Power flow tracing based transmission congestion pricing in deregulated power markets

The objective of this paper is to propose a simple transmission congestion pricing scheme based on tracing principle by considering generator fixed cost, cost for incurring loss and transmission congestion cost. Restructuring has brought about considerable changes by the virtue of which electricity is now a commodity and has converted into deregulated type. Such a competitive market has paved way for innumerable participants. This concept of restructuring has led to overloading of transmission lines. In this paper, power flow tracing has been employed by using suitable optimization algorithm, where the real power generation has been maximized. Congestion in the transmission line has been produced in a new fashion by maximizing the real power demand. The power flow under normal operating condition and congestion is determined and hence the difference in power flow is estimated. Based on the estimated power flow difference, the transmission line congestion cost is computed. Pool model and bilateral model has been considered in simulation study to introduce the concept of deregulation. The proposed method is tested and validated on Modified IEEE 30 bus test system and Indian utility 69 bus test system.     

市场条件下输配电网规划新的思路与方法探讨

概括介绍了市场条件下输配电网规划思路的转变及其所面临的不确定性因素,然后具体探讨了市场条件下输配电网规划的新思路与新方法,介绍了不确定条件下输电网的投资决策和负荷不确定性条件下城市配电网的规划.     

Evaluation of electric power procurement strategies by stochastic dynamic programming

In deregulated electricity markets, the role of a distribution company is to purchase electricity from the wholesale electricity market at randomly fluctuating prices and to provide it to its customers at a given fixed price. Therefore, the company has to take risk stemming from the uncertainties of electricity prices and/or demand fluctuation instead of the customers. The way to avoid the risk is to make a bilateral contract with generating companies or install its own power generation facility. This entails the necessity to develop a certain method to make an optimal strategy for electric power procurement. In such a circumstance, this research proposes a mathematical method based on stochastic dynamic programming and considers the characteristics of the start‐up cost of an electric power generation facility to evaluate strategies of combination of the bilateral contract and power auto‐generation with its own facility for procuring electric power in a deregulated electricity market. In the beginning we proposed two approaches to solve the stochastic dynamic programming, and they are a Monte Carlo simulation method and a finite difference method to derive the solution of a partial differential equation of the total procurement cost of electric power. Finally we discussed the influences of the prime uncertainty on optimal strategies of power procurement. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(2): 20–29, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20296     

Impact of energy storage system on load frequency control for diverse sources of interconnected power system in deregulated power environment

This paper focuses Load Frequency Control (LFC) mechanism for multi-generating two areas interconnected power systems with energy storage system in a deregulated power environment. The two areas, demarcated as Area-I and Area-II, consist of thermal, hydro and gas power units. This paper also incorporates the economic load dispatch mechanism into the LFC for economical division of load during load deviation. Small signal stability analysis through participating factor has also been done to determine the oscillation state of the system, i.e., frequency deviation in both areas. Therefore, proper controller is required to reduce the oscillation of the system. The optimum value of the integral gain of the integral controller has to be selected to achieve the goal. Hence, Opposition-based Harmonic Search (OHS) technique is used for the optimization purpose. During major disturbance in the areas, primary and secondary controllers are not sufficient to reduce the frequency and tie-line power oscillation due to slow response of the governor mechanism. Therefore, energy storage system, i.e., Redox Flow Battery (RFB), is used for improvement of the dynamic response of the system which has very small time constant and quick response. The proposed control mechanism has been analyzed in a deregulated power environment with the help of different simulation case studies to find out improved dynamic performance over integral control strategies.     

A stochastic game approach for modeling wholesale energy bidding in deregulated power markets

It has been noted in a recent report (Dec. 2002) from the General Accounting Office of the U.S. that "various design flaws in wholesale markets and transmission services have created operational problems within and between wholesale markets." This paper presents a novel methodology to analyze and design the wholesale energy bidding aspect of a deregulated power market. We adopt a system-wide approach that considers many of the relevant features including transmission congestion. We develop a two-stage model: 1) a nonzero sum stochastic game with average reward for the wholesale energy market operation, and 2) a nonlinear programming (NLP) model for the unit-commitment (UC) and the optimal power-flow aspects. The solution approach for the two-stage model is based on a reinforcement-learning (RL) algorithm, which is designed to obtain Nash equilibrium policies. We use a three-retailer/three-supplier power network with and without congestion to test and benchmark our methodology.     

Hybrid Neuro Fuzzy approach for automatic generation control in restructured power system

In this paper, a hybrid combination of Neuro and Fuzzy is proposed as a controller to solve the Automatic Generation Control (AGC) problem in a restructured power system that operates under deregulation pedestal on the bilateral policy. In each control area, the effects of the possible contracts are treated as a set of new input signal in a modified traditional dynamical model. The prominent advantage of this strategy is its high insensitivity to large load changes and disturbances in the presence of plant parameter discrepancy and system nonlinearities. This newly developed strategy leads to a flexible controller with a simple structure that is easy to implement and consequently it can be constructive for the real world power system. The proposed method is tested on a three-area hydro-thermal power system in consideration with Generation Rate Constraint (GRC) for different contracted scenarios under diverse operating conditions. The results of the proposed controller are evaluated with the Hybrid Particle Swarm Optimisation (HCPSO), Real Coded Genetic Algorithm (RCGA) and Artificial Neural Network (ANN) controllers to illustrate its robust performance.     

