Misjudgment Mechanism and Countermeasures of Directional Elements in Distribution Lines With Hybrid Integration of Grid-following and Grid-forming IBRs
DU Xiaotong, HE Jinghan, LI Meng, et al. Misjudgment Mechanism and Countermeasures of Directional Elements in Distribution Lines With Hybrid Integration of Grid-following and Grid-forming IBRs[J]. 2026, 46(18): 6745-6756.
DU Xiaotong, HE Jinghan, LI Meng, et al. Misjudgment Mechanism and Countermeasures of Directional Elements in Distribution Lines With Hybrid Integration of Grid-following and Grid-forming IBRs[J]. 2026, 46(18): 6745-6756.DOI: 10.13334/j.0258-8013.pcsee.251486.
跟网与构网源混合接入配电线路的方向元件误判机理及应对策略
摘要
跟网型与构网型逆变电源(inverter based resources,IBR)混合接入导致配电网方向元件误判及灵敏性劣化。该文揭示故障穿越策略、负荷容量及过渡电阻对方向元件的耦合影响机制,提出序分量方向元件相角自适应调整策略。首先,结合跟网型与构网型IBR故障穿越策略,解析其正/负序等值阻抗幅相特性;进而,推导出不同负序控制目标下IBR容量、负荷及线路长度与方向元件误判的定量关系,并量化导致相方向元件误判的过渡电阻值。为提升序分量方向元件性能,提出基于阻抗幅值检测的自适应相角补偿策略,及负序相角主动调控策略。仿真结果表明,所提策略可显著增强正序方向元件的灵敏性与负序方向元件的可靠性,可为含多类型IBR的配电网方向保护整定与自适应优化提供一定理论依据。
Abstract
Hybrid integration of grid-following and grid-forming inverter-based resources (IBR) causes directional element misoperation and sensitivity degradation in distribution networks. This paper reveals the coupling mechanism of fault ride-through strategies
load capacity
and transition resistance on directional elements and proposes adaptive adjustment strategies for sequence-component directional elements. Firstly
it analyzes the magnitude and phase characteristics of the positive/negative sequence equivalent impedance of both IBR types considering their fault ride-through strategies. Subsequently
it derives quantitative relationships between IBR capacity
load
line length
and directional element misoperation under different negative- sequence control objectives
and quantifies the transition resistance values causing phase directional element misoperation. For the purpose of enhancing sequence- component directional element performance
an adaptive phase-angle compensation strategy based on impedance magnitude detection and an active negative-sequence phase-angle regulation strategy are proposed. Simulation results demonstrate that the proposed strategies significantly improve the sensitivity of positive-sequence directional elements and the reliability of negative-sequence directional elements
providing a theoretical basis for directional protection setting and adaptive optimization in distribution networks with multi-type IBRs.