With the rapid growth of the national economy and the rapid development of the power grid, the reliability and automation of the power system are increasingly demanding. Regardless of whether it is power generation, transmission, distribution, or electricity, automation, monitoring, control, and protection are proposed. Intelligent requirements.
Low-voltage circuit breakers are the most important control and protection components in low-voltage distribution systems. Its degree of automation and intelligence determine the degree of intelligence of electrical equipment. With the development and application of computer single-chip microcomputer technology, the performance of low-voltage circuit breakers in connection, disconnection, protection, safety, maintenance, etc., has changed significantly compared with low-voltage circuit breakers using thermal magnetic technology. The technical level, output, and quality of universal breakers and molded case circuit breakers in a low-voltage electrical appliance manufacturing plant represent their status in the industry to some extent. And the output value of low-voltage circuit breakers accounts for more than 50% of the total output value of low-voltage electrical appliances.
First, the status of the universal circuit breaker Zhengtai in the production of universal circuit breakers are divided into: economic, intelligent. Economical ACB: It has no selective protection function, simple structure, convenient maintenance, low breaking capacity, large arcing distance and cheap price, such as DW15, DW16, DW17.
Intelligent ACB: with a variety of protection function release, which intelligent controller with built-in open communication protocol, through the standard RS485 interface, and adapter connection, can achieve Modbus protocol and TCP / IP protocol conversion, to achieve the computer Telecommunication. High breaking capacity (Icu=Ics=50kA～125kA), zero arcing, miniaturization, structural modularization, complete accessories, product body adopts integral plastic structure, and beautiful appearance. In recent years, this series of ACB is a rapidly growing trend, such as NA1, NA8 series products.
From the point of view of grid development and application, ACB does not necessarily require that all products pursue high performance, but select different grades of products according to the needs of different grids and the nature of the load. It can be predicted that for a long time to come, ACB will simultaneously There are three grades of economic, standard and intelligent products. However, as the pace of smart grid construction in China continues to accelerate, the three product lifecycles will accelerate (3 to 5 years) the role of change.
Second, the status of molded case circuit breaker In the distribution system as the branch circuit protection function of the molded case circuit breaker must ensure that the branch circuit electricity is reliable, in order to ensure the safety of the entire distribution system. This series of products has a wide range of products, relatively high requirements for processing and manufacturing processes, and the stability of mass production can better reflect the manufacturing level of low-voltage electrical appliances in manufacturing plants.
Chint currently has a relatively large sales volume of MCCB thermal magnetic circuit breakers. It mainly relies on thermal double gold and magnetic system actions to realize various protection functions, and it is increasingly difficult to meet the reliability, accuracy, and safety requirements of distribution systems. , Communication network cannot be realized.
In 2005, Zhengtai Electric introduced a brand new NM8 series intelligent molded case circuit breaker, which adopts a rotary double break arc extinguishing system, which is small in size and high in breaking capacity. Covering a full range of products with less shells is a more advanced product at home and abroad. In addition to all the functions of the traditional MCCB, this series of products adds functions such as communication functions (Prfibus Modbus communication protocol) and fault memory. Improve the protection accuracy, make the distribution network system more reliable, safe and accurate.
Third, focus on innovation activities:
From the end of the 20th century to the beginning of the 21st century, major foreign companies have launched new types of ACBs and MCs. CB, and constantly improve and expand, both in major technical performance, product structure, new technology applications, and other major breakthroughs and innovation. Among them, Germany's Siemens is the most prominent. Its communicable low-voltage electrical appliances can already constitute a very large industrial system, power distribution monitoring system and building automation system; MDU series circuit breakers developed by Mitsubishi can directly realize the power energy monitoring network. System, equipment monitoring network system, etc.
With the research hotspots caused by smart grids at home and abroad, the “intelligent†and “communicable†of low-voltage electrical appliances will eventually develop towards smart grids, forming a low-voltage user-end industry for smart grids. The goal of the smart grid is to achieve reliable, safe, economical, efficient, environmentally friendly, and safe operation of the grid. The low-voltage users of the smart grid also have the characteristics of reliability, safety, economy, and efficiency. It is necessary to create a smart grid that cannot be separated from the grid. The basic low-voltage power distribution system and the low-voltage electrical components are intelligent and communicable. The core devices for control and protection include universal circuit breakers and molded case circuit breakers. The intelligent and communicable devices become natural Low-voltage electrical industry trends.
