Digital-controlled single-phase unified power quality conditioner nonlinear and voltage sensitive load

Power quality has become an important factor in power systems, for consumer and household appliances with proliferation of various electric/electronic equipment and computer systems. The main causes of a poor power quality are harmonic currents, poor power factor, supply-voltage variations, etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply-voltage variation (sag or swell) at the load side, is presented in this paper. The operation and rating issues of the proposed single-phase unified power quality conditioner are highlighted too. To reduce the total cost, but to increase the performance, the system is fully digital-controlled using the fixed-point TMS320F240 digital signal processor. The performances of UPQC that is composed by shunt and series PWM controlled-converters have been verified on a laboratory prototype.