| 引用本文: | 刘素梅,王丹枫,韩 伟,等.计及储能充放电特性的交流耦合光储电站送出线路纵联保护[J].电力系统保护与控制,2025,53(10):66-77.[点击复制] |
| LIU Sumei,WANG Danfeng,HAN Wei,et al.Pilot protection of exporting lines in AC-coupled PV-energy storage power stations considering the charging-discharging characteristics of energy storage systems[J].Power System Protection and Control,2025,53(10):66-77[点击复制] |
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| 摘要: |
| 因储能在充放电模式下潮流流向截然不同，所以与同步发电机甚至光伏电站相比，光储电站的故障特性存在显著差异，传统电流差动保护面临更高的拒动风险。为此，以含有“共享储能”的交流耦合光储电站为对象，首先着重分析推导了储能电站在充放电模式下的短路电流相角变化特性及其计算表达式。进一步分析了交流耦合光储电站的短路电流变化规律，从而揭示了光储电站分别作为电源和负荷运行时，传统电流差动保护不正确动作的成因。针对所存在的问题，提出了自适应调整等值阻抗幅值比的纵联保护新原理。利用线路两侧等值阻抗比，识别区内外故障及正常运行工况。同时通过引入等值阻抗调整系数，放大区内故障下线路两侧等值阻抗之间的差异，以实现即使高比例光储电站接入线上发生高阻故障，所提保护仍能够正确可靠动作。最终，基于PSCAD/ EMTDC搭建了含交流耦合光储电站电网的电磁暂态模型，验证了所提保护的动作特性。 |
| 关键词: 短路电流特性 纵联保护新原理 阻抗幅值比 储能电站 交流耦合光储电站 送出线路 |
| DOI：10.19783/j.cnki.pspc.240603 |
| 投稿时间：2024-05-15修订日期：2024-09-23 |
| 基金项目:国家自然科学基金青年基金项目资助(52107069) |
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| Pilot protection of exporting lines in AC-coupled PV-energy storage power stations considering the charging-discharging characteristics of energy storage systems |
| LIU Sumei1,WANG Danfeng2,HAN Wei3,LI Wei4,SHEN Jiaqi1 |
| (1. School of Technology, Beijing Forestry University, Beijing 100083, China; 2. China Power Hua Chuang Electricity
Technology Research Co., Ltd., Shanghai 200086, China; 3. Electric Power Research Institute, State Grid Henan
Electric Power Company, Zhengzhou 450052, China; 4. State Key Laboratory of Power Grid Safety and
Energy Conservation (China Electric Power Research Institute), Beijing 100192, China) |
| Abstract: |
| Because of the different power flow directions during the charge and discharge modes of energy storage systems (ESS), the fault characteristics of PV-energy storage power stations (PVESPs) differ significantly from those of synchronous generators and standalone PV power stations. As a result, traditional current differential protection faces a higher risk of malfunction. This paper focuses on AC-coupled PVESPs with shared ESS. It first derives and analyzes the phase angle variation characteristics of the short-circuit current from the ESS under both charge and discharge modes, along with their corresponding calculation formulas. Further analysis of the short-circuit current behavior in AC-coupled PVESPs reveals the reasons why traditional current differential protection may malfunction for the station operating as a power source and as a load, respectively. To address these issues, a novel pilot protection criterion is proposed based on adaptive adjustment of the equivalent impedance amplitude ratio. By using the equivalent impedance ratio of the two sides of the line, the method distinguishes between the internal and external faults as well as normal operating conditions. Also, an adaptive adjustment coefficient is added to amplify the difference between the equivalent impedances of the two sides under internal faults, ensuring that the proposed protection mechanism can still operate reliably even during high-resistance faults in lines with a high-proportion of PVESPS. Finally, an electromagnetic transient model of a power grid with AC-coupled PVESPs is built in PSCAD/EMTDC, and the operational characteristics of the proposed protection principle are verified. |
| Key words: short-circuit current characteristics novel pilot protection impedance magnitude ratio energy storage station AC-coupled PV-energy storage power station exporting line |
