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针对风电场并网运行后网络损耗大和收敛性差的问题,提出一种细菌觅食优化算法。在建立含风力发电机组的无功优化数学模型基础上,将细菌觅食优化算法应用到含风电场的无功优化问题中。以IEEE-30节点进行测试算例,分别采用传统算法、粒子群算法和细菌觅食算法优化,得到网损下降率为30.29%、28.70%和36.98%。实验及分析表明,该算法效率高、全局搜索能力强、易跳出局部极值,为含风电场的无功优化提供了一种新方法。 相似文献
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This paper addresses implementation issues associated with secondary voltage control in a doubly-fed induction generator based wind farm. The effects of different system parameters on the performance of the control are considered, namely the short circuit ratio of the interconnection and the inherent communication delay between the wind park and the remote bus. In addition, a strategy for allocation reactive power requirements to each of the generators within the wind park is proposed. The system is developed and simulated for a wind park consisting of six wind generators connected to a typical transmission system. The paper proposes an optimal tracking secondary voltage control method developed to achieve effective voltage regulation, enhance the network voltage profile and provide optimal reactive power compensation to the interconnected power system. The performance of the controller is compared with secondary voltage control at one selected bus, primary voltage control and the optimal voltage profile obtained from the optimal power flow analysis. The performance of the controllers is tested for steady state operation and in response to system contingencies, taking into account the impact of communication time delays and short circuit ratio (SCRs). Simulation results are presented to demonstrate the capability of the controllers to provide the desired reactive power compensation and voltage support to the electric power grid. 相似文献
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充分利用风能是风力发电控制的主要目的之一,为达此目的,本文基于风力机特性和双馈风力发电机的数学模型,提出了一种不依赖于风速测量来实现双馈风力发电系统最大功率点追踪(MPPT)控制的策略。该策略应用定子磁链定向矢量控制技术,对双馈发电机进行有功功率和无功功率的解耦控制,然后通过对发电机输出有功功率进行控制来间接得到与风速相对应的最佳叶尖速比和最优转速,从而实现最大功率点追踪(MPPT)控制。仿真结果证实了基于该方法,双馈风力发电系统在风速变化过程中能自动寻找并追随最大功率点,且控制相对简单,运行可靠,有较高的实用价值。 相似文献
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为使风电并网后的能够稳定运行,从双馈风电机组的自身特点为角度分析双馈风力发电并网对电网系统稳定性的影响,以Matlab/Simulink为平台搭建风电并网的模型,模拟仿真双馈风机在三相故障时加入两种无功补偿装置后的情况,比较得到最优的无功补偿装置以改进风电在并网时的稳定性。结果表明,静止同步补偿器在提升风电并网电力系统稳定性比SVC静态无功补偿器方面有更好的效果。 相似文献
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为了更加有效地实现对电力系统潮流分布的控制,以进一步提高电力系统无功优化的有效性,达到使系统损耗最小的目的,提出了基于粒子群智能优化算法的计及UPFC的无功优化方法。以系统有功网损最小为目标函数,为了有效利用UPFC对潮流的调节作用,采用UPFC的节点注入功率模型。通过IEEE-30测试算例就系统有功网损和电压稳定性,对基于粒子群算法系统装设UPFC装置前后进行比较,发现采用文中方法后,不仅降低了系统的有功网损,提高了电压质量,而且与粒子群算法相比,还减少了算法的迭代次数,仿真结果验证了文中模型和算法的有效性和可行性。 相似文献
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认知无线电中基于Stackelberg博弈的分布式功率分配算法 总被引:1,自引:0,他引:1
在underlay认知无线电场景中,为了让认知用户能随机地接入主用户正在使用的授权频段,且对主用户产生的干扰不高于主用户能够容忍的干扰温度门限,该文采用Stackelberg博弈机制进行认知用户的发射功率分配。将主用户作为模型中的leader,认知用户作为follower,认知用户使用主用户的授权频段时需以干扰功率为单位支付给主用户相应的费用,而主用户则可以通过调整价格,限制认知用户产生的总干扰功率不高于其所能容忍的干扰温度门限,以便获得最大收益。同时,不同认知用户间根据主用户制定的价格,进行非协作博弈。仿真结果表明,与集中式的最优功率分配算法相比,该文可通过简单的分布式功率分配算法获得与其相近的系统性能,且主用户与认知用户间只需进行少量的信息交互,这与需进行大量信息交互的集中式最优算法相比,具有较大的优势。 相似文献
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In this paper, a wind farm controller is developed that distributes power references among wind turbines while it reduces their structural loads. The proposed controller is based on a spatially discrete model of the farm, which delivers an approximation of wind speed in the vicinity of each wind turbine. The control algorithm determines the reference signals for each individual wind turbine controller in two scenarios based on low and high wind speed. In low wind speed, the reference signals for rotor speed are adjusted, taking the trade-off between power maximization and load minimization into account. In high wind speed, the power and pitch reference signals are determined while structural loads are minimized. To the best of authors’ knowledge, the proposed dynamical model is a suitable framework for control, since it provides a dynamic structure for behavior of the flow in wind farms. Moreover, the controller has been proven exceptionally useful in solving the problem of both power and load optimization on the basis of this model. 相似文献
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Poddar G. Joseph A. Unnikrishnan A.K. 《Industrial Electronics, IEEE Transactions on》2003,50(5):1007-1015
A variable-speed controller, for an existing 225 kW fixed-speed wind power generator, is presented in this paper. A sensorless direct torque control algorithm-based controller is proposed for the squirrel-cage induction generator. Generator torque reference is derived based on sensorless maximum power tracking mode algorithm, up to the base speed of the generator. A three-phase front-end converter is used here to deliver the generated power to the grid with unity-power-factor operation at all wind speeds. This algorithm is based on direct active and reactive power control. The experimental waveforms from the actual installation site are presented in this paper with a comparison of the existing fixed-speed system. An interpretation of the results is also presented here. 相似文献
