High Voltage DC Power Supply Design Research

With the rapid development of power electronics technology,high-voltage DC power has penetrated into all aspects of people ’ s lives,and plays an important role in more fields such as medical equipment,military equipment and agricultural production.High-voltage DC power supply is developing in the direction of volume reduction,switching speed acceleration,integration and intelligence.The traditional high voltage DC power supply has been unable to meet the needs of various fields of technical application.More people consider how to use high-efficiency control strategy to improve the comprehensive strength of power supply,which has become the core issue in the field of high-voltage power supply.The basis of switch mode power supply,this text regards and designs a HVDC power system based on STM32.Firstly,the research background,current situation at home and abroad,development trend and research significance of high-voltage DC power supply are introduced.The technical indexes required by the power supply system are analyzed in detail,and the basic principle analysis,circuit parameter calculation and key device selection of each part of the circuit topology are completed considering the economic factors.It is proposed that the Buck circuit is used to realize the modulation of the system output voltage,and the stability of the system output voltage is improved.In the design of high-frequency transformer,the saturated magnetic induction intensity,working frequency and application of different core materials are compared.EE55 ferrite core is determined to be used,and the calculation of transformer turns and conductor cross-sectional area is completed.In order to verify the rationality of the selection of the circuit topology,the calculation of the key parameters and the selection of the device,the system simulation model is built in Matlab / Simulink.The working state of the system under the two control strategies is compared and analyzed.The variation of the output voltage of each part of the system under the two control methods is compared.The simulation analysis shows that the fuzzy PID control system has faster response speed,smaller ripple coefficient and higher stability.The overall planning and design of the control circuit of high voltage DC power supply system is completed,and the microprocessor of STM32F103RCT6 with CortexM3 core is determined as the main control core of the system.Then the hardware circuit of each part of the system is analyzed in detail.The hardware design includes STM32 minimum system design,power supply conversion module demand design,drive module demand design,sampling circuit demand design and protection circuit demand design.The software design of high-voltage DC power supply is carried out,and Keil software is used as the development platform.The program design and debugging are completed by C language,so that the system can better achieve reliable voltage output of power supply on the basis of low cost.Then,PWM waveform,MOSFET waveform,inverter circuit output voltage and voltage doubling rectifier voltage are tested through the experimental prototype.The measurement results demonstrate that has satisfied the design can be basically.