ZHANG Xinyi, GAI Wuyang, SUN Qiaoyu, et al. Single-pole Grounding Differential Protection Method for DC Distribution Systems Based on Current Variation Characteristics[J]. 2025, 53(6): 93-100.
ZHANG Xinyi, GAI Wuyang, SUN Qiaoyu, et al. Single-pole Grounding Differential Protection Method for DC Distribution Systems Based on Current Variation Characteristics[J]. 2025, 53(6): 93-100. DOI: 10.20204/j.sp.2025.06012.
Single-pole Grounding Differential Protection Method for DC Distribution Systems Based on Current Variation Characteristics
In low-current grounding DC distribution systems, traditional differential protection is susceptible to interference from distributed capacitance currents in lines and exhibits poor resistance to transition resistance during single-pole grounding faults. To address this issue, this paper analyzes the charging-discharging characteristics of line distrib-uted capacitance and current loop mechanisms. By comparing differential currents between faulted and healthy lines, a variation characteristic quantity is introduced to represent current changes, serving as the criterion for distin-guishing faulted lines. A single-pole grounding differential protection method based on current variation characteristics is proposed, employing a coordinated two-stage protection threshold setting. A bipolar flexible DC distribution system model was established on the PSCAD/EMTDC simulation platform for verification. Simulation results demonstrate that this method can accurately identify faulted sections without being affected by distributed capacitance currents, while showing strong noise immunity and excellent transition resistance withstand capability.
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