What is HTS cable? What are the advantages of HTS cable?

The first domestic demonstration project of 35 kV km high temperature superconducting cable built by state grid was started in Shanghai on April 30. This is the first commercial application of HTS cable transmission technology in China. The localization rate of the core technology of the project is up to 100%. It is expected to be completed and put into operation by the end of 2020. At that time, it will become the 35kV superconducting cable project with the largest transmission capacity, longest distance and full commercial operation in the world.

High temperature superconductive cable is a kind of power facility which uses the superconductive material which has no resistance and can transmit high current density as the conductor and can transmit large current. It has the advantages of small volume, light weight, low loss and large transmission capacity, and can realize low loss, high efficiency and large capacity transmission. High temperature superconducting cable will be firstly used in short-distance power transmission occasions (such as generator to transformer, transformer center to substation, underground substation to urban power grid port), short-distance high current transmission occasions such as electroplating plant, power plant and substation, and large-scale or ultra large-scale urban power transmission occasions.

The transmission loss of HTS cable is only 0.5% of the transmission power, which is much lower than that of conventional cable. Under the same weight and size, compared with the conventional power cable, the capacity of HTS cable can be increased by 3-5 times, and the loss can be reduced by 60%, which can obviously save the occupied area and space, and save precious land resources. Using HTS cable to modify the existing underground cable system can not only increase the transmission capacity by more than three times, but also reduce the total cost by 20%. Using HTS cable can also change the traditional transmission mode, using low voltage and high current to transmit electric energy. Therefore, HTS cable can greatly reduce the loss of power system and improve the overall efficiency of power system, which has considerable economic benefits.

market demand

Statistics of wire and cable industry show that the annual demand for cross-linked polyethylene insulated power cables of 10kV and above in China is about 100000 km. If 5% of the total is replaced by HTS cables, the annual demand for HTS cables in China will reach 5000 km.

It is predicted that the global market for superconducting applications will reach 244 billion US dollars (about 1516.4 billion RMB) by 2020, and HTS cables will account for about 5% of the market. The existing 130000 km underground cables in the world may be replaced by HTS power cables one after another. Therefore, the market prospect of HTS cable is very broad.

Features and Application

High temperature superconducting cable is suitable for large capacity and high load density transmission. It is generally considered that the conductor current of CD insulated high temperature superconducting cable can reach 10kA or above. Compared with conventional cables, CD HTS cable has the advantage of smaller cable size, larger transmission current and larger transmission capacity under the same transmission capacity. It can replace conventional cables, such as oil filled cables and XLPE insulation, for underground transmission network in city, and solve the difficulties of simultaneous interpreting of underground electric corridors in Metro area. Or use the existing underground cable arrangement facilities, replace the existing conventional cable with high temperature superconducting cable to increase the transmission capacity. The rated voltage of this kind of HTS cable is 35-10kv, the transmission current is 2kA or above, and the transmission capacity is about 400mwa. Another important application of high temperature superconducting cable is to use high temperature superconducting cable to transmit large transmission capacity (capacity can reach more than 1000 MA) into the city load center. If conventional cables are used to transmit loads above 100mva into the urban load center, 500kV cables with rated voltage, such as 500kV XLPE cables, must be used, and 500kV substations must be built in the central urban area or near the area, but the substation location is very difficult; If a large length 500 kV XLPE cable system is adopted, the necessary high reliability 500 kV XLPE coupling joint can only be provided by Japan, and cannot be developed in the near future. The high temperature superconducting cable with super large transmission capacity can transmit 1000MW with the rated voltage of only 11kv. The CD insulated high temperature superconducting cable will be the most competitive alternative to the conventional 500kV cable. (some contents are sorted out from Baidu Encyclopedia)