预挂牌月平衡机制下机组偏差电量月内滚动调度方法

针对我国当前中长期电量交易中的机组合约电量执行偏差,部分省份采用预挂牌月偏差平衡机制作为解决手段,但是该偏差平衡机制对调度工作提出了更高的要求,传统的调度方法难以与之适应,尤其在高比例水电地区,还缺少与之相适应的、定量有效的调度方法。由此提出预挂牌月偏差平衡机制下水火风电系统偏差电量月内滚动月度调度方法。提出考虑机组合约完成进度公平性的机组月度电量分解模型,并以分解后的日计划电量为基础,建立以节能降耗和偏差平衡成本最低为双目标的水火风电系统日前调度模型以及日内调度模型,通过日偏差电量月内滚动的方法实现机组月度合约电量偏差平衡成本最小。算例仿真表明所提调度模型及方法可以有效减少机组月度合约电量偏差,降低机组偏差平衡成本并兼顾节能环保要求。     

Short-term operation scheduling of a hydropower plant in the day-ahead electricity market

This paper presents a novel approach to solve the short-term operation scheduling problem of a hydropower plant that sells energy in a deregulated electricity market with the objective of maximizing its revenue. This paper proposes a nonlinear programming based scheduling model that determines both the optimal unit commitment (start-ups and shut-downs scheduling) and the generation dispatch of the committed units (hourly power output). The power generated by each hydro unit is considered as a nonlinear function of the water discharge and the volume of the associated reservoir. The dependence of the units’ operating limits (maximum and minimum water flows) on the actual gross head has been also taken into account in this model. The results from a case study are also presented to illustrate the application of the proposed approach in a real hydro plant.     

A noise annealing neural network for hydroelectric generationscheduling with pumped-storage units

A new approach based on neural network is proposed for the hydroelectric generation scheduling with pumped-storage units at Taiwan power system. The purpose of hydroelectric generation scheduling is to determine the optimal amounts of generated powers for the hydro units in the system. To achieve an economical dispatching schedule for the hydro units including two large pumped-storage plants, a neural network is employed to reach a schedule in which total fuel cost of the thermal units over the study period is minimized. The neural network model presented can solve nonlinear constrained optimization problems with continuous decision variables. Incorporating the noise annealing concepts, the model is able to produce such a solution which is the global optimum of the original problem with probability close to 1. The proposed approach is applied to hydroelectric generation scheduling of Taiwan power system. It is concluded from the results that the proposed approach is very effective in reaching proper hydro generation schedules     

Congestion management solution under secure bilateral transactions in hybrid electricity market for hydro-thermal combination

The deregulation of power system has created an environment of competitiveness among different market players and the transmission lines are forced to operate near to their thermal or stability limits. It is a challenge with System Operators (SO) to ensure a secure and reliable transmission of power under these conditions. This paper proposes a rescheduling based congestion management strategy in hybrid (pool + bilateral) electricity market structure for a combination of hydro and thermal units. The proposed congestion management problem has been formulated as mixed integer nonlinear programming (MINLP) problem with an objective to minimize the congestion management cost by suitably rescheduling the hydro and thermal units based on their up and down generation cost bids. The hydro units having lowest operational cost and fast startup time have been used to alleviate the congestion by considering non-concave piecewise linear performance curves for them. The secure bilateral transactions have been ensured while rescheduling of the generators for alleviating the congestion. The performance of the proposed model has been demonstrated by solving the congestion management problem on modified IEEE-24 bus system.     

水风光互补系统碳电打捆交易技术及闭环回购策略

文中提出了一种发电企业碳电打捆交易技术及闭环回购策略,并提出了发电企业与用户之间通过签订“中长期电量+附加CCER(国家核证自愿减排量)”的合约交易模式,形成发电企业与用户之间的碳电打捆交易与闭环回购模式。同时,计入电力现货市场和碳市场,发电企业和用户均可以在碳电市场中出售电力或CCER提升其经济性。进一步以水风光互补系统为例,建立了一体化电站碳电市场交易效益评估模型和用户成本评估模型。最后,通过算例仿真,分析了水风光互补系统中长期市场和现货市场下的碳电综合效益,并评估了该碳电交易模式下的用户侧经济性成本。所提方法可以在增加发电企业综合收益、降低用户成本的同时,推动可再生能源消纳,促进电力市场与碳市场的协同发展。     

