Research on Three-Phase Four Wire Inverter Control Based on Double Closed-Loop Control
Three-phase four-wire inverter has better unbalanced load driving ability and is widely used in the field of uninterruptible power supply.For the inverter in this off-grid mode,the voltage and current double closed-loop control mode is usually used to control the output.A voltage and current double closed-loop control without coordinate transformation is proposed to realize the complete decou-pling between the output three phases.Since quasi proportional resonance(QPR)control has better control effect on AC signal,QPR control is adopted for the outer voltage loop and proportional control is adopted for the inner current loop.Experiments show the effec-tiveness of the control method proposed.
three-phase four-wire inverterdouble closed-loop controlquasi proportional resonance controlproportional control