核电半速汽轮发电机单相短路时磁场特性分析

针对发电机单相短路时磁场特征问题，以一台核电半速汽轮发电机为例，采用场-路耦合方式建立了发电机单相短路仿真模型，通过对发电机单机空载时正常及机端单相短路仿真，得到了短路前后发电机内部磁场分布以及气隙磁密的变化特征。指出机端单相短路时发电机磁场仍具有对称性，故障后气隙磁密数值小于正常运行时的气隙磁密数值。通过对故障前后气隙磁密傅里叶分解，指出故障后气隙磁密基波分量明显减小，而奇数次谐波分量增大。

Analysis of Magnetic Field Characteristics of Nuclear Half Speed Turbo-generator with Single Phase Short Circuit

On the magnetic field characteristics of generator with single phase short circuit, take a nuclear power half speed turbo-generator as an example, the simulation model of generator single phase short circuit are established by field circuit coupling method. Through the simulation of normal and single phase short circuit of single generator under no load condition, the distribution of the internal magnetic field and the variation characteristics of the air gap flux density before and after the short circuit are obtained. It is pointed out that the magnetic field of the generator is still symmetrical after fault. The air gap flux density is distorted after the fault，Through FFT，the results show that the fundamental component of air gap flux density decreases obviously, while the odd harmonic component increases.