大规模风电并网背景下火电调峰行为演化博弈模型

为解决大规模风电并网所带来的消纳问题,基于火电机组容量和最高调峰率指标,以公平性原则为前提,针对不同类别的机组,设定了有偿与无偿调峰划分标准。将火电调峰行为转化为上网电量竞价收益与调峰辅助服务收益演化博弈问题,讨论了综合考虑两个市场情景下,各类火电厂的竞价策略及对应策略下的收益,分别求解了稳定策略。针对两类电厂的博弈问题进行了实证分析。结果表明：现阶段的调峰辅助服务补偿额与上网电量收益额存在巨大差距,并且这一情况在今后一段时间内仍将存在。制订合理的辅助服务市场规则,提升火电机组调峰的积极性,从而促进大规模风电消纳是亟须解决的问题。     

考虑可再生能源消纳的火电机组市场力评估

随着可再生能源并网比例的不断提升,实现其全额消纳会对火电机组的市场机会产生越来越大的冲击。针对这一现象,提出了火电机组综合市场力评估方法。考虑可再生能源发电并网下火电机组备用作用的强化,对传统市场力指标——Lerner指数进行修正,建立了反映火电机组在电量市场与备用市场综合市场力的改进Lerner指标;同时计及风电出力的不确定性,采用正态分布与拉普拉斯分布的联合概率密度函数更好地反映风电预测误差的尖峰厚尾特性,完善了备用需求的表达;以电量完全竞争作为假设前提,采用电量—备用联合优化模型模拟电力市场交易,进而完成对火电机组综合市场力的准确度量。以10机系统为例进行仿真计算,验证了改进指标的有效性并分析风电渗透率、风电预测精度等因素变化对火电机组综合市场力的影响。     

含风电机组与电转气设备的虚拟电厂竞价策略

随着电转气(power-to-gas,P2G)技术的不断发展和商业化应用,风电机组(wind power generation unit,WPGU)与电转气设备的协同运行逐步受到关注。电转气设备的运行方式比较灵活,可有效平衡风电出力波动,二者可协同形成虚拟电厂(virtual power plant,VPP)参与电力市场运营。在此背景下,研究了含风电机组与电转气设备的虚拟电厂竞价策略。首先构建了含风电机组与电转气设备的虚拟电厂参与电力市场运营的模型架构。之后,以最大化总体收益为目标,构建了虚拟电厂在日前电力市场的竞价策略模型,并确定虚拟电厂自调度运行策略。然后,考虑到风电出力预测误差的不确定性,发展了基于信息间隙决策理论(information gap decision theory,IGDT)的鲁棒竞价策略和机会竞价策略,以反映虚拟电厂不同的风险偏好水平。接着,采用成熟的商用求解器AMPL/IPOPT求解所构造的非线性优化模型,确定针对预期成本的鲁棒和机会竞价策略。最后,以北欧电力市场的实际数据为例说明所构建的优化模型和采用的求解方法的基本特征。     

电力市场下风电-抽水蓄能混合系统的运行优化

针对风电场与抽水蓄能电站联合运行中可能涉及的发电计划制定及运行优化问题,在风电场功率预测偏差及电价预测模型基础上,通过场景分析以应对风电场出力及电价的不确定性因素,将其划分为日前发电计划制定及运行方式调整的两阶段问题并建立了相应评价模型,在制定发电计划的基础上,通过运行方式调整能一定程度提高风电场及抽水蓄能电站的经济效益,最后通过对一实际算例进行分析,验证了该方法可行有效。     

Optimum scheduling of micro grid connected wind-pumped storage hydro plant in a frequency based pricing environment

This paper presents a new formulation to maximize the operational profit of a micro grid connected hybrid system having wind farm and pumped storage unit for a day ahead electricity market in a frequency based pricing environment. Under frequency based pricing mechanism in India, the pricing for energy exchange is adaptive as per Availability Based Tariff (ABT) rate structure and the payment for deviation from schedule, i.e. Unscheduled Interchange (UI) charge is inversely proportional to the prevailing grid frequency. In this work, a small power system is considered as micro grid and it is expected that the hybrid system connected with the micro grid has a role to play to maintain the micro grid frequency. The pump storage hydro plant is operated to serve the dual role of minimizing the UI flow and maximizing the system economy by participating in frequency control based on energy price. The uncertainties in wind power prediction and loads are considered. The optimum operating schedule of PSH unit in coordination with wind farm is investigated. The optimization is performed by utilizing the water storage availability of pump storage hydro unit. An optimization algorithm is proposed and solved using Artificial Bee Colony algorithm. The solution of the proposed approach gives the strategies to be followed by the hybrid system to operate its pump storage unit. The effect of the initial storage water volume on the performance of the hybrid system has also been investigated. It reveals that the PSH units would not operate simply to compensate for the short fall or the surplus generation of the wind units in a frequency based pricing system. Rather, the pump storage units should take the advantage of the low price periods to maximize the profit of the hybrid system. The hourly energy management scenarios of the hybrid system with the micro grid are reported and the numerical case studies on PSH plant scheduling demonstrate the effectiveness of the proposed approach.     

