110kV矿热炉供电系统高低压无功补偿分析

Analysis of high and low voltage power compensation on 110 kV power supply system in submerged arc furnace

110kV矿热炉供电系统一般采用双绕组变压器供电,存在功率因数低、谐波严重和三相电压不平衡等问题。目前工程中常采用在高压侧集中补偿或在低压侧就地自动补偿的方式进行。但在高压侧集中补偿不能解决矿热炉供电系统造成的谐波严重及三相做功不平衡问题,并且无功损失严重;在低压侧就地自动补偿又出现了控制器采样误差大,辐射干扰严重、电容器出力不够等问题。在详细分析矿热炉高低压侧无功补偿出现的问题后给出建议:110kV矿热炉无功补偿应该高低压侧结合进行或110kV矿热炉变压器给出第三绕组作为专用补偿滤波绕组。

As 110 kV power supply system of submerged arc furnace is generally supplied by duplex winding transformers,some problems like low power factor,serious harmonic and unbalanced three-phase voltage appear.Currently,concentrated compensation at HV side or on-site automatic compensation at LV side is adopted to solve these problems in project.While concentrated compensation at HV side cannot solve serious harmonic and three-phase power unbalance problems and reactive power will severely loss;on-site automatic compensation at LV side will cause the problems of controller sampling error,serious radiation interference,insufficient capacitor output,and so on.This essay analyzes reactive power compensation problems at HV/LV side of submerged arc furnace and gives some suggestions as follow：reactive power compensation should be made at both HV side and LV side or tertiary winding of 110 kV submerged arc furnace transformer should be used as specific compensation filtering windings.