Ramón Alfonso Gallego

Transmission network expansion planning considering multiple generation scenarios

This paper presents a mathematical model and a methodology to solve a transmission network expansion planning problem considering open access. The methodology finds the optimal transmission network expansion plan that allows the power system to operate adequately in an environment with multiples generation scenarios. The model presented is solved using a specialized genetic algorithm. The methodology is tested in a system from the literature.

Transmission network expansion planning considering uncertainty in generation and demand

This paper presents a mathematical model and a methodology to solve a transmission network expansion planning problem considering uncertainty in demand and generation. The methodology used to solve the problem, finds the optimal transmission network expansion plan that allows the power system to operate adequately in an environment with uncertainty. The model presented results in an optimization problem that is solved using a specialized genetic algorithm. The results obtained for known systems from the literature show that cheaper plans can be found satisfying the uncertainty in demand and generation.

Flujo de carga trifásico para sistemas radiales de distribución

In this document, a three phase load flow is implemented. This, takes advantage of distribution systems radial configuration. A solution scheme with a iterative technique forward-backward sweep is presented.

Transmission expansion planning considering conductor proposals with different wire size and technology

In this article a model and a solution methodology is presented to solve the transmission network expansion problem, considering the selection of the wire size and the construction technology of the conductors for transmission lines for each new right-of-way. The optimization problem is solved using a specialized genetic algorithm that uses the logic of the Chu-Beasley Genetic Algorithm combined with an exact technique. The methodology is tested in the Colombian electric system of 93 buses and 155 candidate lines, which is modified in order to allow investment options for the selection of the conductors. The results obtained improve the traditional solution for the Colombian electrical system in the transmission planning study.

Optimal scheduling of vegetation maintenance underneath overhead power distribution lines

The contact between vegetation and the power distribution lines is one of the major causes of interrupting the power service supply. In this paper, two new mathematical models are presented, and they are characterized by having monobjective function. The first one minimizes the non served energy level (NSEL) due to vegetation related failures in a power distribution system, and it is subjected to a set of constraints that include equipment availability, maximum number of vegetation pruning in a section of the system and the reliability constrain in the service. The second one has an objective function that works to minimize the average percentage of violation in the security zone which contains the minimum distance between the power lines and the vegetation. The results of the implementation by using Chu-Beasley Genetic Algorithm include the NSEL, the average percentage of violation in the security zone and the maintenance cost of the vegetation transferred to actual value, as well as the maintenance scheduling in a test system.

Multistage Transmission Expansion Planning via Network Partitioning and Principal Variables Identification

This paper presents a method to solve multistage transmission expansion planning problem (MTEP) for highly complex systems. The method includes three partition criteria to separate the transmission network into several subsystems and four active power injection mechanisms to keep information from the interaction between subsystems. A principal variables identification process is applied to each subsystem in order to modify the limits of addition of new elements according to the significance of each right-of-way. These new limits are used to solve the MTEP for the original network, which now has a reduced search space. The MTEP is represented by an efficient version of the linear disjunctive model (DM). The obtained results show an outstanding performance in terms of quality of the answer and computation time. The best solutions known for complex test systems are improved thanks to this method.

Methodology for optimal distribution system planning considering automatic reclosers to improve reliability indices

In this article a methodology for optimal distribution system planning (DSP) considering automatic reclosers is presented. The methodology has two phases. An optimal configuration of the distribution system is found in phase I, by using a simulated annealing algorithm (SA). It considers costs of installing of new elements and upgrading of existing ones, and operative costs of energy technical losses. In phase II, a simultaneous location strategy of normally open and closed reclosers (NOR and NCR) is applied, in order to improve the power supply reliability indices and allow proper load transference between feeders under certain operative conditions. To solve this phase, the multi-objective evolutionary algorithm NSGA II (non-dominated genetic algorithm) is used. The proposed methodology introduces reliability topics to the DSP problem such as it allows incorporating cost variety, regulatory constraints and own constraints of the problem. Furthermore, it is easier to implement than traditional centralized models. To demonstrate the efficiency of the proposed methodology, a 54-nodes system is used.

TÉCNICAS HEURÍSTICAS APLICADAS AL PROBLEMA DEL CARTERO VIAJANTE (TSP)

The Traveling Salesman Problem is a typical problem of optimization. In this document are presented some optimization heuristic techniques (Genetic Algorithms, Simulated Annealing, Ant Colony Optimization, Tabu Search and Grasp) used in the solution of this problem. To solve this problem is necessary to find the optimal way to travel on n cities without repeat them and ending at the original city.

Long term transmission expansion planning considering generation-demand scenarios and HVDC lines

This paper presents a mathematical model and a methodology to solve the transmission expansion planning problem considering generation-demand scenarios and alternative investments using High Voltage Direct Current (HVDC) links. The methodology determines the optimal expansion plan that allows the power system to operate properly in an environment with extreme generation scenarios and multiple demand scenarios obtained for the pessimistic and optimistic scenarios projected. The multiple generation-demand scenarios produced high investment cost for the future network but this cost can be reduced including HVDC links in the expansion alternatives. The planning problem is solved using C++ and CPLEX. The methodology is tested on the modified Garver system with good results.

FLUJO DE CARGA ARMÓNICO PARA SISTEMAS RADIALES

En el estudio de sistemas con cargas no-lineales el flujo de carga debe ser modificado para incluir la respuesta del sistema a distintas frecuencias armonicas. En este documento se plantean las principales metodologias de solucion al flujo de carga armonico y se presenta un metodo enfocado hacia los sistemas radiales. Para esto se utiliza un algoritmo de barrido iterativo. El procedimiento se presenta para sistemas balanceados pero puede ser expandido facilmente a sistemas desbalanceados.