| High power high frequency high voltage power supply has a very wide range of applications,many industry technical innovations,such as aerospace power supply,industrial electrostatic dusting power supply,medical X.ray imaging technology,etc.Distribution parameters of transformer are produced because of the power supply's high voltage characteristic,which complicates the circuit work course,high tens the difficulty of the system's design and brings out more requirements to the safety of the system.Meanwhile,many switching loss is generated on account of the high frequency characteristic,where switching frequency is limited and the question of EMI has a strong impact on the reliable operation of the system.So a good high frequency high voltage power supply control system is necessary to be made to solve the problems above.At first,the topological structure is analyzed and a LCC serial-parallel resonance model,which works in discontinuous mode,is built.On the basis of theoretical analysis of work courses,main parameters' mathematical expression are got through mathematical derivation,where the soft switching conditions are given.Voltage regulation characteristic's mathematical modeling and simulated analysis are made on the basis of serial parallel resonance circuit model,getting the voltage to frequency characteristic law in different load.A resonance circuit parameters design method is proposed to achieve effective voltage regulation control.Finally,simulation experiment is conducted to prove the method's effectiveness and practicability.Then,voltage-doubling rectifier circuit as the power supply output filter circuit,which have small buck,low weight,high efficiency and high stability.This paper proposes a new voltage-doubling capacitance matching scheme through the optimization of voltage-doubling capacitance and the guarantee of the voltage ripple under certain conditions.In the end,Software and hardware design are made for the high voltage and high frequency power supply's control circuit,including the PWM circuit design,sampling circuit design and the system's control flow and protect measure.PWM signals generated by DSP,connect the drive circuit,to easily control the on and off of the switch tube IGBT.Key signals of voltage and current are sampled,to achieve the safe and reliable actions of the system.On the basis of the hardware design,a software control measure is proposed to maintain the power supply's safe and reliable operation.A digital start circuit is designed,to protect the system from the current surge strike caused in the start work course. |
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