| 引用本文: | 戴志辉,杨骐跃,韦舒清,等.基于正序电流故障分量幅值的新能源送出线路新型电流纵差保护[J].电力系统保护与控制,2026,54(10):150-161. |
| DAI Zhihui,YANG Qiyue,WEI Shuqing,et al.A novel current differential protection scheme for new energy transmission lines based on the magnitude of positive-sequence fault current components[J].Power System Protection and Control,2026,54(10):150-161 |
|
| 摘要: |
| 针对光伏场站低电压穿越期间受控输出特性导致送出线路传统纵差保护依赖的工频电流幅相关系失效、保护性能下降的问题，提出一种耐受高过渡电阻的新型电流纵差保护方案。首先，结合光伏场站低压穿越动态输出特性，分析了不同故障场景下送出线路区段两侧正序电流故障分量的相位特征，及其在高阻故障下表现出的前移现象。其次，利用故障区段两侧正序电流故障分量的综合幅值与相位差，分别构造了保护的动作量和自适应制动阈值，显著提升了保护对过渡电阻的耐受能力。最后，在 PSCAD/EMTDC 平台上搭建典型光伏场站送出线路模型进行多场景验证。结果表明：该方案灵敏度高，动作性能基本不受故障类型、故障位置及新能源接入容量的影响，在高阻故障下仍能可靠动作。 |
| 关键词: 电流纵联差动保护 新能源场站 正序电流故障分量 过渡电阻 |
| DOI：10.19783/j.cnki.pspc.251095 |
| 分类号: |
| 基金项目:国家自然科学基金项目资助 (52577108) |
|
| A novel current differential protection scheme for new energy transmission lines based on the magnitude of positive-sequence fault current components |
|
DAI Zhihui1, YANG Qiyue1, WEI Shuqing2, LIU Junyi1, LUAN Kun1
|
|
1. State Key Laboratory of New Energy Power System (North China Electric Power University), Baoding 071003, China; 2. Weinan Power Supply Company, State Grid Shaanxi Electric Power Co., Ltd., Weinan 714000, China
|
| Abstract: |
| To address the performance deterioration of conventional longitudinal current differential protection for transmission lines during low-voltage ride-through (LVRT) operation of photovoltaic (PV) plants, where controlled output behavior invalidates power-frequency current amplitude relationships, a novel current differential protection scheme with enhanced tolerance to high transition resistance is proposed. First, considering the dynamic output characteristics of PV plants under LVRT conditions, the phase characteristics of the positive-sequence fault current components at both terminals are analyzed under various fault scenarios, along with the phase-advance phenomenon under high-resistance faults. Then, a protection operating index and an adaptive restraining criterion are constructed by combining magnitude and phase differences of the positive-sequence fault current components at both ends of the faulted line section, thereby significantly enhancing the protection's tolerance to transition resistance. Finally, a representative PV plant transmission line model is built in PSCAD/EMTDC for validation under multiple scenarios. The results demonstrate that the proposed scheme offers high sensitivity, weak dependence on fault type, fault location, and new energy penetration level. It can still operate reliably under high-resistance faults. |
| Key words: current longitudinal differential protection new energy plant positive-sequence fault current component fault resistance |
