摘  要

风能作为一种取之不尽、用之不竭的绿色能源，越来越受到全世界的关注。变桨距风力发电机以其能最大限度地捕获风能、输出功率平稳等特点，日渐成为风力机的主流机型。变桨距系统作为影响兆瓦级风力发电机组的主要因素之一，应该进行更深入的研究和分析[1]。

随着风力发电技术的越发成熟, 变桨机构的形式也日渐趋于多样化, 目前国际上大型的风力发电的变桨距机构主要有两种实施方案: 电机传动变桨距机构和液压驱动变桨距机构[2]。通过深入的分析和了解, 为了使风力发电机在输出功率在高于额定功率时，运行平稳， 又避免大的波动, 且要使风力发电机组传动系统具备特别好的柔性, 变桨机构在变桨精度问题上，就更加受到世界上国内外研究机构的普遍关注, 而该问题在液压变桨距系统中体现得特别突出。

针对国内外传统的依靠曲柄机构来驱动桨叶旋转的统一变桨方式，本文主要做了以下几方面的研究：

一、提出了独立液压变桨距控制系统，设计了独立液压变桨距执行机构，并进行了相关分析。

二、查阅相关文献和资料，对桨叶变桨距驱动力、液压系统负载力和流量进行了大致的计算；

三、依据变桨距执行机构，设计了独立液压变桨距控制系统，对液压控制系统的工作原理和各种工况下油液循环路线进行了分析和说明，对液压缸的尺寸参数进行了简单计算，并给出了液压缸的装配图和活塞的零件图。

关键词:风力发电机；变桨距；控制；液压系统

ABSTRACT

Wind energy as an inexhaustible green energy,has attracted more and more attention all over the world. Variable pitch wind turbine with its can maximize capture smooth wind power output power etc,increasingly become the mainstream model of the wind turbine. Variable pitch system as one of the main factors influencing the megawatt wind power generation unit, should be more in-depth research and analysis.

With the increasingly mature of wind power technology , the form of variable propeller mechanism, also increasingly tend to be diversified.Large-scale wind power on the international pitch-controlled system there are two main implementation plan :motor drive variable pitch and hydraulic variable pitch.Through in-depth analysis and understanding,in order to make the wind turbine power output above the rated power point is stable, avoid the fluctuations,and to make the generator drive system has good flexibility,oar institutions of oar accuracy problem has increasingly caught the attention of domestic and foreign research institutions.And the problems in the hydraulic variable pitch are reflected particularly prominent.

According to the dependence of the traditional crank mechanism at home and abroad to drive the blades rotating in an uniform way, this paper mainly do the following several aspects of research:

Firstly, proposed the independent hydraulic variable pitch control system, independent hydraulic variable pitch actuator was designed, and a correlation analysis was carried out;

Secondly, refer to relevant literature and information, on the blade pitch drive, hydraulic system load and flow for the approximate calculation；

Thirdly, based on variable pitch actuator,independent hydraulic variable pitch control system is designed,on the working principle of hydraulic control system and a variety of working conditions the oil circulating route is analyzed and illustrated.The dimensional parameters of the hydraulic cylinder for the simple calculation, and gives the assembly drawing and part drawing of piston of hydraulic cylinder.

Key words: wind driven generator；variable pitch；regulate；hydraulic system