基于PSCAD/EMTDC的直驱式风力发电接入系统建模与仿真

针对频率可变的多极直驱式同步风力发电机接入系统,该文在考虑风力机大转动惯量的情况下,采用电网电压矢量定向和双闭环控制技术,实现了基于背靠背VSC换流器的有功无功独立控制。研究了不依赖于风速测量的直驱式机组最大功率追踪策略,桨距角控制器设计以及变风速下风电机组对电网的无功支持问题。最后通过PSCAD/EMTDC搭建了该接入系统模型,阶跃和随机风速下的仿真结果验证了该模型的合理性及控制策略的有效性。     

直驱式风力发电系统的应用分析

结合目前市场应用和实验研究情况，综合评述了直驱式风力发电系统。具体介绍了5种直驱式风力发电系统的特点、优劣及应用状况，直驱式风力发电系统中应用的电力电子变换器概况。通过综合比较，指出了直驱式风力发电系统的应用前景。     

基于双PWM变换器的直驱永磁同步风力发电机组建模与仿真

直驱永磁同步风力发电(D-PMSG)系统无变速箱,效率高,稳定性好,能获得质量较好的电能,通过变换器与电网相连,可灵活控制系统的电压和频率,能够对输出的有功功率和无功功率进行相对独立的控制。文章利用电力系统分析软件DIGSILENT/Power Factory,在建立D-PMSG和双PWM变换器模型的基础上,结合典型算例系统结构进行了仿真分析,验证了所建模型的正确性。     

直驱式永磁同步风力发电系统的整合模型与仿真

直驱式永磁同步发电机组具有控制回路少、控制简单的优点,在风力发电系统中得到越来越广泛的应用。文章针对直驱式永磁同步风力发电系统的结构、运行特性及功率传输特点,列写出各个模块的电压方程及状态方程,进而建立其整合模型;使用MATLAB进行仿真,验证了该模型的正确性及可靠性,对风电系统的控制策略研究提供了有效帮助。     

适于直驱型风力发电系统的大功率变流器

直驱型变速恒频风力发电系统采用低速永磁同步发电机结构,无需齿轮箱,机械损耗小,运行效率高,维护成本低.该系统须采用的大功率变流器单元可以有不同的拓扑结构,根据每种电路拓扑的特点,整个系统的控制方法都会相应地发生变化.文章对直驱型变速恒频风力发电系统基本拓扑结构进行了对比分析,着重分析了常见的中高压变频器主电路拓扑,并对大功率变流器在风力发电系统应用中的可行性进行了相关分析与探讨.     

并网永磁直驱风电机组故障穿越能力仿真研究

随着电力电子器件成本下降,拥有全功率变换器的永磁直驱风机成为各国关注热点。风电场容量不断增大,要求风电机组具有故障穿越能力。本文以直驱同步风电发电机组为研究对象,利用matlab/simulink搭建了直驱同步风电机组的动态数学模型,对直驱同步风电机组故障穿越能力进行仿真研究,试验结果表明：在风电场接入点发生故障时,直驱同步风电机组具有故障穿越功能。尤其在电网发生电压跌落时,直驱风机能为系统提供一定的无功支撑。有效防止系统电压过多降落。提高了系统故障运行的稳定性。     

永磁直驱风力发电系统MPPT控制的研究

文章首先介绍了风力机模型。然后介绍了一种改进型的变步长爬山算法,通过该算法改变直驱风力发电系统三重交错并联Boost变换电路的占空比,从而实现最大功率跟踪,获取最大风能。最后,利用MATLAB/SIMULINK建立直驱永磁风力发电系统仿真模型并进行研究。试验结果表明,改进型变步长爬山算法比传统爬山算法能更快跟踪最大功率点,控制系统具有较好的控制精度和稳定性。     

基于Matlab/Simulink的永磁直驱风力发电机组建模和仿真研究

以永磁直驱风力发电机组为研究对象,建立了包括风力机、传动部分、永磁直驱发电机、矢量控制策略、最大风能捕获策略的整体数学模型;应用Matlab/Simulink工具,以建立的数学模型为基础搭建了永磁直驱风力发电机组仿真模型,并以两次阶跃风速为例对所建模型并网后运行特性进行了仿真研究。实现了永磁直驱风力发电机组的最大风能捕获和功率解耦控制,仿真结果表明,永磁直驱风力发电机组具有良好的运行特性,同时验证了所建模型的正确性和有效性。     

