Study On Measurement Of Electrical Parameters Of Electromagnetic Pulse Protective Devices

The research on measurement of electromagnetic pulse protective devices under nanosecond pulse,is of great significance for testing method and selection of electromagnetic pulse protective devices.Firstly,the basic parameters of electromagnetic pulse protective devices in domestic and international standards were summarized and parameters needed be tested under nanosecond pulse were presented.Then,in order to ensure that the test system is able to withstand the high voltage of 11.8kV,a voltage divider with partial voltage ratio of 2018:1 and a three-port power divider were developped.Based on the pulse direct injection test system,the currents got by voltage calculation and current probe monitor were compared to confirm accuracy of calculation method in order that the I-V curve could be calculated.At the same time,the square wave pulse and double index pulse injection were used for test,comparison and sorting of protective device electrical parameters.Also,two fixtures with circular and rectangular cross sections were applied for the test of lead-wire protective devices and independent of the cross-sectional shape of the test results was proved.Next,a pulse coupled injection test system was established,time and frequency characteristic of the output signal of the coupler were analysized.Based on the comparision of protective device electrical parameters under pulse direct injection and pulse coupled injection test systems,the rising edge is more,pulse width and ampliture were lower,the response charateristics of electromagnetic pulse protection devices are complied with general rules.Finally,the transmission line theory was used to test the impedance of protective devices from 1kHz tolGHz,and capacitance parameters were fitted.The accuracy of voltage calculation method is verified,protective devices parameters under square wave pulse and double index pulse are supplement.The response charateristics of electromagnetic pulse protection devices are complied with general rules under pulse coupled injection,which proves pulse direct injection and pulse coupled injection test systems can be used for testing protective devices,and can be used as reference for protective device test and selection.