The World's Highest Voltage Level UHV Insulation Test Platform Developed Successfully

HIMALAYAL - SHANGHAI - CHINA



In recent years, State Grid has made continuous innovations in UHV transmission technology. With the help of advanced field test technology, the State Grid has successfully developed the world's highest voltage level UHV insulation test platform. The ±1100kV HVDC transmission leads  the world. 

1.Test Site
On May 25, at ±1100kV Guquan Converter Station at the city of Xuancheng in Anhui province, accompanied by the command - "Now start the 1200kV GIS (High voltage composite electrical appliance) integrated insulation test platform and test begins!", the test platform slowly extended. The strong test voltage was applied to the GIS equipment; the AC dielectric and partial discharge tests were successfully carried out.

2.Difficulties at the site
It is understood that the traditional test method can not meet the needs in the field test of ±1100kV Guquan converter station. The traditional bulk GIS test equipment requires high standards; the reactor and voltage divider are independent tower structure; the field test site needs to be large. However, the UHV GIS equipment is compact; the space for field test is narrow; the distance between the HV live equipment and non-test equipment is close, and the discharge will occur when the ambient humidity is slightly high. The air gap discharge test can not be carried out. It is also difficult to transport the equipment. The traditional UHV test equipment has more than 200 parts, totaling more than 20 tons. Some parts are bulky and need 4 trucks with 9.6 meters to transport. In addition, it takes a long time to assemble the test equipment on-site. The tedious test preparation work has been difficult to meet the UHV GIS field insulation test requirements in test time and load capacity. Therefore, how to improve the safety and efficiency of UHV GIS field test has become an urgent problem in the field of UHV field test technology.

3.Platform advantage
The platform integrates the key test equipment such as high voltage reactor, HV voltage divider and air-filled corona ring, adopts the working principle of mobile launching of missile launcher, realizes high efficiency and rapid deployment on the spot through hydraulic chassis and hydraulic lifting and turning device, and realizes the assembly and motorization of the device. Compared with the traditional test equipment, it saves 80% test preparation time and greatly reduces the risk on site.

The "GIS complete insulation test platform" is more efficient than traditional equipment. The test platform has good maneuverability, realizes the integration of reactor and divider on one platform and self-supporting lifting of the complete set, and can quickly respond to the field test requirements. In particular, the corona ring is the key component to reduce the corona loss of the device, which is usually made of aluminum alloy material. It is bulky and difficult to transport. On the basis of many tests, new materials have been used to make the inflatable corona ring. One inflatable corona ring can replace the original four aluminum alloy corona rings.

4.Significant significance
The cost of time is saved by 80%. It is understood that after the commissioning of the Changji-Guquan project, nearly 200 million kilowatt-hours of power is transmitted daily. If the converter station needs to be urgently placed in shortage, the equipment must undergo the insulation test before it can be put into operation. Now with this test platform, all the test tasks can be completed within 8 hours.

It is reported that the test platform will declare more than 10 national patents. The successful application of Guquan converter station caused great concerns in the industry and will greatly enhance the efficiency of China's UHV grid test and security capabilities.