Abstract：The electrical characteristic of compensation grid is changed because of the arc-suppression coil, which brings many difficulties to grounding line selection using the electrical characteristic. And the higher transition resistance has a great influence on result of grounding line selection. To solve the above problems, a small current grounding line selection device is developed based on grounded fault model. First, a mathematical model of grounded fault is established. Transient ground fault, high resistance grounding fault and low resistance grounding fault are identified according to the mathematical models. Line selection device should be locked up when transient grounded fault. According to the characteristics of the high resistance grounding fault, the zero sequence current active component method and its increment method are adopted. The two line selection methods are less affected by the transition resistance. On this basis, a composite grounding line selection device is constituted. Matlab simulation and low-voltage experiments verify the effectiveness of the two methods and achieve satisfactory results of line selection.
2019, Vol. 20 
