500kV/220kV混压同塔四回路感应电压、感应电流的研究

采用电磁暂态仿真程序对某一典型的500 kV/220 kV同塔四回路的感应电压、感应电流进行计算,分析停运工况、潮流大小、线路相序、四回路段占线路长度的比例、土壤电阻率等因素对混压同塔多回路感应电压、感应电流的影响。结果表明,500 kV线路和220 kV线路的感应电压、感应电流均超过B类接地开关的额定参数,220 kV线路的感应值超过500 kV线路;不同相序布置方式下的计算结果差异较大;四回路路段占线路长度的比例对220 kV线路感应电压、感应电流的影响显著。针对此,在设备选型中需要特别注意。

Research on Induced Voltage and Current for 500 kV/220 kV Mixed-voltage Parallel-four-circuit Transmission Lines on the Same Tower

Induced voltage and current for 500 kV/220 kV mixed-voltage parallel-four-circuit transmission lines are calculated by electromagnetic transient simulation program. Impact of operating condition of outrage, power flow, phase sequence of lines, proportion of four-circuit section and resistivity of soil on induced voltage and current for mixed-voltage parallel four- circuit transmission lines is analyzed. The result shows that induced voltage and current of both 500 kV lines and 220 kV lines exceed rated parameter of earthing switchgear B, and induction value of 220 kV lines exceeds that of 500 kV lines; the calculation results vary in different phase sequence arrangements; the proportion of four-circuit greatly influences induced voltage and current of 221） kV lines. Therefore, attentions need to be paid to equipment selection.