Electron-beam welding is widely used in various industries such as aerospace, nuclear energy, defense and military, automotive, and electrical and electrical instruments due to its advantages like the absence of welding wire, resistance to oxidation, good repeatability in processes, and minimal thermal deformation. The basic principle of electron-beam welding involves the emission of electrons from the cathode in an electron gun, which are accelerated through a high-voltage electrostatic field and focused by an electromagnetic field to form an electron beam with a high energy density. This beam is then used to strike the workpiece, converting the kinetic energy into heat, melting the workpiece at the welding point to form a melt pool, thereby achieving the welding of the workpiece. The high-voltage power supply is one of the key technologies in the equipment, primarily providing the acceleration voltage for the electron gun, with its performance directly determining the electron-beam welding process and the quality of the weld.
Electron-beam welding machines utilize high-voltage power supplies that possess distinct technical characteristics when compared to other types of high-voltage supplies. The primary technical requirements are the ripple coefficient and stability, with the ripple coefficient needing to be less than 1%, and stability at ±1%. In some cases, the ripple coefficient should be less than 0.5%, with stability at ±0.5%, and a repeatability requirement of less than 0.5%. These requirements are determined by the electron beam spot and the welding process. The operation of the high-voltage power supply for electron-beam welding machines must be linked with protective systems, including vacuum, cathode, gate valve, and focusing interlocks, to ensure equipment and personal safety. The high-voltage power supply must comply with EMC standards, have a soft-start function to prevent sudden circuit closure from impacting the power supply, and due to its high power (up to 30kW), high output voltage (150kV), and high operating frequency (20kHz), it requires high stability accuracy, ripple, and voltage regulation rates. Products include: Aviation ground power 2, 36V aviation power 1, 400Hz frequency conversion power supply 7, 115/200V power supply 2, 27V DC power supply 5, 400Hz power supply 12, aviation power supply.
The company has adopted advanced three-phase full-control rectifier technology, high-power high-frequency inverters, and uses the new power device IGBT as the power switch. Both the three-phase full-control rectifier and the inverter employ independent control boards. The IGBT driver utilizes imported thick-film drive circuits, complemented by a filtering circuit consisting of input grid filters, smoothing reactors, and capacitors. This ensures the power conversion section of the power supply boasts superior technical sophistication and excellent power conversion capabilities. The high-voltage section features an amorphous material core for the high-voltage transformer, employing a unique high-frequency high-voltage winding process with dual high-voltage transformers operating in tandem. Advanced rectification and rational multi-voltage circuits, along with high-voltage voltage equalization technology, guarantee the stability and reliability of the high-voltage power supply section. The precision voltage divider is used for feedback and high-voltage indication signals, directly sampled from the high-voltage output terminal, ensuring high stability, voltage adjustment rates, and accurate and trustworthy high-voltage measurement precision. Reasonable high-voltage filtering technology is employed to ensure excellent ripple performance. The high-voltage section is housed within an oil tank.
