基于网络拓扑和遗传算法的配电设备检修计划优化模型

根据配电网设备检修计划编制的实际情况,建立了考虑多种约束条件的检修计划优化数学模型。该模型以检修停电电量最小为目标,采用网络拓扑方法实现配电网内在的各种约束,并采用改进遗传算法对优化问题进行求解。网络拓扑方法的引入明确了线路间的关联关系,使检修计划可以按轻重缓急情况排序。对遗传算法的改进可有效地保证其收敛能力并提高其优化能力。最后的算例分析表明,上述方法可以快速有效地得到最优检修计划并降低检修停电损失。     

Transmission constrained maintenance scheduling of generatingunits: a stochastic programming approach

This paper presents a new methodology for maintenance scheduling that takes into account inter-area transfer limitations and stochastic reliability constraints. The optimization model is based on the Benders decomposition technique. The objective of this model is to determine a minimum cost maintenance schedule, subject to technological and system reliability constraints. The model may also be used to assess the adequacy of existing transmission limits under a given set of planned outages of generating units. Case studies with a realistic three-area power system are presented and discussed     

精细化日发电计划模型与方法

电网调度精细化管理水平的提高客观上要求日发电计划的精细化管理。针对传统日发电计划功能单一且难以实现准确的安全校核与网损管理的问题,提出了精细化日发电计划模型及优化算法。该模型以电网状态估计的网络拓扑和参数构造约束条件,决策目标兼顾电网经济性与安全裕度价值,具有应对电网运行不确定性的能力。采用交直流混合迭代优化算法,提出了交流潮流分析与有功优化的一体化决策方法,工程实用性强,有助于实现网损管理和安全校核工作的精细化管理。最后采用IEEE 30节点算例验证了算法的合理性。     

基于改进蚁群算法的发电机组检修计划优化

随着计算机技术的迅速发展,人工智能方法在动态组合优化问题中得到了广泛应用。针对发电机组检修计划优化问题,以系统运行费用最小为目标建立了机组检修计划模型,从检修状态组合的角度将其转化为动态模型,并提出了一种利用改进蚁群算法进行求解的方法。针对基本蚁群算法的不足,从转移概率和信息素动态更新2方面对其进行了改进。利用蚁群算法的状态表记忆机制,较好地处理了检修计划连续性和检修开始时间等约束条件。对于其他约束条件,通过罚函数方式形成增广目标函数。算例结果表明,该方法计算速度较快,灵活性强。     

Optimization of multiplant cogeneration system operation includingelectric and steam networks

The problem of optimizing the short-term operation of a multiplant cogeneration system in a large industrial complex is solved. A cogeneration system is defined as a system that simultaneously produces electric power (electricity) and thermal power (steam). The cogeneration system model includes both the electric and thermal systems. The electric system model includes generation and transmission. The thermal system model includes the individual plants, which comprise boilers, turbines, condensers, deaerators, pumps, and storage tanks and the interconnecting steam network. The optimization problem has as its objective the minimization of the overall cost of all fuels and make up water used during the scheduling horizon (1 to 24 h), subject to satisfying a number of constraints on electric and steam systems. A novel solution approach is introduced which is based on coordinated optimization of the electric and thermal systems. A production-grade computer program has been developed and tested for a real industrial complex     

计及可入网电动汽车的分布式电源最优选址和定容

一些不确定性因素如可入网电动汽车（PEV）的随机充放电行为导致的负荷和输出功率不确定性、风电机组和太阳能电源输出功率不确定性,以及未来燃料价格波动和负荷随机变化,都会给分布式电源（DG）的选址和定容问题带来风险。在此背景下,采用机会约束规划方法来解决DG的选址和定容中这些不确定性因素所引起的风险。以DG的总成本（包括投...     

基于全网统筹的联络线分层优化调度

传统联络线计划完全基于电力交易,与电网运行长期处于松耦合状态且与机组计划相对独立,存在联络线计划调整困难,资源全局配置能力不足等问题。针对上述问题,文中以现有联络线计划编制方式为基础,提出了基于全网统筹的联络线分层优化模型。上层模型通过全网安全约束经济调度求取理想联络线计划。下层模型以理想联络线计划为优化目标,以交易合同实际执行为相关约束求解联络线计划。该模型实现了联络线计划自动编制与灵活调整,提供了一种将联络线计划与电网运行状态相结合的可用方式。将所提模型运用于华中电网联络线计划编制,并对优化结果与传统计划进行对比分析,验证了所提方法的正确性与有效性。     

