不同电流注入点时的接地网冲击接地阻抗测试

Impedance test of grounding grid at different current injection points

针对不同电流注入点时的接地网冲击接地阻抗输出的耦合性较大、测试精度不高的问题,文中提出不同电流注入点时的接地网冲击接地阻抗测试。分析接地网冲击接地阻抗参数,以负阻尼系数、直流调制分量、电压振荡以及输出功率等为约束指标,在不同电流注入点进行接地网冲击接地阻抗的连通性分析。采用自适应加权学习方法计算逆变器直流侧电压波动,在确定的扰动步长和扰动周期作用下进行接地网冲击接地阻抗的抗干扰性分析,计算接地网冲击接地间谐波电流,优化接地网冲击接地阻抗测试,实现不同电流注入点的接地网冲击接地阻抗测试。仿真结果表明,采用该方法进行接地网冲击接地阻抗测试的准确性较高,在最大功率点的特征分辨能力较高,测试精度准确。

In order to solve the problem that the output of the impulse grounding impedance of the grounding grid at different current injection points has great coupling and low test accuracy,an impulse grounding impedance test of the grounding grid at different current injection points is proposed.The parameters of impulse grounding impedance of grounding grid is analyzed.The connectivity of impulse grounding impedance of grounding grid at different current injection points with negative damping coefficient,DC modulation component,voltage oscillation and output power as constraints is analyzed.The adaptive weighted learning method is used to calculate the voltage fluctuation of the DC side of the inverter.Under the action of the determined disturbance step and disturbance period,the anti-interference analysis of the impulse grounding impedance of the grounding grid is carried out,the harmonic current between the impulse grounding of the grounding grid is calculated,the impulse grounding impedance test of the grounding grid is optimized,and the impulse grounding impedance test of the grounding grid at different current injection points is realized.The simulation results show that the method has high accuracy in impulse grounding impedance measurement,high characteristic resolution at the maximum power point and accurate measurement accuracy.