[Abstract] This paper describes the development and application status of welding inverter power supply, briefly analyzes the factors that restrict the popular application of domestic inverter welding machine, and proposes corresponding countermeasures and development trends.
[Key words] inverter power supply; reliability; development trend
1 Introduction – The manufacture of welding power supplies has a history of more than 100 years. After the 1960s, silicon rectifier components, high power transistors (GTR), field effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), etc. The emergence of devices, the development of integrated circuit technology and control technology, provides a broader space for the development of electronic welding power supply, the most striking of which is the inverter welding power supply. The inverter welding power supply is small in size, light in weight, energy-saving and material-saving, and has good control performance, fast dynamic response, easy real-time control of the welding process, and great potential advantage in performance. From a long-term perspective, inverter welding power supply is the development direction of welding power supply, and the development of foreign inverter welding machine also fully illustrates this point. At present, in industrialized countries, manual arc welding / TIG welding / MIG / MAG welding has widely used inverter power. Several major welding machine manufacturers in the world have completed the serialization of inverter welding machines and used this as one of the indicators of the technical level.
2 Development and application status of welding inverter power supply - Inverter power supply is called ''Tomorrow's power supply'', and its application in welding equipment has brought revolutionary changes in the development of welding equipment. First of all, the inverter welding power source and the power frequency welding power source are 20% to 30% more energy efficient, and the efficiency can reach 80% to 90%. Secondly, the inverter welding power source is small in size and light in weight, and the weight of the whole machine is only the traditional power frequency. 1/5 to 1/10 of the rectification welding power source reduces material consumption by 80% to 90%. In particular, the inverter welding power supply has the advantage of fast dynamic response speed, and its dynamic reaction speed is increased by 2 to 3 orders of magnitude compared with the conventional power frequency rectification welding power source, which is beneficial to realize the automation and intelligent control of the welding process. These all indicate that the inverter welding power supply has broad application prospects and market potential. At present, in the electric arc welding machines of Japan Matsushita Electric Co., Ltd. and Osaka Transformer Co., the inverter welding machines are more than 50%. Inverter welders produced by major US welder manufacturers have exceeded 30%. The development speed of inverter welding power sources in Other industrialized countries is also very fast.
The research and development of inverter welding machines in China started in the late 1970s and began to develop in the 1980s. In 1982, Chengdu Electric Welding Machine Research Institute began research on thyristor inverter arc welding rectifier. In 1983, it developed China's first commercial ZX7-250 inverter arc welding power source, and passed the Ministry of the project. Level identification. Subsequently, Tsinghua University, Harbin Institute of Technology, South China University of Technology and Times Company successively introduced inverter welding machines using various switching elements. Now, China's inverter welding machine power supply has formed 4 generations of products: the first generation is the inverter with thyristor SCR as the main attack rate device; the second generation is the transistor inverter; the third generation is the FET inverter The fourth generation is an IGBT inverter with high inverter frequency, reduced saturation voltage, low power consumption, high efficiency, and no noise. Compared with the previous 3 generation inverters, the advantages are more obvious.
3 The development direction of inverter power supply - The general development trend of variable power supply is to become more and more widely applied to the development of large capacity, light weight, high efficiency, modularization, intelligent development and improvement of reliability, performance and widening of use. In various arc welding methods, resistance welding, cutting and other processes. Efficient and high power density (miniaturization) is one of the main goals pursued by international arc welding inverters. High frequency and reduced power consumption of major devices are the main technical approaches to achieve this goal. At present, in Japan, Europe and other countries and regions, the arc welding inverter technology of about 20KHz has matured, the quality of the products is high and the products have been serialized.
4 There is a problem
(1) Quality: Although the inverter welding machine replaces the arc welding rectifier in some occasions, its reliability is still different from that of the general hand arc welding machine. At present, the main factor restricting the promotion and wide application of domestic inverter welding machines is the reliability of the welding machine. Some famous foreign welding machine manufacturers have continuously improved the inverter welding machine, so that its reliability is close to the failure rate of the general welding machine, which is about 1%. Another problem is that compared with foreign countries, the gap between equipment, instruments, tools, tooling, testing methods, personnel quality and raw material components, the reliability of the welder is not guaranteed, and the repair rate is high.
