At present, the concept of "global energy Internet" is in the ascendant. The research and engineering practice of HVDC technology is very active, especially in China, India, South America and the EU. On October 25, the 2nd International High Voltage Direct Current Conference (HVDC2016) was held in Shanghai. During the three-day conference, more than 300 experts from 12 countries focused on high-voltage high-power power electronics, HVDC equipment, conventional HVDC / UHVDC, HVDC, HVDC systems and operations, Transmission, flexible DC transmission, DC transmission equipment and other directions, designed to recommend HVDC technology in the world of research and application. Flexible DC transmission At present, China has fully mastered the manufacturing capability of the core technologies of UHVDC and complete equipment, and has made a number of world-class innovations in areas such as control and protection of large power grids, smart grids and access to clean energy grids. Currently established a system of UHV and smart grid technology standard system, the preparation of the relevant international standards. UHV technology and equipment are independent innovation in the field of energy in China, the world's first, with the dominant international standards and strong competitive advantage of major technology, but also an important symbol of national innovation capability and overall strength. HVDC technology has been widely used in the transmission of long-distance trans-regional power, interconnection of asynchronous power grids, and power transmission in weak power networks. Converter valve technology is the key core of HVDC transmission technology. Nantui Group CPRI Power Engineering Co., Ltd. General Manager Kun Kun inspection focuses on China HVDC converter valve technology and applications. At present, HVDC converter valve technology is divided into two categories, one is the use of LCC technology converter valve, one is the application of VSC converter valve technology. Kun Kun Peng said that most of the UHV / UHVDC projects in operation in China are LCC-commutated valves, and the existing LCC commutation valves have reached the technical specifications of ± 800 kV / 5000 amps. Based on the existing ± 800 kV / 5000 amp technology, two further specifications, ± 1100 kV / 5500 Amperes and ± 800 kV / 6250 Amps, will be further developed. VSC converter valve technology is a new generation of converter technology, which in the new energy grid, island power transmission and other fields with great advantages. The converter valve using this technology has been successfully applied in the Shanghai Southwind Project, Zhoushan Project in Zhejiang Province and Xiamen Project in Fujian Province. In the future, the converter valve with higher voltage and larger capacity will be applied in the back-to-back project of Henan-Hubei in 2017. Zheng Hongju, general manager of Hyosung's grid department, analyzed in detail the recent 20MW VSC-HVDC project in South Korea's HVDC project for wind power grid integration. This application has been researched by government organizations since 2012 and is based on MMC technology. According to reports, South Korea Hyosung also STATCOM technology in the field of applications, in 2015 has been put into operation a 100Mvar capacity STATCOM project and plans to carry out in 2016 the application of MMC technology STATCOM research and development. With regard to the rapid isolation failure in HVDC technology, He Zhiyuan, director of the Institute of DC Power Transmission Technology at the Global Energy Internet Institute, introduced a new DC circuit breaker whose main circuit consists of a mechanical circuit breaker and several full-bridge SMs Module, the bypass circuit consists of several SM modules, the energy absorption circuit is mainly composed of surge arresters. In normal operation, the current flows through the main circuit. When the fault current is generated, the SM module in the main circuit is blocked and the fault current flows through the bypass circuit within 100-200 microseconds. When the main circuit current is zero, the mechanical switch is turned off. Then, the bypass circuit SM blocking makes the DC circuit breaker voltage rise to two stages of varistor level of action, and then complete the disconnect. Today, UHV, high-capacity transmission characteristics of the converter transformer put forward a high technological requirements, so the use of multi-terminal UHV DC transmission technology has become a solution to these problems, a program, multi-terminal UHVDC transmission technology also has Diversified modes of transport, flexible transmission characteristics. Wang Weiguo, Project Development Manager of ABB China Power Grid, introduced ABB's development of UHVDC and flexible DC grid: ABB's dual-mode insulated gate transistor BIGT technology with reverse-conducting IGBT concept further enables VSC converter valve to reach 3000 Ampere / 800 kV technical indicators. ABB currently has the capability to produce 525 kV DC cables and the next step is to develop larger capacity DC cables rated 600 kV to 800 kV. Flexible DC power grid upgrade weapon Flexible DC transmission is a new DC transmission mode after AC transmission and conventional DC transmission. It is the most controllable and adaptable transmission technology in the world at present, which provides an effective technical means for upgrading the power grid. Europe is vigorously promoting the transformation of energy structure and realizing the development and utilization of a high proportion of renewable energy. Plans to connect the North Sea and Atlantic far-sea wind power, hydropower in Finland and Norway, and solar energy in northern Africa to the grid urgently require new transmission technologies. To this end, Europe plans a new transmission network based on flexible DC to achieve a wide range of renewable energy sources to accept and configure. Multiple Way Valves ,Multi-Way Valve,Multi-Way Directional Valve,Multiple Way Reversing Valve Zhejiang Haihong Hydraulic Technology Co.,Ltd. , https://www.haihong-hydraulic.com
HVDC technology to the world!