竞争性电力市场环境下可再生能源发电的国际发展经验和对我国的启示

以西班牙、德国及英国等欧洲国家为例,介绍在开放的竞争性电力市场环境下,通过建立特殊的政策和机制来促进可再生能源发电发展的国际经验,并对一些典型的政策进行归纳,对这些政策的实施效果及对我国的适用性进行分析。提出应建立保证可再生能源上网优先、全部上网和获得合理电价的政策体系,通过将发展可再生能源作为电力企业的强制义务等形式,可起到鼓励可再生能源发电市场发展、带动技术进步和产业发展的效果。我国应吸收国外的成功经验,在进一步推进电力体制改革的同时,完善可再生能源发电的上网、标准及价格等政策体系。     

电力市场操纵力问题探析

分析电力工业改革重组后电力市场操纵力依然存在的基础，探讨测度电力市场操纵力的方向，并介绍世界主要国家电力改革后市场操纵力的实证分析结果。揭示出电力市场操纵力这个在上世纪电力监管要克服的核心问题，仅仅依靠电力工业的按环节拆分重组，并不能从根本上改变其存在与实施的基础。随着我国电力体制改革的推进和电力市场的建立，必须有针对性地制定一系列抑制和消除市场操纵力的政策措施，以全面实现电力体制改革的目标。     

A new Cumulative Gravitational Search algorithm for optimal placement of FACT device to minimize system loss in the deregulated electrical power environment

The optimized position of placing FACT device in an industrial zone is a challenging task. If the FACT device is perfectly placed, the reactive power losses can be controlled within a limit and can improve the real power flow in the power system network. Many algorithms have been developed in the recent years using Swarm intelligence, Genetic algorithm, Honey Bee search and fish schooling algorithms. Gravitational search algorithm based on Newtonian law of gravity between masses is used to find the minimum value accurately. In Opposition based GSA (OGSA) instead of considering both active and passive masses, the passive mass alone is considered which is equivalent to reactive power force component. The active force is not considered. The resultant force obtained is less accurate. But in Cumulative Gravitational Search Algorithm (CGSA) active and passive mass interactions are together considered so the resultant force obtained between the masses will be effectively taken into account. Two different mass inertia, namely active mass and passive mass are applied in CGSA, and exact results can be found. In this algorithm, the search agents are a collection of masses which interacts with each other based on Newtonian gravity and laws of motion. In this research, 72 bus southern grid system and a 16 bus real time industrial zone are tested by conventional method, modeled using MATLAB/Simulink and by using the proposed CGSA. The optimized place to connect the FACT device is found and compared with conventional and modeling method.     

A fast market splitting matching method for the spot electric power market

A fast, innovative matching method for the spot power market, considering network constraints, has been developed. In this method, buy and sell order bids are respectively divided into the aggregated volume of several band prices. Then, the aggregated volume and the center of each band price are used to calculate an index band clearing price, which contains the real clearing price. The division and calculation process is iterated until the band price is less than the tick size of the bidding price. This method is applied to a real problem in the Japan power market, with 9 bidding areas, 10 area‐connecting lines, and 9000 orders (volume/price pairs). Numerical simulation results show that the new method is ten times faster than conventional linear programming, demonstrating the effectiveness of this method. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(4): 21–29, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20694     

Two-stage optimization algorithm for short-term reactive power planning based on zonal approach

There are various methods for procurement of reactive power as an ancillary service in deregulated market environment. Reactive power market model based on voltage control zones and two-step optimal power flow algorithm is proposed in this paper. Zones are formed by splitting the power system or a control area of an interconnected power system into autonomous voltage sub-areas with sufficient reactive power reserves using the electrical distance method. Every zone formes a single reactive power market. First step of an optimization algorithm determines zonal reactive power prices based on generator's cost functions for reactive power production. Total cost minimization is the goal of the second optimization step where the final dispatching decision is made according to transmission losses and zonal reactive power prices respecting power system planned conditions and security constraints. Proposed algorithm is tested on IEEE 39 bus test system ensuring the system operator's minimal payment for reactive power and transmission losses, without jeopardizing power system security.     

竞争性电力市场环境下的频率控制研究

电力系统的安全运行要求对系统频率进行控制,而系统的动态和惯性特性都随着系统频率控制的结果发生变化.在竞争性电力市场环境下,要求所采用的频率控制方法能够实现电网安全运行和可靠供电以及电力市场的经济目标相协调.随着电力系统规模的扩大,各发电厂在电力系统中的地理位置相距较远,在进行经济分配时,则必须考虑电厂间输电线传送功率所带来的网络中的有功功率损耗.本文研究了计及网损和频率变化率约束条件的有功功率经济分配的算法,提出了一种实用有效的频率控制方法并对边际成本进行了分析.     

