جستجوی مقالات مرتبط با کلیدواژه "distribution transformers" در نشریات گروه "برق"

One of the most critical and complex issues in long-term planning of distribution networks is the optimal placement of distribution transformers. In this paper, the optimal placement of distribution transformers was investigated based on a complete and multi-objective function. In the proposed method, location, optimal capacity, and the service area are determined by minimizing costs (investment, operation, reliability) and improving reliability and power quality parameters (voltage drop) due to electric restrictions (radial structure, voltage drop and equipment capacities). The planning of distribution networks is complicated due to the existence of numerous and multiple-criteria decision-making variables in objective functions; hence in this paper, the symbiotic organisms search (SOS) algorithm was used as a new heuristic optimization algorithm to solve the problem of long-term planning of distribution networks. The proposed method is tested on a real distribution network to evaluate the performance of the proposed algorithm,  Comparing the results of the proposed algorithm with the results of studies with genetic algorithms (GA), biogeography-based optimization (BBO) and imperialist competitive algorithm (ICA), indicates the performance and advantages of the proposed algorithm over other algorithms.

The widespread presence of uncontrolled electric vehicles causes overloading of distribution network equipment. One of these equipments is distribution transformer, which should pay attention to overloading and reducing lifetime of this equipment due to charging of electric vehicles. First, strategies have been proposed to investigate the effect of electric vehicle penetration level and charging on network equipment. From these strategies, with the help of Monte Carlo simulation, electric vehicle charging models are obtained for 24 hours. The first strategy involves slow and fast uncontrolled charging modeling in the residential and work areas, and the second strategy is charging only in the workplace. In these models with having parameters such as number of cars, base load, trip information, and electric vehicle penetration coefficient, obtain load profile from summation of total normal load and electric vehicle charge. And then load profile will be given to thermal model of distribution transformer. The output of the thermal model is the transformer hot spot temperature. From the hot spot temperature of the distribution transformer, a reduction in the lifetime of the insulator is obtained, which indicates a reduction in the lifetime of the distribution transformer. The results show that to reduce the lifetime of distribution transformer, it is better to use electricity tariff to smooth the load profile. For simulations MATLAB software is used.