Robust Sliding Mode Voltage Control of Three-phase Power System Converter

For the three phase converters, the conventional linear controllers do not provide an efficient and robust control objective because of the uncertainties, nonlinearities, system perturbations and unmodeled dynamics present in the system model. In this article, a sliding mode controller (SMC) is being designed and analyzed for a three-phase converter. The overall control loop is designed in to two separate loops, the outer loop containing control of voltage and the inner loop containing the control of current. In the given controller scheme, the shaping of the supply currents and the regulation of the voltage are obtained simultaneuosly, thus providing a robust response. The proposed controller is analyzed using Matlab/Simulink. The proposed controller consists of two separate parts, the switching part which forces the trajectory to sliding surface, and also the continuous part for the system to be remained on the sliding surface. The designed controller comparison is also done with the classical control technique. The results show good robustness and better stability of the overall system over a larger operation range with the designed SMC controller.