Electrochemical power sources:key agents for energy sustainability(Ⅱ)

3 Hydrogen distribution and storage3·1 Gaseous and liquid hydrogenIn the gaseous state,the most obvious method for distributinghydrogen would appear to be via pipeline·This has long been thepractice in Germany to supply hydrogen for chemical processes·…     

The 12th Five-Year: Speed Up Structural Adjustment of Power Sources

To the year 2020, China will realize the target of increasing non-fossil generation to 15% of the total energy consumption. Speeding up power sources restructuring comes up as an arduous task during the 12^th Five-Year Plan period. In this article, the author outlines the principles of structure adjustment for various kinds of power sources, and points out the issues needing attention during the restructuring.     

The legal sustainability of energy substitution in Nigeria’s electric power sector: renewable energy as alternative

Non-renewable fuel sources have been the predominant energy sources and a significant source of foreign exchange income for Nigeria, while at the same time there is a severe problem of electricity inconsistency and persistent power blackouts in Nigeria. The research aims to end the concern for deficient energy use, and to encourage energy efficiency and sustainability. Nigeria has not maximized the advantages of renewable energy after the denationalisation of its electricity industry despite the current transformation in the power industry and the rising demand for renewable energy supply. The research adopts a doctrinal legal approach with a library-based legal research technique with a comparative legal method. It reveals that the absence of a comprehensible legal regime with encouragement for the use of renewable energy is the fundamental element causing the slow utilization of renewable energy as a substitute source of energy in Nigeria. It is suggested that, among other reforms, there is a need for a comprehensible legal regime on renewable energy and the encouragement of strict implementation of energy regulatory strategies and policies with incentives for the application of renewable energy sources in Nigeria.     

Strategies for improving resilience of regional integrated energy systems in the prevention–resistance phase of integration

he construction of integrated energy systems can help improve energy efciency and promote global energy transition. However, in recent years, the occurrence of extreme natural disasters has brought certain threats to the safe and stable operation of the integrated energy system. Thus, it is necessary to improve the ability of the integrated energy system to resist disasters, reduce disaster losses, and restore energy supply as soon as possible, i.e., improve its resilience. Considering the infuence of pre-disaster prevention measures and disaster-time operational measures on system disaster resilience and the correlation between the two, this paper proposes a system hardening strategy based on three-layer robust optimization. The upper layer formulates the optimal hardening strategy of the system before the disaster event occurs, the middle layer identifes the failed elements in the worst disaster situation, while the lower layer realizes the system operational optimization by coordinating the energy storage charging and discharging plan of each subsystem. The strategy can reduce the total supply shortage of the integrated energy system and improve the fexibility of the system in the pre-disaster prevention and disaster resistance integration stages.     

Enhanced leader PSO (ELPSO): A new algorithm for allocating distributed TCSC’s in power systems

Allocation of flexible AC transmission systems (FACTS) devices is a challenging power system problem. This paper proposes a new particle swarm optimisation (PSO) variant, called enhanced leader PSO (ELPSO), for solving this problem. This algorithm is capable of solving FACTS allocation problem in a way leading to lower amounts of power flow violations, voltage deviations and power losses with respect to other optimisation algorithms. Distributed thyristor controlled series compensators (D-TCSC’s) are used. D-TCSC’s are installed at all branches except those with regulating transformers. The reactances of D-TCSC’s are found in optimisation process. ELPSO features a five-staged successive mutation strategy which mitigates premature convergence problem of conventional PSO. ELPSO and other optimisation algorithms are applied to IEEE 14 bus and 118 bus power systems for N-1 contingencies and also for simultaneous outage of four branches. The results show that it leads to lower amounts of power flow violations, voltage deviations and power losses with respect to conventional PSO (CPSO) and eight other optimisation algorithms including genetic algorithm (GA), gravitational search algorithm (GSA), galaxy based search algorithm (GBSA), invasive weed optimisation (IWO), asexual reproduction optimisation (ARO), threshold acceptance (TA), pattern search and nonlinear programming (NLP).     

Novel chaos game optimization tuned-fractional-order PID fractional-order PI controller for load–frequency control of interconnected power systems

In this work, chaos game optimization (CGO), a robust optimization approach, is employed for efficient design of a novel cascade controller for four test systems with interconnected power systems (IPSs) to tackle load–frequency control (LFC) difficulties. The CGO method is based on chaos theory principles, in which the structure of fractals is seen via the chaotic game principle and the fractals’ self-similarity characteristics are considered. CGO is applied in LFC studies as a novel application, which reveals further research gaps to be filled. For practical implementation, it is also highly desirable to keep the controller structure simple. Accordingly, in this paper, a CGO-based controller of fractional-order (FO) proportional–integral–derivative–FO proportional–integral (FOPID–FOPI) controller is proposed, and the integral time multiplied absolute error performance function is used. Initially, the proposed CGO-based FOPID–FOPI controller is tested with and without the nonlinearity of the governor dead band for a two-area two-source model of a non-reheat unit. This is a common test system in the literature. A two-area multi-unit system with reheater–hydro–gas in both areas is implemented. To further generalize the advantages of the proposed scheme, a model of a three-area hydrothermal IPS including generation rate constraint nonlinearity is employed. For each test system, comparisons with relevant existing studies are performed. These demonstrate the superiority of the proposed scheme in reducing settling time, and frequency and tie-line power deviations.     