金融危机背景下电力市场发电侧挑战与机遇

从中国电力市场的发展现状入手,深入分析了当前电力体制和经济环境下发电侧所面临的电力需求下降和产能过剩的问题,最后提出了解决方法和建议.     

对"十一五"规划中电力通信业务发展的几点思考

电力通信专业所面临的业务分流、队伍知识老化、规范管理难以纳入企业主流专业管理模式等问题,是造成通信专业可能不断被边缘化的因素,建议通信“十一五”规划中应该突出专业规范化、标准化建设,同时做好主流业务向IP技术发展的规划工作,提前引导维护人员做好知识储备,顺利实现人员的技术转型,从管理、技术、队伍3方面的建设提高专业地位,使通信专业发挥更大作用。     

我国电力工业发展规划问题

在总结“十五”电力工业发展的基础上，提出了2006-2020年电力发展规划设想。共分5个部分：简要分析了“十五”电力工业发展中的10个主要问题；预测了2006-2020年发电量，2010年为3400TW-h．2020年5280TW-h；提出了电力工业发展战略，2010年全国需发电装机754Gw，2020年约需1160GW；分析研究了水电、火电、核电、天然气发电、可再生能源发电的发展战略及发电量、发电装机容量构成；针对电网发展，概述我国六大区域电网，西电东送、特高压交直流输电及全国联网的发展情况；针对今后电力工业发展中的7个问题提出了建议。     

Probabilistic reactive power procurement in hybrid electricity markets with uncertain loads

This paper presents a novel probabilistic algorithm for optimal reactive power provision in hybrid electricity markets. The proposed algorithm is a six-stage multiobjective nonlinear constrained optimization problem which takes into account load forecasting inaccuracies. Considering a set of probable forecasted loads, a three-component expected total market payment function is suggested being minimized as cost function of the first stage. Besides economic issues, expected voltage security margin, deviation from multilateral and pool based energy transactions, deviation from spinning reserve contracts, having adequate local reactive power reserve in each voltage control area of the system and transmission congestion probability are well thought out in stages 2-5 as technical aspects of the market. Finally, in the last stage, using different weighting factors to compromise between all objects, a probabilistic multiobjective function is presented to find the best reactive power market schedule. The proposed algorithm is applied on IEEE 24-bus test system. As a benchmark, Monte Carlo Simulation method is utilized to simulate the market of given period of time to evaluate results of the proposed algorithm, and satisfactory results are achieved.     

Stabilizer design for multimachine power systems using mathematical programming

The problem of tuning of stabilizers in multimachine power systems has been formulated both as a quadratic and a linear programming problem. The objective is to shift the lightly damped poles associated to the system mechanical modes. The structure of the transfer function of the stabilizers has been chosen a priori, being the optimization performed with respect to its free coefficients. A usual phase lead characteristic has been included in the constraints. Numerical results are presented for a three-machine power system.     

基于多Agent的区域电力市场辅助决策系统开发

将Agent技术引入区域电力市场辅助决策系统的研究,提出了基于多Agent的区域电力市场辅助决策系统的结构和设计方案.将区域电力市场辅助决策系统设计为数据搜集Agent、系统管理Agent、预测分析Agent和人机界面Agent的多Agent系统,对各个Agent模块的功能和结构进行了详细介绍,并阐述了该系统的工作原理和运行特点.     

Periodic overhaul planning system for electric power plants

Periodic overhaul planning for boilers and turbines in electric power plants has been done based on expert experience in order to satisfy various constraints that are hard to formalize, such as legal regulations, the overhaul interval restriction between units, the adjustment strategy in the case of including special events, the daily electric power requirement, and so forth. Although computer processing using the knowledge base approach has been tried, it does not lead to good results because of excessive hardware requirements, low performance, and no assurance of optimality. A two‐step approach is proposed based on the categorization of constraints that are hard to formalize into “strong constraints” and “weak constraints.” It replaces the nonlinear integer programming problem corresponding to “strong constraints” by a combination of integer programming and combinatorial analysis. Consequently, it can lead to optimal solution in terms of fuzzy satisfaction measures within an allowable time with a PC. © 1999 Scripta Technica, Electr Eng Jpn, 127(2): 24–31, 1999     

我国现阶段电力综合资源规划的实施机制研究

分析了我国高速经济发展所面临的能源危机与环保压力,提出综合资源规划是解决我国电力供应问题的最有效手段.借鉴国外综合资源规划的实践经验,并基于我国国情,研究提出了我国新形势下综合资源 -规划的实施主体、总体模式和组织体系,为综合资源规划在我国现阶段的实施提供决策参考.