直驱式风电系统网侧变换器控制策略研究

研究了一种适合于直驱式风电系统网侧变换器的控制策略,该变换器选用三相电压源型PWM六桥臂拓扑结构。建立了网侧PWM变换器的数学模型,基于电网电压矢量定向,提出采用d,q轴电流线性化解耦控制策略及空间电压矢量SVPWM调制方式。在Matlab环境下的仿真结果表明,该系统运行稳定,动态响应快,输出直流电压稳定,且脉动很小,各项性能优良。     

直驱型风力发电变流器低压穿越控制策略研究

研究了直驱型风力发电变流器系统低压穿越控制策略。首先提出了一种对三相电量进行快速准确的正负序分离软件锁相环。在此基础上,为消除直流电压的二次谐波,采用正、负序双电流内环控制不对称运行控制策略。正负序分离软件锁相环采用了正负序级联延时信号消除法,能够实现对三相电压电流基波正负序分量在同步旋转坐标下的快速提取,并且通过选择不同的参数,可以滤除任何次数谐波的干扰。该方法无需采用滤波器,从而同时具备了稳态精确性和动态快速性。现场实验结果表明,该软件锁相环为三相并网型风力发电变流器在电网发生跌落及谐波畸变时提供了良好运行控制提供保障,正负序双电流内环不对称运行的控制策略保证了在电网电压不对称跌落时的正负序分离控制,消除了直流电压的二次谐波。     

Modeling and simulation of multi‐scale transients for PMSG‐based wind power systems

In a wind energy conversion system (WECS), multiple‐time‐scale transients that cover a wide frequency range from low‐frequency transient stability up to high‐frequency switching events are observed. This paper presents a methodology of modeling diverse transients for a permanent magnet synchronous generator (PMSG)‐based WECS within the same study. Multiple physical areas of the PMSG‐based WECS are given depending on the appearance of carriers contained in the considered waveforms. In order to eliminate different carrier frequencies, the PMSG and generator‐side voltage source converter (VSC) are modeled in the dq0‐reference frame. On the other hand, the grid‐side VSC and utility grid are dealt with in the multi‐scale model of the network in which the shift frequency is available. The switching‐function and average‐value models of the VSC are selected depending on the carrier shifted. In addition, interface between the control and electrical subsystems is redesigned to offset the computation error caused by one time‐step delay. Two test cases are performed to study the wind power fluctuations and faults ride‐through. The results show that the proposed multi‐scale model is able to simulate slow‐changing dynamic responses up to high‐frequency transients accurately while decreasing the simulation burden. In comparison with the results obtained from the EMTP (electromagnetic transients program) type simulators, the effectiveness and accuracy of the multi‐scale model are verified. Copyright © 2017 The Authors Wind Energy Published by John Wiley & Sons Ltd.     

基于叶素理论的风力机组建模与仿真

基于叶素理论建立了风力发电机组空载状况下的数学物理模型,以攻角为控制对象设计控制器,在此基础上,以Matlab/Simulink为工具,建立了系统仿真模型,采用"试凑法"选择PI控制器的参数,通过设定风速分析了风力发电机组的运行特性,仿真结果验证了理论分析的正确性。该研究对控制器的设计具有参考价值。     

永磁直驱风电系统PMSG的内模控制策略研究

介绍了PMSG控制策略和内模控制的工作原理.采用内模控制策略设计电机侧PWM变流控制器的速度调节器与电流调节器,使控制器参数直接与电机参数相关联,实现对PMSG的控制.仿真结果显示,采用内模控制具有良好的稳态与动态性能,对输入机械转矩、转速给定等外部条件变化的响应速度快,对电机参数误差具有较强的适应性;内模控制应用于永磁直驱风电系统PMSG的控制,容易获取优化的控制器参数,可以有效提高控制性能.     

