Three-level NPC inverter based new DSTATCOM topologies and their performance evaluation for load compensation

Now-a-days for effective load compensation, a conventional three-level neutral point clamped (CNPC) inverter topology is more preferably used. This compensator, however, faces the problems of additional clamping diodes, which reduces the redundant switching states and improves the problem of capacitor voltage imbalance; further increasing the inverter cost. In this paper, a detailed analysis of conventional NPC voltage source inverter (VSI) based Distribution Static Compensator (DSTATCOM) is given for shunt applications and to overcome its limitations, Conergy NPC and Active NPC VSI based new DSTATCOM topologies are proposed, exclusively for the load compensation. To demonstrate the effectiveness of the aforementioned topologies for shunt compensation, a three phase four wire system has been taken into consideration. Instantaneous symmetrical component theory (ISCT) is used for reference current generation, while, the hysteresis current control pulse width modulation (PWM) is used to generate the switching sequence for all the NPC configurations. A detailed simulation study has been carried out in MATLAB environment and the comparative evaluation of all the above DSTATCOM topologies is being provided.