地市级供电企业电力市场开发功能建设浅议

市场开发对于地市级供电企业实现“竞争性生存、可持续发展”具有重要意义。对当前地市级供电企业市场开发的工作现状进行分析，提出应按照专业化、集约化和制度化的要求，不断完善市场开发的信息、计划、实施和控制系统的功能建设并进而建立规范化运作的工作团队；有效集约信息，实施市场开发的全过程管理；落实配套措施，实现开发工作制度化。结合实践说明建立市场开发的常态运行机制既是必须的，也是可行的。     

供电企业如何实现服务角色转变

供电企业实现服务角色的转变，满足客户的需要；激活客户购买欲望；用科技服务手段，建立大服务格局。做好优质服务是发展电力经济的一项紧迫要求。     

当前电力营销环境分析及建议

从生产、销售、使用等方面介绍了电力产品的特点，分析了电力营销的内、外部环境，提出了对电力营销的建议；企业最高决策层主导实施战略营销；以服务创新为载体，突出客户需求导向；整合资源，制定组合营销策略。     

高井发电厂的EAM实施之路

宏观经济环境的变化，使得电力企业必须挖掘内部潜力，向市场要资源、要效益，必须从政策的保护伞下走向市场，必须完成自身管理、技术等种种变革。国家电力公司为电力企业制定的基本改革思路是“打破垄断、引入竞争、提高效率、降低电价、发送服务、促进发展”。基于这种思路，许多电力企业为改革制定了目标：（1）加强生产管理，降低发电成本，实现“竞价上网”；（2）生产与需求直接对应，努力提高资金回报，实现电厂经济效益最优；（3）规模经营产业规模效益；（4）做好企业内部建设，提高办公效率。正是在这样的背景下，高井电厂借EAM（企业资产管理）系统，为企业保驾护航。     

供电企业面临的民事赔偿问题的探讨

正确处理好供用电双方的民事法律关系，是供电企业开展正常经营活动的需要，针对供电企业民事赔偿案件逐步增多这一问题，章提出：就明确供电企业与用户的民事关系；营造良好的法律环境，提高依法维护供电企业权利的能力；搞好安全生产，积极防范和化解安全风险；分清行政责任和民事责任，减少供电企业的诉讼。     

电量竞价上网对发电企业的影响及对策

文中指出发电企业要想提高电能竞价上网的能力，就要从改进报价策略，降低公司运营成本着手，确保企业利益最大化。     

规范电力计量服务企业发展—试谈如何搞好供电企业的计量管理工作

本文立足于当前电力计量发展的实际，从贯彻《计量法》入手，阐述了如何摆正电力计量，确保电力公正，服务企业发展的问题。     

电力营销辅助决策支持系统的研究设计

随着电力改革的深入和买方市场的形成，研究市场、开拓市场、最大限度增供扩销正逐渐成为电力企业的的工作中心。智能化的企业营销管理系统，能够采用基于数据仓库的知识发现技术，通过对企业营销、收益、电信网络应用、客户消费行为和倾向．促销行为等各营销层面的分析和挖掘，发现企业营销运做的内在规律和趋势，发现企业资源利用的规律，从而客观地指导企业决策者进行决策，实现企业营销管理的智能化。在这一过程中，电力营销辅助决策系统的重要性已显得日渐突出。     

探索建立电力优质服务常态运行机制

建立电力优质服务常态运行机制，将优质服务工作经常化、制度化，纳入企业日常工作的范畴。优质服务进入常态运行，首先要确立社会营销观念，平衡公司利润、消费需求满足和公共利益三之间的关系。其次要建立包括运行、保障、考核监督和奖惩机制在内的优质服务常态运行工作机制，通过与服务相关的每个岗位、每个环节的规范化运作来确保电力企业整体服务水平的提高。建立优质服务常态运行机制，既是必须的，也是可行的。     