Novel chaos game optimization tuned-fractional-order PID fractional-order PI controller for load–frequency control of interconnected power systems

In this work, chaos game optimization (CGO), a robust optimization approach, is employed for efficient design of a novel cascade controller for four test systems with interconnected power systems (IPSs) to tackle load–frequency control (LFC) difficulties. The CGO method is based on chaos theory principles, in which the structure of fractals is seen via the chaotic game principle and the fractals’ self-similarity characteristics are considered. CGO is applied in LFC studies as a novel application, which reveals further research gaps to be filled. For practical implementation, it is also highly desirable to keep the controller structure simple. Accordingly, in this paper, a CGO-based controller of fractional-order (FO) proportional–integral–derivative–FO proportional–integral (FOPID–FOPI) controller is proposed, and the integral time multiplied absolute error performance function is used. Initially, the proposed CGO-based FOPID–FOPI controller is tested with and without the nonlinearity of the governor dead band for a two-area two-source model of a non-reheat unit. This is a common test system in the literature. A two-area multi-unit system with reheater–hydro–gas in both areas is implemented. To further generalize the advantages of the proposed scheme, a model of a three-area hydrothermal IPS including generation rate constraint nonlinearity is employed. For each test system, comparisons with relevant existing studies are performed. These demonstrate the superiority of the proposed scheme in reducing settling time, and frequency and tie-line power deviations.     

灯泡贯流式水轮机(Ⅰ)

本文叙述了灯泡贯流式水轮机的有关技术问题,对于不同的结构设计方案进行了比较,并介绍了灯泡贯流式水轮机的设计和科研要点。     

金属丝电爆炸研究进展-(Ⅰ):真空环境

真空中金属丝电爆炸在Z箍缩等离子体、X射线源等有重要应用,特别是纳秒脉冲下金属单丝的电爆炸行为是丝阵Z箍缩的最初始阶段,对丝阵Z箍缩内爆辐射特性有重要影响,因而受到特别关注。目前,利用高时空分辨的等离子体诊断系统和数值模拟手段,真空环境中金属丝电爆炸的研究已在实验诊断、调控方法、理论模型等方面取得了许多重要研究成果。在介绍发展历史的基础上,主要针对真空环境中纳秒脉冲下金属单丝电爆炸的相关研究,描述了金属丝电爆炸的基本特性,总结了电参数和丝参数对电爆炸特性的影响规律,分析了提高金属丝中沉积能量以实现金属丝汽化的调控方法,并综述了数值模拟中电爆炸丝状态方程、输运参数和磁流体模型等的主要进展,最后指出了研究面临的挑战和未来发展的方向,对今后继续深入开展该领域的研究工作具有一定的借鉴意义。     

挤包高压直流电缆的质量控制:采用低频耐压试验检测电缆的关键缺陷(英文)

The main purpose of the work presented here is to evaluate different methods for quality control of polymeric insulated HVDC cables.The insight gained can be used to evaluate proposed test methods for quality assurance of long lengths of polymer insulated power cables.Laboratory experiments were performed using both Rogowski shaped test objects and model cables,insulated with XLPE containing imbedded spherically shaped particles.Tests were performed by stressing the test object with AC(50 Hz),VLF(0.1 Hz) and DC voltages and measuring time to breakdown at the different voltages.The slope of the voltage-time curve for 0.1 and 50 Hz were found to be parallel showing higher breakdown strength for 0.1 Hz than 50 Hz.The number of periods to breakdown is somewhat higher for 0.1 Hz than for 50 Hz.The breakdown strength for DC was much higher than for both AC 50 Hz and 0.1 Hz.The results indicate that the VLF test voltage needs to be 2 to 3 times higher than at 50 Hz power frequency in order to eliminate the same defects within a comparable time.     

A current-based model of the static synchronous series compensator (SSSC) for Newton–Raphson power flow

In this paper, a new approach to modeling a static synchronous series compensator (SSSC) for power-flow calculations by applying the Newton–Raphson method is presented. This new approach differs from known methods in terms of the interpretation of the device's branch. It is considered on the basis of its current and is therefore denoted as a current-based model of an SSSC. This approach might in principle be applicable also for other FACTS devices (i.e., UPFC, IPFC, GUPFC). In the paper, the current-based model of an SSSC is presented as the models of this device have difficulties with convergence in power-flow calculations and there are very few references covering these topics. First, the basic features of an SSSC are presented, as it is the basis for the current-based model that is incorporated into the Newton–Raphson load-flow model. The results of the tests at the IEEE 57-bus system are discussed in detail and compared with the existing injection SSSC load-flow model [X.P. Zhang, Advanced modeling of the multicontrol functional static synchronous series compensator (SSSC) in Newton power flow, IEEE Trans. Power Syst. 18 (November (4)) 2003].     

