自动调频式串联谐振耐压测试系统的研究

摘要

A frequency-turned series resonant voltage withstand test system is introduced.According to the basic principle of the series resonant circuit and capacitor voltage amplitude and frequency characteristics,the maximum amplitude of capacitor voltage occur when the circuit is resonant.The system is used in the range of 30～300 Hz for frequency modulation which can automatically search for the resonant frequency.The series resonant state is judged by real-time sampling amplitude of capacitor voltage,then maintained the constant frequency and adjusted the amplitude of capacitor voltage after the resonance occur in this circuit.The whole process uses unipolar sinusoidal pulse width modulation(SPWM) to control the inverter power supply,so that the output will automatically track the resonant frequency and ultimately control the capacitor voltage to reach the set value,to meet the requirements of the voltage test.%介绍了一种自动调频式串联谐振耐压测试系统.根据串联谐振电路的基本原理并结合电容电压幅频特性,电容电压幅值在电路发生谐振时达到最大.该测试系统可在30～300 Hz范围内连续调频,自动搜寻谐振频率.通过实时采样电容电压幅值判断串联谐振状态,在达到谐振后保持谐振频率恒定并自动调节输出电压幅值.整个过程利用单极性正弦脉宽调制(SPWM)对逆变电源进行控制,使其输出自动跟踪谐振频率并最终控制电容电压达到设定值,满足耐压试验要求.