Multi-operation management of a typical micro-grids using Particle Swarm Optimization: A comparative study

Nowadays, it becomes the head of concern for many modern power girds and energy management systems to derive an optimal operational planning with regard to energy costs minimization, pollutant emissions reduction and better utilization of renewable resources of energy such as wind and solar. Considering all the above objectives in a unified problem provides the desired optimal solution. In this paper, a Fuzzy Self Adaptive Particle Swarm Optimization (FSAPSO) algorithm is proposed and implemented to dispatch the generations in a typical micro-grid considering economy and emission as competitive objectives. The problem is formulated as a nonlinear constraint multi-objective optimization problem with different equality and inequality constraints to minimize the total operating cost of the micro-grid considering environmental issues at the same time. The superior performance of the proposed algorithm is shown in comparison with those of other evolutionary optimization methods such as conventional PSO and genetic algorithm (GA) and its efficiency is verified over the test cases consequently.     

基于粒子群优化算法的板式换热器优化设计

从板式换热器的结构出发,通过对板式换热器中的流程组合数和冷热流体流速优化分析,得出板式换热器最优结构参数的数学模型,并且结合实例,运用粒子群算法对其进行求解,最终得到更为合适的流程组合数和流体流速,使设计的板式换热器更经济,效率更高。     

Multiobjective Particle Swarm Optimization for the optimal design of photovoltaic grid-connected systems

Particle Swarm Optimization (PSO) is a highly efficient evolutionary optimization algorithm. In this paper a multiobjective optimization algorithm based on PSO applied to the optimal design of photovoltaic grid-connected systems (PVGCSs) is presented. The proposed methodology intends to suggest the optimal number of system devices and the optimal PV module installation details, such that the economic and environmental benefits achieved during the system’s operational lifetime period are both maximized. The objective function describing the economic benefit of the proposed optimization process is the lifetime system’s total net profit which is calculated according to the method of the Net Present Value (NPV). The second objective function, which corresponds to the environmental benefit, equals to the pollutant gas emissions avoided due to the use of the PVGCS. The optimization’s decision variables are the optimal number of the PV modules, the PV modules optimal tilt angle, the optimal placement of the PV modules within the available installation area and the optimal distribution of the PV modules among the DC/AC converters.     

Improvement of estimation of surge arrester parameters by using Modified Particle Swarm Optimization

Metal Oxide Surge Arrester (MOSA) accurate modeling and its parameter identification are very important aspects for arrester allocation, system reliability determination and insulation coordination studies. In this paper, Modified Particle Swarm Optimization (MPSO) algorithm is used to estimate the parameters of surge arrester models. The convergence to the local optima is often a drawback of the Particle Swarm Optimization (PSO). To overcome this demerit and improve the global search capability, Ant Colony Optimization (ACO) algorithm is combined with PSO algorithm in the proposed algorithm. The suggested algorithm selects optimum parameters for the arrester model by minimizing the error among simulated peak residual voltage values given by the manufacturer. The proposed algorithm is applied to a 120 kV MOSA. The validity and the accuracy of estimated parameters are assessed by comparing the predicted residual voltage with experimental results.     

太阳能开水器的经济性分析

太阳能开水器以电作为补充能源进行开水供应。本文利用动态的年计算费用法将这种供应形式与电开水器进行了比较。经计算,在长春地区按7月份平均的太阳辐射强度确定出的集热器面积使太阳能开水器年费用最小,与开水供应量相同的电开水器相比,其回收年限为4．1年。从经济性方面来看,这种开水供应形式在长春地区使用是可行的,经济效益比较可观,在全国大部分地区都有推广价值。     

太阳能相变蓄热水箱性能实验研究

利用相变材料蓄热是提高太阳能系统效率的重要途径之一。为对比分析含相变材料蓄热水箱的性能,选用三水合乙酸钠,搭建了一套蓄热水箱实验系统,在初始水温为80℃、进水温度为20℃的工况下,对比分析不同进口流量下(2、6和10 L/min)相变蓄热水箱的热特性。实验结果表明:相变蓄热水箱的蓄热量较普通水箱增加了1.4%;随着流量的增加,水箱的混合数先减小后增大,火用效率逐渐降低,相变蓄热水箱的填充效率先增大后减小,且在6 L/min时达到最大值0.905。     

Optimal placement and sizing from standpoint of the investor of Photovoltaics Grid-Connected Systems using Binary Particle Swarm Optimization

This paper introduces a Binary Particle Swarm Optimization based method to accomplish optimal location and size of a Photovoltaics Grid-Connected System (PVGCS) for distributed power generation. The main technical constraint is the maximum installed peak power, which is limited for utilities Power Distributor Company. The fitness function to be optimized is the profitability index. A fair comparison between the proposed algorithm and other methods is performed. For such goal, convergence curves of the average profitability index versus number of iterations are computed. The proposed algorithm reaches a better solution than genetic algorithms when considering similar computational cost (similar number of evaluations).     

