中文摘要：

垂直轴风力机（VAWT）发电系统是一种应用潜力良好的新型风力发电系统。为了提高机组的风能转化效率，研究了全风速运行范围内的功率控制策略。建立了整机系统的数学模型，讨论了VAWT的气动机械特性及其4种工作模式：在此基础上，分析了机组在额定风速以内MPPT运行模式下，基于最佳叶尖速比（TSR）跟踪原理的最大风功率吸收控制策略：针对在额定风速以上的恒功率运行模式，设计了基于二阶扩张状态观测（ESO）方法的实时气动转矩估计器以及基于恒额定功率发电的最佳角速度控制策略；最后给出了全风速功率控制的系统结构。通过仿真试验，验证了该功率控制策略在全风速运行范围内实现整机高风能转化效率的良好效果。

英文摘要：

Vertical-axis wind turbine （VAWT） based wind power generation system is a new type ot wind energy conversion system （WECS）, and has good potential for commercial application because of its excellent performance. In this paper, an appropriate power control strategy for VAWT generation system is studied to improve wind energy conversion efficiency in the operating condition of all wind speed range. Firstly, a mathematical model of VAWT generation system is set up. After analyzing aerodynamic characteristics of VAWT in all wind speed operating condition, power control requirement is classified into four operating regions. Secondly, wind turbine＇s optimum tip speed ratio （TSR） control algorithm is discussed within rated wind speed range, and its generator angular velocity closed-loop control equation is also worked out to implement maximum power point tracking （MPPT） task. Above rated wind speed range, a second-order extended state observer （ESO） is designed to estimate wind turbine real-time aerodynamic torque, and an optimum generator angular velocity control algorithm is developed to ensure constant power generation output, Finally, an all wind speed power control system structure is made out. Simulation results show that the proposed control strategy can achieve high wind energy conversion efficiency in the operating condition of all wind speed range.