Five-level NPC/H-bridge MLI based electric spring for harmonic reduction and voltage regulation

Electric Spring is new emerging technology for stabilizing future smart grid. Due to integration of renewable energy sources with conventional one, new technological problem arises causing voltage instability in power grid. Electric spring is device which is effective in stabilizing voltage of system in decentralized manner and is more reliable over centralized way. Electric Spring is implemented earlier with using two level inverter, but this paper focused on implementation of Electric Spring using a special type of multilevel inverter i.e. NPC/H Bridge inverter. NPC/H Bridge inverter is further extension of Neutral point clamped inverter (NPC) and show additional effective features over NPC. Simulation is carried out using MATLAB/SIMULINK sucessfully showing comparision of Two-level, Three-level cascaded and Five-level NPC/H-bridge inverter THD's (Total Hormonic Distortion). ES based NPC/H bridge inverter successfully provides superior high frequency harmonic suppression along with improved system THD profile and effective voltage regulation.