Modelling of controlled rectifiers in feedback systems

Controlled rectifiers are often incorporated in closed-loop systems. To determine the small signal performance of such systems the rectifier must be appropriately modelled. The paper reviews the existing models and compares their step response performance, Nyquist plots and stability boundaries. It is shown that a recently developed discrete model that takes into account the commutation angle is in good agreement with experimental results. The rectifier transfer function is obtained and the large signal non-linear behaviour discussed. A rigorous mathematical dynamic model developed is capable of describing both the small and the large signal response of the system.