(2) Research and development: The broad prospects for the development of inverter welding machines have attracted many colleges and universities. However, due to the combination of strong and weak electricity in the inverter welding power source, the traditional experimental method used in the development not only consumes a lot of manpower, material resources and time, but also some problems are difficult to find and solve experimental methods. Therefore, new design methods and means need to be proposed.
5 Countermeasures
Inverter welding machines have reliability and quality problems. The main reasons are:
(1) The technology is not mature, the strength of new product development is insufficient; (2) The structural design and manufacturing process structure and wiring are unreasonable, the protection link has not reached the optimization coordination; (3) the quality assurance system is imperfect, and the testing and testing methods are backward; 4) The manufacturing quality of raw material components (such as IGBT, MOSFYT, magnetic core materials, etc.) is unreliable; (5) The production scale is small, and the assembly line and mold cannot be used for assembly and debugging.
To this end, the following countermeasures are recommended:
(1) Pay close attention to talent development and foreign information collection, and strengthen the construction of special and complete equipment research and test bases to ensure product quality and performance;
(2) The combination of theoretical calculation and test calibration makes it possible to optimize the key main circuit design and protection link to determine the reliability and quality. It is best to use computer simulation and CAD to save design and manufacture debugging. The time of the device can reduce the burning loss of the inverter main circuit components;
(3) Improve the quality of the workforce and improve the testing methods. Through the characteristic tester of the electronic power device, the critical devices (IGBT|, fast diode, etc.) are carefully detected, selected and matched. Aging and testing tests on components and complete machines using a board-specific tester;
(4) Expand the production scale as much as possible so that the production line, automatic operation machine, mold and other advanced means can be used to ensure the consistency and accuracy of the product manufacturing process, thus ensuring the consistency and reliability of each product quality.
[Key words] inverter power supply; reliability; development trend
1 Introduction – The manufacture of welding power supplies has a history of more than 100 years. After the 1960s, silicon rectifier components, high power transistors (GTR), field effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), etc. The emergence of devices, the development of integrated circuit technology and control technology, provides a broader space for the development of electronic welding power supply, the most striking of which is the inverter welding power supply. The inverter welding power supply is small in size, light in weight, energy-saving and material-saving, and has good control performance, fast dynamic response, easy real-time control of the welding process, and great potential advantage in performance. From a long-term perspective, inverter welding power supply is the development direction of welding power supply, and the development of foreign inverter welding machine also fully illustrates this point. At present, in industrialized countries, manual arc welding / TIG welding / MIG / MAG welding has widely used inverter power. Several major welding machine manufacturers in the world have completed the serialization of inverter welding machines and used this as one of the indicators of the technical level.
2 Development and application status of welding inverter power supply - Inverter power supply is called ''Tomorrow's power supply'', and its application in welding equipment has brought revolutionary changes in the development of welding equipment. First of all, the inverter welding power source and the power frequency welding power source are 20% to 30% more energy efficient, and the efficiency can reach 80% to 90%. Secondly, the inverter welding power source is small in size and light in weight, and the weight of the whole machine is only the traditional power frequency. 1/5 to 1/10 of the rectification welding power source reduces material consumption by 80% to 90%. In particular, the inverter welding power supply has the advantage of fast dynamic response speed, and its dynamic reaction speed is increased by 2 to 3 orders of magnitude compared with the conventional power frequency rectification welding power source, which is beneficial to realize the automation and intelligent control of the welding process. These all indicate that the inverter welding power supply has broad application prospects and market potential. At present, in the electric arc welding machines of Japan Matsushita Electric Co., Ltd. and Osaka Transformer Co., the inverter welding machines are more than 50%. Inverter welders produced by major US welder manufacturers have exceeded 30%. The development speed of inverter welding power sources in Other industrialized countries is also very fast.
