Bruno Henriques Dias

Hybrid heuristic optimization approach for optimal Distributed Generation placement and sizing

This paper presents a hybrid algorithm that combines Particle Swarm Optimization (PSO) and Nonlinear Optimal Power Flow (OPF) in the optimal sitting and sizing of Distributed Generation (DG). The objective function considered is to minimize the power losses in distribution systems. The proposed approach makes use of a sensitivity index based on derivatives to identify the best candidate buses for sitting the DG. This index is considered in the PSO initial population aiming at reducing the search space, though, improving the convergence of the method. The OPF is then used to determine the optimal size of each DG. Results are compared with previous papers presenting different methodologies for the 69-bus radial distribution system to validate the proposed approach.

Non-convex Economic Dispatch using Trelea Particle Swarm Optimization

Based in the importance of the Economic Dispatch for operation and planning of power systems, this paper presents the Trelea Particle Swarm Optimization method (Trelea-PSO) applied to this issue. In this paper the ED problem is modeled considering the valve-point effects and multiple fuels, though a non-convex function. Study cases composed of two 10 thermal generators systems are presented to validate the proposed methodology. The results obtained was compared to others presented in literature.

Thermography as a Tool in Electric Panels Maintenance

This paper presents a study to compare gains obtained in hydroelectric generators availability based on thermo vision analysis in electrical panels. Electrical Energy generation companies increase their attention to maintenance costs, specially related with labour costs. A part of maintenance activities demands in industries are related to maintenance of electrical panels. It is important to reduce the execution time of those activities while maintaining the quality of the service. A predictive technique widely used is the thermo vision, that makes use of infrared radiation sensing (heat) emitted by equipments over the absolute temperature. The diagnose obtained is based on the comparison between the radiation intensity from the analyzed equipment and a temperature reference to the same equipment, so verifying the operation conditions compared to standard conditions. This can be of great importance for unplanned corrective actions. Every electrical equipment or system presents heat conditions before a failure. This characteristic can reduce inspections stops or repairs, increasing equipments availability, so reducing costs and increasing the efficiency of the process.

Security constraints for wind power operation

This paper presents a model to include a security constraint for wind power plant in a hydrothermal dispatch problem. The proposed Unit Commitment (UC) is an augmented problem to take into account different scenarios of wind speed during the day. The wind farms are represented by a linear model that the generations are considered proportional to the availability of wind. The proposed optimization model uses DC load flow in which transmission system constraints are included. The hydro plants are considered with constant productivity and the times of starting and stopping of thermal generation units are considered as well as ramp deviation. The results using a test system show that the operation of a hydrothermal system is strongly affected by the inclusion of wind farms.

Stochastic optimization applied to Brazilian hydroelectric seasonalization of assured energy

The Brazilian power system is mainly composed of hydroelectric generation. Due to the stochasticity of inflows each hydroelectric plant receives an assured energy certificate, also known as physical guarantees. In general, the assured energy certificates correspond to the energy that each plant can produce at a 95% confidence level., They also represent the maximum energy each hydro unit can contract. So, the hydro generators are constrained by the assured energy and they determine their portfolio of energy contracts with free consumers, other generators, distribution companies and trade companies accordingly. The portfolio is composed of bilateral contracts that are, mainly composed of long term contracts negotiated significantly before the power delivery. Even considering that the assured energy is constant, each generator can seasonalize it on a monthly base, but keeping to the total annual assured energy. This paper aims to use stochastic dual dynamic programming to optimize the seasonalization of this assured energy considering the bilateral contracts previously assigned and the projection of the spot price. The results obtained show a considerable increase in the revenues of a generator utility from the Brazilian system.

Optimized seasonalization of assured energy in the Brazilian power system

The Brazilian power system is a hydrothermal system mainly composed of hydroelectric generation. In order to deal with the uncertainties related to future water inflows a hydroelectric power plant receives an assured energy certificate. In general, those assured energy certificates correspond to energy that each plant can produce considering a 5% risk of energy not supplied. Also, they represent the maximum energy each hydro unit can contract. So, the hydro generators determine their portfolio of energy contracts with free consumers, distribution companies and trading companies constrained by their assured energy. This portfolio is composed of bilateral contracts that are, mainly composed of long term contracts negotiated before the power delivery. Also, considering that the assured energy is constant, each generator can distribute (seasonalize) it in a monthly basis, but keeping the total annual assured energy. This paper aims to optimize the financial profiles of generation utilities in the Brazilian power market considering the seasonalization of the assured energy. To do so a parameter adjust algorithm, the Twiddle, is used. Results obtained show a considerable improvement in the revenues of a generator utility from the Brazilian system.