Development Of Numerical Control High Voltage DC Power Supply

High-voltage DC power supply is widely used in the fields of electric power testing,agricultural production,automobile technology,environmental protection,military weapons and other fields.The traditional High-voltage DC power supply often adopts linear technology,which is bulky and inefficient.With the development of science and technology,switching power supply technology is gradually applied to the design of High-voltage DC power supply.However,the voltage regulation of the High-voltage DC power supply is still in the mode of potentiometer adjustment.The efficiency and the adjustment precision are low.The High-voltage DC power supply of the numerical control regulation becomes the hotspot of research.A kind of High-voltage DC power source used for electromagnetic pulse source is designed.On the basis of comparing five common main circuit topologies,the semi-bridge topology is selected as the topology of the inverter part.The soft switch technology is applied to the main circuit.The whole circuit design of High-voltage DC power supply includes input filter circuit,step-down rectifier filter circuit,DC chopper circuit,control circuit,inverter circuit,high frequency transformer,voltage rectifier circuit,sampling circuit,overcurrent protection circuit and auxiliary power supply.The Step-down transformer and rectification filter are used to obtain stable low-voltage DC power supply after EMI filtering.After the DC/DC circuit,the voltage adjustable DC output is obtained,which is converted into high frequency AC voltage by the half-bridge inverter.It is sent to the high frequency transformer to boost the voltage,and finally the required adjustable DC high voltage is obtained through the five-step voltage rectification circuitThe control circuit adopts the AT89C52 single chip microcomputer to generate PWM wave as the Buck circuit control signal,and then compares the output voltage with the required target voltage to adjust the PWM wave duty ratio.The output voltage can be adjusted by using Buck circuit.The half-bridge series resonant inverter circuit is designed by analyzing the circuit working mode and calculating the element parameters.In this paper,the design difficulty of high frequency transformer is reduced by using two-stage boost method,UF85 magnetic core is selected by area product method,the line diameter and turn number of high-frequency transformer are calculated.The five-step voltage rectification circuit is designed.The influence of different capacitance values on the output waveform is analyzed through Matlab modeling and simulation,and improvement of the whole voltage rectifier circuit is carried out.In the experiment test of High-voltage DC power supply,the DC chopper circuit adjusts output voltage according to the control signal of the single chip microcomputer.The switch tube of the inverter circuit realizes zero current conduction and closing.The output voltage is 5?50kV DC adjustable,and the ripple coefficient is less than 1%.The High-voltage DC power supply is tested as the initial charging power supply of the 5 grade Marx generator.The pulse output waveform is ideal,and the power supply is stable.