On-site Detecting Method for the Loss Characteristic in 110kV Power Transformer

The loss characteristic of power transformer can reflect its working condition, which is related to the safety and stabilization of the power system. The off-line test needs to shut down the transformer, affecting the continuity of power supply and it cannot reflect real status of transformer. In this paper, a new on-site method supplied by electric grid for the loss characteristic of power transformer is designed. Besides, considering the spectrum leakage and picket fence effect in the signal processing, a developed interpolation algorithm with Blackman-Harris window is applied. Based on the method, an onsite measuring system for the load and no-load losses of transformer is designed. Furthermore, issues of no-load current measurement accuracy, synchronism of signal acquisition and signal interference are solved. Finally, the no-load and load losses on-site tests are carried out in substation. It is proved that the onsite measuring system is feasible.