Domestic welding power is “dumb”, and underwater robot is powerless.

China is a big maritime country with about 3000000 square kilometers of sea area. It is vigorously developing high-end marine resources development and marine rights protection equipment. Once there are cracks in the sea equipment, it is necessary to repair the welding equipment known as industrial sewing machine. According to science and Technology Daily reported on June 20th, deep-sea welding is achieved by underwater robots. The underwater robot welding technology in China has been difficult to upgrade because the high-end welding power technology is controlled by others. Underwater welding power is the key “The oil pipes buried in the deep sea are likely to be collided by ships, or in the spent fuel pools of the nuclear power station, causing cracks and cracks, such as the earthquake, and so on. It is necessary to weld and repair immediately, when the underwater robot is sent out for underwater welding.” Professor Wang Zhenmin, School of mechanical and automotive engineering, South China University of Technology, said, “the quality of underwater welding technology directly affects the service performance of large equipment.” Underwater robots, as the name suggests, are robots capable of performing various operations in different depths. Marine islands and reefs, offshore oil and gas fields, dam construction, large ship repair, nuclear leakage accident emergency underwater repair, military sea defense engineering, and so on, it can be easy to pay. “It dares to go where people don’t dare to go.” Wang Zhenmin said. The welding quality of underwater vehicle is controlled by many kinds of technologies, and the most important is welding power source. “Welding power supply provides energy for welding arc, and stable combustion of arc is the basic requirement during welding.” Wang Zhenmin said. Water and fire are incompatible, but underwater welding is done through fire in water. Because the welding area is always in the strong cold state of the water, there is water on the surface of the workpiece to be welded. In the arc ignition and arc welding process, the arc is easy to extinguish, and the molten metal is difficult to flow and expand, which seriously affects the stability of the arc in underwater welding. Wang Zhenmin indicated that the arc stability mainly depends on the electric characteristics of the welding power source and its dynamic control ability. However, in the field of underwater robot welding in our country, the general use of terrestrial (atmospheric environment) arc welding power is widely used, or on this basis, the structure of the underwater welding power supply is very little. The lack of high performance underwater welding power supply seriously restricts the improvement of the welding quality of the underwater robot. High end welding power is largely monopolized by foreign countries Although China is the world’s largest welding power manufacturing base, its annual production capacity has exceeded 10 million sets, but the high-end welding power supply is still basically monopolized by foreign countries. “The full digital control technology of welding power sources abroad is relatively mature, and analog control technology is still the main technology in China.” Wang Zhenmin said. Because of the non power supply of domestic power supply, the welding technology of underwater robot has been difficult to be improved. “The intelligent degree of arc welding process control is low, the investment of welding foundation research is insufficient and the process accumulation is limited, which causes the product to have no competitive advantage compared with the imported product except the price.” Wang Zhenmin pointed out that the automation level of the domestic welding power supply network is low, which leads to the limited information transmission of the automatic welding parts, and it is difficult to realize the coordinated control of the complex welding process. “The Nordic ocean has been mining very early, with considerable welding technology and deep-sea underwater welding equipment. However, the depth of offshore platforms in China is relatively shallow, and technology is at a stage of development. Shi Yonghua, a professor of the school of mechanical and automotive engineering at the South China University of Technology, said, “they have the ability to weld in waters below one thousand meters deep, and we do not.” Only one foreign company now has mastery of underwater robot welding technology. Our country can only buy abroad, not only the price is high, but also the maintenance cost is extremely high at the same time. At the same time, it must be strictly audited to use the field and scope. “Foreign technicians to repair deep-sea oil pipelines, in the area of problems in drawing a circle, millions or even millions of RMB will be lost.” Wang Zhenmin said. Although technology has a breakthrough, it is difficult to be industrialized. South China University of Technology is the first unit in China to develop modern inverter welding power equipment. In recent years, they have developed a new generation of high power inverter welding power source with high inverter frequency up to 200kHz. The increase of inverter frequency means that the control of welding arc and droplet transition will be more accurate. Compared with the industrial grade welding power supply of 20kHz in foreign countries, although the technology has made a great breakthrough, Wang Zhenmin is not happy, he said: “industrialization still has a long way to go.” The lack of professional welding talents is an important reason. Wang Zhenmin believes that, on the one hand, research in this field is difficult to send papers, many people turn to the direction of research; on the other hand, the welding power involves multidisciplinary field, its control method is closely related to the actual welding process, has a high technical threshold, and the research and Application need to accumulate for a long time, but in the last more than 10 years, China The welding profession of many universities has been abolished. The importance of welding is not enough and the treatment is poor. In addition, “more than 30 state-owned enterprises designated by the original machinery Ministry of the welding equipment industry in our country are mostly in the state of bankruptcy, bankruptcy or shutdown, but at present, the main protagonists in the market are more than 900 joint ventures and private enterprises that have grown up after the reform and opening up, and most of them have few private enterprises.” R & D capability. ” Wang Zhenmin suggested