Flexible Voltage Arc Suppression in Distribution Networks Considering Asymmetric Ground Parameters Based on Power Router

Asymmetric ground parameters (AGPs) of the distribution system impact fault handling, not only causing false triggers potentially, but also leading to arc extinction failures of traditional arc suppression methods. Therefore, this article analyzes the characteristics of the AGPs distribution network integrated with power router (PR) in depth. And an effective resistance-capacitance impedance midpoint grounding is innovatively designed on dc side of PR, without changing the grid grounding mode by control. Thus, novel methods of PR-based active parameters asymmetry identification (APAI), and single line-to-ground (SLG) faults flexible voltage arc suppression (FVAS) considering AGPs, are proposed under the V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub>Q-0, which ensures the zero-sequence decoupling regulation. First, AGPs characteristics are actively detected by interfrequency signal injection (IFSI) via PR, and APAI is initiated to identify the primary cause of the asymmetry by interfrequency damping ratio. Then, if judged as an SLG fault, PR-based FVAS is employed to actively reduce the fault voltage below re-arcing threshold, the compensation mechanism considers AGPs. Finally, simulation and experiment results demonstrate the validity of the proposed 0-axis control under V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub>Q-0, verify the feasibility and effectiveness of PR-based APAI and FVAS.