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1.
When the geographical locations with good wind resources are not close to the main load centers, it becomes extremely important to assess adequate transmission facility to deliver wind power to the power grid. A probabilistic method is presented to evaluate the contribution of a wind power delivery system to the overall system reliability. The basic model incorporates transmission line connecting a remotely located large wind farm to a conventional grid system. The classical generation system adequacy evaluation model is extended to incorporate limited transmission system. The mean Capacity Outage Probability Table (mean-COPT) concept is used to increase the computational efficiency as it allows determination of EUE (expected unserved energy) and LOLE (loss of load expectation) simultaneously in calculation of reliability indices of the generating system. The wind farm generation model is obtained by superimposing simulated wind speed, obtained from developed ARMA time series model, on power curve of WTG. An apportioning method has been used to reduce the number of states in the resulting model, obtaining an equivalent reduced 5-state model. Applying transmission line constraints result in wind generation model ranging from 2- to 5-state models. The study recognizes benefits from fuel offset by wind power, reliability worth and environmental improvement and determines appropriate transmission line capacity based on its contribution to the overall system risk and associated transmission system cost. The paper illustrates results using a real wind farm. The presented methods and discussions should be useful to power system planners and policy makers.  相似文献   

2.
考虑风电出力的预测误差和负荷功率的预测误差具有随预测时间尺度的缩短而减小的特点,以及电力系统旋转备用容量的配置离不开机组组合,建立了多时间尺度下协调机组组合的含并网风电电力系统旋转备用预留容量的优化模型。对该模型的求解,先采用优先顺序法求取各机组的启停机顺序,再通过粒子群算法滚动计算求解得出不同等效旋转备用容量水平下所对应的系统最经济调度计划。通过利用不断更新的风电出力预测和负荷预测结果信息来调整调度计划,在保障系统可靠性达到要求的前提下,减少含风电电力系统旋转备用容量的配置,从而提高风电并网后电力系统运  相似文献   

3.
考虑风电功率与需求响应不确定性的备用容量配置   总被引:3,自引:2,他引:1  
将风电建模为多状态发电机组,以风电停运率考虑风电功率预测误差的不确定性,在基于消费者心理学的可中断负荷响应模型的基础上,综合评估含有风电、可中断负荷不确定性的系统可靠性指标。建立了日前备用协调优化模型,优化模型以满足一定供电可靠性为前提,同时优化可中断负荷备用和发电机备用容量,在24个时段的范围内研究计及风电不确定性下可中断负荷作为备用资源的积极效果。算例结果表明,引入风电后,系统对可中断负荷的需求有所增加,可中断负荷作为一种灵活的调控手段,在应对风电不确定性、降低系统运行成本上有积极意义。  相似文献   

4.
准确预测风/光出力能够提高电力系统经济调度的可靠性。本文提出了一种新型的风/光出力预测误差分析方法,在基于点预测数据基础上,针对风电出力和光伏出力点预测精度不高的问题,采用Copula函数分别计算风电出力和光伏出力的实际值和预测值的联合概率分布,采用聚类的方法分别按天气类型和季度分析历史数据,分别对风电出力和光伏出力预测误差进行建模以提高预测精度,同时在各环境下考虑风电场和光伏电站的相关特性,使预测更加准确。以某风/光电站实际出力数据、天气、时间等为样本进行了实例研究,通过与传统预测方法进行对比验证了模型的精确性。  相似文献   

5.
随着物联网以及智慧电网的迅速发展,供需平衡中需求侧资源的作用逐渐增大。然而,大量无序应用需求响应技术会对配电网的运行可靠性产生影响。针对此类问题,提出了电动汽车基线负荷预测与负荷削减、负荷转移两种激励型需求响应策略相结合的虚拟电厂经济优化调度方法。首先,根据历史数据采用三次指数平滑法完成风/光电站出力及电动汽车基线负荷的数据预测,观测电力用户的可调能力;然后,基于分时电价机制以虚拟电厂经济最优为目标,增加功率平衡、风/光新能源预测出力和储能系统运行成本等系统约束条件,建立虚拟电厂经济最优调度模型;最后,以河南郑州某地5个电动汽车充电站和风光电站等实际数据验证所提出方法的精准性和有效性。  相似文献   