基于内涝防治目标的雨水调蓄池设计

雨水调蓄池是内涝防治的重要措施之一,具有易于推广、工程经济的特点.在现有雨水调蓄池研究的基础上,利用SWMM模型建立淮安市某研究区雨洪模型,通过调整雨水调蓄池各项参数和改变布设位置,分析研究区溢流的结果变化,从而对调蓄池的分散设计策略和容积确定进行研究.结果表明,布设调蓄池前,全区溢流量8 190 m3,最大节点溢流量...     

Investigation of Excessive Material on Insulating Properties Using Different Heat Transfer Fluid for Thermal Energy Storage Development

Though TES （thermal energy storage） is developed hugely in most of the solar power generation plants, it is less growth in implementing a modular type of TES in a solar plant, e.g., solar dish/stifling engine application. The main issue in designing the TES system is its thermal capacity of storage materials, e.g., insulator. This study is focusing on the potential waste material as an insulator for thermal energy storage applications. The insulator usage is to reduce the heat transfer between two mediums and the capability is measured by its resistance to heat flow. It is needed to obtain optimal materials to energy conversion at the same time reduce the waste generation. Therefore, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room without any forced cooling system, e.g., fan. The testing is repeated by changing the insulator using the potential waste material from natural and industrial waste and also by changing the HTF （heat transfer fluid）. The analysis is performed on the relationship between heat loss and the reserved period by the insulator. The results indicate the percentage of period of the insulated tank withstands the heat compared to non-insulated tank, e.g., cotton reserved the period of 14% more than non-insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator in different heat transfer fluids.     

The impact of using Particle Swarm Optimisation on the operational characteristics of a stand-alone hydrogen system with on-site water production

In a previous paper, we analysed the impact of renewable energy intermittency on the operational characteristics of hydrogen energy systems with pre-set Power Management Strategies not subject to optimisation. The research presented in this follow-up paper extends that earlier work and demonstrates the validity of applying Particle Swarm Optimisation (PSO) to size and optimise hydrogen systems. Specifically, PSO is used to iteratively converge on the (short-term) battery capacity (Ah) and hydrogen storage (L) in addition to defining the switching parameters which a Power Management Strategy (PMS) uses. The PSO algorithm is guided by three operational objective functions and conducted using MATLAB/Simulink. Simulations also incorporate laboratory resolved device characteristics.     

新能源系统中双储能耦合燃煤机组的应用策略研究

目的  随着新能源电力消费比例不断提高,燃煤机组耦合双储能技术的能源系统发展受到广泛关注。 方法  文章基于能源系统组成、储能技术特性、项目示范情况以及技术瓶颈等方面的分析,针对风电、光伏嵌入下双储能技术耦合燃煤机组参与电力系统调峰应用开展了运行控制策略研究。 结果  双储能技术耦合燃煤机组可通过不同的结构组成、运行策略优化有效解决新能源系统运行稳定性、能源高效利用以及技术经济性等问题,但目前尚未到实现大规模商业化应用阶段。 结论  双储能耦合燃煤机组在新能源系统中的推广应用,需要对双储能技术的策略优化及储能技术本身的发展突破方面不断开展工作。     

对低碳背景下中国能源战略的若干思考

我国能源需求仍将增长,能源安全压力仍然较大,把供应增量放在进口上风险很大。节能是个大战略,但难度和成本在增加。以煤为主的一次能源结构特征要求我国的煤炭得到高效、清洁和低碳利用。太阳能、风能等开发利用增长势头猛、潜力大,但其能源属性决定,难以担当能源供应重任。因此,必须加大改革力度、引导社会资金进入能源领域,促进能源业的可持续发展。     

直接空冷系统初始温差值的优化设计

直接空冷系统设计,核心之一是最佳初始温差值ITD的优化设计。文中介绍了直接空冷系统初始温差值的优化理论,探讨了优化过程和计算方法,由于初始温差和空气侧流速大小关系到空冷系统造价和系统运行费用,所以以这两者作为设计变量,以空冷系统年总费用为目标函数,对某一空冷机组进行了分析,优化设计了机组ITD值,得到系统最小年总费用和最佳ITD值。     

Operational performance of energy storage as function of electricity prices for on-grid hybrid renewable energy system by optimized fuzzy logic controller

Realization of benefits from on-grid distributed generation based on renewable energy sources requires employment of energy storage to overcome the intermittency in power generation by such sources, while accounting for time-varying electricity prices. The objective of this study is to examine the effects of time-varying electricity prices on the performance of energy storage components for an on-grid hybrid renewable energy system (HRES) utilizing an optimized fuzzy logic controller (FLC). To achieve the objective, FLC membership functions are optimized for minimizing the operational cost of the HRES based on weekly and daily prediction of data for grid electricity price, electrical load, and environmental parameters, including wind speed, solar irradiation, and ambient temperature, using shuffled frog leap algorithm. FLC three inputs include (a) grid electricity price, (b) net power flow as the difference between energy produced and energy consumed, and (c) state of charge (SOC) of battery stack. It is confirmed that accounting for grid electricity price has considerable effects on the performance of energy storage components for operation of on-grid HRES, as the weekly and daily optimized FLCs result in less working hours for fuel cell and electrolyzer and less fluctuations in SOC of battery stack.     

