Large-signal model of power supply modules for implementing inter-connected system simulations

Pursuing rapid simulation speed and requiring reflection of more circuit details are always contradictory in computer simulations, especially for those of complex circuits such as a distributed power system. Simplified models of power supply modules are expected to establish a balance between above two requirements in implementing inter-connected system simulations. After discussing the difficulties in attempting to simulate inter-connected systems with switching models, the features of double-loop controlled power supply modules are investigated, in which cover a range of modules including continuous conduction mode (CCM) power factor correction (PFC) rectifiers and current mode controlled dc-dc converters. A new modeling approach is proposed, which the main idea is to simplify the double-loop controlling structure to a single-loop one by equating the inner current loop with a proportional gain block and furthermore treating the power stage as a power conservation unit that only externally represents the averaged voltage-ampere relations at both input and output ports through arithmetic calculation. A double-loop controlled switching system is transformed to a single-loop controlled non-linear system with continuous averaged variables in the proposed approach. The validity of the proposed model is verified by comparing the simulation speed and waveforms obtained respectively from switching models and the proposed model.