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 harmonic 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 by Matlab 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 impedance model harmonic current amplification mechanism of the distribution cable in this paper has a definite guiding significance in avoiding resonance of the cable line.