The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper analyzes the generation adequacy of Mexico's National Interconnected Power System (MNIPS). The algorithm used computes loss of load expectation (LOLE) and loss of energy expectation (LOEE) indexes. These indexes are calculated through an analytical (recursive) method and are then compared with values recommended by the North American Electric Reliability Council (NERC). The period of study...
Technology of control command system (or instrumentation and control I&C equipment) has evolved dramatically during last 30 years from electromechanical relay, analog relay to digital relay. Then utilities have to maintain different type of devices. Risks linked to this fact are ageing effect on protection relays and technical life time of piece of equipment. After 20 years of use, manufacturers...
Spinning contingency reserve is idle capacity connected to the system to ensure reliable system operations in the case of equipment outages. The reserve has an economic value since it reduces the outage costs. In several electricity markets, reserve demand functions have been implemented to take into account the value of reserve in the market clearing process. These often take the form of a step-down...
This paper introduces a method for designing a standalone photovoltaic system to improve the load point reliability, extend the operation life, and minimize the design cost. This approach examines the impacts of solar panel sizes, tilt angles and battery volumes toward load point reliability, as well as the expected system life, by using real insolation data in a given location and random load burdens...
Wind is being recognized as an encouraging and cost effective generation source both in large grid connected systems and small isolated applications. The actual benefits obtained from utilizing wind energy for electric power generation can be investigated using reliability and economic evaluation techniques. The focus of these techniques is usually directed to the areas of reliability and the investment/operation...
This paper describes a probabilistic approach for assessing the criticality of bulk transmission system components in the de-regulated electricity market. The proposed method is based on the analysis performed by the Hydro One probabilistic composite system evaluation program and use of a simplified reliability model for the transmission system network. The method accounts for random failures of system...
This paper proposes a new design guideline for reliability improvement of distribution networks using distributed energy resource (DER). The proposed guideline is advised to maintain CDI values of all customers under a certain pre-defined threshold value. The impact of the switching devices failure on the reliability is also considered and proper corrections are made on various threshold values within...
There are two fundamentally different forms of uncertainty in power system reliability assessment. Aleatory uncertainty arises because the study system can potentially behave in many different ways. The component failure and repair processes are random and create variability known as aleatory uncertainty. There are also limitations in assessing the actual parameters of the key elements in a reliability...
Maintenance managers of today's electrical distribution systems are faced with the problem of where their maintenance resources will be utilized best. In previous work the authors have developed a method for maintenance policy optimization for electrical networks. This paper presents results from an application study performed for a distribution system, including both urban and rural parts, for this...
Value at Risk (VaR) is an appropriate method in financial world for evaluating risks. The method measures the losses within a considered time interval and a defined confidence level in actual currency. The simplicity and objectivity of VaR concludes to the idea to apply this method for power systems risk assessment. In this paper the methodology is applied for risk evaluation in the context of asset...
Sweden was re-regulated in 1996 followed by new laws and regulations. These new circumstances have become incentives to adopt more comprehensive and quantitative analysis methods applied on Electrical Distribution Systems (EDS). This paper provides a systematic presentation of the current risk management at a Distribution System Operator (DSO) as an integrated part of the net planning process. The...
Interruptions in the supply of electricity to customers are inevitable but it is important to measure, monitor and minimize the costs incurred. In this paper it is shown that customer interruption costs (CIC) depend on a variety of factors. They include the type of country and locality in which the interruptions occur. Actual costs depend on the types of appliances that are interrupted and the sectors...
This paper presents a new methodology for determining the optimal number of spare transformers (pole-mounted type) to be stored in regional centers of distribution companies, in order to balance reliability and cost criteria. The proposed method is based on chronological Monte Carlo simulation to evaluate reliability indices like probability, frequency and duration of failures in distribution systems...
This paper presents an evaluation technique incorporating the impact of the diversified demand side load shift on the system reliability and nodal reliabilities of restructured power systems. In this technique, demand and price correlations are represented using a demand-price elasticity matrix which consists of self/cross-elasticity coefficients. The diversity of customers is represented using different...
The original method of switchyard types optimization for transmission network (330 and 110 kV) is structured in the article reviewing the following aspects: 1) the principle of the method; 2) switchyard's reliability criteria; 3) algorithm of criteria calculation. This method and algorithm are appropriate for switchyard types optimization of transmission network, applying pilot technology LDM-T&G'08.
There is growing interest in designing and applying deterministic techniques that include probabilistic considerations in order to assess increased system stress due to the restructured electricity environment. The overall reliability framework proposed in this paper incorporates the deterministic N-1 criterion in a probabilistic framework, and results in the joint inclusion of both adequacy and static...
We propose in this paper a novel approach for identifying rare events that may endanger power system integrity. This approach is inspired by the rare-event simulation literature and, in particular, by the cross-entropy (CE) method for rare- event simulation. We propose a general framework for exploiting the CE method in the context of power system reliability evaluation, when a severity function defined...
The transmission system is becoming ever more complex. Furthermore, demand for reliable supply of electricity is growing, increasing the need for a higher level of system reliability. A solution might be to incorporate controllable power components within the system. One such component is the HVDC link. However, in the domain of reliability models for HVDC and the component's impact on the overall...
Reliable operation of power system is fundamental to the on-going industry reform. This paper presents the result of marginal power flow evaluation performed on Korean power system for planning mode. It uses two commercial software packages: physical and operational margins (POM V. 2.2) and probabilistic reliability assessment (PRA V. 3.1), respectively. The case studies of Korea power system for...
This paper introduces the characteristics of relationship between probabilistic reliability (LOLE; loss of load expectation) and deterministic reliability (SRR; supply reserve rate) for 2008 and 2010 years in Korea power system. Korea power system has been using the loss of load expectation criterion (0.5 days/year) to determine the adequacy of installed capacity (ICAP) requirement. The criterion...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.