考虑双馈机组无功调节能力的海上风电场无功优化

Reactive Power Optimization for Offshore Wind Farm Considering Reactive Power Regulation Capability of Doubly-Fed Induction Generators

针对目前海上风电场运行时大量无功传输会引起有功损耗增加的问题,分析了海上风电场集电系统各电气设备的无功特性,以及双馈风电机组(doubly fed induction generator,DFIG)无功出力约束、风速变化对风电场内部无功潮流影响,提出了在保证最大风能利用的前提下将双馈风力发电机组作为连续无功源参与风电场无功补偿的方式,在保证风电场内部节点电压质量的前提下同时获得风电场内部网损最小的目标。以各风电机组的无功实时输出值为控制对象,将风电场无功优化问题转换为一个多变量、多约束的非线性混合优化问题,并采用粒子群优化算法(particle swarm optimization algorithm,PSO)进行求解。算例结果验证了该方法的有效性。

In allusion to the problem that at present during the operation of offshore wind farms the transmission of a large amount of reactive power leads to the increasing of active power loss, the reactive power characteristics of electrical equipments in the power collection system of offshore wind farm, the reactive power output constraints of doubly fed induction generator（DFIG） and the impacts of wind speed variation on reactive power flow within wind farm are analyzed. Under the premise of ensuring maximized utilization of wind energy, a reactive power flow compensation mode, in which DFIG is regarded as continuous reactive power source participating reactive power compensation in wind farm, is proposed, and under the presupposition of ensuring nodal voltage quality within the wind farm the objective of minimizing network loss within the wind farm is realized. Taking real-time reactive power output of each DFIG unit as the controlled object, the reactive power optimization of offshore wind farm is turned into a nonlinear hybrid optimization problem with multi variables and multi constraints and is solved by particle swarm optimization algorithm（PSO）. Case study results show that the proposed method is effective.