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1.
HU Jia-bing HE Yi-kang 《浙江大学学报(A卷英文版)》2006,7(10):1757-1764
INTRODUCTION Due to concerns about emissions from fossil fuels and the depletion of fossil fuel resources, re- newable energy systems are becoming a topic of great interest and investment in the world. In particular, wind energy has been the subject of much recent research and development. In order to overcome the problems associated with fixed-speed wind-turbine system and to maximize the wind energy capture, many new wind farms will employ wind turbines based on Doubly-Fed Induction Ge… 相似文献
2.
A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine (HESM) is introduced
in this paper. The generator is connected to an uncontrollable rectifier, and a fully controlled voltage-source inverter is
used to connect the system to utility grid. An intermediate DC bus exists between the rectifier and inverter. A new control
strategy is proposed which achieves the maximum power point tracking (MPPT) with the control of excitation current of HESM
and stabilizes the DC link voltage with the control of inverter output current simultaneously. Specially-designed buck circuit
is used to control the excitation current of HESM, and grid voltage-oriented vector control strategy is employed to realize
the decoupling of the inverter output power. Simulation results and experiment in 3 kW lab prototype show an excellent static
and dynamic performance of the proposed system. 相似文献
3.
Grid-connected inverter for wind power generation system 总被引：3，自引：0，他引：3
In wind power generation system the grid-connected inverter is an important section for energy conversion and transmission, of which the performance has a direct influence on the entire wind power generation system. The mathematical model of the grid-connected inverter is deduced firstly. Then, the space vector pulse width modulation (SVPWM) is analyzed. The power factor can be controlled close to unity, leading or lagging, which is realized based on PI-type current controller and grid voltage vector-oriented control. The control strategy is verified by the simulation and experimental results with a good sinusoidal current, a small harmonic component and a fast dynamic response. 相似文献
4.
Adaptive rotor current control for wind-turbine driven DFIG using resonant controllers in a rotor rotating reference frame 总被引：1，自引：0，他引：1
This paper proposes an adaptive rotor current controller for doubly-fed induction generator （DFIG）, which consists of a proportional （P） controller and two harmonic resonant （R） controllers implemented in the rotor rotating reference frame. The two resonant controllers are tuned at slip frequencies ωslip＋ and ωslip-, respectively. As a result, the positive- and negative-sequence components of the rotor current are fully regulated by the PR controller without involving the positive- and negative-sequence decomposition, which in effect improves the fault ride-through （FRT） capability of the DFIG-based wind power generation system during the period of large transient grid voltage unbalance. Correctness of the theoretical analysis and feasibility of the proposed unbalanced control scheme are validated by simulation on a 1.5-MW DFIG wind power generation system. 相似文献
5.
This paper proposes an analysis and a direct power control （DPC） design of a wind turbine driven doubly-fed induction generator （DFIG） under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions. 相似文献
6.
A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks 总被引：1，自引：0，他引：1
Chun-hua Li Xin-jian Zhu Guang-yi Cao Wan-qi Hu Sheng Sui Ming-ruo Hu 《浙江大学学报(A卷英文版)》2009,10(2):263-270
To extract the maximum power from a photovoltaic （PV） energy system, the real-time maximum power point （MPP） of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller （FNNC）, which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the filzzy logic control algorithm. 相似文献
7.
HU Jia-bing HE Yi-kang NIAN Heng 《浙江大学学报(A卷英文版)》2007,8(8):1330-1339
This paper presents a unified positive-and negative-sequence dual-dq dynamic model of wind-turbine driven doubly-fed induction generator(DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back(BTB) PWM voltage source converter(VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency,and the two proposed control targets for the rotor-side converter are alternatively achieved,which,as a result,improve the fault-ride through(FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid-and rotor-side converters included is designed. Finally,simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results. 相似文献
8.
针对新能源发电与并网技术课程实验教学设备不能满足教学需求的问题,构建光伏发电并网系统虚拟仿真实验项目。首先,通过StarSim软件搭建仿真电路模型;其次,通过设置太阳辐照度、电池组件并联组件数,改变光伏发电功率;最后,采用Boost升压斩波电路,调节光伏阵列的端电压,进而实现光伏阵列的最大功率点跟踪。 相似文献
9.
In order to improve the output efficiency of a photovoltaic (PV) energy system, the real-time maximum power point (MPP) of the PV array should be tracked closely. The non-linear and time-variant characteristics of the photovoltaic array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP as in traditional control strategies. A neural fuzzy controller (NFC) in conjunction with the reasoning capability of fuzzy logical systems and the learning capability of neural networks is proposed to track the MPP in this paper. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the NFC. With a derived learning algorithm, the parameters of the NFC are updated adaptively. Experimental results show that, compared with the fuzzy logic control algorithm, the proposed control algorithm provides much better tracking performance. 相似文献
10.