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He Guo 《电子科技学刊:英文版》2013,11(1):78-83
As a typical clean and renewable energy, wind power is becoming more and more widely used in electrical industry. However, its characteristics of random and intermittent have brought serious problems to the power system, such as voltage fluctuation and insufficient reactive power. Based on the K-means clustering algorithm, this paper classifies the doubly-fed induction generators (DFIG) according to the operation of propeller pitch angle control. At the same time, to obtain the optimal parameter, advanced particle swarm optimization (PSO) is used. Then the dynamic model of DFIG under the network fault condition is built. What is more, the role that crowbar circuit plays in low voltage ride through (LVRT) is discussed. Finally, simulations in DigSILENT verify the model. 相似文献
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Wind Speed Estimation Based Sensorless Output Maximization Control for a Wind Turbine Driving a DFIG 总被引:2,自引:0,他引:2
Wei Qiao Wei Zhou Aller J.M. Harley R.G. 《Power Electronics, IEEE Transactions on》2008,23(3):1156-1169
This paper proposes a wind speed estimation based sensorless maximum wind power tracking control for variable-speed wind turbine generators (WTGs). A specific design of the proposed control algorithm for a wind turbine equipped with a doubly fed induction generator (DFIG) is presented. The aerodynamic characteristics of the wind turbine are approximated by a Gaussian radial basis function network based nonlinear input-output mapping. Based on this nonlinear mapping, the wind speed is estimated from the measured generator electrical output power while taking into account the power losses in the WTG and the dynamics of the WTG shaft system. The estimated wind speed is then used to determine the optimal DFIG rotor speed command for maximum wind power extraction. The DFIG speed controller is suitably designed to effectively damp the low-frequency torsional oscillations. The resulting WTG system delivers maximum electrical power to the grid with high efficiency and high reliability without mechanical anemometers. The validity of the proposed control algorithm is verified by simulation studies on a 3.6MW WTG system. In addition, the effectiveness of the proposed wind speed estimation algorithm is demonstrated by experimental studies on a small emulational WTG system. 相似文献
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电力系统无功优化是提高电能质量保证电网运行的重要环节,文中建立了综合考虑有功网损和电压偏移最小及电压稳定裕度最大的三目标无功优化模型,引入了自适应变异微粒群算法用于解决三目标电力系统无功优化问题。该算法利用群体的适应度方差来动态监控微粒群聚集的状况,采用增加随机扰动的方法对聚集的微粒进行变异,并对惯性权重进行自适应调整,使该算法既能跳出局部最优,防止早熟,又能提高收敛速度和精度。将该算法与其他算法应用于IEEE-14节点系统中进行无功优化,通过数据的计算和比较,结果验证了该模型和算法用于解决多目标电力系统无功优化问题的优越性和实用性。 相似文献
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A system model consisting of macro and micro base stations (BS) is introduced to solve the problem of power allocation in heterogeneous dense network. In this hierarchical framework, the problem of power allocation is modeled as a stackelberg game. Based on this model, a two-stage pricing algorithm is proposed to allocate power resource to each BS. In this algorithm, a power price is allocated to each micro-BS by macro-BS and all micro-BSs are calculating respective optimal transmit power based on this price to maximize individual utility. Then a grid-based scenario is introduced to verify the proposed theory. Theoretical analysis and simulation results both validate that the proposed scheme makes performance improvement on spectral and power efficiency. Most importantly, the computaitonal complexity of the proposed scheme is greatly improved, especially in dense deployment. 相似文献
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基于直驱型PMSG风力发电系统的变桨自抗扰控制 总被引:2,自引:0,他引:2
为了实现大功率风力发电系统的恒功率控制,首先建立了基于直驱型PMSG风力发电系统的数学模型;其次,以功率偏差为控制器的输入信号,设计了一种基于自抗扰算法的风力发电系统变桨距控制器。最后,在阵风叠加随机风的作用下进行仿真研究。仿真结果表明,该控制器能够有效地控制桨距角,可以实现额定风速以上时系统输出功率的恒定。 相似文献
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Modeling and Control of Brushless Doubly-Fed Induction Generators in Wind Energy Applications 总被引:1,自引:0,他引:1
The development of the brushless doubly-fed induction generator (BDFIG) system and flexible power flow controller for the wind energy conversion is proposed in this paper. The system employs two cascaded induction machines to eliminate the brushes and copper rings in the traditional DFIG. The dynamic model of BDFIG with two machines' rotor electromechanically interconnected is presented and the control strategy for flexible power flow control is developed. The independent control of the active and reactive power flows is achieved by means of a four quadrant power converter under the closed-loop stator flux oriented control scheme. The experimental results obtained verify the proposed controller scheme, which allows wide operational range and reactive power control. 相似文献