A method for generating a driving waveform of a thyristor rectifier and its driving circuit

Abstract

A generation method of the driving waveform of a thyristor rectifier comprises the following steps that power grid voltage signals are collected, and a phase-locked loop follows power grid voltage and outputs a sinusoidal signal the same with the power grid voltage in direction; a reference waveform corresponding to a thyristor drive bridge arm is obtained by calculation according to the sinusoidal signal; the difference between the actual zero time of the reference waveform and the corresponding PWM break time is calculated; according to the time difference, the PWM break time is adjusted, so that a PWM control wave and the reference waveform are synchronous; according to the PWM control wave, a double-narrow pulse drive wave is output to control upper and lower thyristors on the corresponding thyristor drive bridge arm to work. According to the scheme, high-precision PWM control wave emission is achieved, breakover time control on the thyristors is more accurate, and working precision and stability of the thyristor rectifier are improved effectively.

Description

technical field [0001] The invention belongs to the field of electronic circuit control, and in particular relates to a method for generating driving waveforms of a thyristor rectifier and a driving circuit thereof. Background technique [0002] In industrial production, thyristor rectifiers are widely used in AC variable-speed soft-start systems, especially in high-power applications, and their performance directly affects the operating indicators of the system. The driving signal generation circuit is the core control part of the three-phase thyristor circuit. The analog pulse trigger used in the traditional thyristor rectification or inverter system uses multiple analog devices, and the device parameters are scattered. Not only is it inconvenient to debug and use, but also the generated The pulse symmetry is poor, and the analog signal directly controls the pins of the chip, so the interrupt working mode cannot be used, because the interrupt will interrupt the analog wave...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the technical problem that the PWM waveform and the reference sine wave cannot be synchronized in the prior art, and there is a delay error between the actual interrupted wave generation time and the zero-crossing time of the AC sine wave voltage, and provides a thyristor rectifier driving waveform generation method to realize high-precision wave generation of PWM waveform

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