Design and implementation of a novel high-voltage power supply in electron beam welding machine

Traditional high-voltage power supply of electron beam welding machine has complicated circuit and huge volume. For improving the property of electron beam welding machine, a novel 60 kV/100 mA high-voltage power supply is developed in this paper. First, the three-phase electric is rectified to 540 V DC voltage. Then The voltage regulator circuit part adopts a full-bridge direct current converter controlled by pulse width modulation (PWM) method to regulate the 540 V DC voltage to adjustable 0-500 V DC voltage. A full-bridge inverter is used to change the DC voltage to 20 kHz AC voltage. Cascade-connected transformers and voltage doubling rectifiers are employed in the high voltage circuit part to achieve the 60 kV high-voltage output. In order to make the high-voltage output more stable, the double closed-loop control system based on proportion integration differentiation (PID) is adopted in the control circuit part. A high-voltage testing platform is established to measure the assembled high-voltage power supply and the test results show that the power supply has stable output voltage and high control accuracy. The ripple factor and stability are all in the 1% range, which can meet the requirement of electron beam welding machine.