广东电网500kV大容量变压器阻抗参数的选择

Selection of Impedance Parameter for 500kV Large Capacity Transformers in Guangdong Power Grid

结合广东电网500kV枢纽变电站应用大容量变压器的实际需要,对大容量变压器短路阻抗与短路电流水平、无功功率补偿容量、变压器结构、损耗的关系进行分析,认为提高变压器高-中阻抗电压虽可降低短路电流,但会增大变压器造价、电能损耗、无功功率损耗、电网运行费用等,因此建议广东电网500kV枢纽变电站1 500MVA大容量变压器高-中阻抗电压可选择于22%~24%之间,并兼顾制造工艺、变压器的电能损耗和无功损耗等因素。

Combining actual demand for large capacity transformers in 500 kV load-center substations of Guangdong power grid,relationship among short-circuit impedance,short-circuit current level,reactive power compensation capacity,transformer structure and loss are analyzed.It is believed that raise of medium and high impedance voltage can reduce breaking current,but it also increases construction price of transformers,energy losses,reactive power loss and operating expenses of power system and so on.Accordingly,it is suggested that the medium and high impedance voltage of 1500 MVA large capacity voltage in 500 kV load-center substations of Guangdong power grid can be selected between 22% and 24%,taking manufacturing technology,energy loss of transformers and reactive power loss and other facors into account.