Research on Unbalanced Current Compensation Control Strategy Based on Neutral Point Clamp Converter

Abstract

The use of distributed generation systems has led to serious power quality problems in low-voltage distribution networks. Low voltage distribuion network power quality needs to be valued. In this paper, a multi-function power converter (MPC) device with balanced three-phase asymmetrical current, reactive power compensation, power factor improvement and harmonic elimination is proposed. The paper introduces a MPC topology which has three-level inverter with a neutral point clamped (NPC) and a voltage balancer (VBC). A new control method combining the network current reference algorithm and PQ decoupling is given in this paper. Finally, the 100kW simulation system is built to verify the effectiveness of the proposed control strategy, which can effectively solve the power quality problems in the low voltage distribution network by using MPC. Some simulation and experimental results are illustrated to show the prototype device’s performance.