Research on Circuit Parameter Configuration of DC Superimposed Impulse Voltage Test on UHV DC Cable

Transient impulse voltage is an important threat to the insulation of UHV DC cables in operation. The selection and parameter calculation of equipment in the 800 kV DC cable voltage superposition test system were carried out. Studies have shown that, the specifications of the DC power supply and the impact power supply of the DC superimposed impulse voltage test system shall take into account the requirements of type test and pre-qualification test. The superposition of DC and different types of impulse voltage has different requirements for isolation resistor. Different DC blocking capacitance and cable sample length will change the impulse voltage amplitude and waveform obtained by the sample. The impulse insulation withstand level of the DC blocking capacitor and isolation resistor shall be equivalent to the cable sample. The research results provide a reference for the selection and configuration of the DC superimposed impulse voltage test device for UHV DC cables.