Compared with a conventional cascaded multilevel inverter (CMI) using the diode rectifiers and limiting regeneration operation, a four-quadrant CMI using the voltage source PWM rectifiers enables a bidirectional power flow and finds wider application fields than the classical one. A CMI synthesizes a high-voltage output based on series connection of power cells, each consisting of a voltage source PWM rectifier at the line side, a dc capacitor, and a H-bridge inverter at the motor side. Each voltage source ...