变压器绕组介损及电容异常分析

Analysis of Abnormal Dielectric Loss and Capacitor of Transformer Winding

对变压器进行绕组间、绕组对铁芯间介损测量时出现负介损或介损过小、过大、电容量严重偏小等问题进行分析,发现出现异常情况的变压器,均只有铁芯引出接地,而无夹件引出接地。认为是铁芯地屏经夹件在变压器内部接地导致了异常情况的发生。建议今后在预试中碰到此类问题时,应设法采用常规方法进行复测。

Problems encountered during the measurement of transformer dielectric loss between windings or between winding and iron core, such as negative or too big, or too small value of dielectric loss or serous small value of capacitance, are analyzed. It is founded that all abnormal transformers have only iron core grounding but don＇t have clamp grounding. It is because iron core earth screen was grounded through clamp in transformer that leads to abnormal results. It is suggested that dielectric loss should be remeasured by routine method when such kind of problems are encountered in preventive test.