Hierarchical decentralized autonomous control in super‐distributed energy systems

This paper deals with a decentralized autonomous control strategy of a super‐distributed energy system with a hierarchical structure in order to reduce the complexity of control. In this paper, distribution systems are assumed to be composed of multiple small‐scale power systems in which many customers with dispersed generators exist. A small‐scale power system can be considered as a unit with a generator state and a load state, or as a customer with dispersed generators. Control components of small‐scale power systems are interconnected with each other and are used to operate distribution systems. An expanded decentralized autonomous control method for a super‐distributed energy system with a hierarchical structure is proposed on the basis of the Hopfield neural network. It is demonstrated that super‐distributed energy systems with a hierarchical structure can be controlled autonomously by applying the proposed method. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Forecasting electric power generation in a photovoltaic power system for an energy network

Recently, there has been an increase in concern about the global environment. Interest is growing in developing an energy network by which new energy systems such as photovoltaic and fuel cells generate power locally and electrical power and heat are controlled with a communication network. We developed the power generation forecast method for photovoltaic power systems in an energy network. The method makes use of weather information and regression analysis. We carried out forecasting power output of the photovoltaic power system installed in Expo 2005, Aichi Japan. As a result of comparing measurements with prediction values, the average prediction error per day was about 26% of the measured power. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 16–23, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20755     

Embedding sensitivity theory in ordinal optimization for decentralized optimal power flow control

In this paper, the decentralized optimal power flow with continuous and discrete control variables problem is firstly formulated as a NP-hard optimization problem - Block Additive constrained with Continuous and Discrete variables (BACD) problem. Secondly, an algorithm of embedding sensitivity theory (ST) in ordinal optimization (OO), abbreviated as STOO, is proposed for solving this NP-hard optimization problem. The STOO algorithm consists of three stages and three models of performance evaluation. The proposed method not only copes with the computational complexity due to huge solution space but also obtains a good enough solution with high probability guaranteed by the OO theory. Finally, this work demonstrates the computational efficiency of the STOO algorithm via various tests on the IEEE 118-bus and 244-bus systems partitioned into four subsystems using a 4-PC network and compares the results with those obtained using other heuristic methods, Genetic Algorithm, Tabu Search, Ant Colony Optimization and Simulated Annealing. Test results show the validity, robustness and excellent computational efficiency of the STOO algorithm for obtaining a good enough solution.     

电网电能量计量系统设计的探讨

从电网电能计量系统的特点出发,分析了电能量计量系统的功能目标和设计原则,提出了电能量计量系统体系结构的设计思路及系统就必备的功能指标。并根据电网的不同规模,提出了电能量计量系统的设计方案,这对于各地电能量计量系统的建设具有一定的意义。     

Experiment of an electric water heater with autonomous frequency regulation

Integration of wind power generation into power systems has been limited because of the problem of frequency regulation during light‐load periods at night in some areas in Japan. As a solution, autonomous frequency regulation by electric water heaters (EWHs) has been proposed. A control board to control the power consumption of an EWH is fabricated. It measures both the power system frequency and thermal energy stored in a hot‐water tank, and then turns on/off a heating element according to a control algorithm. It is confirmed that the board can measure power system frequency every 1 s with a resolution of better than 0.01 Hz and that it can measure the vertical temperature distribution in the storage tank with an acceptable accuracy to calculate the future power consumption ratio, which is a parameter that decides the turn on/off of the heating element while considering end‐user comfort. Then, an EWH with autonomous frequency regulation is fabricated by embedding the board, and the EWH is operated to investigate the performance. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电网降损技术的探讨

针对电网用电量迅猛增长带来的电能利用率和效益问题,阐述了电力网电能损耗构成、电力网的线损及其降损主要途径.结合电能实际使用情况,提出了新技术和新设备降低电能损耗的方法,有效地提高了电网负荷率、降低了线损.     

建设先进高效、安全可靠的电力信息网

电力市场的兴起以及电网建设的进一步发展，使得传统的电力系统业务发生了变化，电力信息化迫在眉睫。建立一个先进高效、安全可靠的电力通信网络，能够整合现有的办公自动化(OA)、MIS系统、电力市场和营销系统、电力调动系统(EMS)、配电管理系统(DMS)和呼叫中心(Call Center)各种业务的需求，同时面向未来，支持更多的用户、更大的宽带以及新业务的需求。     

Basic concept and decentralized autonomous control of super‐distributed energy systems

New small‐scale dispersed generation systems, such as fuel cells and micro gas turbines, have made remarkable advances lately and they will be applied practically in the near future. Although a large number of researches on the introduction of small‐scale dispersed generation systems have been carried out, only a small number of small‐scale dispersed generation systems are considered in these researches. Therefore, little is known about problems to be solved when a large number of small‐scale dispersed generation systems are introduced into electric power systems. This paper deals with a super‐distributed energy system that consists of a great number of dispersed generation systems such as fuel cells, micro gas turbines, and so on. The behavior of a customer with a dispersed generation system is simulated as the Ising model in statistical mechanics. The necessity of a distribution network in super‐distributed energy systems is discussed based on the Ising model. The feasibility of decentralized autonomous control using vicinity information is also investigated on the basis of stability analysis of the Hopfield neural network model. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(1): 43–55, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10368     

