Charging Ahead with E-Buses: Benefits, Costs, and Transition Roadmap

This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.

Optimizing bus services with variable directional and temporal demand using genetic algorithm

As a major mode choice of commuters for daily travel, bus transit plays an important role in many urban and metropolitan areas. This work proposes a mathematical model to optimize bus service by minimizing total cost and considering a temporally and directionally variable demand. An integrated bus service, consisting of all-stop and stop-skipping services is proposed and optimized subject to directional frequency conservation, capacity and operable fleet size constraints. Since the research problem is a combinatorial optimization problem, a genetic algorithm is developed to search for the optimal result in a large solution space. The model was successfully implemented on a bus transit route in the City of Chengdu, China, and the optimal solution was proved to be better than the original operation in terms of total cost. The sensitivity of model parameters to some key attributes/variables is analyzed and discussed to explore further the potential of accruing additional benefits or avoiding some of the drawbacks of stop-skipping services.

Application Research of Oil Development Costs in Reservoir Management

Based on oil development costs, the application research in the technical and economic limits calculation of oil development and the production optimal allocation to all the oilfields, was finished. At the same time, according to the regression of real development costs, a new method for oil well economic water cut and oil well economic rate are set up, the production optimal allocation is developed with satisfactory results.

Thinking About the Economic Management of Universities Based on Capital and Cost Management Optimization

The economic management of colleges and universities has always been a topic of great concern to China’s educational career,therefore,this paper will firstly make the necessary analysis of the current implementation of the economic management of colleges and universities in China,and then the reasons for the problems of economic management of colleges and universities in China is realized a detailed investigation,and finally,the economic management of colleges and universities based on capital and cost management optimization strategy is made a full discussion,looking forward to providing the necessary guidance for researchers in this field.

Discrimination and Estimation of the Maximum Cost Performance of Proton Exchange Membrane Fuel Cell Power Generation with Seven Constants

This paper is dedicated to analytical expression of the maximum electricity-cost ratio (M-ECR) point of the proton exchange membrane (PEM) fuel cell power generation as the function of cell constants and cost constants. That is to formulize the maximum cost performance (MCP) magnitude and the optimal final operating (OFO) location in the working zone based on the five-constant ideal cell model and the two-constant cost model. The issues are well resolved by introducing the concepts of economic voltage and cost factor and describing the movement of the M-ECR point with cost factor. According to mathematical derivations, the movement can be described in the form of MCP and OFO curves. The derivations lead to a complete set of discriminants and criteria of the M-ECR point of PEM fuel cells that theoretically cover all of cell specialties and all of cost specialties. The discriminants and criteria may act as a general tool for the operation optimization of a diversity of PEM fuel cells and the economic viability estimation of the power generation.

Cost Optimization Modeling of Renewable Energy Sources in Smart-Grid Using SCADA

In recent times, renewable energy production from renewable energy sources is an alternative way to fulfill the increased energy demands. However, the increasing energy demand rate places more pressure, leading to the termination of conventional energy resources. However, the cost of power generation from coal-fired plants is higher than the power generation’s price from renewable energy sources. This experiment is focused on cost optimization during power generation through pumped storage power plant and wind power plant. The entire modeling of cost optimization has been conducted in two parts. The mathematical modeling was done using MATLAB simulation while the hydro and wind power plant’s emulation was performed using SCADA (Supervisory control and data acquisition) designer implementation. The experiment was conducted using ranges of generated power from both power sources. The optimum combination of output power and cost from both generators is determined via MATLAB simulation within the assumed generated output power range. Secondly, the hydro-generator and wind generator’s emulation were executed individually through synchronizing the grid to determine each generator’s specification using SCADA designer, which provided the optimum power generation from both generators with the specific speed, aligning with results generated through MATLAB. Finally, the operational power cost (with no losses consideration) from MATLAB was compared with the local energy provider to determine the cost-efficiency. This experiment has provided the operational cost optimization of the hydro-wind combined power system with stable wind power generation using SCADA, which will ultimately assist in operations of large-scale power systems, remotely minimizing multi-area dynamic issues while maximizing the system efficiency.

