±1100kV换流站管母线选型及地面合成电场研究

Study on Type Selection of Tubular Busbars and Compound Electric Field in ±1100kV Converter Station

直流地面合成电场是衡量换流站电磁环境水平的重要指标,需要控制在合理范围内。换流站内产生合成电场的主要设备是管母线,这使得换流站内地面合成电场的最大值与管母线电压、对地高度和直径密切相关。分析了±1100kV特高压换流站地面合成电场限值,计算了不同直径管母线分别在干燥、潮湿和污秽状态下的地面合成电场与最小对地高度间的关系。在特高压直流试验基地开展的直径300mm和400mm真型管母线地面合成电场试验结果验证了计算方法的有效性。综合考虑地面合成电场的计算结果和试验结果,确定了±1100kV换流站户内和户外管母线型式和最小对地高度。研究结果表明,对于低海拔地区±1100kV换流站,户内推荐采用直径300mm管母线,最小对地高度不宜小于16.5m;户外推荐采用直径400mm管母线,管母线最小对地高度不宜小于17.2m。

Compound electric field at ground level is an important indicator to weigh electromagnetic environment level for DC convertor stations, and should be controlled within a reasonable range. Tubular busbar is a major facility to generate the compound electric field, making maximum value of compound electric field at ground level in converter station closely related to voltage, height and outer diameter of the busbar. In this paper, the limit of compound electric field at ground level of UHV ±1100 kV converter station is analyzed, and relationship between the compound electric field at ground level and minimum height in dry, wet and polluted state of the busbars with different diameters are calculated. Validity of the calculation method is verified with test results of the compound electric field of true tubular busbar of 300 mm and 400 mm diameter at a UHVDC test base. Considering results of calculation and experiment of the compound electric field, type and minimum height of tubular busbars in indoor and outdoor ±1100 kV converter stations are determined. Results show that for ±1100 kV converter station in low altitude, tubular busbar of 300 mm diameter is recommended for indoor use with minimum height not less than 16.5 m, and tubular busbar of diameter 400 mm is recommended for outdoor use with minimum height not less than 17.2 m.