An efficient technique for DC capacitor voltage balancing by using space vector modulated three-level STATCOM

Abstract

A space vector modulation (SVM) based maneuver for a three-level neutral point clamped (NPC) inverter that is habituated as a static synchronous compensator (STATCOM) is presented. The significant attribute of the proposed SVM switching maneuver is that it enables efficient control in the voltage balancing of the DC capacitors while compensating reactive power demand by the load in power system and initiating best voltage regulation with no prior auxiliary devices or any other controlling devices. In the proposed scheme, the most appropriate length of the vector is calculated for which reactive power exchange takes place while maintaining the balance between capacitor voltages. A dynamic model of three-level STATCOM and its performance is demonstrated in MATLAB/Simulink environment. The studies reveal the capabilities of the SVM based maneuver to maintain the capacitor voltages of the three-level NPC under various operating scenarios.