3-PHASE 4 WIRE VOLTAGE-CONTROLLED AC LINE CONDITIONER WITH UNITY INPUT POWER-FACTOR AND MINIMIZED OUTPUT VOLTAGE HARMONICS

The paper presents a new high performance AC line conditioner isolatin g any configuration of nonlinear loads for three-phase four wire appli cations. The proposed conditioner is composed of a switch mode rectifi er (SMR) and a ROM based sinusoidal pulse width modulation (SPWM) inve rter. The three-phase half bridge type SMR operates under voltage mode control. No current sensing is required. The inverter is also a half bridge type controlled by a ROM based SPWM modulator. Preoptimised SPW M control patterns rejecting effects of DC link voltage ripples and de ad times are programmed. Owing to the nature of the three-phase scheme , the voltage imbalance problem between the DC link capacitors can be lessened. High quality three-phase AC outputs can be obtained while ne arly sinusoidal input currents are drawn.