Simulation of an isolated Wind Diesel System with battery energy storage

The subject of this paper is to present the modelling and simulation of an isolated Wind Diesel Hybrid System (WDHS) comprising a Diesel Generator (DG), a Wind Turbine Generator (WTG), the consumer Load, a Ni-MH battery based Energy Storage System (BESS) and a Dump Load (DL). The BESS consists of a battery bank and a power converter which performs the DC/AC conversion to interface the battery with the isolated grid. The Ni-MH battery high power capability, low maintenance, resistance to abuse and absence of hazardous substances make it the best choice for WDHS. The modelling of the previously mentioned components is presented and the performance of the WDHS is tested through dynamic simulation. Simulation results with graphs for the frequency and voltage of the Isolated Power System, active powers generated/absorbed by the different elements and the battery voltage/current/state of charge are presented for load and wind speed changes. The simulation results for the BESS/no BESS cases are compared and show a remarkable improvement in the system dynamics due to the use of the BESS.     

Modelling and simulation of a high penetration wind diesel system with battery energy storage

Wind Diesel Hybrid Systems (WDHS) are isolated power systems which combine Diesel Generators (DG) with Wind Turbine Generators (WTG). Depending on the generators which are supplying, high penetration (HP) WDHS have three operation modes: Diesel Only (DO), Wind Diesel (WD) and Wind Only (WO). The HP-WDHS presented in this article consists of a Diesel Engine (DE), a Synchronous Machine (SM), a Wind Turbine Generator, the consumer load, a Ni-Cd Battery based Energy Storage System (BESS) and a Dump Load. The DE can be engaged (DO and WD modes) or disengaged (WO mode) from the SM by means of a clutch. All the models of the previously mentioned components are presented and the performance of the WDHS has been tested through dynamic simulation. Simulation results with graphs for the frequency and voltage of the isolated power system, active powers generated/absorbed by the different elements and the battery voltage/current/state of charge are presented for a load change in WO mode and for the transition from WO to WD mode in order to substitute a supplying BESS for the DE as the active power source.     

A fuzzy logic supervisor for active and reactive power control of a variable speed wind energy conversion system associated to a flywheel storage system

In this paper, we propose a Wind Energy Conversion System (WECS) at variable speed using a Doubly Fed Induction Generator (DFIG) controlled on the rotor side through converters. A Flywheel Energy Storage System (FESS) is connected to the studied wind generator at the DC bus in order to evaluate its capacity to participate to the ancillary services. We study the improvement of the active and reactive power quality produced by the wind generator and its effect on the load voltage regulation connected to the wind generator. For that, a fuzzy logic supervisor is established to control the FESS operation and the DC bus voltage in order to smooth the active power fluctuations due to the random wind speed variations. A control law is also described to smooth the reactive power at the connection node to the grid.     

含分布式电源的配电网中电池储能系统运行策略

针对配电网中因分布式电源(DG)的接入和负荷变化而引起的供需平衡问题,提出一种同时考虑DG和分时电价的蓄电池储能系统(BESS)充放电策略。第一步以降低能耗的收益与BESS套利之和最大为目标,以BESS各时段充放电功率为控制变量,以节点电压和充放电功率等为约束条件,在假设电池容量足够大的理想情况下建立划分充放电时段的数学模型;第二步以确定了充放电状态的各时段BESS功率为控制变量,并在第一步数学模型的基础上考虑荷电状态等约束,确定充放电功率的大小,并进一步划分充电、空闲和放电时段。修改的IEEE 33节点系统验证了所提策略的有效性。     

微电网储能系统下垂协调控制与母线电压控制策略

针对风光互补微电网内风力发电系统和光伏发电系统运行特性,提出采用蓄电池储能系统(Battery Energy Storage System,BESS)与超级电容储能系统(Super Capacitor Energy Storage System,SCESS)下垂协调控制策略基础上对微电网母线电压采用对应的控制策略,进而优化无功功率控制,以此进一步提高对微电网内负荷供电的稳定性。文中对微电网模式切换过程,加以控制策略理论分析,再通过PSCAD/EMTDC仿真软件,验证文中所提出控制策略的有效性及可行性。     

Modelling,simulation and optimisation of robust PV based micro grid for mitigation of reactive power and voltage instability

This paper proposes a robust H-infinity STATCOM controller for compensating reactive power in stand-alone micro grid consisting of a PV–Wind–Diesel hybrid system. In order to carry out MATLAB based simulation, a small signal linear model of the stand-alone hybrid power system is considered, comprising of a photo voltaic cell, a DFIG based wind turbine and a diesel generator. Synchronous generator based DG acts as a backup for the hybrid system. Generally these standalone systems experience frequent variation of loads, wind power input and solar radiation, which affect the vital system parameters like reactive power, terminal voltage and frequency to a great extent. These variations of system parameters with variation of load inputs are studied and its impact on overall system stability and reactive power compensation is properly monitored. Furthermore the system performance is improved and the robustness of the controller is enhanced with the incorporation of GA and PSO.     