考虑风电及分时电价的机组组合问题研究

近年来,风电等清洁能源的接入以及负荷侧分时电价的管理增加了电网调度的复杂性,为实现在风电接入及分时电价管理背景下的火电机组的经济调度和分时电价策略优化,首先研究了负荷需求对峰谷时段电价的响应模型,接着基于模糊机会约束理论建立了考虑风电及分时电价的机组组合模型,然后提出了一种双层混合粒子群算法求解该机组组合模型,以得到与风电相配合的分时电价定制策略以及火电机组出力值。最后仿真结果表明,所提出的方法可以实现负荷侧分时电价策略与供电侧火电出力的有效配合并降低火电机组的发电成本。     

含流域梯级水电的水火风互补发电系统联合运行优化

大规模水电和风电并网后,来水和风速的随机性降低了发电的可控性,如何科学地在多元电源系统联合运行中确定旋转备用容量,更好地协调系统经济性与可靠性,是市场化背景下亟需解决的理论和现实问题。在分析水电和风电的自然与技术互补特性的基础上,建立考虑水流滞时效应的梯级水电水量平衡关系。通过结合传统梯级水电联合调度模型与火电、风电的经济调度模型,引入水力发电的水资源费用成本,综合考虑梯级水电能量转换、水量耦合、库容限制、水流滞时和风电穿透率等多类复杂约束,在分析电能市场与备用市场顺序决策经济意义的基础上,构建以运行成本最小为目标的考虑梯级水电的水火风互补发电系统短期优化运行模型。采用外点罚函数法将模型转化为无约束优化问题,基于加惯性权重的粒子群优化算法,运用MATLAB软件编程实现优化功能。4个梯级水电、3个常规火电、2个大型风电场构成的算例系统验证了所提模型的有效性和适用性。     

考虑风电不确定性的蓄热式电采暖消纳弃风经济性分析

针对冬季采暖期我国北方地区严重弃风和燃煤导致的空气污染问题,综合考虑风电预测误差及供给价格弹性,以采暖期系统运行成本最小为优化目标,构建基于终端热负荷特性的电锅炉日前优化调度模型,并在电力市场背景下分析了蓄热式电采暖供暖系统的运行经济性。通过引入储热装置来更加合理地利用各时段弃风电量,从而进一步提高供热系统运行经济性。在求解阶段,采用CPLEX软件包下的分支定界法(BBA)对模型求解,并通过具体算例仿真结果验证了所提方法的有效性。     

计及碳交易的热电联产-储热-电锅炉风电消纳策略

为解决传统热电联产机组的热电耦合特性以及冬季采暖期间弃风消纳问题,提出了计及碳交易含储热热电联产机组和电锅炉联合运行的弃风消纳策略。首先将储热设备、电锅炉与热电联产机组联合运行来满足系统所需热负荷,从而提高热电联产机组电调峰能力。其次,为进一步控制碳排放量,引入阶梯式碳交易与优化电锅炉运行模式,兼顾系统运行成本、弃风消纳量以及碳排放量,构建计及碳交易的热电联产-储热-电锅炉风电消纳模型并进行求解。最后,以IEEE-30节点为例进行算例分析,结果表明所提策略能够有效促进风电消纳、减少碳排放量且有效降低系统运行成本。     

风电全消纳下虚拟电厂内部资源鲁棒调度策略

虚拟电厂运行机制为可再生能源以及需求侧分布式电源并网提供了技术支撑。针对含风、火、水以及柔性负荷的虚拟电厂,构建了两阶段鲁棒优化模型。该模型在对风电出力全部消纳的情况下,优化其内部各单元出力,缓解风电的不确定性和随机性,保证虚拟电厂满足对某些负荷稳定供电的情况下,达到运行经济性最优。针对min-max-min型两阶段优化问题,将其分解为混合整数特性的主问题以及计及风电出力不确定性的线性优化子问题。然后引入线性优化强对偶理论与列约束生成算法对主问题与子问题进行迭代求解,与此同时,在迭代过程中采用Big-M法将子问题的对偶模型线性化。最后通过算例仿真验证了所提两阶段鲁棒模型的有效性。     

