Research And Design On Low-voltage High-power Variable-frequency Power Supply

With the rapid development of the opportunity to enter the global industrial industry 3.0 to 4.0 transition, high-power variable-frequency power supply, ushered all outstanding challenges and opportunities. Low-voltage High-power variable-frequency power supply has a wide application in aerospace, electroplating, welding and other fields. The research about its technologies has strategic importance.This paper focuses on Low-voltage High-power variable-frequency power supply. the final choice of a full-bridge full-wave type structure as the main circuit topology of the power supply, Full-wave structure cycloconverter using synchronous rectification MOSFET in parallel, in order to accommodate larger currents. This paper describes a phase shift of the unipolar switching characteristics and small signal characteristics of the control strategy.Based on the 12V/1000 A outputs, this paper designs simulation and hardware circuit. Based on MATLAB simulation software, the paper do open-loop and closed-loop control simulation. Open-loop simulation waveforms related to detailed analysis, but also for the design of the hardware parameters provides a reference and verification. This paper introduce the power supply from the main circuit, control circuit, auxiliary power supply. The main circuit section comprises a three-phase rectifier, soft-start circuit, the switch selection and so on; Control circuit includes a driving circuit, overcurrent protection circuit and so on; Auxiliary power supply section describes the topological structure of programs and hardware design in cascade structure of a multi-output switching power supply.Finally, this paper design a 12V/1000 A experimental platform and do relate experiments: auxiliary power experiments show that the auxiliary power has good performance. DSP digital implementation and experimental results show that DSP can be used in flexible implementation; Driving circuit experiment shows the validity of the driving circuit; Control strategy results show the feasibility of unipolar phase shift control strategy and effectiveness.