Control of AC–DC grid side converter with single AC current sensor

Abstract

Conventionally, two AC side current sensors are needed in vector control of grid side converter for AC-DC bidirectional power conversion. The present paper proposes a technique where the control can be achieved with the use of only one AC side current sensor. The control principle utilises the information of unsensed second current sensor for its estimation, which is embedded and readily available in conventional control technique itself. In the proposed method, the grid side d-q axis reference currents of the current controllers are used for estimation of b-axis component of grid current, while the a-axis component of grid current is calculated by one AC side current sensor. Effect of voltage unbalance on the control is also studied in this paper. The proposed control is validated with detailed simulation and experimental observations for both steady-state and transient conditions. The proposed control gives satisfactory performance.