Harmonic Detection And Suppression Of Civil Grid

In recent years, the rapid development of active power filter and control algorithmmakes it one of the important devices,which is used to process harmonic andcompensate grid.Compared with other traditional filer,it has many favorite workcharacteristic like real-time, response，high accuracy and dynamic compensation．For widespread civilian power grid voltage instability, three-phase unbalance andneutral current big issues, this article focuses on the three-phase four-wire parallel activepower filter and establishes a mathematical model structures. The traditional methodsbased on the instantaneous reactive power theory exists error in dealing with theirproblems, this paper utilizes the combination of symmetrical components、zero-sequencecurrent separation and PI regulator to establish new mathematical model and theimproved algorithm to detect civilian power grid harmonic current and reactive currentbased on its theoretical foundation, lay the foundation for the accuracy of the activepower filter compensation. For the space vector analysis of the output voltage of theshunt APF, the paper used a three-dimensional space vector pulse width modulationalgorithm (3D-SVPWM), which greatly reduces the switching frequency and is wellcompensated neutral current, convenient and simple algorithm, easy to implement. Thetraditional3D-SVPWM algorithm is based on coordinates，is complicated,needs largecalculation and is prone to error. However, this article use3D-SVPWM based on abccoordinate, which requires little amount of calculation, avoids the complicatedcoordinate transformation and is practiced easily calculationsThe algorithm is simulated through MATLAB/SIMULINK simulation and theresults verify the correctness and effectiveness of the program．...