500 kV变电站自耦变压器公共绕组运行工况分析

针对电网内自耦变压器不同运行工况,详细分析了自耦变压器公共绕组的运行特性及其负载特性。以500kV自耦变压器为例,分析了在自耦变压器不同运行工况下,功率因数和低压侧无功补偿容量对公共绕组负载能力的影响,并得出结论:主变在中压侧向高压侧送电工况下投入低压电抗器,或在高压侧向中压侧送电工况下投入低压电容器,都会增加主变公共绕组的负担,使主变的负载能力下降。针对电网内现有的无功补偿装置可能产生的副作用,并根据电网的实际情况提出解决方案,即改善系统功率因数,减少主变低压侧无功补偿装置的投入。

Analysis of autotransformer common winding operational conditions in 500 kV substations

Operational features and load characteristics of autotransformer common winding under different work conditions are analyzed in detail.With 500 kV autotransformers as examples,the influence of power factor and reactive compensation capacity at low voltage side on the load ability of common winding is analyzed and the conclusion is got:putting LV(Low Voltage) reactor into operation when power is sent from MV(Middle Voltage) side to HV(High Voltage) side of main transformer or putting LV capacitor into operation when power is sent from HV side to MV side of main transformer will increase the load of its common winding and lower the load ability of main transformer.Aiming at the by-effect of reactive compensation device,solutions are put forward according to actual situation of power grid:improving the system power factor and reducing the reactive compensation capacity at the LV side of the transformer.