牵引站馈线谐波电流的分析与预测

Analysis and Prediction of Harmonic Current in Feeder of Traction Substation

电气化铁路作为电力系统中主要的谐波源,它的接入会导致电网谐波畸变恶化,威胁电气设备的安全运行,给电网造成定的经济损失。首先采用模拟火和小二乘法相结合的算法,对馈线基波电流建立了对数正态分布的概率密度模型。根据牵引负荷的谐波特性,进步模拟了电气化铁路谐波的随机波动过程,生成了波动的谐波电流数据并得到谐波电流特征值的估算结果。通过仿真实例验证了该模型的有效性。后针对新建牵引站较少的已知条件,选择合适的牵引站馈线电流数据作为基础,提出了种新建牵引站谐波电流预测评估的方法,同时为下步电网影响分析研究以及电网电能质量治理措施的确定提供了理论依据。

As a major source of harmonics, grid-connection of electrified railway makes harmonic pollution in power grid deteriorated and jeopardizes secure operation of power equipments, so leads to a certain economic loss in power grid. Firstly, using the algorithm combining simulated annealing with least squares a logarithmic normal distribution probability density model of fundamental current in feeder is established. According to harmonic characteristic of traction load the random fluctuation of harmonics in electrified railway is further simulated, and the fluctuant harmonic current data is generated and the estimation result of characteristic value of harmonic current is obtained. The effectiveness of the proposed model is validated by simulation example. Finally, based on the less known condition of newly built traction substation, taking the data of appropriate feeder current as the foundation, a method to predict and evaluate the harmonic current in newly built traction substation is put forward, which may be available for reference to further analysis on the impact of harmonic current on power grid and to the determination of harmonic management.