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1.
随着电容式电压互感器(Capacitor Voltage Transformer,CVT)在电力系统中的广泛使用,运行中也出现了一些问题,其中较常见的是内部电容元件的击穿故障,目前多数CVT在线监测系统需增加一次硬件设备,这不仅增加了系统投入,更可能影响系统的可靠性,文章利用广东电网中运行成熟的能量管理系统(EMS)中的CVT二次电压数据,研究二次电压变化与CVT自身状态的关系,通过理论计算与统计分析相结合确定了故障判断阈值,在不增加一次系统的硬件投入的基础上,建立了实时监测CVT运行状态的故障分析系统,避免了CVT故障的发展、威胁系统的安全,从而达到提高电力系统运行可靠性的目的。  相似文献   
2.
 为了探究结晶器电磁搅拌(M EMS)对大圆坯结晶器内综合冶金行为的影响。以大断面圆坯连铸结晶器冶金行为为研究对象,基于电磁热流体与凝固传输理论建立三维耦合数值模型。揭示大圆坯连铸常用五孔水口浇注条件下结晶器内电磁场、流场、传热与凝固等综合冶金行为,提出电磁搅拌对结晶器冶金性能影响的多参量评价方法。以中碳铬钼齿轮钢650 mm大圆坯连铸为例,指出结晶器电磁搅拌存在最佳搅拌电流,可获得相对较好的综合冶金效果。具体表现为弯月面保持一定的切向速度和过热度,有利于保护渣的熔化和夹杂物的上浮去除;液面波动幅度在控制范围内,可避免卷渣、改善表面质量;结晶器内钢液过热得到有效耗散,有利于等轴晶形核改善铸坯内部质量;侧孔出流钢液速度得到有效控制,可抑制注流对初凝坯壳的冲刷,提高了初生坯壳生长的均匀性。此外,电磁搅拌产生的水平旋流强度也可得到有效控制,有利于避免常见的皮下白亮带现象。  相似文献   
3.
The rapid increase of renewable energy sources made coordinated control of the distributed and intermittent generation units a more demanded task. Matching demand and supply is particularly challenging in islanded microgrids. In this study, we have demonstrated a mixed‐integer quadratic programming (MIQP) method to achieve efficient use of sources within an islanded microgrid. A unique objective function involving fuel consumption of diesel generator, degradation in a lithium‐ion battery energy storage system, carbon emissions, load shifting, and curtailment of the renewable sources is constructed, and an optimal operating point is pursued using the MIQP approach. A systematic and extensive methodology for building the objective function is given in a sequential and explicit manner with an emphasis on a novel model‐based battery aging formulation. Performance of the designed system and a sensitivity analysis of resulting battery dispatch, diesel generator usage, and storage aging against a range of optimization parameters are presented by considering real‐world specifications of the Semakau Island, an island in the vicinity of Singapore.  相似文献   
4.
This work aims to construct an efficient and robust fuel cell/battery hybrid operating system for a household application. The ability to dispatch the power demands, sustain the state of charge (SOC) of battery, optimize the power consumption, and more importantly, ensure the durability as well as extend the lifetime of a fuel cell system is the basic requirements of the hybrid operating system. New power management strategy based on fuzzy logical combined state machine control is developed, and its effectiveness is compared with various strategies such as dynamic programming (DP), state machine control, and fuzzy logical control with simulation. Experimental results are also presented, except for DP because of difficulties in achieving real‐time implementation and much faster response to load variation. The given current from the energy management system (EMS) as a reference of the fuel cell output current is determined by filtering out various harmful signals. The new power management strategy is applied to a 1‐kW stationary fuel cell/battery hybrid system. Results show that the fuel cell hybrid system can run much smoothly with prolonged lifetime.  相似文献   
5.
Energy crisis and the global impetus to “go green” have encouraged the integration of renewable energy resources, plug-in electric vehicles, and energy storage systems to the grid. The presence of more than one energy source in the grid necessitates the need for an efficient energy management system to guide the flow of energy. Moreover, the variability and volatile nature of renewable energy sources, uncertainties associated with plug-in electric vehicles, the electricity price, and the time-varying load bring new challenges to the power engineers to achieve demand-supply balance for stable operation of the power system. The energy management system can effectively coordinate the energy sharing/trading among all available energy resources, and supply loads economically in all the conditions for the reliable, secure, and efficient operation of the power system. This paper reviews the framework, objectives, architecture, benefits, and challenges of the energy management system with a comprehensive analysis of different stakeholders and participants involved in it. The review paper gives a critical analysis of the distributed energy resources behavior and different programs such as demand response, demand-side management, and power quality management implemented in the energy management system. Different uncertainty quantification methods are also summarized. This review paper also presents a comparative and critical analysis of the main optimization techniques used to achieve different energy management system objectives while satisfying multiple constraints. Thus, the review offers numerous recommendations for research and development of the cutting-edge optimized energy management system applicable for homes, buildings, industries, electric vehicles, and the whole community.  相似文献   
6.
With the development of smart grid, residents have the opportunity to schedule their household appliances (HA) for the purpose of reducing electricity expenses and alleviating the pressure of the smart grid. In this paper, we introduce the structure of home energy management system (EMS) and then propose a power optimization strategy based on household load model and electric vehicle (EV) model for home power usage. In this strategy, the electric vehicles are charged when the price is low, and otherwise, are discharged. By adopting this combined system model under the time-of-use electricity price (TOUP), the proposed scheduling strategy would effectively minimize the electricity cost and reduce the pressure of the smart grid at the same time. Finally, simulation experiments are carried out to show the feasibility of the proposed strategy. The results show that crossover genetic particle swarm optimization algorithm has better convergence properties than traditional particle swarm algorithm and better adaptability than genetic algorithm.  相似文献   
7.
介绍海洋石油平台电力组网的EMS系统设计。针对海上石油平台电网的特点,提出了集SCADA、在线安控及电站综合自动化等功能为一体的EMS系统建设方案,并对EMS的有功功率(频率)控制、电压无功控制、优先脱扣、高周切机、通信故障控制策略进行研究,解决了小电网的安全稳定控制问题。  相似文献   
8.
A high EMS current-mode SPI interface for battery monitor IC (BMIC) is presented to form a daisy-chain bus configuration for the cascaded BMICs and the communication between the MCU and master BMIC. Based on analog and digital mixed filtering technique, the proposed daisy-chain can avoid the isolated communication issue in electromagnetic interference environment, and reduce the extensively required I/O ports of MCU, at the same time reduce the system cost. The proposed daisy-chain interface was introduced in a 6-ch battery monitor IC which was fabricated with 0.35 μm 30 V BCD process. The measurement result shows that the presented daisy-chain SPI interface achieves better EMS performance with different EMI injection while just consuming a total operation current up to 1 mA.  相似文献   
9.
在分析典型调度主站软件系统架构和特性的基础上,通过对调度主站软件系统的输入/输出(I/O)空间分析,给出了更加符合调度主站软件系统特征的检测模型.基于该模型分析了软件检测设计中的某些规律,并基于所提出的检测模型对调度主站软件系统的检测工作进行了分析和说明,所提模型为调度主站软件系统检测工作的简化奠定了理论基础.  相似文献   
10.
传统内燃机汽车,多采用真空助力伺服制动系统来实现助力。其真空源来自于发动机进气歧管。现在汽车随着发动机排量的减小和负载的增加,真空度在某些工况下将出现严重不足的问题,尤其是高海拔地区。通过对发动机EMS的标定,实现了对整车真空助力系统的适应性优化。整车道路性试验表明,优化后的真空助力系统满足整车使用要求。  相似文献   
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