利用数值仿真方法确定三相变压器深度饱和等效电路模型参数

精确的变压器深度饱和模型是分析电网过电压暂态过程的基础。而目前端口试验的方法只能得到额定运行时等效电路模型的参数,却无法得到过电压下深度饱和区的参数。该文提出利用数值仿真的方法确定三相变压器深度饱和等效电路模型参数,数值仿真的方法分为两种,包括基于端口数值试验的方法和基于电磁场分布计算磁阻方法。前者通过磁场和电路耦合的方法在变压器的端口设置开路或短路状态以确定等效电路参数,后者利用变压器各部分的磁通和能量的积分结果计算磁阻,再转换得到等效电路参数。计算磁阻的方法更适用于分析拓扑复杂、深度饱和的变压器等效电路模型参数。

Determination the Parameters of Deep Saturated Equivalent Circuit Model of Three-phase Transformer by Numerical Simulation Method

Accurate transformer deep saturation model is the basis of the analysis of transient process of overvoltage in power grid.However,the current port test method can only get the parameters of the equivalent circuit model under rated operation,but can not get the parameters of the deep saturation area under overvoltage.In this paper,the numerical simulation methods are used to determine the parameters of three-phase transformer model.The numerical simulation methods are divided into two types,one is base on the port-based numerical experiment,and anther is the reluctance calculation method based on the electromagnetic field distribution.The former determine the equivalent circuit parameters by setting the open circuit or short circuit state in the transformer port,the latter calculate the reluctance based on the magnetic flux and energy distribution in the transformer.The numerical simulation method based on reluctance calculation is more suitable for the analysis of transformer equivalent circuit model parameters with complicated topology and deep saturation.