神木电厂串补送出方案次同步谐振的计算分析

为评估神木电厂一期串补送出方案的次同步谐振(SSR)问题,采用电气阻尼频率特性计算与时域仿真相结合的方法,对该方案的SSR进行了全面、深入的计算和分析。首先采用基于时域仿真实现的复转矩系数法-测试信号法计算了不同串补度和运行工况下发电机组的电气阻尼频率特性;然后据此计算出使次同步谐振不发散所需的最小发电机机械阻尼,并与已知的发电机机械阻尼进行了比较,判断出不同串补度和运行工况下神木电厂一期串补送出方案的次同步谐振稳定性;最后采用PSCAD/EMTDC,基于发电机组轴系的多刚体模型进行了时域仿真,验证了已得到的结果。所得的计算分析结果对神木电厂一期串补送出方案的设计具有指导意义。

SSR Analysis of Compensation Transmission Scheme for Shenmu Power Plant

An integrated method combining the calculation of electrical damping versus frequency and time domain simulation is applied in analyzing the SSR problem of Shenmu Power Plant phase one caused by its series compensation transmission scheme.Firstly,the electrical damping versus frequency in different series compensation degrees and different operating conditions is calculated using the complex torque coefficient method realized by time domain simulation,namely the test signal method.Secondly,based on the calculated electrical damping,the required minimum mechanical damping for stabilizing SSR is calculated,and the required minimum mechanical damping is compared with the real mechanical damping of the Shenmu Power Plant machines to determine the stability of SSR.If the sum of the mechanical damping and the electrical damping is more than zero,it means that the SSR is stable;otherwise,the SSR is unstable.Finally, based on the multi-mass model of the machines,time domain simulation using PSCAD/EMTDC is performed to verify the above results.The final results of the paper can be used as a guidance to design the series compensation transmission scheme for Shenmu Power Plant phase one.