分析了基于IEC安全火花试验装置的简单电容电路短路放电特性,将其放电过程分为一次放电、电压维持及二次放电三个阶段.建立了基于场致发射的放电数学模型,得出了放电电流和电压的时域表达式.运用实验方法建立了放电时间与电容及其初始电压间的函数关系.以放电结束时刻的电压和电流为约束条件,给出了模型中待定参数的确定方法.进行了实例验证并设计了软件评价器,结果表明理论分析及所提出模型的正确性和非爆炸评价的可行性.
The paper introduces a kind of bidirectional switch type five level inverter, and puts forward the com-pound control scheme in which repetitive control and PI adjustment are combined. Repetitive control can suppress the periodic perturbation which comes from the network side and load side of the grid-connected output current, and can reduce the total harmonic distortion coefficient of grid-connected current. PI adjustment can let the grid-con- nected current which is output by inverter track the given reference sine signal in real-time, so that the system has excellent static and dynamic characteristics, and improves the control precision of the inverter. The simulation and experiments show that the output grid-connected current waveform of five-level inverter using repetitive control and PI adjustment is stable, and harmonic distortion coefficient is small and can achieve real-time fast tracking the phase of the network voltage, so that the system can work in the condition of high power factor.