6.
随着风电渗透率的不断上升,大规模风电参与调频成为风电发展的重中之重,功率分配方法也需更加智能化和简便化。因此,利用目标函数优化法对风场层功率分配进行优化。首先,对整个风电场进行调频功率函数的建模,使整个风电场的实时功率变化值追踪整个风电场待分配功率,将上述两者偏差值最小作为目标函数。其次,通过超短期预测方法得到一定周期内每台风机风速和有功出力的上下限,结合桨距角的变化限度作为约束条件。最后,求解得到各台风机优化后的功率偏差值,将其叠加到各台风机出力的基础值上进行调频。通过与其他功率分配方法对比,验证了目标函数优化法的优越性,其可以提高风电场调频的快速性和可靠性。  相似文献   

7.
This paper presents a general framework for identifying the optimum wind capacity to be integrated in a power system with interconnection lines. Wind generation is treated as negative demand, together with the load demand, which must be covered by the conventional power generation and the energy interchange with neighboring systems. Under the presumption that the time-varying wind and load together with the trading price with neighboring systems could be statistically modeled by specified probability distributions, a chance constrained programming (CCP) model is formulated to address the wind capacity planning problem. The objective is to maximize the yearly net profit of the entire power system subject to the operational constraints and the reliability requirement. Wind power curtailment and load shedding are allowed to improve the system flexibility but incur penalty costs. The optimization problem is solved using a hybrid intelligence algorithm incorporating Monte Carlo simulations, a neural network and a genetic algorithm. The feasibility of the proposed approach is verified by a case study on a given power system.  相似文献   

8.
This paper presents a new switching strategy for electrolyzer used in hydrogen generation which is connected to the terminal of a wind farm. The output of wind generator, in general, fluctuates greatly due to the random wind speed variations, which has a serious influence on the power system operation. In this study, the wind farm is composed of variable speed wind turbines (VSWT) driving permanent magnet synchronous generators (PMSG). The hydrogen generator (HG) is composed of rectifier and 10 electrolyzer units where each unit is controlled by the chopper circuit. To smoothen the wind farm line power, at first, a reference for the line power is generated from the difference of exponential moving average of wind farm output and its standard deviation. Then the switching strategy is developed in such a way that the proposed cooperative system can smoothen the wind farm line power fluctuation as well as generating hydrogen gas absorbing the fluctuating portion of wind farm output that lies above the reference line power. This novel switching strategy helps each electrolyzer unit working in full load and shift operation conditions and hence increases its lifespan and efficiency. The performance of the proposed system is investigated by simulation analyses, in which simulations are performed by using PSCAD/EMTDC.  相似文献   

9.
由于风电和光伏发电受自然因素的影响较大,其出力具有随机性和波动性,将对系统的调峰能力造成严重影响。该文首先针对风电自身的出力特性,从系统调峰能力的角度对区域电网可以接纳的风电容量进行评估;然后根据风电和光伏发电在时间尺度上存在的互补性,建立以系统失负荷率最低和弃风、光率最小为目标的优化模型,利用改进惯性权重的粒子群算法对模型进行求解,得到最优的风电和光伏发电出力。最后,利用实际区域电网风电、光伏发电以及负荷的历史数据对该文所提方法的有效性进行验证,结果表明采用风光互补优化策略对风电和光伏发电的输出功率进行优化后,系统出力波动有所降低且消纳能力有明显提升。  相似文献   

10.
考虑大规模电动汽车(Electricvehicle, EV)随机接入含高比例可再生能源电力系统后会进一步加大系统运行的稳定性问题,根据风光特性将联合系统划分为"有风有光"、"有风无光"、"有光无风"、"无风无光"四种运行模式,提出一种计及EV充电负荷的风电-光伏-光热协调调度策略。在"多能源端"通过外加电加热模块将盈余电功率转换成热功率储存在光热电站(Concentrating solar power,CSP)的蓄热系统(Thermal energy storage,TES)中,在可再生能源出力不足时,通过TES放热推动汽轮机组出力,从而减少功率波动性。在"负荷侧"将EV负荷划分为无序EV、单纯有序EV和V2G(Vehicle-to-grid)三种不同的EV负荷。最后利用Matlab进行仿真分析,仿真结果验证了所提调度策略在减少净负荷方差、增大可再生能源消纳、减小传统机组波动等方面的有效性。  相似文献   

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