基于等微增率并计及机组功率约束的火电机组最优负荷分配精确解

火电机组最优负荷分配是电力系统经济运行的重要模型,也是电力系统本科生专业基础课《电力系统分析》的重要教学内容之一。经典教科书采用等微增率方法求解该问题,并给出了相应的物理含义。由于等微增率法是基于不考虑火电机组上下界物理约束而推导出来的,部分教科书补充了计及火电机组上下界物理约束时的情况,即如果某台机组的无约束最优解违背了上(下)界约束,则将该机组对应的最优解限制到相应的出力上(下)界,然后对其余火电机组再进行重新的等微增率分配。然而,简单算例表明,补充求解方法的适用范围是有限的。为此,该文对火电机组最优负荷分配问题进行重新探索,推导教材方法适用的一个充分条件与一个必要条件。面向本科生与研究生,分别提出考虑机组上下界约束后的最优负荷分配方法,并进行严格的理论推导。理论推导与大量的仿真算例表明,在机组数量较少时,教材中的求解方法有可能适用,而机组数较多时,可能出现不适用的情况。该文所提方法可以将适用范围扩展到机组数量较多的场景,并且进行严格理论推导。希望该文可以为《电力系统分析》教学过程与教材修订提供帮助。

城市轨道交通列车系统部件集中维修规划布局研究

实现城市轨道交通列车系统的部件集中维修对于提高维修效率、优化资源配置、节省投资费用具有重要意义。研究首先筛选出适用集中维修的车辆部件集合;然后以集中修部件往返转运总里程和部件维修中心总费用最小为优化目标,构建部件集中维修规划布局模型;最后以某城市轨道交通线网为例进行验证,研究权重系数、最短路面转运距离限制2个关键参数对优化方案的影响。案例结果表明:所得结果相比现行方案可在略微增加转运总里程的情况下,显著节省50.25%的维修中心总费用;企业可通过对优化目标的偏好调节权重系数,提升所得集中修方案与运维需求的适配性;转运距离限制可实现所得结果匹配实际需求,保证了布局方案在实际轨道交通线网中的可行性。

基于两阶段鲁棒优化的轨道交通自洽能源系统新能源-储能规划配置

“双碳”战略和“交通强国”战略使得轨道交通系统向着高效能、高弹性和绿色化的方向发展。轨道交通系统自身具有丰富的资源,通过在其路域铺设新能源,并根据需要配置储能,构建轨道交通自洽能源系统,可实现系统的资产能源化,助力系统向绿色化方向演进。但随机性轨道交通负荷与随机性新能源出力相交织,使得轨道交通自洽能源系统的规划配置面临难题。为此,该文构建了轨道交通路域风力、光伏以及牵引负荷的不确定集合,从而考虑了供需双向不确定性;在此基础上,以年均成本最小为目标函数,并针对牵引变压器等自洽能源系统的组分进行分析,形成系统内各组分应满足的约束条件,从而构建了适应轨道交通运行需求的新能源-储能规划配置两阶段鲁棒优化模型;针对该模型的特点,采用改进列和约束生成(improved column and constraint generation,IC&CG)算法予以求解。算例分析结果表明,所提出的模型可以使得系统的自洽率满足设定要求,并降低了系统的碳排放成本,对推进轨道交通绿色化具有积极的推动作用。

Economic Power Dispatching from Distributed Generations: Review of Optimization Techniques

In the increasingly decentralized energy environment,economical power dispatching from distributed generations(DGs)is crucial to minimizing operating costs,optimizing resource utilization,and guaranteeing a consistent and sustainable supply of electricity.A comprehensive review of optimization techniques for economic power dispatching from distributed generations is imperative to identify the most effective strategies for minimizing operational costs while maintaining grid stability and sustainability.The choice of optimization technique for economic power dispatching from DGs depends on a number of factors,such as the size and complexity of the power system,the availability of computational resources,and the specific requirements of the application.Optimization techniques for economic power dispatching from distributed generations(DGs)can be classified into two main categories:(i)Classical optimization techniques,(ii)Heuristic optimization techniques.In classical optimization techniques,the linear programming(LP)model is one of the most popular optimization methods.Utilizing the LP model,power demand and network constraints are met while minimizing the overall cost of generating electricity from DGs.This approach is efficient in determining the best DGs dispatch and is capable of handling challenging optimization issues in the large-scale system including renewables.The quadratic programming(QP)model,a classical optimization technique,is a further popular optimization method,to consider non-linearity.The QP model can take into account the quadratic cost of energy production,with consideration constraints like network capacity,voltage,and frequency.The metaheuristic optimization techniques are also used for economic power dispatching from DGs,which include genetic algorithms(GA),particle swarm optimization(PSO),and ant colony optimization(ACO).Also,Some researchers are developing hybrid optimization techniques that combine elements of classical and heuristic optimization techniques with the incorporation of droop control,predictive control,and fuzzy-based methods.These methods can deal with large-scale systems with many objectives and non-linear,non-convex optimization issues.The most popular approaches are the LP and QP models,while more difficult problems are handled using metaheuristic optimization techniques.In summary,in order to increase efficiency,reduce costs,and ensure a consistent supply of electricity,optimization techniques are essential tools used in economic power dispatching from DGs.

