A novel indirect current control for single-phase PWM rectifier at low switching frequency

This paper presents a novel indirect current control technique applied to a Single-Phase PWM rectifier to increase power factor and reduce harmonic current. It is applied to railway traction converters with low switching frequency, high voltage and high power. To get better stability and easier realization, indirect current control scheme is used in the inner loop control. Much computing such as extraction of square root and arc tangent affects the switching time of power devices and reduces the control accuracy. A new PWM control technique based on volt-seconds equalization is adopted. Simulation and experiment results proved the proposed scheme.