An Improved Physical Model of Power Diode in the Rectifier Circuit

Considering the weakness of the conventional physical model of power diodes in the rectifier design, an improved lumped-charge model is presented in this paper to achieve both high accuracy and high efficiency in the simulation of power electronic equipment. To improve the convergence of the physical model simulation in the rectifier circuit, the transmission-line-theory is implemented in the model. Furthermore, a dynamic partition method is implemented in the model to achieve high accuracy of the transient characteristics of the diode during the level transition of the rectifier, with reducing the number of numerical solutions through reallocation of computing resources. Compared with the conventional model, the simulation error is decreased. This successfully adopts the physical model to realize both equipment-level simulation and high accuracy of device simulation in the design of the rectifier and RC snubber circuit. The experimental results show that the error of the proposed model is less than 10% and 5% the minimum, which is a maximum 30% decreasing compared with that of the conventional model. The half-cycle (500μs) simulation of the rectifier circuit with 10 and 20 power diodes cost 18s and 33s.