利用零序变化量线性度的灵活接地系统高阻接地故障检测方法OA

The fault current in flexible grounding systems under high-impedance faults becomes weak in terms of ampli-tude,leading to insufficient sensitivity when using the traditional detection methods.To solve this problem,a high-im-pedance grounding fault detection method is proposed in this paper,which utilizes the linearity features of zero-se-quence variations.First,the variation patterns of zero-sequence components before and after the parallel resistor is put into operation are studied,and an expression for the linearity between the zero-sequence current variation and zero-se-quence voltage variation is derived,highlighting the distinctive differences between the faulty and healthy lines.On this basis,the Pearson correlation coefficient is introduced as an indicator for the linearity of zero-sequence variations,and a high-impedance grounding fault detection criterion is formulated accordingly.Finally,the performance of the pro-posed method was validated on the PSCAD simulation platform.Results demonstrate that this method can accurately identify faulty lines under high-impedance grounding faults,and it only relies on local electrical quantities with low computational complexity.Therefore,it is suitable for scenarios with unbalanced systems and integration of distributed generations.Moreover,it also exhibits strong anti-interference capability,which is valuable for engineering applica-tions.