According to the welding energy to produce the basic characteristics of the welding process, the welding methods, it can be divided into five categories, i.e., arc welding, resistance welding, special welding, gas welding and brazing. Different types of welding equipment have different testing methods and testing equipment, the welding power of the mechanical, electrical performance testing projects and the focus is also different. Electric arc welding and resistance welding are the most widely used welding method. Electric arc welding and resistance welding power supply detection equipment is the most commonly used two power detection equipment.

1 resistance welding power supply test equipment

Traditional resistance welding power test equipment is the main current tester, was generally detected only welding current size and the length of time, detection of welding current only two forms as the alternating current and the secondary rectifier DC current. Along with the increasing development of electronic technology and computer technology, new inverter DC, AC, square wave pulse, capacitors and other forms of resistance welding power source emerge in endlessly, this kind of power source welding current with non sinusoidal, non periodic, also in addition to Welding Machine electrical performance parameters were detected need the mechanical properties of welding electrode pressure size, welding in the process of electrode displacement size (reflecting the quality of welding parameters, cooling water flow rate etc. parameters were tested and the test results in the formation of the report, the traditional testing equipment has been unable to meet the the test requirements.

In recent years, Japan, Germany and other developed countries has already introduced and industrial control computer connection information, the welding quality control and inspection for various multifunction resistance welding testing equipment. Such as Japan Miyachi MM-360A for resistance spot welding tester in the welding process in the simultaneous measurement of pressure and current welding, and show that both waveform, but also with on-line computer processing of the measured data; MM-730A resistance welding tester by diamagnetic interference displacement sensor and the welding electrode displacement monitoring, so as to realize the indirect control of welding nugget formation. Germany Boschrexroth inverter resistance welding and its precision control technology has been widely used in industrial production systems.

Boschrexroth can be said to be the world’s largest medium frequency resistance welding system manufacturer, the multifunctional if welding controller PSI63S “(resistance welding constant power control technology and ultrasonic control technology), is not in the traditional sense of the intermediate frequency controller. It has integrated the common intermediate frequency controller, a welding controller monitors (constant power control technology and ultrasonic technology control) and servo movement controller (pneumatic or electronic components motor) universal controller, it can be closed loop control of welding current, welding time, welding power, welding nugget size, welding position, welding displacements, welding pressure parameters. The development direction of the resistance welding control monitoring system is the real time control of all welding parameters and the welding controller at the same time.

2 arc welding power source

With the development of resistance welding equipment, welding power supply testing equipment has also experienced different stages of development. With its technical content and characteristics, it is divided into four stages. In China’s welding and testing equipment, the most representative arc welding power supply testing equipment to Chengdu Electric Welding Machine research, national electric welding machine testing center (Chengdu electrical inspection), Chengdu Third Party Electric Co., Ltd. mainly developed test bench.

A) the first generation of detection equipment to Chengdu electric welding machine research the production of HHC series arc welding power source test bench as the representative, traditional transformers, shunts are used for current sensing original and to the pointer type current, voltage, power station, on the measurements of the welding power supply current, voltage, power, with switching contactor and change without a sense of the magnitude of the load resistance to simulate arc. At present, the testing equipment in part of the welding power producing plant still use. It has characteristics of high precision, good stability and reliability, but the volume is large, use and maintenance of the complex, single function, the degree of automation of the bottom, it is difficult to meet the modern high-efficiency production test.

B), second generation test equipment to Chengdu Electrical Inspection Institute, Chengdu Sanfang Electrical Appliance Co., Ltd. research and production of the digital TDC series power test bench as the representative, digital instrument replaced the pointer table, the Hall current sensor instead of transformer and shunt, in terms of function and testing accuracy and first generation device, but volume is greatly decreased, the use and maintenance have greatly improved, visual reading, convenient operation, national most welding power production enterprises are widely used, but it still carries the disadvantage of first generation devices.

C) of modern manufacturing technology and welding production development, higher requirements on welding testing equipment in the test content, real-time and accuracy of test all aspects, making traditional detecting instrument in the structural and functional limitations highlight the growing, is difficult to adapt to and meet the needs of high efficiency, large information of modern detection work. The third generation of detection equipment is by Chengdu Sanfang Electric Co., Ltd. in on the basis of the prototype of the involved in the development of the national Ministry of science and technology special fund project “intelligent AC / DC power supply test system”, after the second development of the design of the launch of the new generation PTE series of information detection system is a typical representative. It with virtual instrument technology for the implementation of the platform, with the advantages of large amount of information, the detection speed fast, excellent man-machine interface, high precision and strong flexibility, also the realization of the analysis, the real-time measurement of power factor and efficiency, and other important parameters of arc welding power source harmonic current.