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In this paper, a systematic risk-based transmission line expansion approach is studied. The approach addresses three objectives: load-driven expansion, security-enhancement expansion and risk-based expansion. The first problem identifies transmission expansions necessary to correct inadequacy; the second problem identifies transmission expansion necessary to correct insecurity; the third problem balances...
In order to schedule the choice of maintaining or refurbishing MV equipment, an electrical utility may study ageing effects on different pieces of such equipment. In this paper, the analysis is based on record of outages (MV power cuts) during several years where causes of outages are noticed (and ages of pieces of equipment are also known). Failure rate versus age estimation results are given for...
This paper discusses a number of aspects of operational-risk assessment of transmission systems, operational-risk assessment uses techniques developed from reliability analysis to predict the performance of the transmission system during a short period of time (several hours) starting from a well-defined operational state. The influence of weather parameters on the momentary failure rate and the operational...
A Power System Stabilizer (PSS) is one of the most widely used power system controllers to enhance the stability of the power systems. In this paper, a new optimization technique for tuning PSSs in multi machine power system is presented. It is used to tune five PSSs in a 39-Bus IEEE New England network to enhance the small signal stability. The technique used is based on Low Discrepancy Sequence...
The latest political initiatives on energy saving are forcing distributors to implement actions that increase the energy efficiency of their system. Among these actions distributors can drive the development of the distributed generation (DG) on their networks. The inclusion of the energy saving goal among the terms of the objective function makes the DG allocation problem more and more complicated,...
This work presents a procedure to validate sags monitoring results based on a stochastic assessment of voltage sag indices. The main practical use of this methodology is to analyze the accuracy of sag indices obtained from very short monitoring periods. Probabilistic models of several factors can be taken into account: lines and busbars fault rate, pre-fault voltage, fault type distribution, fault...
This paper describes the mid-continent area power pool (MAPP) transmission equipment outage data collection scheme and presents bulk transmission line average outage statistics for forced outage category for the 230 kV and above systems computed using the data for the ten-year operating period from 1991 to 2000. In addition, a causal and seasonal contribution to forced outages of bulk transmission...
The application of the telecontrolled switching elements in MV distribution networks is an effective tool for influencing the electricity supply continuity perceived by individual customers considerably. In this way, it is also a tool for reducing the possible costs resulting from breaching the customer's standards of electricity supply continuity. A method generally utilizable when making decisions...
The electric power market is restructuring to be price-based and auctions are considered a good pricing mechanism to be used. To assure that the market functions satisfactorily, strictness of guarantee of sellers' deliveries and buyers' receipts must be taken care properly by the central coordinator. This paper proposes market mechanisms for single-class auctions, which specifies the minimum strictness...
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...
This paper proposes a new estimation technique of the load duration curve (LDC) which takes into account recent modifications of the load demand in the Tunisian power system (STEG) related to the increasing of the air conditioning load. This approach is based on the estimation of the hourly peak load distribution by asymmetric generalized Gaussian distribution (AGG). Numerical results indicate that...
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...
In this study hourly wind speed time series data of Eskisehir region, Turkey have been used for stochastic generation of wind speed data using the transition matrix approach of the Markov chain process. Previous work on synthetic data generation did not focus on the effects of different choices of wind states. In this work, it was observed that increasing the number of states has a significant benefit...
In this paper it is proposed an efficient contingency screening and ranking algorithm for assessment and classification of multiple contingencies of an Electric Power System using the Rough Set theory. The developed methodology produces a classification of the system operation in five possible states: normal, alert, emergency, in-extremis and restorative. These different operating states correspond...
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...
Electric utilities schedule power transformers in high voltage load stations (customer delivery or regional supply systems) for planned outages such as unit refurbishment, unit replacement, etc. that may last for a few weeks. During the planned outage time, companion units may fail causing a complete loss of supply to customers. Mobile unit transformers (MUT's) could be used in these emergency situations...
Uncertain wind power forecasts is a disadvantage in an electricity market where the majority of the trading is performed several hours before the actual delivery. This paper presents a model which can be used to study how changes in the trading arrangement-in particular changing the delay time between closure of the spot market and the delivery period or changing the imbalance pricing system-would...
Cost-effective maintenance scheduling of power system equipment is critical, especially with present economic scenario of power industry. Apart from long-term maintenance policy, asset planners need to come up with revised short term maintenance strategies mainly due to the shrinking budget allocations for various reasons. The problem may be formulated as follows: if it is the same availability of...
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