分析了风力机的基本特性,阐述了风力发电机组控制系统在低于额定风速时风力机的最大风能捕获及高于额定风速情况下的变桨距控制。在此基础上,利用SVM(support vector machines)优化风力机的风能利用系数以及变桨距控制系统的控制参数。仿真分析表明,风能转换系数的支持向量机模型具有很好的精度和泛化性能,而优化后的变桨距控制系统可对输出功率的调节获得较好的效果,保证风电系统的恒功率输出。 相似文献
11.
提出了一种两阶段多功能光伏逆变器(QMFI),有功功率借助于该结构可以在一个功率转换器内从光伏阵列直接传输到电网或负载,从而提高转换效率。此外,考虑QMFI最大功率点跟踪(MPPT)的实现和非有功电流的补偿,提出了QMFI的数学模型,从而获得有效的控制参数。在求解过程中,采用基于旋转坐标系的分析模型,并推导了QMFI的空间矢量脉冲宽度调制策略,直观地揭示了非有功电流补偿对两阶段有功潮流的影响。最后,通过3 kVA样机验证了所提方案的可行性和有效性。 相似文献
12.
风速的随机性、间歇性及不确定性,必将导致风电场的输出功率也具有随机波动性和间歇性,风电系统的输出功率影响电网的安全稳定运行和电能质量．通过构建了以鼠笼式感应电机为发电系统的定速变桨距风力发电系统,展开功率跟踪控制系统分析．给出了风力机空气动力学特性和建模方法,建立了传动链数学模型和感应发电机的数学模型．设计了转矩控制环、速度控制环,给出了实现功率跟踪的功率控制环设计思路,仿真结果表明,该系统能实现风电系统的最优功率跟踪控制． 相似文献
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14.
微逆变器可实现独立的光伏模组最大功率点追踪控制,极大优化并网光伏发电系统的光伏能量转换,提供即插即用概念。光伏微逆变器在功率变换中,常采用高频变压器升压产生期望的输出交流电压,根据直流链配置可以分为直流链、伪直流链和无直流链3种微逆变器拓扑结构。微逆变器控制技术包括最大功率点追踪控制技术、输出电流控制技术、孤岛效应侦测与保证技术等,且功率开关对于改善微逆变器的转换效率至关重要。 相似文献
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16.
太阳能光伏发电新能源实验研究平台 总被引：1，自引：0，他引：1
作为清洁能源的太阳能发电已越来越受到重视并得到应用。介绍了新型能源——太阳能光伏发电在实验室中的发展,分析太阳能光伏发电的原理和最大功率追踪技术,记录并网运行所发电量及带来的二氧化碳减排量。研究光伏电池发电的特性是光伏发电大规模发展的基础。 相似文献
17.
郑雪钦 《鹭江职业大学学报》2013,(3):35-39
为了实现双馈风力发电系统无冲击并网,避免并网瞬间冲击电流对电网和发电系统的影响,在MT坐标系下建立系统的数学模型和仿真模型.网侧变换器采用电压电流双闭环控制;在机侧变换器控制中增加消除转子电压和电流交叉耦合的补偿项.仿真结果表明,系统并网过程动态响应快,对电网几乎无任何冲击,定子侧电流和电压稳态时均为正弦波,双矢量PWM双馈风力发电系统并网控制策略无须增加额外的并网装置就可以实现无冲击软并网,是一种较理想的并网方式. 相似文献
18.
This paper presents a control strategy of a hybrid fuel cell/battery distributed generation （HDG） system in distribution systems. The overall structure of the HDG system is given, dynamic models for the solid oxide fuel cell （SOFC） power plant, battery bank and its power electronic interfacing are briefly described, and controller design methodologies for the power conditioning units and fuel cell to control the power flow from the hybrid power plant to the utility grid are presented. To distribute the power between the fuel cell power plant and the battery energy storage, a neuro-fuzzy controller has been developed. Also, for controlling the active and reactive power independently in distribution systems, the current control strategy based on two fuzzy logic controllers has been presented. A Matlab/Simulink simulation model is developed for the HDG system by combining the individual component models and their controllers. Simulation results show the overall system performance including load-following and power management of the HDG system. 相似文献
19.
根据光伏阵列的输出特性与蓄电池充电特性,设计了一套具有最大功率点跟踪的光伏充电系统。该系统以dsPIC30F5011单片机为控制器,采用Cuk电路为充电主回路,根据蓄电池端电压对蓄电池采用四阶段充电控制策略。在欠电压充电阶段,采用基于PI调节的涓流对蓄电池充电;在快速充电的阶段,使用基于电导增量法的最大功率跟踪算法对蓄电池充电;在过冲与浮充阶段,使用基于PI调节的带有温度补偿的恒压充电。试验结果表明,最大功率点跟踪能快速跟踪外界环境的变化,并稳定工作在最大功率点,提高光伏电池的使用效率;过冲和浮充电压精度高,能延长蓄电池使用寿命。 相似文献
20.
提出了采用最大功率点跟踪技术提高太阳电池的输出功率．跟踪器实时调整太阳电池的输出,电压和电流,使其工作在最大功率点上．建立了最大功率跟踪的测量装置,并可直接对比有、无跟踪条件下的输出功率．本实验条件下,采用最大功率跟踪后,其平均功率增益可达10．61％． 相似文献