基于乘客出行特征和综合成本均衡的城轨列车开行方案优化研究

基于乘客的出行特征和线路运营特性,研究构建一个多目标非线性整合优化模型,旨在实现乘客等候时间、车辆运用时间及走行公里的最优组合。该模型以列车开行频率和小交路折返位置为关键决策变量。为简化问题,通过线性加权方法将各项指标转化为总成本,从而将原模型简化为单目标优化模型。以北京地铁A线为例,深入研究如何找到均衡总成本最低的列车开行方案。研究结果表明:与常规交路列车开行方案相比,精准匹配乘客出行特征的大小交路开行方案能够显著降低整体运营成本,最高可降低11.9%;在比较不同覆盖区域和行车间隔的大小交路列车开行方案时,发现越能精准匹配乘客出行特征的方案,其总成本越低,可在满足乘客需求的同时,有效避免运力浪费;当小交路运行区段过短时,可能会使乘客出行不便,且无法进一步降低企业的运营成本。

基于含多微网接入的主动配电系统自主优化经济调度

针对含多微网接入的主动配电系统经济调度方法在中断负荷的影响下,调度结果与微网出力情况不一致导致的经济性差的问题,提出基于含多微网接入的主动配电系统自主优化经济调度方法。以多微网的电源特性为依据,计算主动配电系统的运行成本和环境成本,以运行成本和环境成本经济效益最大化为目标,建立自主优化经济调度目标函数,并从环境成本和运行成本两方面设计目标函数的约束条件,进行支路潮流约束,限制微网的输出功率等,使配电系统输出功率变化与电池出力情况变化趋势保持一致,在约束条件下求解目标函数,获得目标函数解集,求解集合中各个解与理想权重的接近程度,筛选出最优解,实现主动配电系统的自主优化经济调度。实验结果表明:设计的调度方法在中断负荷的情况下,运行成本低,优化水平高,微网输出功率稳定,并且与电池出力情况一致,该方法的经济性得到了提高。

计及分时电价下的楼宇光储系统成本效益分析

近年来,楼宇光储系统颇受关注,但对影响楼宇光储系统经济收益的因素分析不足,同时缺少综合性经济评估方法。综述了已有的相关文献,着重考虑从分时电价、储能寿命以及系统容量配置优化等三方面展开分析,提出了基于以上三因素的楼宇光储系统成本效益模型,并以净现值为基准对楼宇光储系统进行成本效益分析。以某楼宇内的光储系统为案例,采用所提模型进行成本效益分析,得到配置优化前后的净现值,并以此为基础分析其经济性。仿真结果表明,优化后系统能够更快地回收前期投资,且净现值也得到了明显的提升,但整个系统的获利能力主要取决于光伏,储能的获利只占小部分。由于未考虑向电网售电的获利情况,因此在仅考虑能源自耗和减少能源账单支出的情况下,储能的盈利能力约为光伏的16%左右。

基于二层邻居牵制一致性的并网微电网经济优化控制方法

为提高并网微电网系统经济优化响应速度,降低整体发电运行成本,提出二层邻居牵制一致性算法。该算法将成本微增率(incremental cost rate,ICR)定义为状态变量,引入功率偏差消除项快速消除总功率偏差,利用二层邻居项和牵制项实现快速收敛于最优ICR,计算得到各分布式电源(distributed generation,DG)的最优有功出力参考值。随后提出基于二层邻居牵制一致性的并网微电网经济优化控制方法。该方法基于构建的三层分布式分层架构,第一控制层为双闭环反馈的下垂控制,第二控制层采用电压频率优化控制,稳定系统的频率和电压,第三控制层将各DG最优有功出力参考值输出到P/f下垂控制层,从而实现系统经济优化以及负荷功率供需平衡的目标。最后搭建8个DG并联运行系统仿真模型进行仿真实验。仿真结果表明,所提方法能完成有功出力的经济分配,且系统响应性能优,在负荷突增、功率越限、分时电价、拓扑切换、计及线路损耗、即插即用等因素影响系统运行时,所提方法能使微电网快速达到经济优化状态。

