考虑非理想器件模型的电力电子系统状态方程分析法

针对目前电力电子仿真软件存在的对功率开关器件电磁瞬态过程仿真不够准确,强刚性电路引起数值仿真计算发散等问题,提出一种基于量化状态系统(QSS)的离散状态事件驱动(DSED)仿真分析方法。该方法需要加入自动识别电力电子系统开关过程以及根据电路拓扑和所处状态自动列写状态方程的相关算法。针对该需求提出一种基于图论方法的状态方程及输出方程提取分析方法。首先,经理论分析得到,将选用的器件模型代入电路可以得到状态方程的标准形式;进而,提出电力电子系统电路的参数结构矩阵程式化列写方法,并基于此方法针对开关电路每一次开关器件切换都需要重新列写状态方程这一特点进行了相关分析。最后,对几个典型电力电子系统电路进行仿真计算,结果证明了该提取分析方法的有效性。

State Space Method to Analyze the Power Electronics Circuits Considering Devices' Non-Ideal Models

At present, there are some problems in the simulation software of power electronics, such as rough simulation waveforms for device switching transients, non-convergence for stiff systems etc. Hence, our group has proposed an analysis method—discrete state event drive (DSED) based on quantized state system (QSS). In this method, the algorithm based on circuit topology and state is integrated that can identify the switching states of devices and extract state space equations. Thus, a graph-theory-based algorithm that can extract the state and output equations is proposed. It is proved theoretically that the state space equations of power electronic systems are always in norm-form. Furthermore, parameter-structure matrix is proposed. Some discussions are carried out to the problem that every time a switch alters its status, the coefficient matrices of state space equations must be recalculated. Finally, simulation results of classical circuits have verified the proposed method.