Relay industry has huge potential for development

With the gradual implementation of the industrial revitalization policy, experts predict that during the “Twelfth Five-Year Plan” period, the required amount of the relay and the application field will continue to grow and develop. The traditional electromechanical relay will grow at a speed of about 8%, and the development speed of solid state relays will increase. Will remain at about 15%, special relays will be rapid development of more than 20%.

UHV relay technology is a challenge According to the introduction of Professor Yang Qixun, an academician of the Chinese Academy of Engineering and a professor of North China Electric Power University, the development of power grids and the application of new power grid technologies have promoted the development of relay protection technologies, and have also increased the complexity of relay protection technologies. Traditional relay protection applications and management methods pose even greater challenges. The rapid increase of short-circuit current level requires a higher speed of relay protection; the application of DC transmission and series compensation technology requires a technical breakthrough in relay protection; compact lines, multi-circuit lines on the same pole, and short-circuit lines in cities with high voltage The emergence of a large number of them makes the configuration, setting and cooperation of relay protection more complicated. The development of power grid equipment and operation control technologies, such as digital substation research, application of unattended substations, and construction and operation of UHV power grids, will impose higher requirements on the technical performance of relay protection. It is necessary to study and propose new relays. Protection solution. The actual operation of the power grid and lessons learned from domestic and foreign power grid accidents indicate that failure of a single component of a single relay protection device or device may lead to power grid accidents, and the reliability of relay protection equipment still needs to be further improved.

UHV power grids have distinct features that distinguish them from ultra-high voltage power grids. At present, there are many technical difficulties in relay protection, such as the influence of capacitive currents on the protection characteristics of ultra-high voltage lines, the influence of submergence currents on reclosing, and UHV Relay protection equipment such as electromagnetic compatibility. It is understood that at present China's relevant agencies have carried out a series of independent research and development work, and have achieved initial results.

Microcomputer protection is the technological development of relay protection in the development direction, and it is inextricably linked with the development of electronics, information, and communication technologies. In the future, with the gradual improvement of electronic CT (Current Transformer) and PT (Voltage Transformer), and the further improvement of the IEC61850 standardization protocol, it can be foreseen that digital technology will be used more widely. In China, there are 110 kV and 220 kV voltage-grade electronic CTs and electronic PTs that have been put into trial operation. The research and development of relay protection devices for electronic CT and PT will promote the development of relay protection technology and promote relaying. Changes in the protection of new principles, new technologies, and new applications have become new topics for protection researchers.

Microcomputer protection is achieved by software protection functions, compared with the traditional transistor, integrated circuit protection, has a strong self-test function, high integration of protection features, stable operating characteristics, high reliability, low maintenance and other significant advantages, represents the following The development direction of electric protection technology.

China's microcomputer relay protection research started in the late 1970s. In 1984, the first microcomputer line protection device in China was identified and applied in the system. After more than 20 years of development, domestic microcomputer protection technology has been continuously improved, and many achievements and patents have been achieved in terms of computer protection hardware, software, and algorithms. Four generations of microcomputer protection devices have been introduced, and all performance and operating indicators have exceeded imports. Products are in a leading position in the world. Domestic microcomputer protection has replaced transistors, integrated circuits and other protections, and has occupied a dominant position.

With high industry barrier characteristics, power equipment is divided into primary equipment and secondary equipment. Primary equipment refers to equipment that directly assumes the functions of power generation, transmission, transformation, distribution, and power usage, such as generators and transformers. The technical content is relatively low. There are many manufacturers and competition is fierce. Secondary equipment refers to various equipment required for the normal operation of a primary equipment and the realization of power management objectives, such as generator set protection and dispatching automation systems. Compared with the same equipment, secondary equipment production has higher industry barriers. The industry's products bring together modern electronic technology, communication technology, computer and network technology, with high technical content and high added value, and are typically high. Technology industry. Although the relay industry in our country has achieved remarkable results after years of development, there are still only a handful of companies capable of producing secondary equipment in China.