750kV变压器电压不平衡两相补偿快速计算方法

Fast Calculation Method of Two⁃phase Compensation for Voltage Unbalance of 750 kV Transformer

750 kV变压器是确保西北主网架正常运行的关键设备,但在更换其中一相变压器后常会出现电压不平衡问题。文中分析了750 kV变压器低压侧对地电压不平衡原因,并考虑变压器绕组电容影响,建立了电压不平衡分析计算模型;提出了两相电容补偿快速迭代计算方法,可快速确定补偿相别以及补偿电容值;针对某750 kV变电站低压侧电压不平衡问题,通过快速迭代计算方法设计了两相电容补偿方案,并通过仿真计算验证了本快速计算方法的有效性。文中提出快速迭代计算方法能够自动确定自耦变压器电压不平衡的电容补偿方案,可提高现场解决电压不平衡问题的反应速度和可靠性。

750 kV transformer is the key equipment to ensure the normal operation of the backbone grid of northwest power system,but the voltage unbalance often occurs after replacing one phase transformer.The analysis and calcu⁃lation model of voltage unbalance was established considering the influence of capacitance of between windings and windings to ground;A fast iterative calculation method of two⁃phase capacitance compensation was proposed to de⁃termine the compensation phase and the corresponding compensation capacitance;for the voltage unbalance of tertia⁃ry winding of 750 kV transformer,the capacitance compensation scheme was designed by using the fast iterative cal⁃culation method,and the effectiveness of this calculation method was verified by simulation.The fast iterative calcu⁃lation method proposed in this paper can quickly determine the two⁃phase capacitance compensation scheme and compensation capacitance,which greatly improves the speed and reliability of solving voltage imbalance on site.