电力变压器剩磁测量方法研究

Study on measurement method of remanence of power transformer

为了进行电力变压器稳态剩磁的定量研究,提出了一种直流助磁模拟剩磁的间接测量方法,用来解决常规的磁通测量方法不能直接用于测量变压器分闸后的剩磁问题。通过变压器空载合闸后的励磁涌流第一峰值,借助直流励磁峰值曲线,得到相应直流磁化力。再通过变压器峰值磁化曲线导出相应的磁通,该磁通即为相应空投前的剩磁。最后通过物理模拟试验验证了该方法的可行性。该方法可以用于研究变压器铁芯的剩磁特性,也可以用于对剩磁估算结果的验证。

For the quantitative study of steady-state remanence of power transformers,an indirect measurement method for simulating remanence by DC magnetization is proposed.It is used to solve the problem that the conventional flux measurement method can not be directly used to measure the remanence of transformer after switching off.Through the first peak value of inrush current after no-load switching on of transformer,the corresponding DC magnetization force is obtained by means of the peak value curve of DC excitation.Then the corresponding flux is deduced from the peak magnetization curve of the transformer,which is the remanence before the corresponding no-load switching on.Finally, the feasibility of the method is verified by physical simulation.This method can be used to study the remanence characteristics of transformer core and to verify the estimation results of remanence.