Digital control system of asynchronous motor soft starter

Abstract

The invention relates to a digital control system of an asynchronous motor soft starter. The digital control system comprises a synchronous signal detection circuit, a thyristor control module, a contactor, an electromotor signal detection module, a complex programmable logic device (CPLD) trigger pulse generation circuit and a digital signal processor (DSP) master control circuit, wherein the synchronous signal detection circuit is arranged on a three-phase power supply; the thyristor control module is connected with the three-phase power supply and an electromotor respectively; the contactor is connected with the three-phase power supply and the electromotor respectively; the electromotor signal detection module is connected with the electromotor; the CPLD trigger pulse generation circuit is connected with the synchronous signal detection circuit and the thyristor control module respectively; and the DSP master control circuit is connected with the CPLD trigger pulse generation circuit, the contactor and the electromotor signal detection module respectively. Compared with the prior art, the digital control system has the advantages that a DSP and a CPLD is combined, the running efficiency and the control accuracy of the system are improved, the stability, the interference resistance and the security of the system are enhanced, and the digital control system has high universality and maneuverability.

Description

technical field [0001] The invention relates to an asynchronous motor soft starter, in particular to a digital control system of the asynchronous motor soft starter. Background technique [0002] With the increase of motor voltage and capacity, the impact of high current caused by direct starting on the motor and the power grid is also increasing, which seriously affects the service life of the motor and brings great harm to the power grid. Thyristor soft start technology came into being and made great progress. Through the thyristor phase-controlled voltage regulation technology, the motor voltage can be smoothly increased, thereby reducing the current impact during the starting process and realizing the soft start of the motor. During the soft start process of the motor, the control system needs to accurately calculate the phase control angle and pulse width of the trigger pulse in real time, and output a stable trigger pulse to ensure the reliability of the thyristor pha...

AI Technical Summary

Problems solved by technology

[0003] 1) Use the main control chip software to generate trigger pulses, which need to occupy multiple capture interrupts and timer interrupts, frequent access to interrupts, reduce system stability, and affect the operation of the main program algorithm

[0004] 2) Many soft starters on the market have an 8-segment digital tube display. When more parameters need to be set, the operation is cumbersome and error-prone, and it is not conducive to reading system operating status information

[0005] 3) The traditional control system design scheme needs to design different hardware circuits and software according to the driving mode, which has poor versatility

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