变速恒频DFIG的fal函数积分滑模控制

双馈发电机有功、无功功率的解耦控制是变速恒频双馈风力发电系统的关键技术.首先对双馈异步发电机的动态数学模型以及基于定子磁场定向的矢量控制方案进行了分析,进而针对传统矢量控制在双馈风力发电机功率解耦过程中的动态性能不佳现象,提出基于积分滑模变结构控制方案,并将幂次函数引入积分滑模控制中,构建了基于幂次函数的积分滑模控制器,实现了双馈风力发电机有功、无功功率的解耦及风能最大追踪.仿真实验表明与传统PI控制器相比,该控制策略具有优良的动、静态性能和控制精度.     

变速恒频双馈风力发电技术概述

概述了变速恒频双馈电机风力发电的技术,其中包括双馈电机运行理论、交流励磁用变换器技术、发电机并网技术、有功功率和无功功率独立调节的矢量变换控制技术以及风电系统输出电能质量控制技术等.分析了当今的热点及进一步的工作,为大型风力机组的工程实现奠定了一定的理论及技术基础.     

双馈风力发电系统MPPT控制技术的研究

介绍了变速恒频风力发电的基本原理,并采用定子磁链定向的矢量控制方法得到了双馈发电机的矢量控制系统模型.本文利用Matlab软件建立了该系统的仿真模型,仿真结果验证了这种矢量控制策略既能保证定子输出频率的恒定,又能达到有功功率和无功功率的独立解耦控制,同时还能较好地跟踪风力机的最大功率输出.     

双馈异步发电机应用于风力发电中的仿真研究

介绍了双馈异步发电机的数学模型和基于变速恒频矢量控制的风力发电系统动态仿真模型的建立。对风电系统进行了特性分析和动态响应过程的仿真研究,仿真表明这种基于变速恒频矢量控制风力发电系统对于电网电压和转速扰动的适应能力很强．研究结果为风力发电系统的进一步应用研究提供了可靠的理论依据．     

电传动内燃机车微机控制系统

随着计算机技术的不断发展,微机技术开始在内燃机车上得到广泛的应用。本文作者根据我国 的实际情况,初步研究开发了一套电传动内燃机车微机控制系统。该系统通过单片机实现机车 的恒功率控制与空转防护。论文介绍了该系统的基本结构组成、控制算法及模拟试验结果,理 论分析与试验结果表明、该系统具有良好的控制性能。      

双馈风力发电系统的转子侧变换器高阶滑模控制

为了提高双馈电机功率解耦控制的动态性能,提出了一种高阶滑模控制策略.首先分析了双馈异步电机数学模型以及基于电压定向矢量控制原理,然后针对传统控制方法在实现功率解耦存在动态性能不佳现象以及风机模型的非线性,构造一种基于幂次函数趋近律的高阶滑模控制器,最终实现了变速恒频双馈风力发电机有功、无功功率动态解耦控制.仿真结果表明,所提出的控制策略的精度、鲁棒性、动静态性能均优于传统PI控制器.     

基于ESO的PMSG风力发电系统无源自抗扰控制

为实现直驱式永磁同步风力发电系统在低风速下的最大功率追踪,提高风能的利用率,提出了无源自抗扰转速控制策略.利用基于能量成形、PCHD的原理以及扩张状态观测器(ESO)技术,设计出基于ESO的无源电流控制器,同时通过基于反双曲正弦函数的ESO对系统扰动项进行实时性观测并补偿.针对速度调节器响应速度慢、抗负载能力差的问题,设计了基于反双曲正弦函数的速度控制器并得到期望的定子电流.仿真结果表明,该控制方法能保证系统稳定运行,具有较强的转速跟踪性、抗负载能力以及鲁棒性,同时具有较小的电磁转矩脉动.     

液压挖掘机油泵控制系统节能分析

分析了日立ＥＸ系列液压挖掘机油泵变量控制系统，该系统采用微机控制，既实现了恒功率变量，又使油泵在空载和超载时近似于零排量，同时还能使油泵排量随发动机的功率而变化，从多个角度实现了节能。     

双馈风机网侧变流器直接功率控制研究

针对目前双馈感应风力发电机(DFIG)采用背靠背结构通过网侧变流器与电网相连,提出了一种采用直接功率控制方案,直接功率控制(DPC)仅需要测量交流侧的电压与电流,计算出瞬时有功功率,无功功率。与参考的有功功率,无功功率进行比较来控制网侧变流器。该方法能对直流侧电压有良好的控制,同时能保证网侧变流器接近单位功率因数运行。     

MMC的无锁相环直接功率控制仿真

目前新型模块化多电平换流器（modular multilevel converter,MMC）多采用电压外环电流内环的双闭环直接电流控制策略,研究MMC的直接功率控制（direct power control,DPC）策略以减少系统控制参数,改善动态响应慢等问题。在αβ坐标系下推导关于MMC的DPC数学模型,并设计了一种无锁相环的DPC控制系统,为消除系统频率和电感参数的变化对控制系统的干扰,设计了一种无系统角频率和电感参数的功率解耦控制器,将双闭环简化为功率单环。考虑电网强度对换流站运行特性的影响,计算出直接功率控制策略适用于交流系统强度范围。最后在MATLAB/Simulink中仿真验证,结果表明上述设计控制策略的有效性。     

Design of fuzzy controller for direct drive wind turbines

Based on the research results of these years, this paper proposes a design of 3MW direct-driven wind generation inverter, and takes much effort in the control algorithm research and MATLAB simulation. Some wonderful results are obtained. All this may provide the reference for practical application. The fuzzy controllers are designed, based on fuzzy logic control theory, which can perfect control of wind generation system with no mathematic model. Models of permanent magnet synchronous generator (PMSG) and dual pulse width modulation (PWM) converter with their controllers are set by MATLAB/Simulink. In addition, experiments are made on the simulation platform of variable speed constant frequency (VSCF) wind power generation system. The behavior of dual PWM converter is demonstrated by simulations and experiment, and the control strategy is valid and correct.     