甘肃电力通信网的建设

总结了近年来甘肃电力通信网的基本情况和发展经验，认为通信尚不发达的地区在建设光纤通信电路的同时，应因地制宜地对现有微波通信电路进行改造，形成双路由的保护电路，是非常必要的。文章提出了在建设传输网络时，应不断完善通信各应用子系统的建议。     

粒子群-神经网络混合算法在短期电价预测中的应用

为了提高电力市场环境下的电价预测精度,在研究短期电价预测中采用了粒子群和反向传播神经网络相结合的混合算法,先利用粒子群算法确定初值,再采用神经网络完成给定精度的学习.对我国四川电网电价进行预测的结果表明,粒子群优化的神经网络算法收敛速度快于神经网络算法,预报精度显著提高,平均百分比误差可控制在2%以内,平均绝对误差最大值为1.87￥/MWh.该算法可有效用于电力系统的短期电价预测.     

浙江电力调度通信网的组建

重点介绍浙江省电力调度交换网的概况，简述关键技术问题的解决方案和网络优越性。     

基于电网影响因子的电力通信网关键节点识别

作为电力系统的通信专网,电力通信网具有明显的行业特点。为准确识别网络关键节点,从电力通信网与电网的特殊关系分析节点的重要性,提出电网影响因子的概念。根据节点所处的站点在电网中的地位及作用,即站点类别因素和负荷因素两方面评价节点权重。然后利用电网影响因子,并结合所定义的聚合系数指标,分析电力通信网中重要节点的分布密集状况,得到各节点在网络拓扑中的相对重要性。仿真表明,相对于现有其他算法,该算法能够更好地结合电力通信网的应用特点区分网络拓扑中节点位置相似的节点的重要性,在电力通信网运行风险分析中具有较大的参考价值。     

电力系统网络安全体系研究

随着电力行业信息化的不断发展,信息安全面临日益严峻的考验。结合电力系统网络环境,分析了威胁电力系统网络安全的四个主要来源,依此给出了一套电力系统安全体系总体设计及解决方案,为电力系统网络安全体系建设提供了可参考的理论和实践依据。     

A new electric power network for effective transportation of small power of dispersed generation plants

This paper proposes a new electric power network that makes it possible for many types of dispersed generation plants owned by nonutility organizations to participate in an electric power market without the disadvantages of existing power utility and customers. This power network is called an open electric energy network (OEEN) because the network is open to the many types of plants for the participation. For achieving such openness, electric power storage devices, load controller at each customer and data communication network are installed in OEEN; the flow of excess electric power generated by each plant is controlled autonomously and in a distributed way. That is, the control is done by transmitting the data on excess electric power such as generation and demand point, power quality, price, etc., from each dispersed generation plant to the power storage devices and the load controllers through the communication network. Since this data-driven power flow control is similar to the mail system for a packet with the addresses of sender and receiver, it is called packet electric power transportation. In OEEN the storage device plays a different role from load leveling. Therefore, the way to determine the storage capacity differs from the conventional approach. In this paper, the applicability of queuing theory for determining the capacity is also discussed.     

对在电力交换网中扩展智能网业务的展望

介绍电力交换网的发展，概述智能网的原理和结构，展望智能网技术在电力通信中的应用。     

简析宁夏电力设施被盗严重的原因及其对策

论述了宁夏电力设施被盗的严重现状,分析了造成电力设施被盗严重的原因,提出了加强电力设施保护、确保电网的安全运行的对策.     

电力通信网宽带接入技术的探讨

介绍了ITU的接入网规范,还详细介绍了光纤接入、混合光纤同轴、数字用户线和宽带无线技术,最后还对它们在电力通信网中的应用进行了探讨。     

探讨电网中调峰电源的设置

目前,我国电网削峰填谷的任务日趋繁重,选择合理的调峰方式已成为需要认真探讨的一个问题,采用调峰改造的火电机组和建设一批大容量的联合循环机组作为调峰方式,能够取得良好效果.300 MW机组调峰改造投资省、见效快,而大容量联合循环机组具有优越的调峰性能,是电网调峰电源的最佳选择之一（气源充足、有保障的地区）.在机组参与电网调峰运行工况下,应关注机组的寿命损耗和电厂获得的经济效益.     

利用电力企业内部网开展网络教学初探

鉴于目前企业内部网的功能主要集中在办公自动化、信息传播等方面,而利用其开展教学培训较少的现状,通过对网络教学的主要形式及其特点的分析比较,论述了利用现有的电力企业内部网开展网络教学的过程,并对其优越性和局限性作了简单介绍,同时指出电力企业建立网络教学势在必行.