The research and development of inverter welding machines in China started in the late 1970s and began to develop in the 1980s. In 1982, Chengdu Electric Welding Machine Research Institute began research on thyristor inverter arc welding rectifier. In 1983, it developed China's first commercial ZX7-250 inverter arc welding power source, and passed the Ministry of the project. Level identification. Subsequently, Tsinghua University, Harbin Institute of Technology, South China University of Technology and Times Company successively introduced inverter welding machines using various switching elements. Now, China's inverter welding machine power supply has formed 4 generations of products: the first generation is the inverter with thyristor SCR as the main attack rate device; the second generation is the transistor inverter; the third generation is the FET inverter The fourth generation is an IGBT inverter with high inverter frequency, reduced saturation voltage, low power consumption, high efficiency, and no noise. Compared with the previous 3 generation inverters, the advantages are more obvious.
3 The development direction of inverter power supply - The general development trend of variable power supply is to become more and more widely applied to the development of large capacity, light weight, high efficiency, modularization, intelligent development and improvement of reliability, performance and widening of use. In various arc welding methods, resistance welding, cutting and other processes. Efficient and high power density (miniaturization) is one of the main goals pursued by international arc welding inverters. High frequency and reduced power consumption of major devices are the main technical approaches to achieve this goal. At present, in Japan, Europe and other countries and regions, the arc welding inverter technology of about 20KHz has matured, the quality of the products is high and the products have been serialized.
4 There is a problem
(1) Quality: Although the inverter welding machine replaces the arc welding rectifier in some occasions, its reliability is still different from that of the general hand arc welding machine. At present, the main factor restricting the promotion and wide application of domestic inverter welding machines is the reliability of the welding machine. Some famous foreign welding machine manufacturers have continuously improved the inverter welding machine, so that its reliability is close to the failure rate of the general welding machine, which is about 1%. Another problem is that compared with foreign countries, the gap between equipment, instruments, tools, tooling, testing methods, personnel quality and raw material components, the reliability of the welder is not guaranteed, and the repair rate is high.
(2) Research and development: The broad prospects for the development of inverter welding machines have attracted many colleges and universities. However, due to the combination of strong and weak electricity in the inverter welding power source, the traditional experimental method used in the development not only consumes a lot of manpower, material resources and time, but also some problems are difficult to find and solve experimental methods. Therefore, new design methods and means need to be proposed.
5 Countermeasures
Inverter welding machines have reliability and quality problems. The main reasons are:
(1) The technology is not mature, the strength of new product development is insufficient; (2) The structural design and manufacturing process structure and wiring are unreasonable, the protection link has not reached the optimization coordination; (3) the quality assurance system is imperfect, and the testing and testing methods are backward; 4) The manufacturing quality of raw material components (such as IGBT, MOSFYT, magnetic core materials, etc.) is unreliable; (5) The production scale is small, and the assembly line and mold cannot be used for assembly and debugging.
To this end, the following countermeasures are recommended:
(1) Pay close attention to talent development and foreign information collection, and strengthen the construction of special and complete equipment research and test bases to ensure product quality and performance;
(2) The combination of theoretical calculation and test calibration makes it possible to optimize the key main circuit design and protection link to determine the reliability and quality. It is best to use computer simulation and CAD to save design and manufacture debugging. The time of the device can reduce the burning loss of the inverter main circuit components;
(3) Improve the quality of the workforce and improve the testing methods. Through the characteristic tester of the electronic power device, the critical devices (IGBT|, fast diode, etc.) are carefully detected, selected and matched. Aging and testing tests on components and complete machines using a board-specific tester;
(4) Expand the production scale as much as possible so that the production line, automatic operation machine, mold and other advanced means can be used to ensure the consistency and accuracy of the product manufacturing process, thus ensuring the consistency and reliability of each product quality.
Yugong Machinery Manufacturing Factory , http://www.gybiomassmachine.com