改善大型风电场电压稳定性的无功电压闭环控制策略研究

With the concentrated development of large-scale wind power, the issues of voltage stability control are more and more severe in large-scale wind plants. The control of wind turbines and the SVC or other compensation devices is not harmonized. The voltage stability status is very low for some large wind plants. Therefore, with the quick variation of the active power in the wind plant, the reactive power control technology to support the operation of bulk grid are expected to be improved. This proposal is to study the reactive power control mode and their impact mechanism on the volatage stability in large wind plants. The two-layer voltage colosed-loop control strategy will be proposed.In the upper layer, the control strategy of slow response devices are established considering the ultra-short wind power prediction. The multi-object reactive power control model to maximize the voltage protection margin of the wind turbine nodes, to minimize voltage control error of PCC, to minimize the reactive power of SVC is set up considering the control capability of various reactive power sources. By comparison of two types of algorithm, the reactive power closed-loop control model to adapt the weighted factor automatically are investigated.In the lower layer, the control mode of wind turbines and SVC to accommodate the quick variation of active power are studied. Also, the transition model for fault and non-fault are set up. Finally, the dynamic simulation are used to verify the validity and applicability of the control model by various scenarios simulation. This study is to solve the issues of reactive power and voltage control problem by combining of modeling,algorithm for solving and dynamic simulation method. A practical control strategy will be set up to provide technical support for the safety operation of bulk grid with large-scale wind power integration.

现有大型风电场无功电压控制未能实现协调优化，场内电压稳定水平低，大型风电场无功电压协调控制策略有待进一步探究。本申请通过研究大型风电场无功电压控制模式及其对场内电压稳定性影响机理，提出风电场两层无功电压闭环控制措施。上层：基于超短期功率预测，研究超前投退慢速控制无功设备策略；基于机组布局及各无功源无功裕度，建立以场内各节点离电压保护点裕度最大、并网点电压满足调度要求、集中无功补偿装置投入容量小为目标的多无功源协调控制模型；通过实用化算法对比研究，形成自适应权重因子的优化控制策略。下层：研究风电机组和集中无功补偿设备响应有功快速变化的控制模式及故障和非故障控制过渡模型。最后，动态仿真验证故障与非故障条件下该控制策略的适应性。本研究采用建模、算法求解和动态仿真相结合的方式，将突破大型风电场无功电压控制稳定水平低的难题，建立实用化的控制策略，为我国风电大规模并网的安全稳定控制问题提供技术支撑。

风力发电以其丰富的资源和成熟的技术成为我国目前最具规模化开发和商业化应用前景的可再生能源发电形式之一。分析大型风电场以及风电场群接入电力系统的电压稳定影响机理，并相应制定改善其电压稳定性的无功控制策略，对于大规模集群式风电资源的有效开发利用具有重要的理论研究意义和工程应用价值。首先，分别采用PV曲线法和时域分析法从静态和暂态角度研究了大规模风电集中接入电力系统对于电压稳定的影响因素，为后续无功电压控制策略提供决策依据。其次，从风电场内多无功源在时间尺度上的动态响应特性和空间粒度上的物理分布特性出发，制定了大型风电场无功调节设备的协调控制原则，并提出了一种考虑风电机组电压稳定性的风电场无功优化控制策略。再次，基于分级电压控制思路，建立风电场群无功优化控制的系统结构，依据多断面运行信息提出一种计及风电功率波动影响的风电场群无功优化控制策略。项目发表论文5篇，其中SCI论文1篇，授权专利3项。培养博士一名。