م.م. رشا ياسين عبد
قسم القدرة والمكائن
The Distributed generations (DGs) are small-scale power generation technologies of low voltage type that provide electrical power at a site closer to consumption centers than central station generation. It has many names like Distributed energy resources (DER), onsite generation, and decentralized energy. Its smaller then 50-100MW, electric Power Research Institute defines distributed generation as generation from few kilowatts up to 50MW and that are directly connected to the distribution network.
These resources include renewable and nonrenewable energies. Renewable energies that are applicable for DG include wind, solar, and biomass. On the other hand, nonrenewable energies include micro turbines, gas turbines, and fuel cells. It is the ideal solution for many goals because smaller generation units are readily available, simple to install and operate, easy to relocate, modular and cost effective.
The presence of Distributed Generations (DG) in power systems may lead to several advantages such as providing sensitive load protection, reducing transmission and distribution network congestion and expansion, and improving the overall system performance by reducing power losses and enhancing voltage profiles .The disadvantage impacts, such as an increase in the short-circuit level. These impacts depend on the type, capacity, and place of these resources.
The optimal DG allocation is a complex problem with nonlinear objective function and nonlinear constraints, in which heuristic algorithms are a good choice for placing DGs. A range of techniques has been proposed to define the optimal locations and capacities of DGs. The optimization techniques such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Evolutionary Programming (EP), Ant Colony Optimization (ACO) and other heuristic methods are usually used in finding the optimal size of DG. With this optimization method, it could help the power system planner to have an idea the optimal capacity of DG size for the network and reduce the chances for the network to have higher power losses.