运用成本效益分析的风/柴/储能系统规划方法

提出了一种基于成本效益分析的风/柴/储能系统规划方法.该方法采用蒙特卡罗仿真计算风/柴/储能系统的可靠性指标,通过保持该系统的供电可靠性在某一水平下,用风力发电机(wind turbine generator,WTG)和储能系统来扩张系统容量以满足负荷增长,同时在考虑风电运行约束、风力资源、燃料价格以及相关设备安装和维护费用的前提下,运用成本效益分析找出风力发电机安装容量和能量储存容量的最优组合.实例系统仿真结果表明,该方法合理、有效.     

提高STATCOM/BESS风电系统频率与电压支撑的智能联调优化控制方法

针对风电并网系统运行中负荷突变引起的频率波动和并网点电压的骤升/骤降问题,提出一种基于储能型静止同步补偿器(STATCOM/BESS)的频率与电压智能联调优化控制方法,该方法在具体实施过程中分为实时监测层、动态决策层和执行控制层3层,各层之间紧密联系,形成可靠闭环。首先,在实时监测层,基于风速分区与模糊控制判断风机的调频能力、系统有功需求及无功需求;其次,在动态决策层,综合考虑惯性常数和并网点电压,结合风机无功可调范围,动态优化有功、无功分配策略;最后,在执行控制层,风电机组与STATCOM/BESS对功率指令进行控制执行,STATCOM/BESS强化虚拟惯性时,考虑蓄电池(BESS)荷电状态,基于反馈动态调整其工作模式,控制结束后将相关参数及时反馈。仿真结果表明,基于STATCOM/BESS的风电系统智能联调优化控制可有效改善频率与电压的动态响应,提高频率与电压支撑能力。     

A study of the flywheel capacity of the power compensator for the wind turbine generator

Nowadays, the Wind Turbine Generator (WTG) system is remarkably increasing as a renewable energy resource in Japan. But in the WTG, the power fluctuations caused by the wind speed fluctuation are the most crucial issue in providing their energy to the utility. It was found that a power compensation system (PCS) of suitable capacity is not yet available. In this paper, the time range and standardized wind speed including fluctuations are discussed. We estimated the storage capacity of PCS at different wind profiles by standardization of wind speed and verified the validity of their capacities using a computer simulation. In this way we determined the suitable capacity of the power compensation system. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(4): 64–71, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10122     

IEC标准在风机实际功率曲线测定中的应用

IEC标准在风机功率曲线测定中常被采用,然而实际运营的风电场由于现场条件复杂,各种条件很难达到IEC的标准。为了研究IEC标准在实际风场中的应用情况,按IEC标准方法测定达坂城某风电场中风机的实际功率曲线,并对一些程序进行了适当的简化。经实际测定按照IEC标准测定的实际功率曲线与理论功率曲线比较接近。可见,IEC标准应用于测定风电场实际功率曲线是可行的。     

大型双馈风机稳态运行特性的仿真研究

利用Weibull分布的风速统计模型,建立了适用于双馈风机DFIG（Double FedInduction Generator）仿真研究的合成风速数学模型,并结合一个实际的DFIG系统．对DFIG的稳态运行特性进行了仿真研究。从仿真结果可见：当渐进风起作用时．有功功率和无功功率均增加．并快速达到设定值：当阵风开始起作用后,有功功率和无功功率均未发生变化．电压基本平稳．风机的运行特性较好．同时输出功率保持稳定。通过对大型变速双馈电机稳态运行特性的仿真研究表明．对于变速变浆矩风机．通过调节风轮转速．使其在给定的风速条件下保持风能利用系数达到最优．就可以实现对风机机械功率的最优控制。但是．浆矩角的变化,必然限制风力发电机的功率达到其额定值。     

永磁同步风力发电机并网运行研究

首先比较了2种主流变速恒频风力发电系统,再对永磁同步发电机系统的并网电路进行了分析。针对不控整流器加并网PWM变换器这种结构,提出采用直流母线电压控制同时实现并网与最大风能跟踪。分析了并网PWM变换器通过功率解耦控制直流母线电压的原理,提出采用直流母线电压作为参数的直接并网方法。分析了直流母线电压与发电机转速间的关系,提出采用直流电压变步长扰动替代转速定步长扰动实现最大风能跟踪。进行了详细的仿真,证明提出的控制策略简单可行,具有实用价值。     

超导储能蓄电池混合储能在风力发电中的应用

风力发电输出功率的波动性导致其直接并网会对电网带来不良影响,需要电力储能装置来提高并网性能,而常用的单一电池储能由于受到充放电次数的限制而易损坏。在建立用于平滑风电功率波动的超导储能和电池储能的混合储能模型基础上,设计超导储能用于平抑高频尖峰功率,电池储能用于平抑低频波动功率,并给出了两种储能装置的功率和容量确定方法。算例的仿真结果表明该方法同单一电池储能相比,可以有效地平抑风场并网的功率波动并减小电池的功率等级,减少电池的充放电次数和放电深度,从而延长了电池使用寿命。     

