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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...
Under electricity market operation, the competitiveness of wind power generation may be reduced because of the stochastic nature of the wind resource, which often results in increased regulation costs. The negative impact associated to the stochastic nature of the wind resource may be reduced by coupling the wind farm with energy storage facilities, thus constituting a virtual power plant. In this...
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...
This paper provides an approach to the problem of power distribution network renewal planning where the challenge to the decision maker is to determine the most cost- effective multi-year development plan in terms of what feeders in the network to refurbish, by which renewal alternative and at what time in the planning horizon. The problem is subjected to several constraints of service requirements...
One of the major problems in liberalized power markets is loss allocation. In this paper, a new method for allocating transmission losses to pool market participants is proposed. The proposed method is fundamentally based on Bialek's "Tracing the flow of electricity" method. The losses is allocated to market participants using the loss weight factors (LWFs) which are obtained from the square...
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...
Most electric power utilities utilize probability methods in the planning and operation of generating capacity. Deterministic criteria, however, are usually used in the planning and operation of composite generation and transmission or bulk electric power systems. The most commonly applied deterministic criteria dictate that specific credible outages should not result in system failure. The traditional...
This paper addresses the problem of predicting a wind farm's power generation when no or few statistical data is available. The study is based on a time-series wind speed model and on a simple dynamic model of a DFIG wind turbine including cut-off and cut-in behaviours. The wind turbine is modeled as a stochastic hybrid system with three operation modes. Numerical results, obtained using Monte-Carlo...
The main development trend of wind power generation system is large offshore wind farms with grid connection. Due to extraordinarily high investment, many technical issues yet to be solved and limited experience, the risk of building offshore wind power generation system is always very high. The study presented in this paper takes a view of the effect of offshore wind farm topology on its reliability...
Con Edison's distribution systems supply power to more than 3 million customers in New York City and Westchester County. About 85% of the load in the Con Edison service territory is supplied by underground low-voltage network systems. The reliability of underground low-voltage network systems is extremely high and Con Edison uses Network Reliability Index (NRI) programs - the Contingency program and...
The objective of this paper is to introduce analytical models for accurate prediction of failure probabilities of existing shield wires and to recommend a time window for wire replacement at an acceptable failure threshold. Ductile and strength tests results and failures records of shield wires were examined to determine the trend of wires deteriorations as they age. Since most of failures occurred...
This paper focuses on the application of risk-based models to cogeneration system planning in the presence of uncertainties. Starting from the electrical and thermal load patterns, and the electricity and gas prices for a reference year, the uncertain variables for the successive years of analysis (demand and energy prices) are represented by using average values and covariance matrices, taking into...
This paper describes a method for predicting circuit breaker time-to-failures using a probabilistic operational model that incorporates generation capacity growth. Increases in generation capacity may cause fault current levels to approach or exceed circuit breaker ratings. This condition may increase the probability of a circuit breaker failure. Circuit breaker failures result in common-mode multiple...
Knowledge of the reliability of power transformers is of growing importance to the asset manager. A method is presented for determining the reliability of a power transformer based on the mechanical strength of winding insulation paper. In addition to the modelling technique, there is a validation method for the modelling technique presented. The validation method depends on a good data management...
Decisions on maintaining, repairing, refurbishing and replacing cable systems are usually a compromise between what technically is advised and what economically is feasible. To implement an optimal maintenance and/or replacement strategy, asset managers and/or maintenance engineers need appropriate tools to provide them with reliable information on the condition of the cable systems. Partial discharge...
The problem of choosing the optimal location and size for shunt capacitors in unbalanced distribution systems can be formulated as a mixed, non-linear, constrained optimization problem and is usually solved in deterministic scenarios. However, distribution systems are stochastic in nature, leading thus to inaccurate deterministic solutions. To take into account the unavoidable uncertainties which...
The following topics are dealt with: uncertainty forecasting; wind generation; decision making; generation planning; load forecasting; power generation scheduling; ageing model; power system reliability; distributed generation; failure probability; transformer reliability; electricity markets; power equipment optimal allocation; power system protection; power system planning; and HVDC.
The impact of a pulse load charging event on a notional all-electric ship is investigated through simulation in the context of uncertainty in the parameters of the system and event. In order to efficiently carry out the study, the system is modeled on a large-scale parallel processor simulator. A surrogate modeling approach is used to characterize the behavior of the system for the purposes of sensitivity...
This paper proposes an optimization algorithm suitable to choose the optimal number and position of the measurement devices in active distribution networks. In active distribution networks distributed energy resources may be controlled and the topology modified to optimize power flows and to solve critical contingencies. The proposed algorithm, based on the techniques of the dynamic programming, has...
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