In view of the accelerating expansion of internationally renowned companies in China, the adjustment of China’s strategy, a new round of asset restructuring and resource integration, it will have an impact on the industrial restructuring and future development of the low-voltage electrical industry in China. With the rise of smart grids, our high-end, medium-to-high-end low-voltage electrical appliances will move closer to the direction of smart grids, and will gradually form the low-voltage end of the smart grid industry, becoming a new growth point for the low-voltage electrical appliance industry.
According to the analysis of the company's industrial conditions and technological conditions, we are developing a research and development model with talented people and collaborative development, creating a common technology research platform that fully utilizes the company’s comprehensive advantages, and extensively absorbs social resources and deep multi-discipline system integration. Forward-looking and innovative research projects are as follows:
1. Establishing the quality of key parts and components manufacturing bases directly affects the overall quality and reliability of low-voltage electrical appliances. In the highly clustered low-voltage electrical industry, low-voltage electrical components are often provided by upstream manufacturers. The parts and components supplied by upstream manufacturers vary greatly, and parts manufacturers are reluctant to invest heavily in improving the quality of parts and components. With only price competition, quality is getting worse. Therefore, it is imperative to establish key parts manufacturing bases. At the same time, we must increase the potential of suppliers with potential to enhance their management capabilities, technical quality assurance capabilities, and processing equipment to meet company requirements.
2. Development of low-voltage electrical computer-aided design software Computer-aided design and simulation of low-voltage electrical equipment, such as mechanical design CAD, circuit design CAD and simulation, is a tool for low-voltage electrical design. However, computer-aided design of low-voltage electrical appliances has strong pertinence in design, many models and nonlinear characteristics of low-voltage electrical design, complex design, and large one-time investment. Computer-aided design and simulation of low-voltage electrical appliances are still in the primitive primary stage, lacking systems. Software. Therefore, computer-aided design of low-voltage electrical appliances, secondary development of software for each system, and the training of professionals are important parts of the R&D system of low-voltage electrical products.
3. Development of testing equipment in the manufacturing process of low-voltage electrical appliances The detection efficiency and accuracy of testing equipment in the manufacturing process of low-voltage electrical appliances are the key factors in ensuring the quality and reliability of low-voltage electrical products. Through the development of low-voltage electrical equipment with intelligent testing equipment, product reliability screening, the establishment of relevant databases, low-voltage electrical product optimization design, so as to achieve the purpose of improving the quality of low-voltage electrical products.
4. The key technologies of low-voltage electrical appliances for smart grids Study of low-voltage power distribution equipment and low-voltage user-end appliances for smart grids will be the main direction of future development of low-voltage electrical appliances. Therefore, it is of great significance to study the key technologies through the form of projects.
1) Research on communications technology and related standards for electrical-grade communications Research on communications technologies is mainly focused on communications standards and communications media. Communication standards: It will focus on the communication standard of the user-side terminal equipment on the power-supply side, that is, the two-way communication related standard for intelligent low-voltage electrical appliances. This standard can realize the organic combination of product performance and communication requirements, so that the products have better interoperability. Communication media: the choice of communication media In addition to the traditional fiber-optic high-speed network, the user-side is more focused on power carrier and wireless communication technologies.
2) Wide-area measurement and control technology Wide-area measurement and control technology is the most fundamental means to achieve self-healing power grid security. It dynamically monitors the power grid in real-time and synchronously acquires the operational information of the wide-area power grid, discovers disturbances in time, and takes corresponding countermeasures. Passive processing is the active suppression of accidents. It focuses on low-voltage appliances with remote measurement and control terminal (RTU) functions.
3) Regional interlocking and selective protection technology Research on low-voltage circuit breakers' regional interlocking and zone selective interlocking technologies to improve the reliability of selective protection, shorten the selective protection time, and eliminate the phenomenon of step-by-step tripping of low-voltage circuit breakers.
Study the new type of circuit breaker that can achieve Icu=Ics=Icw and realize full selective protection.
Study the multi-level selective protection technology from the power outlet to the load side, especially at the level of selective protection: focus on (1) the time for detecting faults is short;
(2) Sending a logic wait signal is faster, allowing multiple breakers of the superior to lock at the same time.
4) Intelligentization and communication technology of low-voltage circuit breakers Research and improve the intelligent functions of low-voltage circuit breakers. With multiple bus coexisting situations, communication functions can be realized through the use of communication adapters. It integrates functions such as protection, measurement, fault early warning, self-diagnosis, monitoring, and energy management.