原油管道节能降耗优化技术研究

基于降低原油管道水力消耗和热力消耗的目的,通过核算管输经济成本分析了不同输量对油单耗、电单耗及单位周转量运行能耗等参数的影响,研究了能耗最优和经济成本最优对应的最佳输量,分析了以气代油和用电方式改变对管输经济成本的影响。得到如下结论,单位周转量运行能耗随着输量的增大先增大后减小,在输量为1 050 m^(3)/h时的运行能耗最优;不同年份的燃料价格和电价对经济成本的影响较大,最低经济成本对应的输量也有所不同;将燃油加热炉改为燃气加热炉后,预计全年可节约热力成本1 840万元;将用电方式从一般工商业调整为大工业用电,且计价遵循最大容量时,预计全年可节约水力成本1 610万元。研究结果可为同类原油管道的运行优化提供实际参考。

提高建筑造价管理中工程经济效益的途径

伴随着新中国的成立、改革开放等国家政治举措的实现,社会开始飞速地运转发展,建筑工程的建设与管理变得越来越受到重视,同时也进一步使得建筑行业的市场竞争变得激烈。一个企业如果想在激烈的市场中生存下去,就必须要做好工程造价管理,在实际应用中采取着实有效的方案措施对工程造价管理进行优化,持续提升造价管理员工的专业素质,促进其造价管理的专业水平,提升所在企业的核心竞争力,企业才能得到良好的发展。

基于终端代价函数的连续搅拌反应釜无穷时域经济性预测控制优化

针对连续搅拌反应釜,设计一种基于不变集技术和终端代价函数的无穷时域经济性预测控制优化算法。在经济指标中引入动态指标,构造基于寻优动态指标加权矩阵系数的二次复合性能指标,进而通过不变集技术离线计算终端约束集和终端代价函数;将有限时域内的复合性能指标附加终端代价函数,构造无穷时域性能指标,对连续搅拌反应釜进行无穷时域优化控制,改善经济性能;仿真验证了所设计算法的有效性。

Simulation Modelling and Techno-Economics of Supercritical Carbon Dioxide Recompression Closed Brayton Cycle

In recent years, there has been global interest in meeting targets relating to energy affordability and security while taking into account greenhouse gas emissions. This has heightened major interest in potential investigations into the use of supercritical carbon dioxide (sCO2) power cycles. Climate change mitigation is the ultimate driver for this increased interest;other relevant issues include the potential for high cycle efficiency and a circular economy. In this study, a 25 MWe recompression closed Brayton cycle (RCBC) has been assessed, and sCO2 has been proposed as the working fluid for the power plant. The methodology used in this research work comprises thermodynamic and techno-economic analysis for the prospective commercialization of this sCO2 power cycle. An evaluated estimation of capital expenditure, operational expenditure, and cost of electricity has been considered in this study. The ASPEN Plus simulation results have been compared with theoretical and mathematical calculations to assess the performance of the compressors, turbine, and heat exchangers. The results thus reveal that the cycle efficiency for this prospective sCO2 recompression closed Brayton cycle increases (39% - 53.6%) as the temperature progressively increases from 550˚C to 900˚C. Data from the Aspen simulation model was used to aid the cost function calculations to estimate the total capital investment cost of the plant. Also, the techno-economic results have shown less cost for purchasing equipment due to fewer components being required for the cycle configuration as compared to the conventional steam power plant.

基于粒子群优化算法的含多种供能系统的微网经济运行分析

从成本和效益2个方面详细分析了微网的经济性,在微网基本结构的基础上进行了简化,给出了供电、供热、供气一体化的微网结构,建立了考虑温室气体、污染物排放的以微网运行成本最低为目标函数的微网经济模型,并用粒子群优化算法对上述模型进行求解。算例结果验证了该模型的有效性和可行性,表明在大电网中并入微网具有较高的经济性。

基于风险控制的供应链结构优化问题

供应阶段的供应链结构问题实质是供应商数量问题.在定量分析供应商数量与供应风险及采购总成本关系的基础上,建立了多目标优化模型.通过模型求解,给出在指定供应风险水平下最优供应商数量与采购总成本.