Optimal power flow solutions for power system operations using moth-flame optimization algorithm

Optimal power flow (OPF) has gained a growing attention from electrical power researchers since it is a significant tool that assists utilities of power system to determine the optimal economic and secure operation of the electric grid. The key OPF objective is to optimize a certain objective function such as: minimization of total fuel cost, emission, real power transmission loss, voltage deviation, etc. while fulfilling certain operation constraints like bus voltage, line capacity, generator capability and power flow balance. Optimal reactive power dispatch (ORPD) is a sub-problem of optimal power flow. ORPD has a considerable impact on the economic and the security of the electric power system operation and control. ORPD is considered a mixed nonlinear problem because it contains continuous and discrete control variables. Another sub-problem of OPF is Economic dispatch (ED) which one of the complex problems in the power system which its purposes is to determine the optimal allocation output of generator unit to satisfy the load demand at the minimum economic cost of generation while meeting the equality and inequality constraints. In this thesis, a recent metaheuristic nature-inspired optimization algorithm namely: Moth-Flame Optimizer (MFO) is applied to solve the two subproblems of Optimal power flow (OPF) namely: Economic dispatch (ED) and Optimal reactive power dispatch (ORPD) simultaneously. Three objective functions will be considered: generation cost minimization, transmission power loss minimization, and voltage deviation minimization using a weighted factor. The IEEE 30-bus test system and IEEE 57-bus test system will be employed, to investigate the effectiveness of the proposed MFO in solving the above-mentioned problems. Then the obtained MFO methods results is compared with other reported well-known methods. The comparison proves that MFO offers a better result compared to the other selected methods. In IEEE 30-bus test system, MFO outperform the other optimization methods with 967.589961$/h compared to 971.411400$/h, 983.738069$/h, 975.346233$/h, 985.198050$/h, 1035.537820$/h for Improved Grey Wolf Optimizer (IGWO), Grey Wolf Optimizer (GWO), Ant Loin Optimizer (ALO), Whale Optimization Algorithm (WOA), and Sine Cosine Algorithm (SCA) respectively. In IEEE 57-bus test system, MFO offers a minimization of 19.16% compared to 19.03% and 18.98% for Grey Wolf Optimizer (GWO), Whale Optimization Algorithm (WOA) respectively. Moreover, the MFO have speedy convergence rate and smooth curves more than the other algorithms

Machine learning-enabled globally guaranteed evolutionary computation

Evolutionary computation, for example, particle swarm optimization, has impressive achievements in solving complex problems in science and industry; however, an important open problem in evolutionary computation is that there is no theoretical guarantee of reaching the global optimum and general reliability; this is due to the lack of a unified representation of diverse problem structures and a generic mechanism by which to avoid local optima. This unresolved challenge impairs trust in the applicability of evolutionary computation to a variety of problems. Here we report an evolutionary computation framework aided by machine learning, named EVOLER, which enables the theoretically guaranteed global optimization of a range of complex non-convex problems. This is achieved by: (1) learning a low-rank representation of a problem with limited samples, which helps to identify an attention subspace; and (2) exploring this small attention subspace via the evolutionary computation method, which helps to reliably avoid local optima. As validated on 20 challenging benchmarks, this method finds the global optimum with a probability approaching 1. We use EVOLER to tackle two important problems: power grid dispatch and the inverse design of nanophotonics devices. The method consistently reached optimal results that were challenging to achieve with previous state-of-the-art methods. EVOLER takes a leap forwards in globally guaranteed evolutionary computation, overcoming the uncertainty of data-driven black-box methods, and offering broad prospects for tackling complex real-world problems

Modelado y solución del despacho óptimo reactivo multiperiodo mediante una técnica de optimización metaheurística

RESUMEN: El despacho óptimo de potencia reactiva (DOPR) es un problema clásico de los sistemas de potencia que consiste en la gestión óptima de reactivos, normalmente con el objetivo de reducir pérdidas. Si bien el DOPR ha sido ampliamente estudiado, existen relativamente pocos trabajos que han abordado este problema desde la perspectiva multiperiodo; siendo uno de los principales desafíos el modelado para limitar el número de maniobras de los taps de transformadores y elementos de compensación de potencia reactiva. En este estudio se realiza una revisión exhaustiva de las estrategias empleadas en la literatura técnica para modelar el despacho óptimo de potencia reactiva multiperiodo (DOPRM). Se presenta un modelo matemático con un nuevo manejo alternativo de restricciones, y se realiza una aplicación de una técnica metaheurística conocida como MVMO (Mean Variance Mapping Optimization Algorithm) en los sistemas IEEE 30-bus y IEEE 57-bus. Los resultados muestran la efectividad del modelo matemático en encontrar soluciones de alta calidad, que cumplen las metas planteadas horarias y diarias de maniobras para equipos de compensación reactiva, reducción de pérdidas de potencia activa, límites de tensión en nodos de generación y nodos de carga y límites máximos de los flujos por las líneas de transmisión