Simulating intra‐hourly wind power fluctuations on a power system level

In wind integration studies, sub‐hourly, load synchronous wind data are often preferable. These datasets can be generated by a hybrid approach, combining hourly measurements or output from meteorological models with a stochastic simulation of the high‐frequency fluctuations. This paper presents a method for simulating aggregated intra‐hourly wind power fluctuations for a power system, taking into account the time‐varying volatility seen in measurements. Some key elements in the modelling were transformations to stationarity, the use of frequency domain techniques including a search for appropriate phase angles and an adjustment of the resulting time series in order to get correct hourly means. Generation data from Denmark and Germany with 5 and 15 min temporal resolution were used for training models. It is shown that the distribution and non‐stationarity of simulated deviations from hourly means closely follow those of measurements. Power spectral densities and step change distributions agree well. Of particular importance is that the results are good also when the training and objective power systems are not the same. The computational cost is low in comparison with other approaches for generating high‐frequency data. Copyright © 2016 John Wiley & Sons, Ltd.     

基于Matlab的含风电电网建模与仿真

介绍了应用Matlab 7.0对含风电的电网建模以及风速突然变化、系统电压突然下降和电网发生单相接地短路3种情况的仿真分析方法和机理。仿真结果表明，变速风力机驱动双馈式异步风力发电机组的变速平稳。机组效率高，对电网也可以起到一定的稳压和无功调解的作用。     

风-水-火电互补系统中风电穿越功率的研究

针对风电容量与风-水-火电互补系统稳定性的关系问题,研究了风电机组的数学模型,搭建了风-水-火电互补系统的仿真模型.将遗传算法(GA)应用于风电穿越功率的研究,建立了基于遗传算法的风电容量的优化数学模型,构造了适值函数.对实际电网中的风电容量进行了优化编程计算和仿真,优化和仿真结果虽有差异,但很近似,验证了所建优化数学模型的合理性及遗传算法应用于风电穿越功率计算的可行性.     

1.5MW低风速风力发电机组主传动系统设计及动力学分析

低风速风力发电机组具有广阔的市场前景,其主传动系统的设计和分析是整个风机研发的关键技术之一。通过对风机各种传动系统结构形式的分析、对比和优化,设计了适于1.5 MW低风速风力发电机组的最佳传动方案,即内置式主轴、二级行星加一级平行轴齿轮传动的结构形式。采用多体动力学软件SIMPACK建立了该风机主传动系统的精确模型,找出系统的固有频率及激振源,并进行共振分析;对共振危险点进行时域仿真,根据仿真结果研究振动对风机系统的影响。最后根据系统的动态特性分析结果,验证所设计的主传动系统的可靠性。     

Modeling and control design of hydrogen production process for an active hydrogen/wind hybrid power system

This paper gives a control oriented modeling of an electrolyzer, as well as the ancillary system for the hydrogen production process. A Causal Ordering Graph of all necessary equations has been used to illustrate the global scheme for an easy understanding. The model is capable of characterizing the relations among the different physical quantities and can be used to determine the control system ensuring efficient and reliable operation of the electrolyzer. The proposed control method can manage the power flow and the hydrogen flow. The simulation results have highlighted the variation domains and the relations among the different physical quantities. The model has also been experimentally tested in real time with a Hardware-In-the-Loop Simulation before being integrated in the test bench of the active wind energy conversion system.     

Dynamic simulation of thermal energy storage system of Badaling 1 MW solar power tower plant

In this paper, the thermal energy storage system of Badaling 1 MW solar power tower plant is modelled from mathematical models for whole of the working conditions using the modular modelling method. This model can accurately simulate the recharge and discharge processes of thermal energy storage system. The dynamic and static characteristics of the thermal energy storage system are analyzed based on the model response curves of the system state parameters that are obtained from different steam flow disturbances. Conclusions of this paper are good references for the design, operating, and control strategy of solar thermal power plant.     

Steam turbine governor modeling and parameters testing for power system simulation

The theoretical modeling, parameters test and model correction for a steam turbine (ST) governor are discussed. A set of ST Governor system model for power system simulation is created based on this research. A power system simulation for an actual power grid accident is conducted using this new model and the comparison between the simulation and actual data show that the results are satisfactory.