基于功率给定的双馈风力发电最大风能捕获策略

MPPT control strategy based on active power reference

在综合分析风力机运行特性和双馈发电机功率关系基础上,推导了风力机功率与定子端有功功率的数学关系,构建了转速-定子端功率曲线,系统以定子端有功功率为控制量,通过功率闭环控制,利用功率平衡关系自动捕获最大风能点。定子端参考功率以发电机角速度为输入信息,根据电机角速度变化实时计算最佳功率,是一种无需检测风速且算法较为简单可靠的最大风能捕获方法。为对定子端功率进行实时控制,将矢量控制技术用于发电机定子有功、无功解耦控制,并对转子电流进行基于前馈算法的线性化解耦控制,实现了电机的功率解耦。系统仿真与实验结果验证了该方案的可靠性与可行性。

Based on the analysis of the relationship between wind-turbine characteristics and DFIG power,the mathematic equation of the stator power and the wind-turbine power is deduced,and the speed-power curve is constructed.With the stator power as the control variable,the automatic maximum power point track is implemented via the power close-loop control based on the power equilibrium.The optimal power,as the stator active power reference,is calculated in real time according to the angle speed variation of DFIG.It is a simple MPPT method without wind speed sensor.In order to control the stator power in real time,the linear decoupling control of rotor current is carried out based on the feedforward algorithm and the vector control technique is applied in the generator power decoupling control.The results of system simulation and experimental research verify its feasibility and reliability.