Market and future development trend of HVDC transmission system in countries of the world and China

As we all know, my country has a vast territory, uneven energy distribution, uneven load development, water resources are concentrated in the southwest provinces, coal resources are concentrated in the central and northwest provinces, and loads are concentrated in the eastern coastal areas. inevitable trend of development. In recent years, many large and medium-sized power transmission projects in my country have successfully used this power transmission technology and achieved remarkable results. High-voltage power transmission technology also has a number of advantages that AC power cannot replace in realizing the power market economy. important role.

High voltage direct current (HVDC) is a high voltage direct current transmission system. In the case of long-distance power transmission and submarine cable power transmission, compared with the current AC power transmission system, high-voltage direct current transmission has large transmission power and less loss, so the cost is lower. However, in the case of short distances, the cost of the current AC power transmission system is cheaper.

Compared with traditional AC transmission, HVDC transmission has less investment and lower power loss, so it has more advantages in long-distance power transmission, and the power transmission efficiency between power point and load center is higher. Compared with AC transmission, with the same output power, DC overhead lines can save about one-third of the steel-cored aluminum wire, one-third of the steel, one-third of the line cost, and line loss. The power loss of DC transmission is generally 3% per 1000 kilometers, which varies with the voltage level and structure.

High-voltage direct current transmission (HVDC) is a high-power long-distance direct current transmission that utilizes the advantages of stable direct current with no inductive reactance, capacitive reactance does not work, and no synchronization problems. The power transmission process is direct current. It is often used in submarine cable power transmission, communication between asynchronously operating AC systems, etc. The HVDC transmission system includes converters, converter transformers, smoothing reactors, AC filters, DC arresters, control and protection equipment, transmission lines, etc. The new crown epidemic has had a certain impact on the supply chain of some HVDC transmission systems.

At present, major manufacturers in the world include Hitachi ABB Power Grids, Siemens, Prysmian Group, China XD, GE Grid Solutions, TBEA, XJ Group, Nexans, NKT, Toshiba Energy Systems & Solutions, Mitsubishi Electric, etc., 2020 will be the world's top The top ten HVDC system manufacturers account for about 71% of the market share. Competition in the industry is expected to intensify in the next few years, especially in the Chinese market. At present, domestic enterprises participating in the competition in the HVDC transmission system industry mainly include China Xidian, TBEA, XJ Group, and NARI.

In recent years, benefiting from the promotion of the country's domestic substitution policy for high-voltage power transmission equipment and the improvement of product strength brought about by years of technology accumulation, the market share of domestic high-voltage direct current transmission system manufacturers has continued to rise. The growing trend of the domestic HVDC power transmission system camp has had a certain impact on the competition pattern of the domestic HVDC power transmission system market, and the market competition has continued to intensify. ?High-voltage direct current transmission has always occupied an important position in the development of my country's power grid. As the advantages of direct current transmission have become more and more obvious in recent years, the research and development of high-voltage direct current transmission technology in my country has been strengthened, and equipment manufacturing and transmission technology have been vigorously developed. Some power grid structure and control protection technology can improve the stability and safety of DC transmission and promote the development of my country's power grid. The development of power transmission technology in the future will inevitably have the characteristics of economy and safety. Although DC transmission technology has been developed for many years and related equipment and technologies are becoming mature, there is still a lot of room for development, especially in the transmission voltage. In terms of leveling and reducing the probability of failure, if breakthroughs can be made in these areas, my country's DC transmission technology will inevitably make greater progress.