新能源电站接地方式选择及接地变与配套设备选型解析

Analysis on the Selection of Grounding Mode and Grounding Transformer and Accessory Facilities of New Energy Power Station

新能源电站电缆-架空混合线路电容电流较大,为限制故障电流及系统过电压,开展接地方式分析和设备计算选型显得尤为重要。整理并分析了新能源电站接地方式的各类规程条款,分析了主变低压侧35kV系统常用的两种接地方式,阐述了消弧线圈接地和小电阻接地的选择方法及优缺点。重点对电容电流计算、消弧线圈容量选择、小电阻值选择、站用负荷计算、接地变选型进行了解析说明,为新能源电站接地系统选择及优化设计提供了借鉴经验。

The capacitive current of cable-overhead hybrid line of new energy power station is relatively large,causing fault current and system over-voltage,so it is more important to carry out grounding mode analysis and computing equipment selection.In the paper,regulations and clauses of grounding mode of new energy power station and two common grounding mode of low-voltage side of main transformer in 35kV system are analyzed,the selection and advantages and disadvantages of grounding by arc-suppression coil and low resistance grounding are elaborated.Greater importance is attached to explaining calculation of capacitive current,selection of arc-suppression coil capacity and low resistance value,load calculation and grounding transformer,which provides references and experience to select and optimize grounding system of new energy power station.