CN103166568A - Pulse-width modulation (PWM) alternating current (AC) variable frequency speed regulating master control circuit - Google Patents

Abstract

The invention relates to a pulse-width modulation (PWM) alternating current (AC) variable frequency speed regulating master control circuit. In the field of electric drive, with the continuous improvement of the technological level of a self turn-off device, PWM technology increasingly matures as well, PWM AC variable frequency speed regulating has the advantages of being high in efficiency, high in power factor, good in output waveform, simple in structure and the like, and thus PWM AC variable frequency speed regulating is widely used in equipment such as an underground draught fan, a water pump and a paper machine. The PWM AC variable frequency speed regulating master control circuit comprises a rectification filter circuit, a three-phase inverter circuit and a singlechip. An AC power supply is connected with a three-phase asynchronous motor through the rectification filter circuit and the three-phase inverter circuit. A control loop of the rectification filter circuit sequentially passes through a detection circuit, a protective circuit, the singlechip, a sine PWM wave generator and a drive circuit and is output to the three-phase inverter circuit. The protective circuit is connected with the drive circuit. According to the PWM AC variable frequency speed regulating master control circuit, the singlechip is adopted, the circuit is simplified, arithmetic speed is fast, precision is high, a memory cell with large capacity is used, complex control can be achieved, zero drift does not exist, and control precision is high.

Description

PWM ac variable frequency speed regulation governor circuit

Technical field

The present invention relates to a kind of PWM ac variable frequency speed regulation governor circuit.

Background technology

In the electric drive field, along with improving constantly of self-turn-off device technical merit, pulse modulation technology (being called for short the PWM technology) also reaches its maturity, the PMW ac variable frequency speed regulation is widely used in the equipment such as Underground Fan, water pump, paper machine with its high efficiency, High Power Factor, good output waveform, advantages of simple structure and simple.

Summary of the invention

Technical problem solved by the invention is to provide a kind of PWM ac variable frequency speed regulation governor circuit.

For solving above-mentioned technical problem, the technical scheme that the present invention takes:

A kind of PWM ac variable frequency speed regulation governor circuit, its special character is: comprise current rectifying and wave filtering circuit, three-phase inverting circuit, single-chip microcomputer, AC power is connected with threephase asynchronous by current rectifying and wave filtering circuit, three-phase inverting circuit, and circuit, protective circuit, single-chip microcomputer, sinusoidal pulse width modulation wave producer, drive circuit output to three-phase inverting circuit to the control loop of current rectifying and wave filtering circuit after testing successively; Protective circuit is connected with drive circuit.

Above-mentioned single-chip microcomputer adopts the AT89C51 model.

Compared with prior art, the present invention adopts single-chip microcomputer to simplify circuit, fast operation, and precision is high, and jumbo memory cell is arranged, and can realize comparatively complicated control, the inferred-zero drift, control precision is high.

Description of drawings

Fig. 1 is circuit block diagram of the present invention.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

Referring to Fig. 1, the present invention includes current rectifying andwave filtering circuit 4, three-phase invertingcircuit 5, single-chip microcomputer 1, AC power is connected with threephase asynchronous by current rectifying andwave filtering circuit 4, three-phase invertingcircuit 5, andcircuit 3, protective circuit 2, single-chip microcomputer 1, sinusoidal pulse widthmodulation wave producer 7,drive circuit 6 output to three-phase invertingcircuit 5 to the control loop of current rectifying andwave filtering circuit 4 after testing successively; Protective circuit 2 is connected withdrive circuit 6.

Above-mentioned single-chip microcomputer 1 adopts the AT89C51 model.

Claims (2)

1. PWM ac variable frequency speed regulation governor circuit, it is characterized in that: comprise current rectifying and wave filtering circuit (4), three-phase inverting circuit (5), single-chip microcomputer (1), AC power is connected with threephase asynchronous by current rectifying and wave filtering circuit (4), three-phase inverting circuit (5), and circuit (3), protective circuit (2), single-chip microcomputer (1), sinusoidal pulse width modulation wave producer (7), drive circuit (6) output to three-phase inverting circuit (5) to the control loop of current rectifying and wave filtering circuit (4) after testing successively; Protective circuit (2) is connected with drive circuit (6).

2. a kind of PWM ac variable frequency speed regulation governor circuit according to claim 1, is characterized in that: described single-chip microcomputer (1) employing AT89C51 model.

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