A fast algorithm of steady-state and transient simulations for controlled switching power supplies

One of most popular circuit simulators is SPICE, which is virtually the standard simulator for switching power supplies. However it is also true that SPICE is not the best simulator for the analysis of switching power supplies. SPICE is not initially intended to simulate switching mode circuits and therefore has a very long simulation time even when a powerful computer system is used. This situation is even worse in the case controlled switching power supply simulation. In order to solve this problem, fast algorithms have been reported for the analysis of switching power converters. However these papers focused on PWM power converters and did not touch upon resonant power converters and switching frequency modulation control at all. This paper presents a new fast algorithm for the steady-state and transient simulation of controlled switching power supplies. This algorithm deals with any switching power converters and the control strategies of pulse width modulation (PWM) and switching frequency modulation (SFM). Based on the algorithm, an actual simulator was developed. Consequently the steady-state and transient characteristics of controlled switching power supplies are simulated in some ten seconds using a personal computer.