以BuckBoost电路为例,求解了变换器的平均模型及其线性化后的小信号模型。利用Simulink软件分别搭建状态平均方程等效电路、线性化小信号模型等效电路。通过动态模型仿真与开关器件电路仿真结果对比,验证了动态模型的正确性,讨论了断续电流模式(DCM)平均模型的适用范围与存在的缺陷。理论分析结果表明:大信号和小信号模型,在宏观时间尺度上,可以较好地模拟实际开关电路的动态特性。小信号模型只能用来求解扰动较小的情况,即当扰动过大时,小信号模型求解的误差将会很大。

Taking BuckBoost circuit as an example, the average model of the converter and its linearized smallsignal model were solved. Simulink software was used to build the equivalent circuits of state average equation and linearized smallsignal model respectively. By comparing the simulation results of dynamic model with those of switching device circuit, the correctness of the dynamic model was verified. The application scope and shortcomings of discontinuous current mode (DCM) average model were discussed. The theoretical analysis results showed that the largesignal model and the smallsignal model could better simulate the dynamic characteristics of the actual switching circuit on the macroscopic time scale. The smallsignal model could only be used to solve the case of small disturbances, namely when the disturbance was too large, the error of the smallsignal model solution would be large.

TM 46