基于优化减载与动态惯量控制的DFIG参与系统一次调频研究

Research on primary frequency regulation of DFIG based on optimized load shedding and dynamic inertia control

离线计算或由经验获得的风电机组减载率,无法根据系统变化进行动态调整,存在灵活性不足、调频能力差等问题。文章提出了新型优化减载控制方法,系统正常运行时,将转子动能增加等效为收益;发电量减少等效为成本,建立减载收益目标函数。采用粒子群算法对目标函数优化求解,得到不同风速下最优减载率,再根据系统负荷情况动态调整。系统受到扰动后,通过改变叶尖速比动态调整风电机组减载率,以参与系统一次调频。同时,为充分发挥风电机组调频能力,根据风电机组运行状态,动态调整虚拟惯性系数。仿真结果表明,所提控制方法能在不同风速、负荷下减小频率波动,提高系统稳定性。

The load shedding rate of wind turbines is often calculated off-line or obtained from experience,which cannot be dynamically adjusted according to system changes.There are some problems such as insufficient flexibility and poor frequency regulation capability.A new optimized load shedding control method is proposed.When the system works normally,to establish a objective function of the load shedding benefit,the increase of rotor kinetic energy is regarded as a benefit,and the reduction of power generation is regarded as a cost..The particle swarm optimization algorithm is used to optimize the solution to obtain the optimal load shedding rate under different wind speeds.And then the rate is dynamically adjusted according to the system load.After the system is disturbed,the load shedding rate of the wind turbine is dynamically adjusted by changing the blade tip speed ratio to participate in the system's primary frequency regulation.At the same time,in order to give full play to the frequency regulation capability of the wind turbine,the virtual inertia coefficient is dynamically adjusted according to the operating state of the wind turbine.The simulation results show that the proposed control method can reduce the frequency fluctuation and improve the system stability under different wind speeds and loads.