Solid state power frequency changers are used for various purposes.The usual practice to get variable frequency power source is to use rectifier-inverter combination.Unfortunately the conventional diode/thyristor bridge rectifiers at the input side cause several problems such as: low input power factor, considerable harmonic distortion of ac currents and harmonic pollution on grid. The PWM rectifier is a preferred choice for providing ac to d.c conversion, due to its capability of input p.f regulation, line harmonic current mitigation, d.c voltage control and bidirectional power flow.In this...