Mathematical Model of Operability of a Single-phase Bridge Rectifier

Rectifiers are widely used to convert alternating current to direct current. During operation rectifier voltage changes both under the influence of external factors (temperature) and due to degradation of semiconductor crystal. The task of determining the technical state of the rectifier (the presence and the stage of faults development) based on monitoring of its parameters is actual. This article presents the methodology of modeling of diode open- and short-circuit of single-phase bridge rectifier. The open circuit simulation is achieved by including a resistor in series with the diode. It was found that output voltage of rectifier at no-load is determined by reverse resistance of diodes. When the rectifier works under load its voltage is determined by the ratio of diode resistance to the total rectifier resistance. Short-circuit simulation is achieved by shunting the diode. A generalized model of single-phase rectifier operability is given. The use of this model will make it possible by comparing the rectifier input and output voltages to determine the nature and degree of diode fault development.