This paper describes an application of optimal power flow, solved by a direct interior point (IP) method, to restore system solvability. Using the P-Q load representation, flow unsolvability occurs when, for given set active and reactive bus injections, equations have no real solution. The control actions in IP algorithm includes rescheduling generators, adjustments on terminal voltage tap changes LTC transformers, as last resort, minimum shedding. formulation allows observation impact each...

This paper presents a set of investigations into the bulk reliability performance evaluation new IEEE Reliability Test System (RTS-96). Several system indices representing hierarchical level two (HL-II) assessment are provided. The full representation including three areas is analyzed and all results based on AC flows evaluations considering corrective remedial actions. tool was NH-2 program.

The objective of NEWAVE model, based on stochastic dual dynamic programming algorithm, is to solve the long term operation planning problem large scale interconnected systems, such as Brazilian one. year 1998 milestone for first official use model in Brazil, whose development has started 1993 by Electric Energy Research Center (CEPEL). This paper outlines key features and recent improvements that allowed keeping state-of-the art its broad range practical applications agent studies decision...

This paper describes two parallel methodologies for composite reliability evaluation using sequential Monte Carlo simulation. The are based on coarse grain asynchronous implementations. In the first methodology, a complete simulation year is analyzed single processor and many simulated years necessary convergence in parallel. second adequacy analysis of system operating states within performed checked one at end each year. implemented 10 nodes IBM RS/6000 SP scalable distributed memory...

The authors describe a new methodology for frequency and duration (F&D) assessment in composite generation transmission reliability evaluation. proposed approach uses the concept of conditional probability to characterize contribution each component indices, allows calculation F&D indices at both system bus level. algorithm is easy implement, requires same computational effort as estimation loss load (LOLP) expected power not supplied (EPNS) indices. Case studies with utility-derived systems...

This paper presents a new methodology for maintenance scheduling that takes into account inter-area transfer limitations and stochastic reliability constraints. The optimization model is based on the Benders decomposition technique. objective of this to determine minimum cost schedule, subject technological system may also be used assess adequacy existing transmission limits under given set planned outages generating units. Case studies with realistic three-area power are presented...

This paper describes a methodology to evaluate the maximum simultaneous power transfer of large interconnected systems. The approach combines Monte Carlo simulation and AC optimal flow, solved by direct interior point algorithm, in order calculate capability. In developed procedure, system problems caused contingencies including voltage collapse are also taken into account. Cost studies with IEEE RTS-96 1600-bus network derived from Brazilian South/Southeast/Central West presented discussed.

The authors present a new methodology for frequency and duration (F&D) assessment in composite generation transmission reliability evaluation. F&D indices are obtained from nonsequential Monte Carlo simulation scheme. Computational effort is reduced by using the Lagrange multipliers associated with adequacy of each state to identify boundary wall between failure success states. illustrated case studies IEEE test system two utility-derived systems. proposed approach allows practical...

The paper presents a general frequency and duration (F&D) method that is especially adequate for predominantly hydro generating systems. based on the property not only probabilities of reserve states can be evaluated recursively by discrete convolution, but also their frequencies. Therefore, appropriate truncation rounding techniques introduced allowing an efficient computation indices large-scale performance proposed F&D algorithm analysed with two test IEEE Reliability Test System used to...

While hydropower scheduling is a well-defined problem, there are institutional differences that need to be identified promote constructive and synergistic research. We study how established toolchains of computer models organized assist operational in Brazil, Norway, the United States' Colorado River System (CRS). These three systems have vast resources, with numerous, geographically widespread, complex reservoir systems. Although underlying objective essentially same, operated different...

This paper describes a methodology for calculating the sensitivity of reliability indices such as loss load probability (LOLP), expected power not supplied (EPNS) and frequency (LOLF) with respect to variations in equipment failure repair rates. information can be used assess cost/benefit improving reliability, either reducing downtime by hiring additional personnel repairs or extending uptime through more sophisticated monitoring maintenance techniques. The also estimate impact parameter...

