地磁感应电流对系统电压影响研究

针对地磁风暴发生时系统电压降低的现象,研究了地磁感应电流引起的直流偏磁对电力系统电压的影响。基于PSCAD/EMTDC平台搭建了地磁感应电流—直流偏磁的仿真模型,并用低频正弦交流电模拟地磁感应电流,记录了变压器无功功率的需求变化和系统的电压,另外研究了地磁感应电流对发电机出力的影响,同时与单极运行直流电流对电压的影响进行对比研究。结果表明,磁感应电流会导致变压器无功需求周期性增多,系统电压周期性降低,最大下降约为10%,同时地磁感应电流会导致发电机有功出力减小、无功出力增大。而直流电流与系统电压成比例关系,最大下降为13%左右,因无功补偿装置系统电压会逐渐恢复但达不到额定电压。

Study on the Influence of GIC on Power System Voltage

The influence of Direct Current(DC)bias caused by Geomagnetism Induced Current(GIC)on power sys?tem voltage is studied in view of the phenomenon that the power system voltage decreases when geomagnetic storms occur.A GIC?DC bias simulation model is established based on the PSCAD/EMTDC software.A low frequency sinu?soidal alternating current is used to simulate GIC in this model.The transformer reactive power and the system volt?age are recorded correspondingly.The influence of GIC on the generator output is studied.And the influence of DC current on voltage is compared with GIC.The results show that,the transformer reactive power demand will increase periodically with the increase of GIC,while resulting in periodic decrease of the system voltage which the maximum decrease of about 10%.At the same time,the active output reduces and the reactive power increases of the generator.The DC current is proportional to the system voltage,and the maximum decrease is about 13%,because the voltage of the reactive power compensation device will gradually recover,but it can’t reach the rated voltage.