750kW失速型风力发电机组控制系统关键技术设计

控制系统是风力发电机组的核心部件之一。在介绍750kW失速型风力发电机组控制系统的组成与功能的基础上,重点介绍失速型风力发电机组控制系统的关键技术和可靠性设计,该控制系统在实际中得到了应用。     

垂直轴永磁同步风力发电系统建模及瞬时功率控制策略

以垂直轴风轮(VAWT)和永磁体励磁多极直驱式同步风力发电机组(D-PMSG)为对象,建立了包括风力机模型、传动系统模型和发电机模型的垂直轴永磁同步风力发电系统的数学模型及结构,提出对有功功率、无功功率进行瞬时控制策略:通过频率控制环和电压控制环对负载或并网瞬时有功功率和无功功率进行分解计算,得到逆变器输出电流参考值,与实际的逆变器输出电流测量值比较后产生控制波,再与定频三角载波信号比较,产生PWM控制信号控制逆变器的各桥臂导通和关断.运用Matlab/Simulink建立了系统仿真模型,对有功功率、无功功率瞬时控制策略进行仿真,结果验证了该模型的合理性及控制策略的正确性和可行性.     

A Theoretical and Experimental Study of a Laboratory Wind Turbine Emulator using DC-Motor Controlled by an FPGA-Based Approach

Abstract

The aim of this study is to carry out a Wind Turbine Emulator (WTE) which represents the important hardware part to behave as a real wind turbine system with respect to the introduced wind timeseries for improving the wind power system technology control in laboratory. The proposed WTE consists of a variable speed drive which controls a DC motor as a prime mover coupled to a PMSG operated in open loop. The novelty appears in the modeling and configuration of wind timeseries, aerodynamic and mechanical aspects of the wind turbine and its control strategy by using Xilinx System Generator (XSG) as a dataflow design tool based on graphical user interface Simulink which ensures a rapid architectures prototyping. Moreover, the dynamic performance of the modeled system under Matlab/XSG environment is presented and discussed. The motor drive is performed by a DC/DC buck converter controlled by PWM strategy implemented on FPGA board. An experimental platform of the entire wind energy conversion system is built. Experimental results verified and validated the wind turbine emulator operation using a variable wind speed.     

考虑双馈异步风电机组无功极限的静态电压稳定概率评估

风电机组中双馈异步发电机(DFIG)恒电压运行时具备一定无功调压能力。为了准确评估含DFIG风电机组的电力系统电压稳定性,得到更为精确的临界功率或负荷裕度的统计信息,构建了考虑DFIG风电机组恒电压运行的无功极限的静态电压稳定概率分析模型,并采用蒙特卡罗法结合内点法加以求解。模型中将风电场接入节点作为PV节点,考虑了风机网侧变换器的注入无功功率,分析了风速随机性和相关性对风电机组注入无功功率和系统电压稳定性的影响。IEEE 118和300节点标准系统的计算结果验证了所提模型和方法的有效性。     

基于模糊控制的开关磁阻风力发电系统最大功率点跟踪控制

研究了基于风速跟踪的开关磁阻风力发电系统最大功率点跟踪二维模糊控制算法,确定了模糊变量的隶属度分布和相应的模糊控制规则,采用MATLAB/Simulink中的PowerSystems建立了开关磁阻风力发电系统最大功率点跟踪模糊控制系统的仿真模型,对风速阶跃变化、负载变化等工况下的开关磁阻风力机组运行情况进行了仿真,仿真结果表明所设计的开关磁阻风力发电机模糊控制器具有良好的鲁棒性,能使开关磁阻风力发电系统以优良的动静态性能实现最大功率点跟踪。     

Finite-time convergence robust control of battery energy storage system to mitigate wind power fluctuations

Wind energy is envisioned to be one of the most promising clean and renewable energy to drive our future society. Due to its intermittency nature, wind power may change rapidly and frequently. Wind power fluctuations pose great challenges on power quality, reliability and raise many other issues like frequency and voltage regulation. This paper proposes a finite-time convergence robust control algorithm of battery energy storage system (BESS) to mitigate the wind power fluctuations. The major advantages of the proposed algorithm include, being insensitive to uncertainty and disturbance, enabling adjustable convergence time to accommodate different operating conditions and maintaining the state of charge (SOC) within a proper range for regulation capability reserve. Finite-time convergence of the proposed algorithm is derived through rigorous analysis. Simulation results demonstrate the effectiveness of the proposed algorithm.     

清洁度在风力机生命周期环境评价中的作用

风能是可再生清洁能源,但对于风力发电,在发电设备制造和风力发电场的建设过程中,会对环境产生污染和破坏为评价风力机生命周期内的环境效益,提出了能源利用技术中的一个新概念——清洁度介绍了清洁度系数的定义和计算方法,分析了该参数的物理意义,并得出结论：提高风力机清洁度的主要手段包括合理选择风场、提高发电效率、延长风力机使用寿命和有效运行时间,以及减少其它能量消耗等。