Achieving powerful and comprehensive power management can monitor energy consumption in real time, improve power quality, and formulate distribution system management and maintenance plans based on user conditions, making the distribution system more energy-efficient and efficient.
Low-voltage circuit breakers are the most important control and protection components in low-voltage distribution systems. Its degree of automation and intelligence determine the degree of intelligence of electrical equipment. With the development and application of computer single-chip microcomputer technology, the performance of low-voltage circuit breakers in connection, disconnection, protection, safety, maintenance, etc., has changed significantly compared with low-voltage circuit breakers using thermal magnetic technology. The technical level, output, and quality of universal breakers and molded case circuit breakers in a low-voltage electrical appliance manufacturing plant represent their status in the industry to some extent. And the output value of low-voltage circuit breakers accounts for more than 50% of the total output value of low-voltage electrical appliances.
First, the status of the universal circuit breaker Zhengtai in the production of universal circuit breakers are divided into: economic, intelligent. Economical ACB: It has no selective protection function, simple structure, convenient maintenance, low breaking capacity, large arcing distance and cheap price, such as DW15, DW16, DW17.
Intelligent ACB: with a variety of protection function release, which intelligent controller with built-in open communication protocol, through the standard RS485 interface, and adapter connection, can achieve Modbus protocol and TCP / IP protocol conversion, to achieve the computer Telecommunication. High breaking capacity (Icu=Ics=50kA～125kA), zero arcing, miniaturization, structural modularization, complete accessories, product body adopts integral plastic structure, and beautiful appearance. In recent years, this series of ACB is a rapidly growing trend, such as NA1, NA8 series products.
From the point of view of grid development and application, ACB does not necessarily require that all products pursue high performance, but select different grades of products according to the needs of different grids and the nature of the load. It can be predicted that for a long time to come, ACB will simultaneously There are three grades of economic, standard and intelligent products. However, as the pace of smart grid construction in China continues to accelerate, the three product lifecycles will accelerate (3 to 5 years) the role of change.
Second, the status of molded case circuit breaker In the distribution system as the branch circuit protection function of the molded case circuit breaker must ensure that the branch circuit electricity is reliable, in order to ensure the safety of the entire distribution system. This series of products has a wide range of products, relatively high requirements for processing and manufacturing processes, and the stability of mass production can better reflect the manufacturing level of low-voltage electrical appliances in manufacturing plants.
Chint currently has a relatively large sales volume of MCCB thermal magnetic circuit breakers. It mainly relies on thermal double gold and magnetic system actions to realize various protection functions, and it is increasingly difficult to meet the reliability, accuracy, and safety requirements of distribution systems. , Communication network cannot be realized.
In 2005, Zhengtai Electric introduced a brand new NM8 series intelligent molded case circuit breaker, which adopts a rotary double break arc extinguishing system, which is small in size and high in breaking capacity. Covering a full range of products with less shells is a more advanced product at home and abroad. In addition to all the functions of the traditional MCCB, this series of products adds functions such as communication functions (Prfibus Modbus communication protocol) and fault memory. Improve the protection accuracy, make the distribution network system more reliable, safe and accurate.
Third, focus on innovation activities:
From the end of the 20th century to the beginning of the 21st century, major foreign companies have launched new types of ACBs and MCs. CB, and constantly improve and expand, both in major technical performance, product structure, new technology applications, and other major breakthroughs and innovation. Among them, Germany's Siemens is the most prominent. Its communicable low-voltage electrical appliances can already constitute a very large industrial system, power distribution monitoring system and building automation system; MDU series circuit breakers developed by Mitsubishi can directly realize the power energy monitoring network. System, equipment monitoring network system, etc.
With the research hotspots caused by smart grids at home and abroad, the “intelligent†and “communicable†of low-voltage electrical appliances will eventually develop towards smart grids, forming a low-voltage user-end industry for smart grids. The goal of the smart grid is to achieve reliable, safe, economical, efficient, environmentally friendly, and safe operation of the grid. The low-voltage users of the smart grid also have the characteristics of reliability, safety, economy, and efficiency. It is necessary to create a smart grid that cannot be separated from the grid. The basic low-voltage power distribution system and the low-voltage electrical components are intelligent and communicable. The core devices for control and protection include universal circuit breakers and molded case circuit breakers. The intelligent and communicable devices become natural Low-voltage electrical industry trends.
