Research On The Parallel Hybrid Active Power Filter Used As A Way To Prevent Harmonic Resonance

Nowadays,harmonics contamination become more and more severe problems in power distribution system because of the ever-increasing nonlinear loads,such as converter,variable speed drivers,arc fumace,etc.Active power filter,an effective solution,have been widely researched and developed in the recent years.A parallel byhrid active power filter is proposed in this paper,based on the preventing harmonic currents.The theory of harmonic detecting,the control strategy is fully anlysized.The content contains:1.A novel structure of parallel hybrid active power filter is proposed.lt consists of Passive Filter(LC) and Active Power Filter(APF).Passive filter compensate a majority of harmonic currents.Function of APF only compensate a few harmonic current and prevent harmonic resonance.The power of level of APF is very small because of avoiding to based voltage. 2. The problem of harmonic currents amplied are anlysized in passive filter system.the conditions of harmonic resonance are detailly discussed in this paper.and the simulation results demonstrated the problem of harmonic currents amplied.3.Two different methods of harmonic currents detecting are introduced based on the fully analyzing instantaneous reative power theory.These two harmonic currents detecting methods are compared in this paper.4.Some basic problems of Variable Structure Control(VSC) are introduced.A novel control method is proposed:Learning Variable Structure Control(LVSC) based on VSC.this control method is simply anlysize.5. The control method adopt Integrated Learning Boost Converter Control method by virtue of the characteristic of hybrid active power filter based on LVSC,this control method is detailly anlysize and convergence characteristic are educed. 6. The simulation results of the whole system are successfully completed.