【作者】 李昊；

【导师】 孔祥东；

【作者基本信息】 燕山大学 ， 流体传动及控制， 2013， 博士

【摘要】 变桨距系统是现代大型风力发电机组的重要组成部分。随着风力发电机组大型化的进程，对于变桨距系统的驱动力矩、可靠性和控制性能都提出了更高的要求。以液压缸作为驱动元件的变桨距系统结构复杂、故障率高，而且液压缸负载力与阻力矩之间存在非线性，严重影响了系统的响应特性。针对这些问题本文提出了基于阀控液压马达的变桨距系统，并以液压型风电机组阀控液压马达变桨距系统为研究对象，对变桨距载荷特性、摩擦补偿、速度冲击、载荷模拟以及液压型风电机组的变桨距控制技术展开研究。通过本文的研究旨在掌握阀控液压马达变桨距系统的关键理论、方法和技术，为液压型风电机组的变桨距控制技术提供理论依据。对变桨距载荷特性进行研究，基于叶素-动量理论构建了变桨距载荷的计算模型，对影响变桨距载荷的风速模型、风轮模型、桨叶气动力参数进行了分析。并结合风速特征，获得了不同风速下变桨距载荷随桨距角变化的规律。对影响阀控液压马达桨距角控制精度的主要因素展开研究。构建了阀控液压马达转角控制系统数学模型，对影响桨距角控制精度的各种因素进行了分析。分析结果表明，动态摩擦力矩对阀控液压马达桨距角控制精度的影响最大。基于LuGre动态摩擦模型构建了阀控液压马达变桨距系统模型，采用遗传算法对LuGre摩擦模型的动静态参数进行了辨识。提出了阀控液压马达自适应摩擦力矩补偿控制策略，并进行了仿真和实验研究，与传统的PID加前馈补偿控制方法相对比，采用自适应补偿方法可以在不同载荷条件下实现很好的补偿效果，消除了由于摩擦带来的液压马达低速爬行现象，提高了桨距角控制精度。对变桨距过程中产生的速度冲击问题进行研究。针对桨距角控制过程中变桨距马达转速冲击问题和正反向转速不对称问题提出了阀控液压马达变桨距过程速度位置协调模糊控制策略，构建了变桨马达速度前馈模型，对变桨距过程中马达转速进行了规划，实现了变桨距马达速度前馈和位置反馈协调控制。在不同变桨距载荷条件下对系统进行了仿真和实验研究，实验结果证明采用速度位置协调控制可以有效抑制变桨距速度冲击。在对液压型风力发电机组研究的基础上，提出了液压型风力发电机组额定负荷区发电功率控制策略，在额定负荷区实现了主传动系统和变桨距系统联合控制发电功率。搭建了液压型风力发电机组半物理仿真平台，并针对变桨距载荷模拟问题，设计了变桨距载荷模拟系统。建立了阀控液压马达加载系统的数学模型，对系统的多余力矩进行了分析，提出了一种改进辅助同步补偿多余力矩抑制方法并对该方法的可行性进行了验证。在半物理仿真平台上，对液压型风力发电机组变桨距控制策略进行了实验验证。更多还原

【Abstract】 Variable pitch control system is an important part of the modern large-scale windturbine. With the development of large-scale wind turbine process, higherrequirements for the pitch drive torque, reliability and control performance of thesystem has been put forward. The complex system structure for taking the hydrauliccylinder as the pitch drive components, the high failure rate, and the nonlinear existsbetween the hydraulic cylinder load force and resistance moment, impact on theresponse characteristics of the system seriously. To solve all these problems, this paperproposes the variable pitch-controlled system, which based on valve control hydraulicmotor. With the valve control hydraulic motor as the research object, the pitch loadcharacteristics, friction compensation, simulation speed shock, load simulation, andpitch control technology have been researched. This paper aims to master the criticaltheory, method, and the technique of the variable pitch control system of the valvecontrol hydraulic motor, as well as provide the theory evidence for the hydraulic windturbine pitch control technique.The load characteristics of variable pitch were researched, and calculation modelof blade element momentum theory propeller pitch load was constructed based on theinfluence of load. Variable pitch wind model, the wind wheel blade parameters ofdynamic model were analysied. Combined with the features of wind speed, theregularities of variable pitch load changes with the angle are obtained under differentwind speed.The effects of friction compensation valve-controlled hydraulic motor pitchcontrol precision were studied. Combined with LuGre dynamic friction model,mathematical model of valve-controlled hydraulic motor position control system wasbuilt, and the factors of the precision of pitch angle control were analysed. Theanalysis results show that the dynamic friction torque of valve control hydraulic motorpitch angle control precision influence is very big. This article uses the geneticalgorithm to identify the LuGre friction model parameters, and put forward the valve-controlled hydraulic motor pitch angle control system adaptive frictioncompensation strategy, comparing with the traditional PID control with feedforwardcompensation method, using the adaptive compensation method can achieve goodcompensation effect under different loading conditions, eliminating the friction causedthe hydraulic motor of low speed creeping phenomenon, improve the accuracy of pitchangle control.In this paper, the shock problems occurring in the process of variable pitch windspeed were researched. For pitch angle control in the process of variable pitch motorspeed impact and positive reverse rotation speed asymmetric problems, thevalve-controlled hydraulic motor variable speed and position of composite controlstrategy were put forward. Considering the characteristics of fluctuated remarkably forwind turbines variable pitch wind load, speed and position fuzzy control method wasput forward, and variable propeller motor speed feedforward model was constructed.The motor rotate speed in the process of variable pitch was planned and the positionvariable pitch motor speed feedforward and position feedback compound control wasimplemented. In different variable pitch load conditions the simulation research onsystem has been carried on. Experimental results show that the speed and positioncontrol can restrain the pitch speed impact.Based on the research on hydraulic type wind turbine, the method of using valvecontrol hydraulic motor as the variable pitch control system is proposed, and thehydraulic type wind turbine generation power in rated load area control strategy is putforward. The hydraulic type wind turbine semi-physical simulation platform was built,and according to variable propeller pitch load simulation problem, variable pitch windload simulation system is presented. The mathematical model of valve-controlledhydraulic motor loading system was established, and the system of surplus torque isanalyzed. An improved aided synchronous compensation of surplus torque suppressionmethod is proposed and the feasibility of this method is verified. On semi-physicalsimulation platform, the hydraulic type of wind turbines variable pitch control strategyis proposed. The simulation results show that power control requirements can besatisfied in hydraulic type wind turbine rated load by using valve control hydraulic motor variable pitch control system.Finally, in the laboratory, valve-controlled hydraulic motor variable pitch controland variable pitch load simulation system were set up. In this paper, based on LuGredynamic friction model, proposed the adaptive compensation control method, thevalve controlled hydraulic motor variable pitch speed impact suppression method,improvement of auxiliary synchronous surplus torque suppression method is verifiedexperimentally. According to semi-physics experiment of power control in hydraulictype wind turbine rated load, the results show that the presented theory and controlmethod are feasible.更多还原