低压电缆在谐波环境下的阻抗特性研究

Study on the Impedance Characteristics of Low Voltage Cables in Harmonic Environment

电缆广泛用于低压配电网中,研究低压配电系统中电力电缆的谐波特性十分重要。基于电路理论对电缆在谐波环境下的电阻和电抗计算方法进行分析,提出了在谐波频率下求解电缆全矩阵阻抗的实验测算方法,并探究不同参数对电缆电阻和电抗的影响。对电缆谐波阻抗进行实验测算并与公式计算结果进行对比,结果表明:电缆电阻会随谐波次数的增加而增大,而电缆电感则随谐波次数的增加而减小,电缆谐波阻抗近似计算公式对于单芯电缆和多芯电缆分别具有不同的准确精度,论文研究成果对电缆特性研究具有指导意义。

Cables are widely used in low-voltage distribution networks. It is very important to study the harmonic characteristics of power cables in low-voltage distribution systems. Based on circuit theory,the calculation methods of cable resistance and reactance in harmonic environment were analyzed. An experimental method for calculating cable full matrix impedance at harmonic frequency was proposed,and the influence of different parameters on cable resistance and reactance was explored. The harmonic impedance of the cable was measured experimentally and compared with the calculated results of the formula. The results show that the cable resistance increases with the increase of harmonic number,while the cable inductance decreases with the increase of harmonic number. The approximate formulas for calculating the cable harmonic impedance have different accuracy for single-core cable and multi-core cable,respectively. The research results of this paper have guiding significance for the research of cable characteristics.