共查询到20条相似文献,搜索用时 46 毫秒
1.
Fuzzy rule-based model for hydropower reservoirs operation 总被引:3,自引:0,他引:3
Real-time hydropower reservoir operation is a continuous decision-making process of determining the water level of a reservoir or the volume of water released from it. The hydropower operation is usually based on operating policies and rules defined and decided upon in strategic planning. This paper presents a fuzzy rule-based model for the operation of hydropower reservoirs. The proposed fuzzy rule-based model presents a set of suitable operating rules for release from the reservoir based on ideal or target storage levels. The model operates on an ‘if-then’ principle, in which the ‘if’ is a vector of fuzzy premises and the ‘then’ is a vector of fuzzy consequences. In this paper, reservoir storage, inflow, and period are used as premises and the release as the consequence. The steps involved in the development of the model include, construction of membership functions for the inflow, storage and the release, formulation of fuzzy rules, implication, aggregation and defuzzification. The required knowledge bases for the formulation of the fuzzy rules is obtained form a stochastic dynamic programming (SDP) model with a steady state policy. The proposed model is applied to the hydropower operation of “Dez” reservoir in Iran and the results are presented and compared with those of the SDP model. The results indicate the ability of the method to solve hydropower reservoir operation problems. 相似文献
2.
3.
针对采用设计水头的水电站混合整数线性规划(mixed integer linear programming, MILP)调度模型计算的出库流量与实际出库流量偏差较大的问题,提出了基于运行数据的水电站MILP模型最优代表水头选取方法。首先基于运行数据,采用MILP模型拟合出使模型计算出库流量过程与水电站实际出库流量过程偏差最小的代表水头,然后在实际调度中,以日平均入库流量和日平均出力作为该代表水头特征向量,根据预测入库流量和日计划电量即可选取最优代表水头。计算实例表明,相比于传统固定水头,该方法能够更好的反应水电站实际的出库过程,有利于提高电网制定调度计划中梯级水电站上下游水量匹配精度。 相似文献
4.
5.
6.
水电能源蓄能模型分析与计算 总被引:1,自引:1,他引:0
探讨水电站水库水电能量转换规律,将水库水体分成长方形水体s1、梯形水体tr、长方形水体s2及三角形水体t 4级,利用微元分析法,建立水库水电站发电模型。该发电模型由水体动能、势能、压能和库容压能构成。应用于某梯级水电站的仿真结果表明,模型能有效提高水电站群的年平均发电量,长方形水体s1、梯形水体tr、压力引水管倾角a的合理选择对年平均发电量有很大影响。模型可为未来水电站的运行管理与设计优化提供新的理论支持。 相似文献
7.
K. Najim A. S. Poznyak 《International Journal of Adaptive Control and Signal Processing》1998,12(7):545-565
In this paper we consider the adaptive control of constrained finite ergodic controller Markov chains whose transition probabilities are unknown. The control policy is designed to achieve the minimization of a loss function under a set of inequality constraints. The average values of conditional mathematical expectations of this loss function and constraints are also assumed to be unknown. A regularized penalty function is introduced to derive an adaptive control algorithm. In this algorithm the transition probabilities of the Markov chain and the average values of the constraints are estimated at each time n. The control policy is adjusted using the Bush–Mosteller reinforcement scheme as a stochastic approximation procedure. Its asymptotic properties are stated. We establish that the optimal convergence rate is equal to n-1/3+δ (δ is any small positive parameter). © 1998 John Wiley & Sons, Ltd. 相似文献
8.
梯级水电站水库群短期优化调度中,通常忽略梯级水库间水流滞时的影响或将其作为常数进行考虑,实际上水流滞时是随着上级水库出库流量大小、河道槽蓄状态、区间入流等因素动态变化,想要准确预测下级水库入流是存在困难的。因此,采用多种方法筛选出影响下级水库入库流量的主要因素作为输入,利用神经网络建立输入与下级水库入库流量之间的动态函数关系。以锦东和官地水库梯级为例,建立考虑动态滞时的梯级水电站水库群日优化调度模型,并采用逐次优化法对采用动态滞时与固定滞时的优化方案进行求解和对比分析。结果表明:与固定滞时相比,动态滞时下能够更准确地描述梯级水库间的水流联系,同时能够在一定程度上增加梯级水电站水库群发电效益。 相似文献
9.
10.
在水库群发电调度中,考虑预报信息的联合调度是提高水库群发电效益和稳定性的有效途径。然而降雨预报信息的不确定性将直接影响发电调度的效益。为此,本文首先将降雨量进行分级,给出各降雨量等级的实际降雨概率分布;然后将蓄水库容与径流相融合,并基于参数–模拟–优化模型(PSO)建立PSO-Hedging Rule Curves(PSO-HRCs)调度图。在此基础上,根据实时预报降雨信息,获得各频率条件下的降雨量、径流量和调度决策,同时评估各频率调度决策的弃水和蓄水风险和损失。本文以浑江梯级水库群为例,采用美国全球预报系统(GFS)发布的降雨信息开展研究,结果表明在实例水库采用70%~85%概率对应的调度决策具有较高的效益和稳定性。 相似文献
11.
