风电送出线路自适应重合闸新策略研究

Affected by wind power operation characteristics, success rate of reclosing scheme utilized on wind power outgoing line is so low that the stability of wind power system and wind power accommodation are reduced, and the accuracy of fault characteristic identification methods for conventional power transmission lines is unsatisfactory when it been utilized on wind power outgoing line. Aiming at the problems mentioned above, firstly, the fault models will be built according to the structural feature of wind power outgoing line, based on the characteristics of secondary current and recovery voltage, the influence of wind power operation characteristics on fault characteristic identification and reclosing sequence will be investigated. Secondly, islanding wind farm temporary stability maintaining method based on coordination between attached elements switching and wind turbine control will be brought up. Thirdly, tripping methods to enhance the connection between wind farm and power system will be proposed, reclosing sequence of wind power outgoing line will be optimized considering the factors including wind turbine fault ride through capability, arc extinction characteristics, etc. Lastly, based on all the studies above, New reclosing schemes for wind power outgoing line based on voltage and current coupling, instantaneous power, and injected electric quantities will be established, thus, the reclosing success rate of wind power outgoing line and stability of wind power system will be enhanced. Results of this project are of great theoretical significance and application value. coordinate with wind turbine operational control strategy, adapt the fickle wind farm operation, and Improving the stability of power systems. The results of this project will be of great theoretical significance and application value.

受风电运行特性的影响，风电线路采用的重合策略不判定故障性质、经固定延时，重合成功率低，影响系统稳定和风电消纳。而针对常规能源线路研究提出的故障性质判据不能适应风电多变的运行特征，准确性差。项目将基于风电线路结构特征建立故障模型，研究故障线路的潜供特性和恢复电压特征，剖析风电运行对线路故障性质判据、重合时序的影响机理。提出基于附加元件投切与机组运行控制策略协调配合维持风电孤岛暂稳的方法。提出基于电气量及其耦合特性的各种故障性质判据。研究加强风电线路两侧电气联系的跳闸方式， 综合考虑机组故障穿越能力、熄弧特性等优化重合时序。提出基于电压电流耦合量、瞬时功率和注入电气量变化特性，应用于风电送出线路的自适应重合闸新策略，提高重合成功率，保证风电系统稳定运行。研究成果具有重大的理论意义和应用价值。

相比常规能源线路，受风电运行特性影响，风电送出线路故障性质判定困难，重合成功率难以保证。基于风电送出线路结构建立故障模型，明确了风电运行特性对送出线路重合闸的影响机理，基于故障线路电气量变化特征建立了适用于不同拓扑结构的风电送出线路的故障性质判据，提出了系列适用于风电送出线路的跳闸方式和自适应重合闸新策略。项目取得的主要成果如下：.1）基于风电运行特征及相间耦合特性的研究，发现风电出力波动、故障穿越特性等因素导致跳闸相电气量幅值、故障电弧持续时长变化范围大，影响风电送出线路故障性质判定准确性。.2）研究发现风电送出线路故障相有功、无功特性抗干扰能力好，据此提出了基于故障相功率特性的熄弧判据；结合故障相谐波特性，提出了风电送出线路自适应单相重合闸策略，该策略能够适应障熄弧时间、故障位置、过渡电阻等因素的变化。.3）提出送出线路三相跳闸后，在风电场侧接入替代负荷，避免重合前孤岛运行风电场因有功盈余脱网；在送出线路配置电容，构造振荡回路，解决残余电气量衰减过快，三相跳闸后线路故障状态判定困难问题，提出了风电送出线路自适应三相重合闸新策略。.4）提出选跳分相跳闸策略，减少送出线路三相跳闸几率，将选跳分相后的送出线路多种故障情况等效为单相跳闸。结合单相重合闸故障熄弧判据，构成风电送出线路自适应综合重合闸策略。并将选跳分相跳闸方法的思路应用于同杆双回风电送出线路，提出了应用于跨线接地故障、跨线不接地故障的准两相跳闸策略及安全岛跳闸策略，在实现故障简化分析的同时，增大故障耦合效果，提升了故障性质判别的准确性，使单相自适应重合闸故障熄弧判据的应用范围扩展至了同杆双回风电送出线路智能跳合闸。.理论分析和仿真验证表明，所提自适应重合闸策略原理简单、实用性强、对投资要求低，具有重要的理论意义和工程参考价值。