MHCC Modulation Technique for CHB Multilevel Inverter Based DSTATCOM

Multilevel inverters have been used for medium and high voltage due to significant advantages over conventional three phase inverters. In this paper switching control of cascaded H-bridge (CHB) multilevel inverter as distribution static compensator (DSTATCOM) is discussed. Multiband Hysteresis Current Control (MHCC) belongs to Non-linear close loop control category. In MHCC compensator current is compared with output current and the closed loop system drives the controller to reduce error between compensator current and output current. For DSTATCOM to compensate reactive power and Harmonics the direct current control theory based on Synchronous reference frame theory (SRFT) is adopted for reference current generation. For balancing dc link voltage across each H-bridge PI controller is tuned to reduce steady state error.