Modeling and Control of Current-Source Converter-Based AC Microgrids

This paper addresses the integration of renewable energy sources (RESs) into ac microgrids using current source converters (CSCs). A proportional-and-integral (PI) current controller is designed and implemented in the inner-most loop to regulate the interfacing converters through a vector control strategy. A PI ac voltage controller is then tuned to regulate the common ac bus voltage. In the outer-most loop, a power sharing scheme is implemented using active and reactive droop control to share the common ac loads. The design procedures for the system controllers is presented in detail. Unlike the commonly utilized voltage source converters (VSCs), it is shown that CSC-based ac microgrids have a superior performance against severe faults conditions. Time-domain simulations are developed within the Matlab/Simulink environment to show the effectiveness of CSC-based ac microgrids when compared to VSC-based microgrids.