In reliability assessment of bulk power systems, two methods have been largely studied and used: contingency enumeration non-sequential Monte Carlo simulation. Both their wellknown advantages drawbacks. Contingency is conceptually simple usually requires low computational effort. Conversely, simulation computationally harder, but much more versatile to model random aspects. This paper depicts some major aspects regarding both methods. It also shows that it not a matter choosing the definite...

Abstract Following a global trend, intermittent sources, especially wind, have been experiencing accelerated growth in Brazil—in the last decade, wind power grew 13 times and became second largest source electricity mix (12%), just behind hydropower (60%). Currently, although following regulatory guidelines, representation of long-term operation planning model is done simplified way, based on monthly average five years aggregated generation, thus demanding improvements. The objective this...

Abstract This paper proposes a new methodology to explicitly consider unreliability costs in multi‐stage transmission expansion planning. Starting from reference plan, alternative plans are derived based on postponement/anticipation of circuit implementations. These then ranked by using an economic index merit (EIM) and the associated Pareto‐optimal set is obtained through cost/benefit (trade‐off) analyses. The related variation investments operational each plan. Besides usual (active power...

The objective of this work is to present a methodology capable estimating the incremental payoff carbon market for grid-connected renewable power generation projects in Brazil. proposed consists using NEWAVE model determine optimal operating policy Brazilian Interconnected System over medium-term, and establish hydrological dispatch scenarios plants connected system. Based on these results, criteria defined ACM0002 were used estimate baseline developed response Clean Development Mechanism...

During 2014 and 2015, the Brazilian hydrothermal interconnected system faced critical hydrological conditions, such as extremely low multivariate inflow values on February January 2015. Therefore, an issue that arose in early was whether government would have to implement or not energy rationing. In this sense, paper summarizes a proposed approach technically support decision, based dual stochastic dynamic programming, inflows scenarios generation probabilistic analyses, utilized chain of...

The calculation of power system maximum loadability consists in determining, from a point for which the flow has solution, increase load until reaches collapse. Therefore, it is measurement margin or distance to voltage This problem related computation margins with respect bifurcations. Under certain conditions, saddle-node bifurcations occur when Jacobian matrix associated balance equations becomes singular. These points belong surface defines frontier solvability region. Outside this...

In traditional Newton-Raphson power flow algorithms, the terminal and remote bus voltages are obtained using a local control logic, i.e. reactive LTC taps adjusted to meet pre-specified voltage settings. On other hand, most of optimal flows (OPF) utilised in available reliability programs adopt an optimised logic for control, level is inside bounds, meaning that new settings can be calculated order avoid or minimise load shedding. However, several practical situations this not feasible...

This paper presents an approach to be used by the Brazilian power industry represent uncertainties of monthly wind production in SDDP algorithm applied long-term operation planning model hydro-dominated systems. It embraces four steps: (i) statistical clustering regimes; (ii) evaluation transfer functions between speed and production; integrated for generation multivariate synthetic scenarios inflows winds, considering cross-correlations speeds, inflows, speeds inflows; (iv) representing...

A good solar power photovoltaic generation forecast depends on quality time series data from measurements of global horizontal irradiation and generation. However, measurement system failures errors in handling can corrupt records with gaps outliers that undermine forecasting accuracy. Therefore, it is important the fitting energy prediction models must be preceded by a analysis order to detect correct errors. This paper presents main features an approach for joint cleaning irradiation. The...

A good solar power photovoltaic generation forecast depends on quality time series data from measurements of Global Horizontal Irradiance and Solar Power Generation. However, measurement system failures errors in handling can corrupt records with gaps outliers that undermine forecasting accuracy. Therefore, it is important the fitting energy prediction models must be preceded by a analysis order to detect correct errors. Given Generation are correlated variables, this paper aims present main...