Design And Control Strategy Research Of Shunt Hybrid Active Power Filter

In the harmonic pollution problems,it was considered that the power electronicdevice-Parallel APF developed most perfectly,but the parallel APF existshortcomings that compensating the similar size harmonic,prototype capacity isbiger,switching devices cost higher and so on.This study is a transformer-freeparallel mixed-APF,combination of shunt APF and passive filter.This kind ofappliance does not have the transformer,the active capacity is small,moreover theLC filter in the high frequency place performance are the high impedance,it alsohas omitted the high frequency ripple filter and has saved the cost greatly.Firstly，it describes research background,significance and development ofhybrid APF,followed by analysis of parallel-hybrid APF harmonic compensationprinciple and fundamental, characteristic.Than it describes the parts of a parallelhybrid APF circuit parameters design and calculation of the capacity of the sourcepart, and so on.In order to realize the accurate compensation,it described the two bigproblems,namely,the harmonic current detection and control strategies.Harmonicdetection mainly is based on the instant reactive power theory,using the ip-iqalgorithm.For control strategy,this article has with emphasis studied the electricalnetwork electric current reaction control as well as based on the instantaneousvalue feedback ring combined with the repetitive control outer loop of double loopcontrol strategy.Power current feedback control is based on analysis of mechanismof parallel hybrid APF,equivalent the active part to a feedback gain k,and byadjusting the k controls compensation effection. Simulation and experimentindicate that this method has a certain effect, has been basically the grid currentcompensation for the sine wave. According to that the grid current feedback controlexsits small compensation bandwidth,steady state error,it puts forward doubleclosed-loop control strategy based on repetitive control and p control who is a loopsystem,we can design repetitive controller in terms of both the amplitude and phasecorrection.The simulation and the experiment proved that, the effect of this methodof compensation is extremely good,and it send wave accurately,compensated gridcurrent harmonic distortion is reduced to2.3%.Moreover,using this method,the system dynamic characteristic extremely is also fine,and the usability is very good.At last,it built the prototype design,and analyze the hardware and softwaredesign of the prototype.