电力能量自动调节控制装置初探

本文介绍了智能式电力能量自动调节控制装置的工作原理及应用,装置的硬件设计和系统的软件设计。

基于多尺度熵的电力能量流复杂性分析

电力能量流复杂性主要体现于其动态行为的实时性、非线性及不确定性等,网络动力学行为分析是关键.本文在电力系统动力学平衡方程基础上,构建了系统势能与支路势能函数模型;通过提取扰动(或故障)后系统的能量信息,利用多尺度熵对扰动(或故障)后系统能量流演化过程进行了研究.结果表明:1)稳定运行状态下系统复杂度较低,且随着故障持续时间的增加,系统故障后呈现出更高的复杂度;2)不稳定运行状态下,系统在小尺度时间上表现出更强的不确定性,而在大尺度时间上表现出相对更明显的规则性;3)临界稳定运行状态与临界不稳定运行状态下,故障后的系统复杂度在不同时间尺度上呈现出较明显的差异,这对动态过程中临界点的识别有着积极的参考价值.本文研究揭示了电力能量流在物理动态过程中的演化机制,为电力系统动力学行为分析提供了新思路与新方法.

低压配电网中单相动态电压恢复器与电力系统之间的能量流动

动态电压恢复器(DVR)工作时流经全部负载电流,其输出能量的大小则会影响储能单元充放电时间的长短。详细分析了同相位补偿、故障前补偿和最小能量补偿3种方式下DVR能量流动的规律。同相位补偿时,输出的电压最小,但在大多数时候可能输出的能量较大;故障前电压补偿方式下只要是电压发生暂降,必然需要向系统提供有功和无功才能满足控制的需求,这就对储能单元的功率输出提出了较高的要求;最小能量补偿方式下,指定补偿角的选取是关键。能量流动中有功功率的确定是配置储能单元额定储能量的前提,同时也是控制单元实现和执行补偿策略的理论依据。Matlab的仿真结果证明了以上结论。

储能系统参与多应用场景的协同运行策略

风电出力与负荷需求的时序关系导致仅用于风电消纳的储能具有闲置的时段和容量,故其利用率低、经济效益不佳。针对该问题,探讨了利用此类储能的闲置容量和功率参与电力能量市场和备用辅助服务市场的可行性和兼容性,并提出储能系统参与3种应用场景的协同运行策略,以提高储能利用率。首先,通过最优机组组合问题研究储能用于促进风电消纳的运行计划。然后,优化利用储能闲置容量和功率参与电力能量市场和备用辅助服务市场,修正储能系统运行计划。此外,在储能投标备用容量时设置预留容量空间以保证备用可用。算例仿真验证了该方法可显著提高储能运营收益,并分析了储能初始荷电状态、容量和功率对各应用场景下收益的影响。

水力发电厂电气设备监控管理系统的设计与应用

首先详细介绍了电气设备监控管理系统概论,并且以此作为基础条件,从监控配置、数据收集、监控预警等方面进一步总结出电气设备监控管理系统应用策略,可以促进水力发电厂更好更快的发展。

关于超高压输电线路运行管理问题及优化对策的探讨

近几年,随着我国经济不断发展和进步,电力行业同样得到了巨大的发展机遇,同时电力网络扩建工程的不断增加,同样造成电力线路运行以及管理方面遇到了巨大的挑战。为了进一步优化资源配置模式,进一步扩张线路建设区域,电力网络开始向超高压方向发展,在我国广大地区普遍运用。文章首先对超高压输电线路进行了介绍,然后结合现阶段超高压输电线路运行流程、超高压输电线路运行问题等方面进行综合分析,最后总结出超高压输电线路优化策略。

Sources and significance of variation in basal,summit and maximal metabolic rates in birds

The rates at which birds use energy may have profound effects on fitness, thereby influencing physiology, behavior, ecology and evolution. Comparisons of standardized metabolic rates （e.g., lower and upper limits of metabolic power output） present a method for elucidating the effects of ecological and evolutionary factors on the interface between physiology and life history in birds. In this paper we review variation in avian metabolic rates [basal metabolic rate （BMR; minimum normothermic metabolic rate）, summit metabolic rate （Msum; maximal thermoregulatory metabolic rate）, and maximal metabolic rate （MMR; maximal exercise metabolic rate）], the factors associated with this variation, the evidence for functional links between these metabolic traits, and the ecological and evolutionary significance of avian metabolic diversity. Both lower and upper limits to metabolic power production are phenotypically flexible traits, and vary in association with numerous ecological and evolutionary factors. For both inter- and intraspecific comparisons, lower and upper limits to metabolic power production are generally upregulated in response to energetically demanding conditions and downregulated when energetic demands are relaxed, or under conditions of energetic scarcity. Positive correlations have been documented between BMR, Msum and MMR in some, but not all studies on birds, providing partial support for the idea of a functional link between lower and upper limits to metabolic power production, but more intraspecific studies are needed to determine the robustness of this conclusion. Correlations between BMR and field metabolic rate （or daily energy expenditure） in birds are variable, suggesting that the linkage between these traits is subject to behavioral adjustment, and studies of the relationship between field and maximal metabolic rates are lacking. Our understanding of avian metabolic diversity would benefit from future studies of： （1） the functional and mechanistic links between lower and upper limits of metabolic power output; （2） the environmental and ecological cues driving phenotypically flexible metabolic responses, and how responses to such cues might impact population responses to climate change; （3） the shapes of metabolic reaction norms and their association with environmental variability; and （4） the relationship of metabolic variation to fitness, including studies of repeatability and heritability of minimum and maximum metabolic power output [Current Zoology 56 （6）： 741-758, 2010].

