Demand response for home energy management system

The optimization of energy consumption, with consequent cost reduction, is one of the main challenges for the present and future smart grid. Demand response (DR) program is expected to be vital in home energy management system (HEMS) which aims to schedule the operation of appliances to save energy costs by considering customer convenience as well as characteristics of electric appliances. The DR program is a challenging optimization problem especially when the formulations are non-convex or NP-hard problems. In order to solve this challenging optimization problem efficiently, an effective heuristic approach is proposed to achieve a near optimal solution with low computational costs. Different from previously proposed methods in literatures which are not suitable to be run in embedded devices such as a smart meter. The proposed algorithm can be implemented in an embedded device which has severe limitations on memory size and computational power, and can get an optimal value in real-time. Numerical studies were carried out with the data simulating practical scenarios are provided to demonstrate the effectiveness of the proposed method.     

工业园区混合能源优化配置方法应用与实践

为了充分挖掘多能源之间的互补潜力,使工业园区混合能源系统的配置方式由传统粗放式转变为精确优化配置并降低系统配置方案的保守性,基于粒子群联合CPLEX求解算法对工业园区的系统配置和运行调度方案进行分析优化,并以某生物园区为例进行了实例分析,得到了目标函数下的最优设计方案和运行策略。仿真分析结果表明,优化配置方法的应用能够协调冷热电多种能源的混合利用,提升系统的综合经济性。同时,为工业园区能源供应项目的规划、设计提供参考性支撑,丰富设计手段。     

含氢储能的多源联合发电系统调度研究

风电和光伏发电具有间歇性和随机性,为了降低在多源联合发电系统中的弃风弃光率,采用含氢储能系统和火电机组配合来平滑风电和光电机组出力。文中以系统运行成本最小和弃电惩罚成本最小为目标,以系统功率平衡、火电机组出力和爬坡、热备用、风电和光电出力及储能系统储氢罐容量、电解槽和燃料电池功率等为约束条件构建了多源联合发电系统日前调度模型。通过YALMIP工具箱对模型进行编程,并调用CPLEX对编写的程序进行求解。对含有风电、光电、火电机组以及储能系统的多源联合发电系统进行算例分析,通过对比有无储能系统的弃风弃光量和系统总运行成本,证明了含氢储能系统可以有效降低系统的弃风弃光率,并提高系统的经济性。     

物流包装租赁系统配送库存路径模型与算法

发展物流包装租赁共享系统是解决落后的一次性包装使用方式的有效手段。为优化物流包装租赁系统中的空包装配送与库存控制这一频繁决策问题,将租赁客户点的需求和物流包装租赁系统的服务中心的库存能力、库存费用、车辆容量、单位运费等因素引入模型,建立了总成本费用最小的物流包装租赁共享系统的空包装配送库存路径集成优化模型。针对稍小和稍大规模算例,对利用CPLEX优化软件和带精英保留的改进遗传算法进行了求解比较分析,结果表明：改进遗传算法对稍大规模算例求解的结果虽然稍差,但求解时间大大缩短,这说明了启发式算法对大规模的实际问题是有效的。该模型和算法可为物流包装租赁企业的空包装配送和库存控制的集成优化决策提供参考。     

大规模机组组合问题计及网络约束的线性化求解方法

为了提高求解机组组合问题计算效率,给出线性化方法,将目标函数分段线性化,将启机费用作为约束并将其线性化,同时将网络安全约束通过直流潮流模型进行线性化,从而建立较完备的混合整数线性规划的机组组合模型.采用世界上广为流行的CPLEX优化求解器求解,在对偶间隙设定为较合理的情况下,求解速度快.不同测试算例表明,该方法速度快,精度较高,能够求解较大规模的机组组合问题.     

考虑富氧燃烧技术的电–气–热综合能源系统低碳经济调度

富氧燃烧技术能实现燃煤机组二氧化碳的近零排放,是实现低碳调度的有效手段。该文提出将富氧燃烧技术引入电–气–热综合能源系统,并建立低碳经济调度模型,该模型可兼顾经济性和低碳性。首先,通过挖掘富氧燃烧电厂运行机理,研究其内部能量时移特性,并与燃烧后捕集电厂进行比较,分析其对降低碳排量的优势;其次,建立以运行成本、维护成本、折旧成本、碳交易成本等综合成本最低为目标函数的电–气–热综合能源系统低碳经济调度模型。并通过CPLEX求解。最后,对IEEE-30节点电网模型、7节点气网模型和6节点热网模型的综合能源系统进行仿真,验证模型的有效性。该文研究可为综合能源系统的低碳调度运行提供参考。     

Variable neighborhood search and local branching

In this paper we develop a variable neighborhood search (VNS) heuristic for solving mixed-integer programs (MIPs). It uses CPLEX, the general-purpose MIP solver, as a black-box. Neighborhoods around the incumbent solution are defined by adding constraints to the original problem, as suggested in the recent local branching (LB) method of Fischetti and Lodi (Mathematical Programming Series B 2003;98:23–47). Both LB and VNS use the same tools: CPLEX and the same definition of the neighborhoods around the incumbent. However, our VNS is simpler and more systematic in neighborhood exploration. Consequently, within the same time limit, we were able to improve 14 times the best known solution from the set of 29 hard problem instances used to test LB.     

The challenges of the unit commitment problem for real-life small-scale power systems

Small-scale power systems mainly present two particular problems when it comes to their modeling and solution. Due to their size, it is important to consider and meet various types of reserve requirements in order to have a reliable operation of the power system. It is also important to consider variable start-up costs in order to obtain a more accurate unit commitment. In this paper six different types of reserve requirements are considered for the unit commitment problem: spinning reserve, regulation reserve (AGC per unit), ten-minute reserve, ten-minute non-synchronized reserve, ten-minute operational reserve, and ten-minute distributed reserve. Additionally, a Mixed Integer Programming formulation is introduced to represent variable start-up costs. The model introduced here is currently in use by the Baja California (México) power system operator.     

CPLEX在优化调度中的应用

ILOGCPLEX是目前国际上流行的优化软件包,是一种高性能、健壮、灵活的优化软件,它包括CPLEX接口和CPLEX算法。ILOGCPLEX被广泛应用于物流行业、制造业、通信业、油田地面工程等,使得一些复杂的问题求解变得相对简单、高效。本文着重描述CPLEX在水电调度中的应用,并以美国NU公司的实际调度数据构造算法实例进行验证,得到了较好的效果。     

用于智能电网的有差别射频充电传感器网络

针对应用于智能电网中的无线传感器网络(WSNs)节点能量受限问题,分析了基于无线射频充电技术的为传感器节点充电技术,改进了可持续无线充电传感器网络(SWRSNs),提出有差别射频充电传感器网络(DRRSNs)技术,增加节点的优先级设置,建立整数线性规划模型,用CPLEX求解模型确定标志性节点位置。求解数据表明:节点获得的能量平均提高105%,高优先级节点比低优先级节点平均多获得43%的能量,提高了节点的寿命,保证了WSNs的可靠性,但是路径访问效率平均降低了14%。