Fuzzy Logic Based VCM and CCM Controlled DSTATCOM for Improved Power Quality

Abstract

Power Quality problems in distribution systems can be solved by providing suitable shunt compensation, one such device is Distribution static compensator (DSTATCOM). Power quality issues generally arise due to high-energy demand loads such as pulse loads. In this paper, a new algorithm is proposed to generate reference voltage for a distribution static compensator (DSTATCOM) operating in voltage-control mode. To eliminate high-frequency switching components, three filter capacitors, one for each phase are to be connected in parallel with the DSTATCOM. Dead-beat controller is used to control and maintain the voltage across filter capacitor at the AC bus voltage. The magnitude of the bus voltage is chosen as nominal value, i.e., 1.0 p. u. To maintain the voltage across the DC storage capacitors constant, the required phase angle is obtained through a feedback loop. The proposed scheme ensures unity power factor (UPF) across the load terminals during nominal operation which is not possible in the traditional method. The compensator injects small currents thereby reduces the losses in the feeder and also in the voltage source inverter. The state-space model of DSTATCOM is incorporated with the deadbeat predictive controller for fast load voltage regulation during voltage disturbances. DSTATCOM here proposed provides power factor correction, harmonic elimination and thus tackles power-quality issues. The simulation results in MATLAB

/SIMULINK platform are presented for the load balancing and voltage regulation of the same using the fuzzy logic controller.