Comparison of the Performance of Two Direct Wave Energy Conversion Systems: Archimedes Wave Swing and Power Buoy

Many wave energy conversion devices have not been well received. The main reasons are that they are too complicated and not economical. However, in the last two decades direct conversion systems have drawn the attention of researchers to their widely distributed energy source due to their simple structure and low cost. The most well-known direct conversion systems presently in use include the Archimedes Wave Swing (AWS) and Power Buoy (PB). In this paper, these two systems were simulated in the same conditions and their behaviors were studied in different wave conditions. In order to verify the simulations, results of the generator of the finite element computations were followed. An attempt was made to determine the merits and drawbacks of each method under different wave conditions by comparing the performance of the two systems. The wave conditions suitable for each system were specified.

Supervisory control of the hybrid off-highway vehicle for fuel economy improvement using predictive double Q-learning with backup models

This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimize the engine fuel in real-world driving and improve energy efficiency with a faster and more robust learning process.Unlike the existing“model-free”methods,which solely follow on-policy and off-policy to update knowledge bases(Q-tables),the PDQL is developed with the capability to merge both on-policy and off-policy learning by introducing a backup model(Q-table).Experimental evaluations are conducted based on software-in-the-loop(SiL)and hardware-in-the-loop(HiL)test platforms based on real-time modelling of the studied vehicle.Compared to the standard double Q-learning(SDQL),the PDQL only needs half of the learning iterations to achieve better energy efficiency than the SDQL at the end learning process.In the SiL under 35 rounds of learning,the results show that the PDQL can improve the vehicle energy efficiency by 1.75%higher than SDQL.By implementing the PDQL in HiL under four predefined real-world conditions,the PDQL can robustly save more than 5.03%energy than the SDQL scheme.

0.4kV可控硅动态无功补偿装置的应用

在电力系统运行中,为减少能量损耗,提高供电设备利用率,需要采用无功功率补偿。介绍江苏金坛地区在中频炉、电弧炉客户中,电焊企业、商业、居民用户试用SVC可控硅动态无功补偿装置,构成低压动态无功补偿,提高功率因数,降低线路损耗,提高电能质量,节电效果明显。

华北电网的调度管理

文章介绍了为保障华北电网安全、稳定、经济运行所采取的技术手段和装设的自动装置；为加强频率管理所采取的诸项措施；为加强电压管理所采用的电压调整手段；网间联络线交换电力的管理情况等。着重介绍了为加强华北电网调度管理自动化从国外引进的电力系统能量管理系统（ＥＭＳ）及其实现的功能。最后指出了２０００年前华北电网调度管理所要实现的目标。

Thermodynamic properties and heat capacity of Ru metal in HCP,FCC,BCC and liquid state

Isometric heat capacity cv and isobar heat capacity cp of Ru metal in HCP,FCC,BCC and liquid state were calculated by using pure element systematic theory.The results are in good agreement with joint army-navy-air force(JANAF) experimental value and the calculation result by first-principle(FP) method.But the results have great differences in contrast to Scientific Group Thermodata Europe(SGTE) database.The cause is found that it cannot neglect the electron devotion to heat capacity to adjust cp in one-atom(OA) method.The disparity between OA method and SGTE database was discussed.The main cause is that OA method adopts the crosspoint with iso-Ec-line and iso-a-line in hybritriangle to determine the properties,but SGTE database is obtained by extrapolation from activity measurements and critical assessment of data from a large number of binary system.Thermodynamic properties of Ru metal in HCP,FCC,BCC and liquid state,such as entropy S,enthalpy H and Gibbs energy G were calculated.Therefore,the full description of thermodynamic properties from 0 K to random temperature is implemented.

A new measurement method of crack propagation rate for brittle rock under THMC coupling condition

A new electrical method of conductive carbon-film(with waterproof and anticorrosion ability)was proposed to continuously measure crack propagation rate of brittle rock under THMC coupling condition.A self-designed coupling testing system was used to conduct THMC coupling fracture tests of the pre-cracked red sandstone specimens(where the temperature is only changed)by this new electrical method of conductive carbon-film.Calculation results obtained by the energy method coincide well with the test results.And the higher the temperature is,the earlier the crack is initiated and the larger the crack propagation rate and accelerated velocity are,which can prove the validity of the new electrical method.This new electrical method has advantages of continuously measuring crack propagation rate over the conventional electrical,optical and acoustic methods,and can provide important basis for safety assessment and cracking-arrest design of deep rock mass engineering.

