Parallel active filter control system

Abstract

The invention discloses a parallel active filter control system comprising a non-linear load module, a PWM control circuit and a driving circuit. The output end of the non-linear load module is connected with the input end of the PWM control circuit through a current detection module. The output end of the PWM control circuit is connected with a voltage source inverter through the driving circuit. The current detection module completes the calculation of the harmonic current components of the system according to the non-linear load current and a phase-locked loop output, generates sixe drive pulse signals through harmonic detection and the feedback of a VSI module to control the VSI output current to track and compensate load harmonic current in real time while maintaining VSI DC voltage stability. A band-pass filter is arranged in the forward channel and the feedback loop of a system transfer function in order to achieve good suppression of a resonant peak, thereby ensuring the dynamic response characteristics of the system, and improving the stability of the system.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a parallel active filter control system. Background technique [0002] In recent years, with the massive investment of various nonlinear loads in the power system, the problem of power quality is becoming increasingly serious. As one of the most effective ways to control harmonic pollution and improve power quality, active power filters have gradually become a research hotspot in the field of power electronics. Its filtering effect largely depends on the tracking performance. At present, the tracking control of active power filters based on the voltage source converter topology mainly has two methods: triangular wave current control and current hysteresis control. The former compares the current deviation signal with the high-frequency triangular carrier in real time after being regulated by PI. Although a constant switching frequency can be obtained, the safety and reliability ...

AI Technical Summary

Problems solved by technology

The former compares the current deviation signal with the high-frequency triangular carrier in real time after being regulated by PI. Although a constant switching frequency can be obtained, the safety and reliability of the device are high, but due to many problems such as frequency bandwidth limitation in linear current control, it is difficult to meet the requirements of harmonics. Current Fast Compensation Requirements

Current hysteresis control is a transient feedback system with high precision, fast response, and strong robustness. It can obtain better tracking performance, but the switching frequency fluctuates greatly, and the output filter design is difficult.

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