单相并网变流器直流电压波动规律分析

摘要

为分析单相并网变流器直流侧电压波动规律,从单相并网变流器数学模型出发,推导出直流电压瞬时值的时域表达式及各次谐波分量的幅值表达式,揭示了产生直流侧某次谐波电压的机理及各次谐波电压幅值与交流电压幅值、直流支撑电容、直流电压幅值及交流电流谐波分量间的关系.仿真和实验验证了理论分析的正确性.%In order to analyze the direct current (DC) voltage fluctuation regularity in the DC-link capacitor of the single-phase grid-connected converter,the time-domain expression of the DC voltage and the amplitude of each harmonic voltage are derived from the converter's mathematical model.Furthermore,the mechanism of a certain harmonic generated in the DC voltage and the relationship between the amplitudes of each harmonic voltage and the alternative current (AC) voltage,DC-link capacitor,and the harmonics in the AC current are revealed.Both simulation and experimental results verified the validity of the theoretical analysis.