Supercapacitors and Battery Energy Management Based on New European Driving Cycle

This paper presents a new strategy of embedded energy management between battery and supercapacitors （SC） for hybrid electric vehicles （HEV） applications. This proposal is due to the present trend in the field, knowing that the major drawback of the HEV is the autonomy problem. Thus, using supercapacitors and battery with a good energy management improves the HEV performances. The main contribution of this paper is focused on DC-bus voltage and currents control strategies based on polynomial controller. These strategies are implemented in PICI8F4431 microcontroller for DC/DC converters control. Due to reasons of cost and available components （no optimized）, such as the battery and power semiconductors （IGBT）, the experimental tests are carried out in reduced scale （2.7 kW）. Through some simulations and experimental results obtained in reduced scale, the authors present an improved energy management strategy for HEV.

Optimum line reclosing time for the enhancement of interconnected power system stability

Automatic line reclosing schemes used in an extra-high-voltage power system is an economical and effective means to maintain transient stability. A novel method is proposed in the paper to adaptively optimize the automatic line reclosing time after a transient fault for enhancement of interconnected power system transient stability. Both the study on the transient energy over network and the structure-preserving multi-machines power system model illustrate that the excessive convergence of potential energy on the lines with a certain cutset deteriorate power system stability, and therefore, an optimum line reclosing strategy can be established by minimizing the change in transient potential energy distribution across a cutset lines in the vicinity of the faulty line as an optimization target, and the optimal reclosure time is set to the time of minimum line phase angle difference. Without any pre-determined knowledge, the method is adaptive to various power system operation modes and fault conditions, and easy to implement because only a limited number of data measured at one location on a tie-line linking sub-networks are required. Simulations have been performed with the OMIB(One Machine and Infinite Bus System) and a real inter-connected power system to verify the applicability of the method proposed.

Microstructure and mechanical properties of Al-Zn-Cu-Mg-Sc-Zr alloy after retrogression and re-aging treatments

The mechanical properties and stress corrosion cracking （SCC） resistance of an Al-Zn-Cu-Mg-Sc-Zr alloy under different aging conditions were investigated. The dependence of microstrueture and mechanical properties on aging parameters was evaluated by tensile test, hardness test and conductivity measurement. The results show that for the alloys with retrogression and re-aging treatment （RRA）, the conductivity increases with the retrogression time and temperature, while the tensile strength decreases. The transmission electron microscopy （TEM） results show that the precipitates η（MgZn2） at grain boundary aggregate apparently with retrogression time and the precipitates inside the matrix exhibit the similar distribution to T6 temper, which comprises fine GP zones, large η＇（MgZn2）and η（MgZn2） phases. According to the mechanical properties and microstructure observations, the optimal RRA regime is recommended to be 120℃, 24h ＋ 180 ℃, 30 min ＋ 120 ℃, 24 h. The strength level of the alloy after the optimum RRA treatment is similar to that in T6 condition and the SCC resistance is improved obviously in contrast to T6 condition.

Energy Flexibility in the Power System： Challenges and Opportunites in Philippines

Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study to provide an overview of the current condition of the Philippines＇ power system and discuss the energy flexibility in the Philippines＇ power system. A further discussion and recommendation is conducted in the end of the paper.

Effect of Market Power in Electricity Markets

The main objective of this paper is to show an overview analysis of market power issues.Market power reflects the scarcity of power supply.It is the ability of a particular seller or group of sellers to maintain prices profitably above competitive levels for a significant period of time.Because the electric power system has its own characteristics that are different to other economic systems,both physical factors and economic factors of power system are key elements on this definition.We study some cases here,including different line limit levels,load levels and bid strategy through a market model based on OPF (optimal power flow) with a decommitment algorithm.

Passive control experiment of building with spacious first story by magnet-friction energy dissipation device

Based on the former performance capacity experiments of the magnet-friction energy dissipation devices, including the permanent magnet-friction energy dissipation device (PMF) and electromagnet-friction energy dissipation devices (EMF), a 5-story steel frame model with spacious first story is designed and made according to a scale of 1/4. The magnet-friction energy dissipation devices can realize continuously varied controlling force, with rapid response and reverse recognition. Therefore, they overcome shortcomings usually found in energy dissipation devices whose force models are invariable. The two kinds of devices were fixed on the flexible first story of the structure model, and the shaking table tests have been carried out, respectively. In these tests, the performance of the devices and their effectiveness in structural control were confirmed. In this paper, the test results and analysis are discussed.

The Energy Optimization Mathematic Algorithm on Multi-energy Resource Powertrain of Fuel Cell Vehicle

In order to solve the core issue of the energy regulation （ER） on multi-energy resource powertrain of fuel cell vehicle, the work functions of each component were defined; the mathematical algorithm model of energy regulation was established and the relevant solution was found. This algorithm was evaluated successfully on the hardware in loop （FILL） platform under three typical urban running cycles. The results showed ER control target had been realized and the mathematical algorithm was effective and reasonable. Based on the HIL simulation, some conclusions and ER strategies were made. According to the different power component parameters and real time control request, this algorithm should be modified and calibrated for application in the actual control system.