A Look at DC/DC boost converter topology and balancing of DC-voltage capacitors of 3-level NPC inverter in 7MW PMSG Hydraulic Energy Conversion Chain

This paper treats in detail the performance process of an optimal full power converter topology that's suitable for direct driven megawatt hydraulic energy conversion system. Simulation results approve the high efficiency of the suggested topology using the three-phase uncontrolled rectifier plus three level boost converter 3L-DC/DC followed by three-level neutral-point clamped inverter (3L-NPC) and its control strategy. Since it can be rise greatly the settling time to reach quickly the steady state and progress more waveforms outputs of 3L-NPC inverter. Furthermore, this topology has advantage to reduce the voltage stress of the switches which involves low maintenance cost and longer life span. However, the problem of (3L-NPC) DC capacitors voltage unbalance is realized through the 3L-DC/DC boost converter control.