设备综合管理工程研究(Ⅰ)

本文作为设备综合管理工程研究的上篇,首先介绍设备综合管理工程的发展进程,大致分为事后维修阶段、预防维修阶段、生产维修阶段、维修预防阶段和全面综合管理阶段,之后阐述了设备综合管理工程的主要任务。     

低压电器的计算机辅助设计(Ⅰ)

综述了国内外低压电器计算机辅助设计(CAD)的发展动态,介绍了计算机在低压断路器、熔断器、接触器和电磁铁等特性计算和优化设计方面的应用,以及计算机交互式绘图功能在电器结构设计中所起的作用,提出了国内开展低压电器CAD工作的建议。     

空气中脉冲电压激励的表面微放电特性(英文)

The surface micro-discharge(SMD)excited by pulsed voltage in open air is experimentally studied by measuring its voltage,current,emission image,emission spectrum,and ultraviolet(UV)absorption spectrum.It is found that the SMD occurs intermittently in each cycle,and that it consists of many filaments on the surface of grounded electrode.While the applied voltage’s peak value Up increases from 1.75 kV to 7.25 kV,the discharge area keeps expanding until Up≈6 kV,when the discharge occupies all the available area.The emission spectrum of nitrogen metastable N2(C-B)and the density of ozone increase almost linearly.The ozone density decreases hyperbolically downstream of the grounded electrode due to the diffusion in open air.The characteristics of pulsed SMD are presented and analyzed as well,which may be referred by further investigations.     

电缆外护套环流分布在线监测系统的研制(英文)

The value of metal sheath’s circulating current of cross-linked power cables is very small in ideal condition, but the value is not so small that the circulating current can’t be ignored because of various factors in actual running condition. The circulating current method can judge whether the multipoint earthing fault happens by monitoring the variety of metal sheath’s circulating current value. This article introduces an on-line monitoring system which uses the circulating current method to monitor the multipoint earthing fault of the metal sheath. In the hardware layer, we use distributed current sensors and microcontroller’s acquisition units to complete the signal acquisition and signal conditioning of the circulating current value. After the distributed acquisition and conditioning, the signals, through the RS485 bus, will be sent to the Ethernet Serial Device Server network system and then connected to the console cabinet. The computer of the console cabinet could read the circulating current value on-line by the Real Com Mode of the Ethernet Serial Device Server. This distributed on-line monitoring system has a simple structure, excellent real-time performance and high reliability proved by the practical operation.     

平面电动机的发展现状(Ⅰ)

对国内外平面电动机的研究现状和应用情况进行了综述。平面电动机具有二维直接驱动的特点,作为可以实现高精度、高频响的平面定位装置,近年来受到广泛关注。文章对变磁阻型、感应型以及部分永磁型平面电动机的结构、原理和特点进行了归纳总结。     

2009年国外照明电器新进展(Ⅰ)

<正>SYLVANIA的CAPSYLITE ELOGIC系列推出了新款35WPAR38灯。该产品将电子线路集成在灯头内,其发光强度与60W卤素灯相似,而寿命是它的2倍。其光学性能优于所有其他的线电压PAR38卤素灯产品,而抗冲击和抗震动性能可媲美汽车前灯。(图1)     

2011年国外照明电器新进展(Ⅰ)

OSRAM SYLVANIA推出了OCTRON 800XP/XL系列T8灯产品,它们在使用程控快速启动镇流器、每12h启动一次时的额定寿命为62 000h;而其短开关周期的寿命也大幅提高,当使用占用传感器时,每30min启动一次的情况下寿     

Electrochemical behavior of the Ⅴ(Ⅳ)/Ⅴ(Ⅴ) couple in sulfuric acid medium

The electrochemical behavior of the Ⅴ(Ⅳ)/Ⅴ(Ⅴ) redox couple at a glassy carbon electrode was investigated. Cyclic voltammetry(CV) results indicated that electrode process of the Ⅴ(Ⅳ)/Ⅴ(Ⅴ) couple was electrochemically quasi-reversible with a rate constant of 8×10 -4 cm/S . Increasing concentration of sulfuric acid was electrochemically favourable for the Ⅴ(Ⅳ)/Ⅴ(Ⅴ)couple while elevated temperature was unfavourable for this system. Constant-current electrolysis results showed that current efficiency of more than 95 % could be achieved, which indicated that the Ⅴ(Ⅳ)/Ⅴ(Ⅴ) couple had excellent electrolytic performance and was suitable for the application as the anolyte of redox flow batteries.