配电网检修计划优化模型

从配电网设备检修计划编制的实际情况出发,建立了考虑多种约束条件的负荷转移路径和设备检修时间联合优化模型。该模型以设备检修时间优化为主问题,以负荷转移路径优化为子问题。通过主问题和子问题的反复优化迭代,最终获得供电企业售电损失最小的检修计划以及停电负荷、开关操作次数和系统网损最小的负荷转移方案。针对该模型的特点,采用免疫禁忌混合算法对主问题进行求解,采用改进的待恢复树切割算法对子问题进行求解。针对基本待恢复切割算法需要对联络开关进行全排列,以穷举的方式获取最优解的不足,通过应用“优先选择备用容量较大的联络开关”启发规则以及在恢复树切割过程中引入网损比较环节,在保证解的质量的同时有效地降低了恢复树的切割次数,提高了计算速度。通过算例计算和分析,验证了所提出的模型和算法的正确性和实用性,适合求解配电网检修优化问题。     

Transformer Fleet Optimal Maintenance with Risk Considerations

Abstract

This paper aims at proposing an optimization model for high voltage transformers’ maintenance scheduling to minimize operational cost and risk. The focus of the paper is on the transformer fleet management, and not on a single transformer maintenance procedure or the evaluation of a single transformer failure risk. The proposed methodology takes as inputs the importance (e.g., based on the expected energy not supplied) and failure risk of each transformer (e.g., based on on-line Dissolved Gas Analysis), and the maintenance cost for each transformer. It also considers the main practical constraints in field interventions. As output, the proposed methodology provides the best timing for the maintenance of each transformer from the fleet of interest. The problem has been modeled as mixed-integer linear programming. Eleven months of real data from the Brazilian transmission system are used for setting up the recent history of outages. The following year data are employed to test the effectiveness of the optimization model. The output of the proposed fleet maintenance scheduling tool is the optimum viable intervention calendar for a power transformer fleet within a 52-week horizon. This proposal represents an innovative and robust solution, which can support the operational planning experts’ decision-making process.     

基于改进型遗传算法的企业配电网检修计划系统

本文从企业配电网实际情况出发,以经济性最好为目标,提出企业配电网检修计划数学模型,根据线路因数与设备参数制定多种约束条件,采用改进型遗传算法进行优化,最终以线路电量损失最小为最优检修计划方案,并提出了企业配电网检修计划系统模型,大大提高了企业配电网的能量管理水平。     

Power plant maintenance scheduling: optimizing economics andreliability

The objective of this study is to show the effects that costs, reliability, and constraints have on each other in power plant outage scheduling. A unique and powerful optimizing method is used to study data from a medium-sized utility. Four optimization studies were made. It was found that different optimization criteria give different best maintenance schedules. The optimal reliability and production cost values are coupled to operating constraints and may be improved by relaxing some constraints. The potential savings must be evaluated against the inconvenience and costs of relaxing these operating constraints. Use of an optimum maintenance schedule and judicious relaxation of constraints can lead to production cost reduction on the order of 0.3%. Integer programming can solve real-life maintenance-scheduling problems in reasonable computer time     

考虑交流潮流校正的日内滚动发电计划模型与方法

为了提高日内滚动发电计划的计算效率和潮流计算精度,采用直流潮流建立日内滚动发电计划优化模型,考虑基态和N-1故障方式下的网络安全约束,从而高效求解滚动发电计划; 基于机组有功出力计划,结合无功负荷预测和无功补偿设备投切情况,建立以有功出力调整量最小为目标的交流潮流校正模型,对有功出力计划进行修正,从而提高计划潮流的准确性,满足实时运行的精度要求。基于实际电网的算例分析表明,该方法能够有效提高优化计算效率和潮流准确度。     

A probabilistic approach to generation maintenance scheduler with network constraints

Most generating unit maintenance scheduling packages consider the preventive maintenance schedule of generating units over a one or two year operational planning period in order to minimize the total operating cost while satisfying system energy requirements and maintenance constraints. In a global maintenance scheduling problem, we propose to consider network constraints and generating unit outages in generation maintenance scheduling. The inclusion of network constraints in generating unit maintenance will increase the complexity of the problem, so we decompose the global generator scheduling problem into a master problem and sub-problems using Benders decomposition. At the first stage, a master problem is solved to determine a solution for maintenance schedule decision variables. In the second stage, sub-problems are solved to minimize operating costs while satisfying network constraints and generators’ forced outages. Benders cuts based on the solution of the sub-problem are introduced to the master problem for improving the existing solution. The iterative procedure continues until an optimal or near optimal solution is found.     

