谐波放大对配电电缆的损耗影响分析及谐波抑制技术研究

Influence of Harmonic Amplification on the Loss of Distribution Cable and Harmonic Suppression Technology

以配电电缆为研究对象,基于电路理论建立电缆的单位等效电路,计算了配电电缆的等效电路参数,建立了配电电缆的谐波阻抗模型,分析了电缆漏电容对谐波电流的放大机理,利用Matlab仿真得到了谐波电流放大倍数随电缆长度和谐波次数的变化曲线,从曲线可以得出,曲线的极值点即为并联谐振点;分析了谐波电流放大下的电缆损耗,从电阻损耗和介质损耗两方面展开分析,考虑了谐波电流下的趋肤效应和邻近效应;最后,分析了适合配电电缆系统的谐波抑制方案。本文对配电电缆的谐波阻抗模型和谐波电流放大机理的分析对于避免电缆线路发生谐振有一定的指导意义。

In this paper, the unit equivalent circuit of cable is setup based on the circuit theory taking the distribution cable as study object. The equivalent circuit parameters of the cable are calculated. The har- monic impedance model of the distribution cable is established and the amplification mechanism of the leakage capacitance of the cable to the harmonic current is analyzed. The variation curve of the harmonic current amplification factor with the cable length and the harmonic number wave are obtained byMatlab simulation. It is concluded from the curve that the extreme value point of the curve is the shunt resonant point. The cable loss at harmonic current amplification is analyzed and the skin and proximity effect of harmonic current is considered from such two aspects as resistance loss and dielectric loss. Finally, the harmonic suppression scheme for power distribution system is analyzed. The analysis of the harmonic imp- edance model harmonic current amplification mechanism of the distribution cable in this paper has a def- inite guiding significance in avoiding resonance of the cable line.