摘要
受试验装置容量的限制,750kV变压器现场长时感应耐压试验均采用变频谐振升压装置。由于试验前试验谐振频率不确定,变压器绕组集中参数(电容)难于通过测量得到,导致所需补偿的感性无功功率难于确定;若试验谐振频率估算不准确,会造成所需试验电源容量的估算值与实际值有很大偏差。通过2例750kV变压器现场失败的变频法长时感应耐压试验,就现场试验频率和试验电源容量难于准确计算的问题,提出了一种较为准确计算试验频率和试验电源容量的方法,并在750kV等级变压器现场试验中测量试验谐振频率和试验电源电流加以验证,证实了所述计算方法是有效和准确的。
As limited by the capacity of test equipments, frequency converting resonance boosters are employed in all of on-site long-time induction withstanding voltage tests for 750 kV power transformers. Before a test, the resonant frequency is uncertain, and it＇ s difficult to measure the lumped capacitance of transformer windings. Consequently, the inductive reactive power need to be compensated is difficult to confirm. In addition, the inaccurate estimation of the resonant frequency will lead to large deviation between estimated value and actual value of capacity of testing power. Based on two cases of on-site long-time induction withstanding voltage tests for 750 kV power transformers, which are both failed, and aimed at the difficulty to accurately calculate the on-site testing frequency and the testing power capacity, a method to calculate the two parameters accurately was presented. The validity and accuracy of this calculating method was proved in the 750 kV voltage transformer on-site test when measuring the resonant frequency and the current of testing power.
出处
《中国电力》
CSCD
北大核心
2010年第6期51-54,共4页
Electric Power
关键词
变压器
长时感应耐压
变频法
空载损耗
transformer
long-time induction withstanding voltage
frequency converting method
no-load loss