Contribution à l’optimisation de l’écoulement de puissance par les méthodes d’intelligence artificielle améliorées

La répartition optimale de la puissance réactive (ORPD) est une tâche importante pour atteindre un meilleur état d’économie, de sécurité et de stabilité du système de l’énergie électrique. Il s'agit d'un problème d'optimisation complexe qui vise à identifier les variables de contrôle optimales des différents équipements de régulation du réseau afin de minimiser une fonction objective sous contraintes. De nombreuses techniques méta-heuristiques ont été proposées pour surmonter les diverses complexités dans la résolution du problème ORPD, qui sont caractérisées par l'exploration et l'exploitation du mécanisme de recherche. L'équilibre entre ces deux caractéristiques est un défi à surmonter pour aboutir à une meilleure qualité de solution. L'algorithme de la colonie Artificiel des Abeilles (Artificial Bee Colony - ABC) est une méthode méta-heuristique réputée, s'est avéré efficace en matière d'exploration et faible en matière d'exploitation, ce qui rend nécessaire l'amélioration de la version de base de l'algorithme ABC. L'algorithme Salp Swarm (SSA) est une méta-heuristique nouvellement développée, basée sur un essaim, qui possède la meilleure capacité de recherche locale en utilisant la meilleure solution globale à chaque itération pour découvrir des solutions III prometteuses. Dans ce sujet de recherche, une nouvelle approche hybride basée sur les algorithmes ABC et SSA (ABC-SSA) est développée et appliquée pour résoudre le problème ORPD. L'approche proposée tente d'améliorer la capacité d'exploitation de l'algorithme ABC en utilisant SSA. L'efficacité de l'ABC-SSA est examinée en utilisant quatre réseaux électriques d'essai standard : IEEE 30 bus, IEEE 57 bus, IEEE 118 bus et IEEE 300 bus à grande échelle, en tenant compte des célèbres fonctions objectives du problème ORPD, notamment les pertes totales de puissance active de transmission (Ploss), l'écart total de tension (TVD) par rapport à l’amplitude de tension nominale et l'indice de stabilité de la tension (VSI) des jeux de barres de charge. Les résultats de simulation obtenus ont prouvé que l'ABC-SSA proposé est plus efficace que l'ABC, le SSA et d'autres techniques d'optimisation méta-heuristiques récemment développées dans la littérature du domaine d’application

Hybridization of particle Swarm Optimization with Bat Algorithm for optimal reactive power dispatch

This research presents a Hybrid Particle Swarm Optimization with Bat Algorithm (HPSOBA) based approach to solve Optimal Reactive Power Dispatch (ORPD) problem. The primary objective of this project is minimization of the active power transmission losses by optimally setting the control variables within their limits and at the same time making sure that the equality and inequality constraints are not violated. Particle Swarm Optimization (PSO) and Bat Algorithm (BA) algorithms which are nature-inspired algorithms have become potential options to solving very difficult optimization problems like ORPD. Although PSO requires high computational time, it converges quickly; while BA requires less computational time and has the ability of switching automatically from exploration to exploitation when the optimality is imminent. This research integrated the respective advantages of PSO and BA algorithms to form a hybrid tool denoted as HPSOBA algorithm. HPSOBA combines the fast convergence ability of PSO with the less computation time ability of BA algorithm to get a better optimal solution by incorporating the BA’s frequency into the PSO velocity equation in order to control the pace. The HPSOBA, PSO and BA algorithms were implemented using MATLAB programming language and tested on three (3) benchmark test functions (Griewank, Rastrigin and Schwefel) and on IEEE 30- and 118-bus test systems to solve for ORPD without DG unit. A modified IEEE 30-bus test system was further used to validate the proposed hybrid algorithm to solve for optimal placement of DG unit for active power transmission line loss minimization. By comparison, HPSOBA algorithm results proved to be superior to those of the PSO and BA methods. In order to check if there will be a further improvement on the performance of the HPSOBA, the HPSOBA was further modified by embedding three new modifications to form a modified Hybrid approach denoted as MHPSOBA. This MHPSOBA was validated using IEEE 30-bus test system to solve ORPD problem and the results show that the HPSOBA algorithm outperforms the modified version (MHPSOBA).Electrical and Mining EngineeringM. Tech. (Electrical Engineering