中国电力通信必须适应电力市场发展的需要--兼谈信息通信产业与电力工业的相互依存性及相关技术

论述信息通信产业与现代电力工业的相互依存性和相关性。指出信息通信技术是电力工业现代化的重要技术基础；现代信息产业又要求电力工业提供可靠性更高、动态质量更优的电能。强调在电力工业管理体制和实现电力市场化的改革中，信息通信技术对电网安全更具重要现实意义。对涉及电力系统安全的通信网也应实行“统一调度、分级管理”的原则，防止“厂网分开，通信网分裂”局面的出现。提出在21世纪，委做好电力调度和电力系统自动化工作，确保现代电网的安全可靠运行，必须建设一个统一的、宽带的、综合的电力通信业务平台；从事于电力系统调度运行、电力系统自动化和电力系统信息通信的专业人员也必须掌握电力市场和信息通信的相关理论和技术。     

The impact of large steel mill loads on power generating units

Large steel mills can be potentially harsh loads on an electric power system, producing harmonic currents and unbalanced system loading. Since these large loads are typically supplied from the EHV power system grid, it must be recognized that not only will the system of the host utility be impacted, but neighboring utility systems could be impacted as well. Existing IEEE Standard 519-1992, IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, does not fully address the interharmonic problems generated by steel mill loads. This paper identifies the limits of existing unit protection schemes to detect the potentially damaging impacts which large mill loads can have on nearby power generating units. Preoperational studies are needed to assess the impact of the mill on the power system, followed by field tests to verify the study results. Potential mitigation schemes to protect generating units are identified. Issues are discussed from both a utility and mill perspective. Additionally, the paper provides information needed by both the utility protection engineer and the mill's operators during initial planning discussions prior to operation     

电力用户电压暂降问题分析与仿真

电压暂降事件给用户带来巨大的经济损失.全面分析用户的电压暂降事件,得出导致用户电压质量问题的原因,从而获得解决用户电压暂降问题的方法.分析用户电压暂降事件的类型、地点、发生时间和与天气的关系,并与供电局调度记录对比,以了解用户面I临的主要电压问题和产生的原因.通过建立用户的供电模型,对各种故障情况进行仿真分析,获得不同故障地点对用户电压的影响程度,指出供电区域内的输电网故障是引发用户电压质量事件的主要原因,并分析区域内的薄弱环节,有针对性地为解决用户电压暂降问题和提高用户供电质量提供决策依据.     

Interpreting recent power quality surveys to define the electricalenvironment

Recent AC power line monitoring projects have enabled a better understanding of the typical electrical environment within which sensitive electronic equipment must be able to operate. Voltage variations caused by utility protective and regulation devices, as well as variations caused by load equipment, contribute to the total power quality picture. Regardless of the origin of these variations, the load equipment must be able to operate with some degree of immunity. This paper presents a combined assessment of data from three of the most recent power quality surveys. Results of this assessment suggest that load equipment with reasonable voltage regulation and interruption ride-through will withstand the majority of recorded power line variations. A detailed analysis of monitor capabilities and limitations is presented, along with a discussion of the interpretation of power line variations recorded at different monitoring locations     

Power system compatibility with industrial process equipment

Who has the responsibility of preventing power quality induced downtime for industrial process equipment? Some say the electric utility should provide power free from abnormal variations. Others have said that manufacturers must build equipment that can tolerate any electrical disturbance. Perhaps users should design or specify their industrial systems to be insensitive to power variation. This article presents an overview of a panel of representatives from each of these groups discussing the answer to this question     

Power Supplies for the Electrochemical Industry- An Economic and Performance Comparison Between Diodes and Thyristors

The rectifier system is one of the key components that make up an electrochemical plant. It must be reliable, economic, and perform to meet both the process requirements and utility regulations. Thyristor. and diode equipment is compared in relation to economy, reliability, efficiency, power factor, and harmonic generation. The aim is to assist electrochemical plant engineer who has the responsibility of writing an equipment specification.     

Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces

Power usage in ultrahigh-powered electric arc furnaces requires considerably more investigation into system parameters, furnace secondary circuit analysis, and operating characteristics than previously given to normal powered electric arc furnaces. The power input must be analyzed from the infinite electric utility bus to the arc at the electrode. All interested parties must participate in the analysis to assure a mutual understanding of each other's problems. Various high-voltage systems are compared along with power factor correction applications. An 18-ft (5.5-m) 80-ton (72.6-metric tons (MT)) furnace has been selected for detailed analysis with a 50-MVA furnace transformer. In addition to electrical considerations, the power melting profile and associated refractory erosion is also subjected to analysis in this review. The analysis indicates that with proper application, ultrahigh-powered electric arc furnaces will provide increased production with reasonable refractory erosion.     

Power generation confirmation of induction motors and influence on islanding detection devices

Photovoltaic generation systems must have protection devices and islanding detection devices if they are connected to utility lines of the electric power company. This is regulated in national technological requirement guidelines and the electric equipment technology standards. Islanding detection devices are installed to detect blackouts due to events such as ground faults and short circuits in utility lines. When an islanding detection device detects a power blackout, the photovoltaic generation system must be stopped immediately. It is known that islanding detection devices cannot detect islanding if induction motors are present among the loads. We investigated the influence of induction motors on islanding detection devices and found that when the frequency decreases after a utility line failure, induction motors change over to generator mode, thus compensating the active power imbalance and suppressing voltage variation. In addition, if the postfault frequency is adjusted by PLL control so as to maintain a fixed power factor, induction motors suppress this frequency change, thus extending islanding operation. It is clear from the above results that induction motors are more likely to produce islanding phenomena than static loads. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(4): 8–18, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20962     

风力发电对电力系统的影响

风力发电依赖于气象条件,并逐渐以大型风电场的形式并入电网,给电网带来各种影响。电网并未专门设计用来接入风电,因此如果要保持现有的电力供应标准,不可避免地需要进行一些相应的调整。讨论了在风电场并网时遇到的各种问题。由于风力发电具有大容量、动态和随机的特性,它给电力系统的有功/无功潮流、电压、系统稳定性、电能质量、短路容量、系统备用、频率和保护等方面带来影响。针对这些问题提出了相应的解决建议和措施,以期更好利用风力发电。     

Optimal reactive power control for industrial power networks

In addition to process steam and real power demands, manufacturing processes also have a varying reactive power demand that must be satisfied. Reactive power affects line currents and bus voltages, as well as power factor of the tie-line bringing power into the industrial plant from the local utility. The local utility applies a penalty if the tie-line power demand exceeds an agreed value and often imposes a low power factor penalty as well. Stable system operation requires that bus voltages are maintained within assigned limits, that transformers and connecting cables do not become overloaded, and that generators and synchronous motors run within their reactive capabilities. There can be many acceptable combinations of the settings of generator and synchronous motor excitations, of transformer taps and capacitor banks, all of which lie within the set of electrical system constraints. There are so many variables to manipulate that is very difficult for an operator to make optimal decisions, even under steady-state conditions. It is an even more complicated task during system upsets. This paper discusses a program that runs on a plant's distributed control system that resolves alternatives and presents to the operator the best combination of settings for implementation. The program can be adopted for direct online implementation. The paper discusses cases of three plants where online implementations have been employed     

Power imbalance application region method for distributed synchronous generator anti-islanding protection design and evaluation

This paper presents a novel graphical approach to adjust and evaluate frequency-based relays employed in anti-islanding protection schemes of distributed synchronous generators, in order to meet the anti-islanding and abnormal frequency variation requirements, simultaneously. The proposed method defines a region in the power mismatch space, inside which the relay non-detection zone should be located, if the above-mentioned requirements must be met. Such region is called power imbalance application region. Results show that this method can help protection engineers to adjust frequency-based relays to improve the anti-islanding capability and to minimize false operation occurrences, keeping the abnormal frequency variation utility requirements satisfied. Moreover, the proposed method can be employed to coordinate different types of frequency-based relays, aiming at improving overall performance of the distributed generator frequency protection scheme.