Research Of Shunt Active Power Filter Compensation In Three-phase Three-wire System Based On Predictive Control

Along with electric power electron and Semiconductor Technology development, each kind of non-linear equipment massive uses, cause the electrical energy quality to worsen, for links and so on electric transmission, power distribution have caused the inestimable losses. The active electric power filter have the overtone real-time track compensation, the dynamic performance good, the compensation precision higher merit, has received the extensive research and the attention.This article mainly conducts the research to the active power filter, uses traditional in the harmonic current examination link under the instant reactive power theory i_p-i_q algorithm, because this method is good to the harmonic current track performance, became in active power filter the main examination harmonic current method, in the article to affects the algorithm precision two important link phase-locked loop and the numeral low pass filter has carried on the design, through to many kinds of filter performance comparison, selected in the precision and the speed of response most superior filter. The active power filter compensation there is the problem of the lagging in the text with the Predictive Control Method for the payment of compensation for current predictive control to a more traditional single-step forecast, and cannot be completely eliminated compensation delay, the two concepts forecasting methods, not only can be used to eliminate inverter action lag time, you can also eliminate detection latency, the issues raised in the Lagrangian, the value prediction and improved repeat control methods. The dc side capacitor voltage stability control to start, in order to prevent shock current is too large, the capacitance and current transformer primary circuit damage, with soft-start the DC side capacitor charge; in the context of compensation, in order to assure the DC side voltage stability, PI controller adjust the DC side capacitor voltage stability. And, in order to monitor whether active power filter can fully compensate grid harmonics, detect active power filter is working properly, that the active power filter, remote monitoring, security, and so on. This document uses active power filter and high-precision harmonic test combination of methods, in high-precision harmonic analysis for FFT exists for the problems that exist in a Kaiser pane double-line interpolation of the FFT algorithm, and the value function structure complex difficult to solve the problem, and has proposed a cubic spline interpolation fitting the value function methods to improve analytical accuracy.