A Survey on Load/Power Flow Methods and DG Allocation Using Grasshopper Optimization Algorithm in Distribution Networks.

Abstract: Grasshopper Optimization Algorithm (GOA) is a recent swarm intelligence algorithm inspired by the foraging and swarming behavior of grasshoppers in nature. The GOA algorithm has been successfully applied to solve various optimization problems in several domains and demonstrated its merits in the literature. This paper proposes a comprehensive review of GOA based on more than 120 scientific articles published by leading publishers: IEEE, Springer, Elsevier, IET, Hindawi, and others. It provides the GOA variants, including multi-objective and hybrid variants. It also discusses the main applications of GOA in various fields such as scheduling, economic dispatch, feature selection, load frequency control, distributed generation, wind energy system, and other engineering problems. Finally, the paper provides some possible future research directions in this area.

Abstract: Este trabalho apresenta a implementacao das meta-heuristicas, Greedy Randomized Adaptive Search Procedure (GRASP) e Variable Neighborhood Search (VNS) para a alocacao otima de Geradores Distribuidos (GDs) e seu dimensionamento em redes de distribuicao com operacao radial, visando a reducao das perdas eletricas ativas e, simultaneamente, a melhoria dos niveis de tensao. Nesta metodologia, o algoritmo GRASP e utilizado para a construcao de possiveis solucoes do problema, enquanto o VNS se aplica a uma etapa de busca local, na qual realiza-se um refinamento no espaco de solucoes para aprimorar a convergencia do processo de busca. Para validacao da tecnica, a metodologia foi aplicada em duas redes, uma de 33 barras do IEEE e outra de 135 barras. Dos resultados obtidos, pode-se verificar a eficacia da metodologia em encontrar solucoes de boa qualidade com perdas minimas e consideraveis melhorias nos perfis de tensao.

Abstract: A power flow method is described for solving weakly meshed distribution and transmission networks, using a multiport compensation technique and basic formations of Kirchoff's laws. This method has excellent convergence characteristics and is robust. A computer program implementing this scheme was developed and successfully applied to several practical distribution and transmission networks with radial and weakly meshed structures. The method can be applied to the solution of both the three-phase (unbalanced) and single-phase (balanced) representation of the network, however, only the single-phase representation is treated in detail. >

Abstract: The Grasshopper Optimisation Algorithm inspired by grasshopper swarms is proposed.The GOA algorithm is benchmarked on challenging test functions.The results on the unimodal functions show the superior exploitation of GOA.The exploration ability of GOA is confirmed by the results on multimodal and composite functions.The results on structural design problems confirm the performance of GOA in practice. This paper proposes an optimisation algorithm called Grasshopper Optimisation Algorithm (GOA) and applies it to challenging problems in structural optimisation. The proposed algorithm mathematically models and mimics the behaviour of grasshopper swarms in nature for solving optimisation problems. The GOA algorithm is first benchmarked on a set of test problems including CEC2005 to test and verify its performance qualitatively and quantitatively. It is then employed to find the optimal shape for a 52-bar truss, 3-bar truss, and cantilever beam to demonstrate its applicability. The results show that the proposed algorithm is able to provide superior results compared to well-known and recent algorithms in the literature. The results of the real applications also prove the merits of GOA in solving real problems with unknown search spaces.

Abstract: This paper presents a three-phase power flow solution method for real-time analysis of primary distribution systems. This method is a direct extension of the compensation-based power flow method for weakly meshed distribution systems from single phase to three-phase, with the emphasis on modeling of dispersed generation (PV nodes), unbalanced and distributed loads, and voltage regulators and shunt capacitors with automatic local tap controls. The method proposed here is capable of addressing these modeling challenges while still maintaining a high execution speed required for real-time application in distribution automation systems. The paper also includes test results from the application of a computer program developed based on the proposed method to large primary electric distribution systems. >

Abstract: A direct approach for unbalanced three-phase distribution load flow solutions is proposed in this paper. The special topological characteristics of distribution networks have been fully utilized to make the direct solution possible. Two developed matrices-the bus-injection to branch-current matrix and the branch-current to bus-voltage matrix-and a simple matrix multiplication are used to obtain load flow solutions. Due to the distinctive solution techniques of the proposed method, the time-consuming LU decomposition and forward/backward substitution of the Jacobian matrix or Y admittance matrix required in the traditional load flow methods are no longer necessary. Therefore, the proposed method is robust and time-efficient. Test results demonstrate the validity of the proposed method. The proposed method shows great potential to be used in distribution automation applications.

Abstract: The paper presents a simple and efficient method for solving radial distribution networks. The proposed method involves only the evaluation of a simple algebraic expression of voltage magnitudes and no trigonometric functions as opposed to the standard load flow case. Thus, computationally the proposed method is very efficient and it requires less computer memory. The proposed method can easily handle different types of load characteristics. Several Indian rural distribution networks have been successfully solved by using the proposed method.