Research on Dynamic Response Characteristics of 6MW Spar-Type Floating Offshore Wind Turbine

A 6 MW spar-type floating offshore wind turbine(FOWT) model is put forward and a fully coupled aero-hydro-servo-elastic time domain model is established in the fatigue,aerodynamics,structures and turbulence(FAST) code.Influence rules of wind load and wave load on the characteristics of 6 MW spar-type FOWT are investigated.Firstly,validation of the model is carried out and a satisfactory result is obtained.The maximal deviations of rotor thrust and power between simulation results and reference values are 4.54% and-2.74%,respectively.Then the characteristics,including rotor thrust,rotor power,out-of-plane blade deflection,tower base fore-aft bending moment,and mooring line tension,are researched.The results illustrate that the mean value of dynamic response characteristics is mainly controlled by the wind-induced action.For characteristics of tower base fore-aft bending moment and platform pitch motion,the oscillation is dominated by the wave-induced action during all conditions considered.For characteristics of out-of-plane blade tip deflection and mooring line tension,the oscillation is commanded by combination effect of wave and wind loads when the wind speed is lower than the rated wind speed(hereinafter referred to as below rated wind speed) and is controlled by the wave-induced action when the wind speed is higher than the rated wind speed(hereinafter referred to as above rated wind speed).As to the rotor thrust and power,the oscillation is dominated by the wind induced action at below rated wind speed and by the combination action of wind and wave loads at above rated wind speed.The results should be useful to the detailed design and model basin test of the 6 MW spar-type FOWT.     

几种大型风力发电机组技术特点及应用

大型风力发电机组技术不仅体现当代电机制造、材料工程、电力电子、自动控制、流体力学和地质气象等领域的科技水平,而且引领着未来风力发电机组设计制造技术的发展方向。根据发电机驱动方式的不同,风力发电机系统可分为双馈式、直驱式和半直驱式。分析3种驱动方式下各风力发电系统的技术特点及优缺点,并简要介绍各种风力发电机系统的应用状况。     

Wind Generator Stabilization with Doubly-Fed Asynchronous Machine

This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation controlling.Simulation results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line failures.Comparison studies have also been performed between wind turbine pitch control and proposed method.     

Data-Driven Process Monitoring and Fault Tolerant Control in Wind Energy Conversion System with Hydraulic Pitch System

Wind energy is one of the widely applied renewable energies in the world. Wind turbine as the main wind energy converter at present has very complex technical system containing a huge number of components,actuators and sensors. However, despite of the hardware redundancy, sensor faults have often affected the wind turbine normal operation and thus caused energy generation loss. In this paper, aiming at the wind turbine hydraulic pitch system, data-driven design of process monitoring(PM) and diagnosis has been realized in the wind turbine benchmark. Fault tolerant control(FTC) strategies focused on sensor faults have also been presented here, where with the implementation of soft sensor the sensor fault can be handled and the performance of the system is improved. The performance of this method is demonstrated with the wind turbine benchmark provided by Math Works.     

Design and Parametric Investigation of Horizontal Axis Wind Turbine

This research focuses on design and calculations for the horizontal axis wind turbine to fulfill energy demands at small scales in Pakistan. This is the design to produce about 5 kilowatts of electricity to share the load of average home appliances. Area chosen for this research is Pasni, Balochistan in Pakistan to build the wind turbine for electricity. Design values are approximated by appropriate formulas of wind energy design. In current research, turbine blade profile is designed by blade element momentum (BEM) theory. Warlock wind turbine calculator is used to verify the design parameters like wind speed, tip speed ratio (TSR) and efficiency factor. Effects of wind speed, wind power, TSR, pitch angle, blade tip angle, number of blades, blade design and tower height on power coefficient are analyzed in this research. Maximum power coefficient is achieved at a designed velocity of 6m/s. Design analysis is also performed on simulation software ANSYS Fluent. It is observed that designed velocity parameter of this research is very suitable for the turbine blade, so blade designing is perfect according to wind speed range.     

直驱永磁风电系统PWM变流器的非线性控制研究

为分析直驱永磁风电系统在小扰动下的稳态性能和动态特性,建立了以PWM变流器为控制目标的数学模型,通过对PWM导通情况的调节来实现对直驱永磁风电系统输出的控制,设计了非线性控制策略。Matlab/Simulink 的仿真结果表明该控制策略能增强系统的稳定性控制性能,保证系统在较大的风速变化范围内实现功率地有效调节,并能较好的实现风电系统在小扰动状况下的稳定。     

汽车尾气能量转换基础研究

利用汽车车辆排放的高温废气可以通过磁流体（MHD）能量转换发电机产生电能.此电能可以取代混合动力汽车中使用的交流发电机充电系统,且可为车载电能存储系统供电.通过数值模拟计算,磁流体发电机利用汽车尾气余热提高汽车的能量利用效率,汽车尾气可产生2.4 kW的能量.研究结果表明：磁流体能量转换发电机可适用于汽车尾气能量转换系统,可以将汽车尾气的能量转换效率提高至19.5％.将磁流体发电技术应用于尾气的能量转换,这在能量转换方面是一个新的概念.它不仅扩展出一个新的磁流体发电技术的应用领域,还提出了对于汽车尾气问题的一个新的解决方法.