基于配电网无功优化的变速恒频双馈风电机群控制策略

针对接入地区配电网络的大规模变速恒频双馈风电机群与系统运行状况,基于单台风电机组的分段分层控制及配电网的无功优化思想,提出了变速恒频双馈风电机群并网运行的实时控制策略。并以北方某风电场及其接入系统为例,针对风速发生渐变扰动及系统侧某节点发生无功突变2种情况,对风电机群及其接入系统在该控制策略下的运行特性和关键节点的电压特性进行了仿真和分析。仿真结果说明该控制策略不但能保证风电机群最大限度地、安全地捕获风能,同时也能充分发挥机群的无功调节能力,平衡无功扰动,提高风电机群和接入系统的电压稳定性,实现全网的无功优化。

A Control Strategy of Doubly-Fed Variable Speed Wind Turbines Based on Reactive Power Optimization of Distribution Systems

According to the operation situation of regional distribution network and large scale doubly-fed variable speed wind turbine(VSWT)group connected to such distribution network and on the basis of the idea of sectional and hierarchical control strategy of single VSWT and reactive power optimization of distribution network,a real time control strategy for VSWTs interconnected with distribution network is proposed.Taking a certain wind farm in North China and the system interconnecting the wind farm with distribution network for example and with regard to two conditions that the wind speed gradually changes and the sudden change of reactive power of a certain node in distribution network occurs,the simulation and analysis on operating characteristics of VSWTs including their interconnecting system and voltage characteristics at key nodes under the proposed control strategy are performed.Simulation results show that using the proposed control strategy,not only the optimal operation of VSWTs can be realized,i.e.,the wind power energy can be maximally and safely utilized,but also the reactive power adjusting capability of VSWTs can be fully brought into play,so the voltage stability of wind turbines and their interconnecting system can be ensured,the reactive power balance of power grid can be improved and the reactive power of whole distribution network can be optimized.