【作者】 耿华；

【导师】 杨耕；

【作者基本信息】 清华大学 ， 控制科学与工程， 2008， 博士

【摘要】 随着全球能源的紧缺和环保的要求,风力发电机技术得到了世界各国的重视。其中变速变桨距风电系统具有广阔的前景,但由于系统的多参数、强耦合、非仿射非线性等特性,其高效控制成为一个具有挑战性的问题。传统的风电系统能量优化研究着重解决不同风速下单机系统的效率和可靠性问题。随着电网内风电容量的增加,对风电系统的输出能量提出了新的要求,如动态时要求风电系统提供足够的能量支撑;稳态时要求其输出功率足够平稳。这些内容已成为当前风电系统能量优化的研究重点。本文系统地研究了变速变桨距风电系统的动态风能捕获和输出功率水平控制问题,主要的研究工作和创新性成果如下:1.提出了考虑动态性能的最大风能捕获控制策略。迄今,最大风能捕获策略基于稳态寻优的思想,忽略了系统的动态能量捕获。本文基于反馈线性化方法,对风力发电机的输出有功和无功功率进行了解耦控制;利用“零观测器”间接观测系统的动态功率,并对最大风能捕获控制进行动态补偿。该策略提高了系统的全局效率和对电网的动态能量支撑能力。2.提出了一种用于风电系统输出功率水平控制的逆系统方法。针对本质为非仿射型非线性的风电系统,该方法设计了核心为风电系统逆模型的非线性桨距角控制器。与传统线性控制器相比,该方法工程实现非常简单,可以保证较大风速范围内风电系统的稳定性和输出功率水平控制所要求的动态性能,并且对风机参数的小扰动具有一定的鲁棒性。3.提出了一种用于风电系统输出功率水平控制的逆系统鲁棒控制方法。该方法复合了逆系统控制方法和鲁棒补偿方法,与逆系统控制方法相比,该方法在实现系统输出功率水平的控制的同时,对风机参数的大范围扰动以及其它有界不确定性扰动具有较好的鲁棒性。4.构建了基于硬件在环方式的风电系统模拟实验平台。对以上用于风电系统的能量优化控制方法进行了计算机仿真实验和基于该平台的半实物仿真实验。实验结果验证了上述方法的有效性和优越性。更多还原

【Abstract】 The wind generation technology has gained much attention all over the worldbecause of the global energy shortage and the environmental protection require-ments. However, due to the multi-variable and highly coupled nona?aine structure,high-performance control of the variable-speed variable-pitch wind generation system(VSVP-WGS) becomes a challenging problem. Conventional researches on the energyoptimization of the wind generation system focus on the e?ciency and reliability ofthe single set system in di?erent wind speed regions. However, along with the increaseof the wind power capacity in a power grid, more requirements have been proposedfor the safety operation of the grid, such as enough power supply in dynamic state andsmooth power injection in steady state from the VSVP-WGS. All the contents havebeen today’s key issues for the energy optimization of the VSVP-WGS. In this disser-tation, the controls of the dynamic energy capture and the steady output power levelwere systematically investigated. The main works and innovative contributions of thisdissertation are as follows.1. The maximal power point tracking (MPPT) strategy taking the wind turbines’dynamics into account was proposed. Conventional strategies of the maximal powerpoint tracking control are based on the steady optimization algorithm, and do not con-sider the turbine dynamics. With the feedback linearization theory, the control of theactive and reactive power of the generator is discoupled. And with a”zero-observer”,the dynamic power of the wind generation system is observed indirectly, which is usedfor the dynamic compensation of MPPT. As the results, the e?ciency and the dynamicpower supply capability of the wind generator system are improved.2. The inverse-system pitch control strategy is proposed for the output power levelcontrol of the VSVP-WGS. Based on the inverse-system theory, a nonlinear pitch con-troller is designed for the control of the nona?ne wind generation system. Comparedwith the classical linear controller, this nonlinear one reserves the capabilities of the simple implementation. Moreover, the controller keeps not only stable and rapid re-sponse in a large wind speed region but also robustness to the small disturbance of thewind turbine parameters.3. The inverse-system based robust pitch control strategy is proposed for the out-put power level control of the VSVP-WGS. The strategy combines the inverse-systemand robust compensation method. Compared with the inverse-system pitch controlstrategy, it can keep not only the output power level of the VSVP-WGS but also robust-ness to the large scaled disturbances of the wind turbine parameters and other boundeduncertainties.4. The performances of the nonlinear control methods mentioned above for theenergy optimization of the VSVP-WGS are verified by the simulations and experimentsbased on a hardware-in-loop platform of the VSVP-WGS which is partly establishedby the author.更多还原