Experimental Study on Electro-magnetic-heat Effects of Scaled-down Transformers Under Simulated Extreme Geomagnetic Induced Current Injection
Extreme geomagnetic induction currents with high amplitude and long pulse width pose a significant threat to the normal operation of power equipment and power systems.In order to study the effect of transformer neutral point pulsed geomagnetic induced current on transformer equipment under the strong electromagnetic pulse environment,firstly,a pulse injection device with output half pulse width of tens of seconds and amplitude of hundreds of amperes is developed.Secondly,the circuit topology of extreme geomagnetic induced current injection test is constructed,and the no-load injection circuit is formed by connecting the two scaled-down transformers back to back,and the excitation current of transformer is investigated during the injection process.The results indicate during the injection process,the transformer excitation current can reach hundreds of amperes,far exceeding the rated current of the transformer.The core enters into deep saturation state,the even harmonic content appears in the excitation current,and with the increase of the amplitude of the injected current,the distortion rate of the excitation current will decrease.Finally,during the extreme geomagnetic induction current injection transient process,transformer windings and core appear obvious temperature rise.When the injected current amplitude of 50 A,the winding transient more than 29℃,the core main column surface transient more than 14℃.The test results provide an important reference for the study of transformer equipment effects in the strong EMP environment.
万方数据
维普
