High-power And High-voltage DC Power Supply

With the rapid development of power electronics technology and unparalleledsuperiority contrast to linear power supplies, the use of switching power supply deepinto the various fields of social, domestic and industrial more and more. Depending onprople’s requirement, switching power supply industry develops rapidly toward adirection of lighter, smaller, lower noise, higher reliability, anti-jamming.This paper describes a switching power supply with adjustable output. It mainlyused in the space electromagnetic levitation system for precise control of the current, toachieve a high degree of stability, precise identification of the control signal andreduction of the switching noise, and thus control the movement of object suspended inspace electromagnetic levitation system accurately by precise control of the currentsize.The key technologies include the inverter circuit with IGBT full-bridge and thePulse Width Modulation (PWM). Full-bridge inverter circuit is formed by the powerswitch and transformer. Four IGBT divided into two groups turn on and off alternatelycontrolled by pulse width modulation circuit. Then the output turn into a formation ofhigh-frequency AC signal. PWM is a technology the duty cycle of the output pulsecontrolled by regulating the pulse width. The voltage feedback from the output putsinto the negative feedback side of the SG3525after the PI regulator, so the entirepower is work in real-time and closed-loop. And the width of the output pulse isadjusted at the same time, so does output voltage.The experimental data given in the paper show that the device can transform ACcollected from the grid into DC, and adjust the output with input by manually orcomputer. Therefore, the design and structure is correct and feasible. Simulation andexperimental results show the device good performance, high efficiency, reliability andoutput stability, precise regulation, applicable to electromagnetic motors and magneticlevitation system. In addition it has advantages of small size, light weight, low cost,easy to operate.