In view of the accelerating expansion of internationally renowned companies in China, the adjustment of China’s strategy, a new round of asset restructuring and resource integration, it will have an impact on the industrial restructuring and future development of the low-voltage electrical industry in China. With the rise of smart grids, our high-end, medium-to-high-end low-voltage electrical appliances will move closer to the direction of smart grids, and will gradually form the low-voltage end of the smart grid industry, becoming a new growth point for the low-voltage electrical appliance industry.
According to the analysis of the company's industrial conditions and technological conditions, we are developing a research and development model with talented people and collaborative development, creating a common technology research platform that fully utilizes the company’s comprehensive advantages, and extensively absorbs social resources and deep multi-discipline system integration. Forward-looking and innovative research projects are as follows:
1. Establishing the quality of key parts and components manufacturing bases directly affects the overall quality and reliability of low-voltage electrical appliances. In the highly clustered low-voltage electrical industry, low-voltage electrical components are often provided by upstream manufacturers. The parts and components supplied by upstream manufacturers vary greatly, and parts manufacturers are reluctant to invest heavily in improving the quality of parts and components. With only price competition, quality is getting worse. Therefore, it is imperative to establish key parts manufacturing bases. At the same time, we must increase the potential of suppliers with potential to enhance their management capabilities, technical quality assurance capabilities, and processing equipment to meet company requirements.
2. Development of low-voltage electrical computer-aided design software Computer-aided design and simulation of low-voltage electrical equipment, such as mechanical design CAD, circuit design CAD and simulation, is a tool for low-voltage electrical design. However, computer-aided design of low-voltage electrical appliances has strong pertinence in design, many models and nonlinear characteristics of low-voltage electrical design, complex design, and large one-time investment. Computer-aided design and simulation of low-voltage electrical appliances are still in the primitive primary stage, lacking systems. Software. Therefore, computer-aided design of low-voltage electrical appliances, secondary development of software for each system, and the training of professionals are important parts of the R&D system of low-voltage electrical products.
3. Development of testing equipment in the manufacturing process of low-voltage electrical appliances The detection efficiency and accuracy of testing equipment in the manufacturing process of low-voltage electrical appliances are the key factors in ensuring the quality and reliability of low-voltage electrical products. Through the development of low-voltage electrical equipment with intelligent testing equipment, product reliability screening, the establishment of relevant databases, low-voltage electrical product optimization design, so as to achieve the purpose of improving the quality of low-voltage electrical products.
4. The key technologies of low-voltage electrical appliances for smart grids Study of low-voltage power distribution equipment and low-voltage user-end appliances for smart grids will be the main direction of future development of low-voltage electrical appliances. Therefore, it is of great significance to study the key technologies through the form of projects.
1) Research on communications technology and related standards for electrical-grade communications Research on communications technologies is mainly focused on communications standards and communications media. Communication standards: It will focus on the communication standard of the user-side terminal equipment on the power-supply side, that is, the two-way communication related standard for intelligent low-voltage electrical appliances. This standard can realize the organic combination of product performance and communication requirements, so that the products have better interoperability. Communication media: the choice of communication media In addition to the traditional fiber-optic high-speed network, the user-side is more focused on power carrier and wireless communication technologies.
2) Wide-area measurement and control technology Wide-area measurement and control technology is the most fundamental means to achieve self-healing power grid security. It dynamically monitors the power grid in real-time and synchronously acquires the operational information of the wide-area power grid, discovers disturbances in time, and takes corresponding countermeasures. Passive processing is the active suppression of accidents. It focuses on low-voltage appliances with remote measurement and control terminal (RTU) functions.
3) Regional interlocking and selective protection technology Research on low-voltage circuit breakers' regional interlocking and zone selective interlocking technologies to improve the reliability of selective protection, shorten the selective protection time, and eliminate the phenomenon of step-by-step tripping of low-voltage circuit breakers.
Study the new type of circuit breaker that can achieve Icu=Ics=Icw and realize full selective protection.
Study the multi-level selective protection technology from the power outlet to the load side, especially at the level of selective protection: focus on (1) the time for detecting faults is short;
(2) Sending a logic wait signal is faster, allowing multiple breakers of the superior to lock at the same time.
4) Intelligentization and communication technology of low-voltage circuit breakers Research and improve the intelligent functions of low-voltage circuit breakers. With multiple bus coexisting situations, communication functions can be realized through the use of communication adapters. It integrates functions such as protection, measurement, fault early warning, self-diagnosis, monitoring, and energy management.
Achieving powerful and comprehensive power management can monitor energy consumption in real time, improve power quality, and formulate distribution system management and maintenance plans based on user conditions, making the distribution system more energy-efficient and efficient.