Research on Electromagnetic Transient Process Simulation Calculation of ± 800kV UHVDC GIL

UHVDC GIL has the advantages of large transmission capacity, smaller occupied area, high reliability and small influence by the external environment, and has a wide application prospect in special environments. At present, the typical result unit and true test platform of DC GIL in UHV voltage level have not been established. For the time being, the electromagnetic transient simulation calculation model of ± 800kV DC GIL can only be established according to the research experience of AC UHV. Aiming at the internal and external overvoltage of GIL with different lengths, the electromagnetic transient process formed by lightning and operation, the electromagnetic transient process formed by grounding fault in UHV DC GIL is simulated and studied. The overvoltage waveform of the electromagnetic transient process is obtained, and the corresponding insulation coordination and protection scheme is proposed.