An elegant emergence of optimal siting and sizing of multiple distributed generators used for transmission congestion relief

Abstract

Abstract:After the implementation of deregulation in a power system, an appreciable volume of renewable energy sources is used to generate electric power. Even though they are intended to improve the reliability of the power system, the unpredictable outages of generators or transmission lines, an impulsive increase in demand, and failures of other equipment lead to congestion in one or more transmission lines. There are several ways to alleviate this transmission congestion, such as the installation of new generation facilities in the place where the demand is high, the addition of a new transmission facility, generation rescheduling, and curtailment of load demand processes. Among the above methods generation rescheduling and load shedding are normally preferred, since the other methods require additional investments.However, some critical cases require improved methods to alleviate congestion. With the extensive application of distributed generation (DG), congestion management is also accomplished by the optimal placement of multiple DG units. It is well known that incorrect sizes and improper locations of DG undoubtedly create higher power losses and an undesirable voltage profile. Hence, this research effort employs the line flow sensitivity index to establish the optimal location of DG units and genetic algorithm-based optimization for determining the optimal sizes of DG units. The objective of this research is to minimize the total losses and real power flow performance index and to improve the voltage shape of the modified IEEE 30-bus test system. The results of this proposed approach are encouraging and help in anticipating higher efficiency by satisfying all the objectives.

Optimal rescheduling of real power to mitigate congestion using gravitationalsearch algorithm

“…In [6] multiobjective CM was proposed based on the optimal location of flexible alternating current transmission system (FACTS) devices to maintain the voltage levels within limits. Rajamanickam et al implemented distribution generation to manage congestion by reducing the losses and enhancing the voltage levels [7]. Reddy [8] managed congestion by adopting load shedding in association with rescheduling of generators.…”

Minimizing reverse current flow due to distributed generation via optimal network reconfiguration

“…The total power loss in the system can be determined by using a standard power loss formula as shown in Eq. (1).…”

“…DG normally includes solar, wind, biomass, combined heat and power, or small rating power plant. The main advantages of DG include low investment cost, managing transmission line congestion [1,2], reduction in greenhouse gas emission [3], minimization of power losses [4,5], possible islanding operation that minimizes interruption time, and increased reliability [6][7][8]. Thus, many researchers are focusing on optimizing DG size or placement in distribution networks, with different objective functions to improve its performance.…”