The solar energy resources of high-altitude areas in Northwestern China are abundant and the large-scale grid-connected photovoltaic(PV)power station affects the safety and stability of the northwest power grid. The low voltage ride-through(LVRT)capability is an important indicator for the reliable access of PV power station to the northwest power grid. The LVRT test of PV power generation system in ultra-high altitude areas with an altitude over 4 000 meters needs to solve the problems of frequent operation overvoltage of test equipment and insulation coordination of plateau electrical equipment to prevent the occurrence of insulation discharge accidents. The insulation discharge problem of the test system depends not only on the high-frequency overvoltage generated by the switching reactor

but also on the optimal design of the equipment layout structure in a small space. An LVRT experimental system for PV power generation is proposed

and a method for the development of LVRT test equipment for PV power station in the ultra-high altitude regions is proposed. The factors that affect the transient overvoltage are analyzed theoretically

and the measures for the suppression of overvoltage in the test process are finally suggested. Through the finite element analysis method

the electric field strength inside the vehicle-mounted space is checked to ensure that no risk of insulation discharge occurs in the narrow space structure of the vehicle under the ultra-high altitude environment

and the electrical insulation safety of the equipment is ensured. The design scheme has been successfully applied to LVRT test system at an altitude of over 4 000 meters

and LVRT tests are carried out for several power stations.