大型同步发电机单相接地故障的暂态多回路分析——数学模型

大型同步发电机定子单相接地故障是发电机常见故障，其潜在的危害很 大，因此相关的仿真研究非常重要，但是准确分析其暂态规律非常困难。文中采用准分布电 容等效实际定子绕组对地的分布电容，将定子绕组每个支路划分成若干个电路单元，建立大 型发电机定子单相接地故障的多回路分析暂态数学模型，推导出实际值形式和标幺值形式的 状态方程，并给出了相应的数值解算方法以及仿真结果。该模型可以同时考虑定子绕组对地 分布电容的影响，以及定子绕组内部接地故障带来的定子绕组结构上不对称的影响。〖ＫＨ ５Ｄ〗〖ＨＴＨ〗

TRANSIENT MULTI-LOOP ANALYSIS ON THE STATOR GROUND FAULT OF LARGE SYNCHRONOUS GENERATOR--Mathematic Model

The stator ground fault of large synchronous generator is a frequent fault and it has great latent damage to the generator. So, it is very important to do simulation research. However, it is very difficult to analyze the transient characteristics accurately. This paper constructs a mathematical model, which is based on the multi loop method, for the transient simulation of the ground fault in the stator windings of the large synchronous generator. In this model, the stator windings are partitioned into many unit circuits, and the distributed capacitance of the stator windings to the ground is equivalent to the quasi distributed capacitance. This paper not only deduces the state equations under two forms: real value and per unit, but also presents the numerical solutions and the simulation results. This multi loop model can better consider the influences of the distributed capacitance and the nonsymmetrical stator windings when stator ground fault occurs in interior of the stator windings.