Research On Harmonic Suppression Scheme Of Weighted Active Power Filter Based On Ray Network

In the distribution network,the harmonic voltage generated by the penetration of the superior grid and the harmonic current generated by the nonlinear load will seriously damage the electrical equipment and the grid system.In order to solve the resonance problem of voltage and current in the distribution network due to the existence of background harmonics,the resistive active power filter(R-APF)analyzes and studies its control method from the perspective of the transmission line,and obtains the current reference through the voltage detection of the installation point port signal.The VI-APF control method further divides the compensation signal into two parts,voltage and current,and performs frequency division adjustment for specific sub-harmonics.In order to reduce the complicated theoretical derivation and control method of R-APF and VI-APF,this dissertation proposes a weighted active power filter(W-APF,Weighted active power filter).In view of the incompleteness of R-APF analysis and the complexity of VI-APF calculation,this paper replaces the load in the schematic diagram of the series active power filter with a 9km distribution network transmission line,which is characterized by an equivalent long-distance transmission line.The current and voltage signals are taken from the end of the line,that is,the W-APF installation point,and weighted control is performed according to the weighting coefficient derived from the detection current control mode and the detection voltage control mode.The method has a simple theoretical derivation process,few variable parameters,and has an inhibitory effect similar to VI-APF.This dissertation compares the system overshoot and overshoot time of different PI controller parameters by writing the m function,and obtains more appropriate PI parameters after simulation and debugging.It can be known from related literature that only 6k±1(k is a positive integer)harmonics flow into the power grid,and the higher the harmonic order,the lower the content.Therefore,for the 5th,7th,and 11 th harmonics with a lot of content in the power grid,three kinds of harmonics with different orders are selected for simulation verification.Finally,the simulation results show that the weighted control strategy proposed in this paper can suppress the total harmonic distortion rate of each node in the transmission line to a lower level.Finally,this dissertation builds a 9km transmission line model,verifies the existence of background harmonic phenomenon amplification through the transmission line no-load test,builds a weighted active power filter platform based on DSPTMS28335 control,and verifies that the weighted control method is effective in long-distance transmission lines the effectiveness of harmonic suppression.