一种电容式调压脉冲功率电源设计和工作分析

为了设计研制一种电容式调压脉冲功率电源并分析其工作特性,采用双向晶闸管调压、升压整流和限流的充电方式,以及先粗调后细调的策略向电压给定单边逼近以实现快速高精度充电。分析了3种感性负载的放电脉冲工作形式:弦波脉冲电流配合电容反充能量回馈,可用于重复频率要求较高的场合;续流波电流的有效脉宽较宽,可用于要求放电高频分量相对较小的场合;交流衰减波电流可用于永磁体的退磁等应用中。放电电流峰值由负载电感和电阻值共同决定,减小电感能大幅度提高输出功率,但受放电晶闸管的指标di/dt的制约电感有最小值。电容反充电压能量回馈是提高脉冲功率电源效率和增加电源重复频率最有效的手段。给出了评价和使用该类电源技术指标的计算方法,除了最高工作电压、最大储能之外,可根据负载给出最大输出功率、输出峰值电流、最大电压重复频率等技术指标,并可在给出的曲线上选取匹配的工作参数。

Design and Operation Analysis of a Capacitive Adjustable Voltage Pulsed Power Supply

A capacitive adjustable voltage pulsed power supply is developed.The charging circuit consists of the triac voltage regulator,the boost rectifier,and the limited current circuit.The model of charging voltage vs.time is established and the operation of adjustable voltage charging is analyzed.By using coarse-fine control strategy to make one-side approximation to the target voltage,fast,high precise,non-overshotting charging on capacitor can be achieved.Pulsed discharging to the inductive load includes three modes,sine-wave,freewheeling wave and decayed alter wave.The sine-wave pulses can be used in situations requiring for higher repeating frequency.The freewheeling wave pulses can be used in situations requiring for wider pulse width.The decay oscillating wave pulses can be applied in situations such as demagnetization of permanent magnets.The peak value of pulse current is determined by both of the load resistance and inductance.The output power can be raised greatly by reducing the load inductance,which has the minimum value limited by di/dt of the thyristor.The energy feedback of reverse charging voltage on capacitor is the most effective method to increase the efficiency and the repetitive frequency of the power supply.The calculating method for the technical specification of evaluating and using this type of power supply is presented in the practical example.Besides the maximum operating voltage and the maximum stored energy,indexes such as peak output current,peak output power and repetition frequency under the maximum voltage can also be obtained according to the load parameters,and suited operating parameters can be chosen at the given curves.