Introduction to the category of the hottest 500kV

2022-07-24
  • Detail

500kV EHV cable category introduction

500kv oil filled cable, 500kV polypropylene film wood fiber composite paper insulated oil filled cable, 500kV XLPE cable and 550kV oil filled cable

1. 500kV oil filled cable

500kv oil filled cable has been running for more than 70 years. It is recognized as a high-voltage and ultra-high voltage cable with excellent insulation performance and reliable operation in the world. However, due to the large dielectric loss coefficient, the transmission of large capacity electric energy under EHV is challenged by other types of cables. Since the 1970s, 500kV oil filled cables have been installed and operated in foreign hydropower stations. Since 1964, 66 kV, 110 kV, 220 kV and 330 kV oil filled cables have been successively operated in power plants, hydropower stations and urban power stations according to applicable voltage levels in China. The 500kV oil filled cable has also been operated on the Jinzhou Liaoyang line of northeast electric power. At present, China Shenyang cable factory and Shanghai cable factory have mastered the manufacturing technology of 500kV oil filled cable. Hongqi Cable Factory has a production line for manufacturing 500 kV and higher voltage oil filled cables

the working oil pressure of 500kV oil filled cables made in China is 0.4 ~ 0.8 MPa. When the laying drop is 130 meters, the oil pressure of the lower cable reaches 1.6 ~ 2.0 MPa. The cable metal can be lead sheath or corrugated aluminum sheath. The lead sheathed oil filled cable needs to be reinforced with non-magnetic metal strips in radial and longitudinal directions. Corrugated aluminum sheathed oil filled cable does not need metal belt reinforcement, and can meet the requirements of the power station for the laying height difference of 500 kV cable of 130 meters

series design and Ampacity calculation of 500kV oil filled cable are carried out. The maximum conductor temperature of 500kV oil filled cable is 85 ℃. The series design and Ampacity calculation of 500kV oil filled cable are carried out. The common section range of 500kV oil filled cable is 800 ~ 2500 mm2

2. 500 kV XLPE cable

lpe cable has low dielectric loss and large transmission capacity. It is suitable for high drop laying and can realize oil-free. In 1998, 500kV corrugated aluminum XLPE cable was first installed and operated in Jishi power station and Xiaxiang power station in Japan [1]. The cable terminal inserted into the totally enclosed switchgear is put into operation at the same time as the XLPE cable. However, the 500 kV XLPE cable connector has not been developed and applied. For XLPE cable, especially for the long-term operation of ultra-high voltage XLPE cable with good formability and reliability, countries all over the world pay close attention to it. The operation experience of 500 kV XLPE cable in Japan has played a positive role in promoting the adoption of 500 kV XLPE cable in 500 kV system

in order to completely isolate moisture and moisture from the cable sheath into the insulation, so as to prevent water tree, the 500 kV XLPE cable must use a metal sheath. The power station requires a cable laying drop of 130 meters. Due to the low strength of the lead sheath, it is not suitable to use the lead sheath XLPE cable. Corrugated stainless steel sleeve has large resistance. When the metal has high short-circuit current flow requirements, additional current carrying conductor is required under the corrugated stainless steel sleeve. Therefore, corrugated aluminum sleeve structure shall be considered for 500 kV XLPE cable with high drop for power station. The maximum conductor temperature of 500kV XLPE cable is 90 ℃. The system design and Ampacity calculation of 500kV XLPE cable are also carried out, and the section range is 800 ~ 2500 mm2

3. 500 kV polypropylene film wood fiber composite paper insulated oil filled cable (hereinafter referred to as PPLP cable)

after decades of exploration, development and Research on low loss coefficient wrapping materials, polypropylene film wood fiber composite paper (PPLP) has been recognized as an insulating material that can be used to manufacture high voltage to ultra-high voltage low loss oil filled cables. In 1988, Japan laid a 127 km 500 kV PPLP cable between Honshu and the four countries in case of high-altitude disintegration. The 22 circuit km 500 kV PPLP cable was used, indicating that the 500 kV PPLP cable has reached the stage of industrial practical application. The loss coefficient of PPLP cable is small, and its maximum working gradient is relatively high, which is 17 ~ 18 kV/mm (the maximum working gradient of 500 kV oil filled cable is 15 kV/mm). The insulation thickness of 500kV PPLP cable is 25mm (the insulation thickness of 500kV oil filled cable in China is 31mm). The structure of metal sheath and outer sheath of PPLP cable is the same as that of oil filled cable, and its production equipment is basically the same as that of oil filled cable. It can be considered that China has the basic conditions for the development and production of 500 kV PPLP cables

carry out series design and Ampacity calculation for 500 kV PP LP cable except for emission characteristics. The maximum conductor temperature of 500 kV PPLP cable is 85 ℃. Carry out series design and Ampacity calculation for 500 kV PPLP cable, with a section range of 800 ~ 2500 mm2. (end)

Copyright © 2011 JIN SHI