储冰桶换热管组流动特性研究

分析了储冰桶换热器管组的流动过程,建立实际流动的物理模型,通过理论推导,获得了分析解。为准确计算换热器组流量分布,系统压降以及设计提供了一种理论方法。     

考虑运行经济成本的风电场储能容量优化

储能技术作为一种新兴的调节风电功率输出方法,能够有效平抑风电出力波动.储能系统容量规划问题正成为重要的研究课题.以蓄电池作为研究对象,将放电深度和过放电现象对电池寿命的损伤折合为运行经济成本,同时考虑惩罚成本及固有成本,在确保风电出力尽可能接近期望出力的前提下,建立了以总经济成本最小为目标,以容量限制、功率限制及充放电次数限制为约束条件的储能容量优化模型,采用遗传算法求解目标函数.算例分析结果表明,该方法可以配置合理的储能容量,使得储能系统在平抑风电出力波动的同时使总经济成本降至最低,实现稳定性和经济性的相协调.     

Energy management and design of centralized air-conditioning systems through the non-revisiting strategy for heuristic optimization methods

It is getting more and more popular to apply heuristic optimization methods, like genetic algorithm (GA) and particle swarm optimization (PSO), to handle various engineering optimization problems. In this paper, optimization problems of typical centralized air-conditioning systems were solved by the non-revisiting (Nr) strategy, which was proposed to be incorporated into the common heuristic methods for improving the optimization effectiveness and reliability. This approach can store the evaluated fitness values in an archive with minimal computer memory, detect the revisits and prevent them from re-evaluating. It is particularly useful for the problems formulated by dynamic simulation or detailed modeling with very demanding computational time for function evaluation. The non-revisiting strategy can facilitate the search of the global optimum by its parameter-less adaptive mutation capability. In the optimization problems of central air-conditioning systems, it was found that the NrGA and NrPSO could search better solutions at a limited number of function evaluations than the conventional GA and PSO did. The ultimate goal is to determine the required parameters for optimal design and energy management. The proposed strategy can be applied to similar types of air-conditioning or engineering optimization problems, and possibly incorporated into other kinds of heuristic optimization methods.     

Optimum energy storage techniques for the improvement of renewable energy sources-based electricity generation economic efficiency

The high wind and solar potential along with the extremely high electricity production cost met in the majority of Greek Aegean islands comprising autonomous electrical networks, imply the urgency for new renewable energy sources (RES) investments. To by-pass the electrical grid stability constraints arising from an extensive RES utilization, the adaptation of an appropriate energy storage system (ESS) is essential. In the present analysis, the cost effect of introducing selected storage technologies in a large variety of autonomous electrical grids so as to ensure higher levels of RES penetration, in particular wind and solar, is examined in detail. A systematic parametrical analysis concerning the effect of the ESSs’ main parameters on the economic behavior of the entire installation is also included. According to the results obtained, a properly sized RES-based electricity generation station in collaboration with the appropriate energy storage equipment is a promising solution for the energy demand problems of numerous autonomous electrical networks existing worldwide, at the same time suggesting a clean energy generation alternative and contributing to the diminution of the important environmental problems resulting from the operation of thermal power stations.     

以空气为携热介质的开式太阳能蓄能热泵循环研究与分析

以空气为携热介质的开式太阳能吸收式热泵系统为研究对象，在原有制冷循环基础上，根据冬季蓄能热泵循环运行特点对系统进行改进；并以西安地区为例对循环进行计算和分析，探讨其蓄能情况和影响系统工作性能的因素。     

源网荷侧新型储能商业模式及成本回收机制研究

目的   在“双碳”目标下,以新能源为主体的新型电力系统在“源网荷”侧均赋予了储能重要战略地位,在灵活电力市场机制下,挖掘储能商业模式及成本回收机制,完善储能相关市场规则和支撑政策机制,对促进储能可持续发展,推进新型电力系统的建设和双碳目标的实现有着重要意义。 方法   基于国内外储能收益定价经验,采用经营期定价法、成本+合理收益、电力失负荷价值等多种方法对储能收益来源及成本回收机制进行了测算。 结果   基于现有政策路径,全面梳理了“源网荷”侧新型储能应用场景、商业模式及成本回收机制,总结了现存问题及政策建议。 结论   研究成果具备较好的可操作性和参考性,可为储能大规模发展和政策制定提供有益参考。