基于改进粒子群的风电-火电-蓄热电锅炉联合优化调度

蓄热式电锅炉是增加风电-火电系统弃风消纳的重要手段,但是当前风电成本仍高于火电成本,风电消纳和降低蓄热式电锅炉用能成本存在矛盾,考虑多方效益,合理优化风电、火电机组及蓄热式电锅炉的出力,对于降低用能成本、提高风电消纳具有重要意义。文章建立了考虑多目标的含风电、火电机组和蓄热式电锅炉的优化调度数学模型,通过采用偏小型隶属函数将以风电、火电机组运行成本最低和弃风量最小的多目标函数转化为单目标函数,在满足各部分约束条件下求取隶属度最佳的风电、火电机组出力。进一步,提出一种改进的粒子群算法,对上述模型求解。该算法可以跳出局部最优解,具有较快的收敛速度和较高的计算精度。最后,基于某电网的实际数据进行仿真,仿真结果验证了所提方法的有效性。     

Parameterisation effect on the behaviour of a head-dependent hydro chain using a nonlinear model

This paper is on the problem of short-term hydro scheduling (STHS), particularly concerning a head-dependent hydro chain. We use a method based on nonlinear programming (NLP), namely quadratic programming, to consider hydroelectric power generation a function of water discharge and of the head. The method has been applied successfully to solve a test case based on a realistic cascaded hydro system with a negligible computational time requirement and is also applied to show that the role played by reservoirs in the hydro chain do not depend only on their relative position. As a new contribution to earlier studies, which presented reservoir operation rules mainly for medium and long-term planning procedures, we show that the physical data defining hydro chain parameters used in the nonlinear model have an effect on the STHS, implying different optimal storage trajectories for the reservoirs accordingly not only with their position in the hydro chain but also with the new parameterisation defining the data for the hydro system. Moreover, considering head dependency in the hydroelectric power generation, usually neglected for hydro plants with a large storage capacity, provides a better short-term management of the conversion of the potential energy available in the reservoirs into electric energy, which represents a major advantage for the hydroelectric utilities in a competitive electricity market.     

用电价分布概率预测的发电商报价策略模型

电力市场环境下发电企业的报价策略直接影响着该企业的收益。以市场边际电价报价既可成功竞价上网又能使发电利润达到最大,是最理想的报价方案。波动剧烈的实际市场电价很难精确预测,但可预测出其可能的分布概率。为此建立了一个基于电价分布概率预测的发电企业报价策略模型,并提出了采用二维实数编码策略的改进遗传算法优化求解。针对市场竞价中申报数据要求为一组符合递增规律的“价格—电量”数据点的要求,特别设计了独特的遗传操作算子以得到合理有效的报价方案。算例仿真验证了该模型与算法的可行性。     

促进风电消纳的供需互动合约机制与多市场购电策略

中国售电侧市场的逐步开放为风电大规模消纳的市场化解决提供了新的可能途径。研究了以促进风电消纳为目标的风电商—售电商供需互动市场机制构建框架。在长期电能市场、现货电能市场、备用市场等市场化交易体系的支撑下,考虑售电公司的需求侧响应能力,建立了以综合购电成本最小为目标的风电—售电多市场购电的随机规划模型。通过对模型结构的分析,给出了在给定价格序列下单时段子问题的解析最优解以及基于情景树的价格序列生成方法,实现了期望意义下购电决策问题的快速求解。最后通过算例分析,讨论了在多市场购电决策层面,供需互动机制促进风电消纳的关键因素。     

基于非合作博弈的独立售电公司最优规划方法

随着电力体制改革持续推进,电力市场进一步开放,新增售电主体接入配电网,在丰富配电侧可调配资源的同时增大了规划难度。为了指导独立售电公司合理参与配电网建设,形成良好的市场环境,提出一种基于非合作博弈的最优规划方法,以确定售电公司发电设备的投资方案。首先,提出独立售电公司综合运营策略及模型;然后,基于完全信息非合作静态博弈,以独立售电公司的综合收益作为各主体的优化目标,建立非合作博弈模型;最后,研究非合作静态博弈流程,为了求解复杂的混合整数非线性模型,采用二阶锥松弛方法将模型转化为混合整数二阶锥规划问题,提出基于数学优化的迭代搜索算法用以求解所提模型的Nash均衡解。以IEEE 33节点系统为例,仿真结果表明了所提模型的合理性与算法的有效性。