Upgrade test capability for ±800kV/6250A and ±1100kV/5454A UHVDC valve

The paper mainly described the upgrade study of UHVDC converter valve type test capability, which will meet all the test requirements of ± 800kV/6250A and ±1100kV/5454A thyristor valves. By optimizing and upgrading rectifier transformer and water-cooled systems, especially that a new synthetic fault test circuit, the operational test capability reaches rated current 7500 A, and fault current peak is 62 kA. In addition, surface electric field intensity on shielding cases of the impulse test equipment is calculated by using Galerkin boundary element method. According to existing conditions, a feasible measure is proposed, which can be employed to decrease electric field dramatically and avoid corona discharge of shielding cases. Another effort in the dielectric test is theoretically analysis and test study for the DC test equipment with rated voltage ±2400kV. Finally, the parameters and results for the ± 800kV/6250A and ±1100kV/5454A prototype will be presented.