Optimized Allocation of DGs to Improve System Reliability Based on Loading Effects.Arabian Journal for Science and Engineering

Abstract

The results obtained by recent researches on distributed generations (DGs) have shown that distribution systems adequacy can be improved using DGs. The features supported by DGs improving the system reliability are different. DGs can help decrease devices failure rate by improving the current passing through each distribution line and any device of system. In this point of view, DGs have the same effects as redundant lines. It is interesting that by minimum capacity of DG sources, the maximized reliability improvement can be achieved. The placement of DGs is one of the most important parameters of their planning. In this paper, a novel method is proposed to optimize the placement of DGs based on decreasing failure due to the enhancement of loading effects. Average system interruption frequency index is selected to define the objective function. Moreover, the optimization problem is solved by genetic algorithm (GA). MATLAB GA toolbox is used to implement the optimization problem solving. The method is applied to a 20 kV, 33-bus realistic system of Tehran Regional Electrical Company. Test results illustrate by optimal allocation of 2,000 and 1,000 kVA DGs generation capacity according to proposed method, 12.32 % and 6.35 % ASIFI decrement can be achieved, respectively. Furthermore, the system in view point of protective device placements, maximum DGs generation capacity, the critical lines and the most important sections are studied.