M. Gitizadeh, M. Kalantar,
Volume 4, Issue 4 (12-2008)
Abstract
This paper presents a novel optimization based methodology to allocate Flexible
AC Transmission Systems (FACTS) devices in an attempt to improve the previously
mentioned researches in this field. Static voltage stability enhancement, voltage profile
improvement, line congestion alleviation, and FACTS devices investment cost reduction,
have been considered, simultaneously, as objective functions. Therefore, multi-objective
optimization without simplification has been used in this paper to find a logical solution to
the allocation problem. The optimizations are carried out on the basis of location, size and
type of FACTS devices. Thyristor Controlled Series Compensator (TCSC) and Static Var
Compensator (SVC) are utilized to achieve the determined objectives. The problem is
formulated according to Sequential Quadratic Programming (SQP) problem in the first
stage. This formulation is used to accurately evaluate static security margin with congestion
alleviation constraint incorporating voltage dependence of loads in the presence of FACTS
devices and estimated annual load profile. The best trade-off between conflicting objectives
has been obtained through Genetic Algorithm (GA) based fuzzy multi-objective
optimization approach, in the next stage. The IEEE 14-bus test system is selected to
validate the allocated devices for all load-voltage characteristics determined by the
proposed approach.
M. Ghotbi-Maleki, R. Mohammadi Chabanloo,
Volume 17, Issue 4 (12-2021)
Abstract
Expansion of power system causes short-circuit currents (SCC) of networks to exceed the tolerable SCCs of equipment. The utilization of fault current limiter (FCL) in such networks is needed to address this issue. This paper presents a new method for optimal allocation of FCLs to restrain the SCCs under permissible value. In this method, it is suggested to select a line as FCL location where the addition of FCL to this line will have the greatest impact on reducing the SCC of buses which their SCCs exceed the permissible value (known as exceeded buses). Since the optimization algorithms are not capable for optimal allocation of FCL especially in large networks, therefore, the proposed FCL allocation method is presented in the form of a computational process. In this computational process, the candidate lines for FCL location are firstly prioritized by a new index based on the effect of location of FCL on the reduction of SCCs. Then, the FCL size is determined by solving a quadratic equation firstly presented in this paper. The proposed method is implemented on networks with different sizes, and the obtained results show the performance of the proposed method over previous FCL allocation methods.
