The Tibet Yangbajain Project

June 15, 2025, marked the quiet opening of a new chapter signifying a leap in capability for the world's highest-altitude power testing and research base. The construction project, "WJQ-3000kVA/1500kV High-Altitude SF6 Gas-Insulated Test Transformer", successfully passed comprehensive acceptance. Its performance and high stability were perfectly suited to meet a series of complex and stringent testing and research challenges, including those for UHV AC bushing equipment and gap discharge at 4500 meters above sea level.

The introduction of this equipment has not only significantly enhanced the performance benchmarks for electrical equipment in high-altitude regions—enabling them to adeptly handle discharge phenomena encountered during external short-circuit tests—but has also constructed a robust defense line for the safe and stable operation of power equipment. This milestone achievement undoubtedly provides an indestructible technological foundation for us to delve deeper into the realm of power scientific research under the unique conditions of high-altitude environments.

The project for the "WJQ-3000kVA/1500kV High-Altitude SF6 Gas-Insulated Test Transformer" commenced its full-scale equipment development in March 2022. In July of the same year, the complete set of equipment, having undergone rigorous factory acceptance tests, was successfully dispatched to the Yangbajain Test Base. However, as the Yangbajain high-voltage hall was not yet ready for installation, all equipment components had to be temporarily stored outdoors.

It was not until November 2023 that the team successfully completed the testing of a 1100kV Resin-Impregnated Paper (RIP) Capacitive Transformer Bushing at the outdoor site. By December 2024, the equipment was finally moved into the high-voltage test hall. After approximately five months of diligent effort, preparation and commissioning work concluded successfully on June 13, 2025, marking readiness for final acceptance.

On June 14, 2025, the on-site acceptance work formally commenced, including withstand voltage tests, partial discharge tests, and overcurrent fast-trip protection tests.

Over the course of two days, all key stages of the tests were successfully completed. During on-site self-testing, under operating conditions of 1500kV voltage and 656.8mA current, the measured partial discharge level was 6.65 pC.