Effects of open and closed loop system of a six-pulse three phase controlled rectifier on variation in load, firing angle and source inductances

This Paper discusses the Simulink Models of open and closed loop systems of a three phase controlled rectifier and its study in terms of variation of load. The relationship between the source inductance, firing angle and commutation angle is important as these entities directly affect the Total Harmonic Distortion (THD) of the power system and this paper uses a graphical method to develop a relationship between source inductance, firing angle and commutation angle. This paper also discusses some trade-offs of using a Proportional - Integral (PI) controller in the design of closed loop system of the rectifier circuit and the effects of using active filters to reduce the Harmonic Components of the source current that may lead to commutation failure in the three phase controlled rectifier circuit.