention discloses a digital controller of a single-phase alternating current motor, comprising a micro controller unit (MCU), a power circuit which is connected with the MCU, a zero cross detection circuit, an information display circuit, an information input circuit, a speed feedback circuit and a motor actuation circuit, wherein the power circuit, the zero cross detection circuit and the motor actuation circuit are connected with an alternating current power supply; and the speed detection circuit and the motor actuation circuit are connected with the single-phase alternating current motor. A closed-ring control loop is formed by acquiring the real-time speed of the single-phase alternating current motor and the set reference speed, a pulse signal with a certain dutyfactor is output by integrating an acquired alternating current power zero cross signal to control the on and the off of controllable silicon, and control all types of rotation of the single-phase alternating current motor, such as forward rotation, reverse rotation and stopping; the pulse signal with a certain dutyfactor is output to control the on and the off of the controllable silicon, so that the component of the direct current is distributed to the single-phase alternating current motor so as to realize braking; and intense current and weak current are isolated through a coupler and a transformer, so that the intense current and the weak current do not interfere with each other, and the stability of the loop is ensured.

Description

technical field [0001] The invention relates to the technology in the field of AC motor drive control, in particular to a digital controller for a single-phase AC motor. Background technique [0002] With its simple structure, low cost, excellent performance, high reliability and easy maintenance, AC motors are widely used in various industries, such as household appliances (washing machines, refrigerators, electric fans), power tools (such as hand drills), Medical equipment, automation instruments, etc. [0003] In the prior art, commonly used AC motor drive controllers include frequency conversion control and voltage control. The frequency conversion control method is to change the speed of the motor by adjusting the frequency of the alternating current. The frequency conversion speed regulation is easy to realize the forward and reverse rotation of the motor by changing the switching sequence of the internal inverter tube, and the acceleration and deceleration time can b...

AI Technical Summary

Problems solved by technology

This control method is simple, but it cannot automatically change the forward and reverse directions, nor can it realize the function of sudden rotation and emergency stop. It can only control the speed simply, and the speed control accuracy is not high. The analog control method also makes it impossible to isolate the strong and weak currents, which is easily disturbed and the components are easily damaged.

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