CONTROL OF UNIFIED POWER QUALITY CONDITIONER UNDER GRID VOLTAGE SAG AND NONLINEAR LOADS

Tóm tắt

In this paper, a control scheme based on  feedback linearization (FL) control technique with or without resonant control for unified power quality conditioner (UPQC) which is known as series active filter and shunt active filter, is proposed to compensate both the load voltages 
and grid currents under grid voltage sags and nonlinear loads. A nonlinear model of the system consisting of series active filter and shunt active filter in the dq synchronous reference frames is  derived.  The  load  voltage based  on FL with resonant control  and  grid current controllers 
based on only FL in dq components is designed, depending on series and shunt active filters, respectively.  With  the  proposed  scheme,  the  load  voltages  are  regulated  to  reach  the  rated value and both waveforms of load voltages and grid currents are controlled to become almost sinusoidal,  compared  with  the  proportional-integral  (PI)  controller.  Simulation  results  are given to prove the effectiveness of the proposed method.