变速恒频风电系统效率-可靠性优化控制

OPTIMAL CONTROL FOR EFFICIENCY-RELIABILITY OF VARIABLE SPEED CONSTANT FREQUENCY WIND POWER GENERATION SYSTEM

针对变速恒频风电系统,采用双频环优化控制结构研究多目标优化控制策略。低频环采用风能转换效率作为稳态优化指标,通过最佳叶尖速比法求解优化控制律;以转矩脉动作为控制变量、叶尖速比脉动作为状态变量,建立高频环优化控制模型,并在改进的高频环线性化模型基础上,以转矩脉动作为优化控制目标,应用LQG算法求解高频环优化控制律。最终实现了变速恒频风电系统的动、稳态指标综合优化控制,仿真结果证明了所设计方法的有效性。

Based on two-frequency-loop optimal control structure, multi-objective optimal control strategy for varia- ble speed constant frequency wind power generation system was studied. The steady state optimization objective of low frequency loop is energy conversion efficiency, and its optimal control law was obtained by the optimal tip speed ratio control. The torque pulsation was selected as control variable, and the tip-speed ratio pulsation was selected as state variable, then the optimal control model of high frequency loop was established. The dynamic optimization ob- jective of high frequency loop was torque pulsation, and the optimal control law for high frequency loop was ob- tained by Linear Quadratic Gaussian （LQG） algorithm based on the improved linearized model of high frequency loop. Then the optimal control combination between steady state and dynamic state objectives was realized, and simulation results prove the validity of designed multi-objective optimal control strategy.