配电网检修计划制定的实用方法研究

以电力系统可靠性和经济学的成本-效益分析法为基础,提出了用成本-效益法制定电网检修计划的方法；定义了电网检修成本、检修效益、检修迫切性指标的概念和计算方法；提出了按检修迫切性指标,对检修项目进行排序的检修计划制定方法。按以上原理开发了制定电网检修计划的实用软件,并以延安地区电网为例进行了试验计算。计算结果表明了该方法的可行性和合理性。     

含抽水蓄能电网安全约束机组组合问题的混合整数线性规划算法

抽水蓄能机组的投运对电网发电调度计划的制定具有很大影响,建立了含抽水蓄能机组电网的安全约束机组组合模型。以考虑了抽水蓄能机组启停费用的所有机组总运行费用为目标函数,根据抽水蓄能机组的不同运行工况给出旋转备用容量的解析表达式,同时在系统功率平衡约束中考虑了网络损耗的影响,并考虑了抽水蓄能机组的运行调度约束及网络安全约束。为了保证模型求解的可靠性和提高模型求解的计算效率,将目标函数进行分段线性化,并根据抽水蓄能机组的运行特点将其旋转备用容量约束等价转化为线性表达式。同时采用一种动态分段线性化方法近似逼近网络损耗,从而将机组组合模型转化为混合整数线性规划模型,并采用成熟的数学优化求解器CPLEX进行求解。对某实际23机306节点电网算例的计算结果表明,所提出的混合整数线性规划调度模型的网损逼近效果合理正确,算法求解速度快,具有较好的工程实用价值。     

防灾应急电源优化调度的机会约束规划方法

在电力系统防灾应急体系中,需要合理调度防灾应急电源,以最大限度地降低停电损失。在实际停电事故发生时,调度环境非常复杂且具有很多不确定性因素,而现有防灾应急电源优化调度方面的研究大多未计及多重不确定性因素的影响。在此背景下,假定应急电源的行驶时间近似服从正态分布,失电用户的缺电功率近似服从区间均匀分布,在此基础上建立基于机会约束规划的防灾应急电源优化调度模型。该模型以重要失电用户的总停电损失最小为优化目标,采用置信水平处理模型中的不确定参数,并在量子进化算法中嵌入蒙特卡洛仿真来求解。算例分析结果表明所提方法可以处理电力应急过程中的多重不确定性因素,合理分配防灾应急电源,进而降低停电损失。     

基于遗传算法的配电网检修计划优化

配电网检修计划优化是一个多目标多约束的优化问题,针对考虑多种约束条件、以经济性最好为目标的配电网检修计划优化模型的特点,对约束条件进行简化处理,采用遗传算法进行优化,获得供电企业售电损失最小的检修计划方案。并通过算例计算和分析,验证了所提出的算法的正确性和实用性,适合求解配电网检修优化问题。     

基于改进TLBO算法的输电网规划

输电网规划问题维数高、变量多以及约束条件复杂,导致问题难于求解。本文采用新型的智能算法教与学算法(TLBO)对问题进行求解。教与学算法具有收敛速度快、设置参数少的优点,但在求解时容易陷入局部最优解。本文通过加入自主学习环节和反思环节以及自适应扰动策略,提高算法寻找全局最优解的能力,使其适应大规模输电网规划问题的求解。采用目标函数为线路投资费用、网损费用、过负荷费用之和的输电网规划模型,通过在Garver-6节点系统和IEEE-18节点系统中的计算,验证了该算法可以正确有效地解决输电网规划问题。     

A Simulated Annealing based approach to solve the generator maintenance scheduling problem

The scheduling of maintenance actions of generators is not a new problem but gained in recent years a new interest with the advent of electricity markets because inadequate schedules can have a significative impact on the revenues of generation companies. In this paper we report the research on this topic developed during the preparation of the MSc Thesis of the second author. The scheduling problem of generator maintenance actions is formulated as a mixed integer optimization problem in which we aim at minimizing the operation cost along the scheduling period plus a penalty on energy not supplied. This objective function is subjected to a number of constraints detailed in the paper and it includes binary variables to indicate that a generator is in maintenance in a given week. This optimisation problem was solved using Simulated Annealing. Simulated Annealing is a very appealing metaheuristic easily implemented and providing good results in numerous optimization problems. The paper includes results obtained for a Case Study based on a realistic generation system that includes 29 generation groups. This research work was proposed and developed with the collaboration of the third and fourth authors, from EDP Produção, Portugal.     

计及储能损耗和换流成本的交直流混合微网区域协调调度

根据并网型交直流混合微网的结构及运行要求提出4层运行方式。为了反映储能损耗的非线性特性,提出一种储能损耗成本积分计算模型,并以设备维护成本、储能及换流损耗成本和购售电费构成的日运行费用最小为目标,建立了交直流混合微网经济优化模型。实际算例分析表明经济参数之间的耦合关系决定交直流微网的运行方式,分析结果验证了所提并网型交直流混合微网运行方式、经济优化模型及储能损耗积分模型的合理性。