Parallel single-phase H-bridge cascade type active electric power filter control device and method thereof

Abstract

The invention discloses a parallel single-phase H-bridge cascade type active electric power filter control device and a method thereof. A DC voltage equalization control unit detects the DC side voltage of the H-bridge power unit of a cascade type active electric power filter, outputs the phase correction of a reference voltage signal to an output compensation current control unit, and outputs an active current to a reference compensation current calculating unit; the reference compensation current calculating unit detects a bus current, performs sinusoidal signal integration and bandpass filtering processing on the bus current, and calculates a reference compensation current according to instantaneous power and the active current; and the output compensation current control unit, according to the phase corrections of the reference compensation current and the reference voltage signal, obtains the reference voltage signal of the H-bridge power unit and obtains the driving signal of the power unit. By using the device and method provided by the invention, system resonance can be effectively inhibited, reference compensation current calculating exerts no influence of time delay and attenuation on fundamental wave signals, harmonic wave components and DC biases can be well inhibited, besides, the calculating is simple, the precision is high, the implementation is easy, and the versatility is high.

Description

technical field [0001] The present invention relates to a power filter control device and its method, in particular to a parallel-connected single-phase H-bridge cascaded active power filter (Active Power Filter) applied in the field of power electronic harmonic control and reactive power compensation. Filter, APF) control device and its method. Background technique [0002] With the wide application of power electronic equipment, the harmonic pollution in the power grid is becoming more and more serious. At the same time, the power factor of most power electronic equipment is low, which brings additional reactive load to the grid. Therefore, suppression of harmonics and improvement of power factor have attracted widespread attention. In recent years, with the rapid development of rail transit, the impact of large-capacity single-phase loads represented by traction power supply systems on power quality has become increasingly prominent. Other single-phase loads in the pow...

AI Technical Summary

Problems solved by technology

[0011] (1) All control algorithms need to use a phase-locked loop and a low-pass filter, and the phase-locked loop and low-pass filter have an important impact on the accuracy and real-time performance of the detection algorithm. Frequency fluctuations and voltage distortion will affect the phase-locked loop accuracy, the time delay introduced by the low-pass filter will also reduce the real-time performance of APF compensation;

[0012] (2) Some of the control strategies in the prior art are more complex and have a large amount of calculation, which are limited to theoretical research, and the feasibility of realization needs to be further verified;

[0013] (3) Some control algorithms in the prior art are not universal enough, parameter setting is difficult, and are not suitable for the control requirements of cascaded APF;

[0014] (4) Some control algorithms in the prior art do not consider the influence of voltage distortion on APF performance; and no relevant research is carried out on the DC bias of the detection signal

[0015] (5) Most of the APF control strategies in the prior art need to detect the load current, which does not meet the actual working conditions in high-voltage and large-capacity applications

From the perspective of the power grid, the control strategy for detecting load current is actually an open-loop control, and the compensation effect is not ideal

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