Delta-connected cascaded H-bridge converter application in unbalanced load compensation

This paper presents the application of a Delta-Connected Cascaded H-Bridge Converter in unbalanced load compensation. The compensation includes positive sequence reactive power current and negative sequence current compensation. The controller designed based on the detail power flow analysis which can achieve dc capacitor voltage balancing control by zero sequence current injection even when compensating the negative sequence current. But zero sequence current injection may cause high peak phase current which may break converter switches. This paper also proposed Peak Current Limit Control (PCLC) in delta-connected cascaded converter. Laboratory and Simulation test results are provided to validate the proposed PCLC method.