水电站短期发电计划编制一般采用预报径流进行,但受预报精度限制,预报值与实际值往往存在偏差,当电站位于近边界水位运行时,该偏差就可能带来弃水或出力不足问题。为定量分析径流预报误差的模糊特性及其对水电站短期发电调度的影响,本文提出了一种基于最优贴近度准则的径流预报误差模糊隶属函数优选方法,并引入可信性理论,建立了水电站在两种典型近边界工况(正常蓄水位和死水位)下的发电调度模糊风险分析模型,实现了水文预报误差模糊性与水电站短期发电调度风险的耦合与转化。实例研究中给出了锦西电站在两种近边界运行工况下的高风险区域及建议运行区域,可为该电站实际短期发电调度提供有力的参考和借鉴。 相似文献
12.
13.
14.
建立了基于出库流量和耗水率的水电站水库模型,并考虑了来水衰减因子和来水时延因子的梯级水电站来水关联关系,以提升水电站时序模拟精度。为最大程度消纳水风光等清洁电力,通过考虑水风光出力特性、负荷特性、机组调峰能力以及电网网络传输等约束,建立了清洁能源时序生产模拟模型。建立的模型为混合整数模型,通过分支定界法进行求解。以实际电网参数构建的仿真系统为例,对水风光消纳过程进行定量化分析。计算结果验证了清洁能源时序生产模型以及水库建模的合理性和有效性,对我国清洁能源实际运行和消纳具有积极意义。 相似文献
15.
16.
大型灌区中的小水电群优化运行方案研究对促进区域清洁能源利用、减少区域碳排放和保护生态环境具有重要意义。本研究以位于中国安徽境内的淠河灌区为例,开展气候变化条件下大型灌区水资源系统模拟和小水电群运行优化研究。结果表明,随着未来区域降雨和气温的微量增加,按现状工程运行方案系统不能满足设计期城市供水保证率要求,而水电站群年均总发电量增加几可忽略。经优化设计后,佛子岭水库汛限库容提高6.2%,供水专线流量方案变更为25.7m3/s,非灌溉期充止库容0.98×108m3,灌溉期充止库容为0.59×108m3,则水电站群年均可多发电115×104k W·h,使灌区供水、发电系统获得可观的社会及经济效益。 相似文献
17.
本文提出了一种计及多种因素间协调的梯级水电站群调度策略,以兼顾梯级水电站群的经济效益和社会效益。首先引入发电弃水量、抗旱放水量、以及泄洪水量等参数,用以完善梯级水电站数学模型;提出采用虚拟水库来表征流域分布泄洪点及抗旱灌溉点,并建立相应的数学描述;考虑梯级水电站水力调度,火电站的发电机组出力、能耗成本及污染排放三者之间,梯级电站的出力、发电流量、发电弃水量、防洪水量、抗旱水量与其它水力耦合参数之间,以及水火电机组联合调度之间综合效益基础上,建立了多目标综合节能调度模型;算例验证了该算法的可行性,并具有较为明显的节能效果和社会效益。 相似文献
18.
19.
National and international policies encourage increased penetration of solar and wind energy into electrical networks in order to reduce greenhouse gas emission. Solar radiation and wind speed variations complicate the integration of wind and solar generation into power systems and delay the transition of these sources from centralized to distributed energy sources. The increased penetration of nontraditional energy sources into the electric grid stimulates the demand for large capacities in the field of energy storage. A mathematical model, which describes the operation of a proposed hybrid system, including solar PV, wind energy, and a pumped storage hydroelectric power plant is developed in this paper. This hydropower plant utilizes seawater as a lower reservoir, and only a tank has to be built in order to reduce the installation cost of the storing system. The pumped storage power plant used for compensation of the variation of the output energy from the PV and wind power plants by discharging water from the upper reservoir, which is previously pumped in the case of surplus energy from PV and wind turbine power plants. The impact of the proposed system on the grid utility is investigated in accordance with the values of energy exchange(deficits and surpluses of energy) between the considered hybrid system and the grid. The optimum design is determined by the pump and turbine capacities, upper reservoir volume, and the volume of water left in the tank for emergencies. Different scenarios of the optimum operations are presented for analysis. The results obtained from the examined scenarios indicate the ability of such a hybrid energy system to reduce the exchange of energy with the grid. This paper indicates the technical feasibility of seawater pumpedstorage hydropower plant for increasing the Egyptian national grid's ability to accept high integration of renewable energy sources. 相似文献
20.
为减少风光出力波动性造成的弃风、弃光,利用梯级水电和抽水蓄能等不同类型水电之间的调蓄特性,提出一种多类型水电协调参与风光消纳的联合运行策略。考虑多类型水电站出力、水库库容和联络线传输功率等约束,以风光电站投资建设成本、系统运行维护成本及购电成本最小和风光发电占负荷需求比例最大为目标,建立一种多类型水电协调的风光电站容量优化配置模型,采用基于极限学习机的粒子群算法(ELM-PSO)对模型进行求解。以青海某地区为例,通过仿真分析,得出综合考虑系统经济性和风光发电占负荷需求比例最优的容量配置方案,验证了所提策略和所建模型的可行性及有效性。 相似文献