牵引负荷接入产生的负序分量对近端发电机影响的评估

Assessment on Impact of Negative-Sequence Component on Nearby Generators due to Grid-Connected Traction Load of Electrified Railway

提出了电力牵引负荷接入电网时所产生的负序分量对对近端发电机的影响的评估方法;计算了牵引负荷平均负序容量;在分析负序磁通路径特点的基础上,讨论了传统发电机组及各类风力发电机组的负序阻抗特性。利用叠加原理计算发电机端口的负序电压,进而得到流过发电机的负序电流,参考典型发电机的负序电流限值标准对负序的影响水平进行评估。该方法利用了电力系统计算分析软件中已有的潮流数据文件及稳定数据文件,省去对区域电网重新建模仿真的复杂过程。算例结果验证了该方法的有效性。

A method to assess the impacts of negative-sequence components on nearby generators due to grid-connected traction load of electrified railway is proposed. The average negative-sequence capacity of traction load is calculated. On the basis of analyzing the features of negative-sequence flux path the negative-sequence properties of traditional generation sets and various kinds of wind power generators are discussed. Using superposition principle the negative-sequence voltages at generators＇ terminals are calculated and then the negative-sequence currents flows through generators can be obtained. Referring to the negative-sequence current limit of generator specified in the standard, the impact level of negative-sequence components is assessed. In the proposed method, the power flow data files and stability data files in PSD-BPA software are utilized to omit the complex process for re-modeling and re-simulation of regional power grid. Results of calculation examples show that the proposed method is effective.