针对基于不可控桥式整流电容滤波电路的单相非线性负荷,建立精确的频域谐波模型,该模型得到仿真和实验的验证,可用于对该类非线性负荷的谐波衰减特性进行研究。通过基于模型的分析研究,提出2个表征谐波衰减特性的新指标,即电路导通角衰减系数和电压峰值衰减系数。仿真结果表明,这2个指标与该类非线性负荷的电流谐波总衰减系数有较好的相关性,可以较好地反映系统电压畸变对该类负荷电流谐波特性的影响,揭示了其谐波衰减效应发生的原因,并在一定程度上实现了对非线性负荷谐波衰减效应的定量分析。
This paper developed a precise frequencydomain harmonic model of single-phase nonlinear loads, which use uncontrolled rectifiers with DC-smoothing capacitors as their power supply. This model was validated by simulations and measurements, so it could be used to analyze the harmonic attenuation effect of aforementioned nonlinear loads. Model-based analyses of these loads were performed, and two new indices, namely conduction angle attenuation factor(?af) and peak voltage attenuation factor(Paf), were proposed for characterizing the harmonic attenuation effect. Good correlation between these indices and total attenuation factor(FAFtotal) of harmonic current was verified by simulation, so these indices could be used to characterize the influence of system voltage on harmonic current. Furthermore, quantitative analysis of harmonic attenuation effect can be done by using these indices.