Priyanath Das

Placement of UPFC for minimizing active power loss and total cost function by PSO algorithm

In this paper Particle Swarm Optimization (PSO) technique has been used to minimize the active power loss and the total cost function, which includes the generation costs and the UPFC investment cost, through optimally placing the Unified Power Flow Controller (UPFC) in the power system network. Three objective functions are taken as the indexes of the system performance; identification of most suitable buses using line loss sensitivity index, minimization of active power loss and total generation cost by employing PSO. For the validation and comparison purposes of the proposed techniques, simulations are carried out on modified IEEE 14-bus power system. Results validate that the static performances of the power system can be successfully improved due to the optimal allocation of single UPFC controller.

A comparative study in improvement of voltage security in a multi-bus power system using STATCOM and SVC

In this paper an effort is made to assess local and global voltage security of multi-bus power system in presence of STATCOM and SVC. A Global Voltage Security Indicator (GVSI) derived from series network equivalent of multi-bus power system has been employed to assess overall system voltage security. Thevenins equivalent of the power system with respect to a particular load bus has been used to assess the local voltage security. A comparative study on effectiveness of STATCOM and SVC in improvement of voltage security using network equivalents has also been presented and validated using the well known L-index. STATCOM found to be more effective than SVC to ensure voltage security and at the same time it is also capable to reduce reactive power line loss considerably.

A comparative study on the computation of directional overcurrent relay coordination in power systems using PSO and TLBO based optimization

Purpose – Directional Overcurrent Relay (DOCR) coordination computation allowing for desired and high-level accuracy in interconnected power systems is very difficult and is a highly constraint-oriented optimization problem. The purpose of this paper is to study the effectiveness of a newly reported optimization technique, Teaching Learning Based Optimization (TLBO), in protective relay coordination comparing with a widely used optimization technique, Particle Swarm Optimization (PSO). Design/methodology/approach – DOCR coordination in electric power systems is considered as an optimization problem by formulating objective function and specifying problem constraints. Optimum values of the DOCR adjustment parameters (time dial setting and plug setting) in terms of reliable coordination margin and operating times of relays are computed by both the algorithms, TLBO and PSO. Optimal coordination is verified in three test bus systems: IEEE 6-bus, Western System Coordinating Council 9-bus and IEEE 14-bus system...

Parameter tuning of power system stabilizer using a meta-heuristic algorithm

Low-frequency oscillations in power systems sometimes lead to larger disturbances leading to instability. Addition of power system stabilizer (PSS) is very effective in damping the oscillations. The main purpose of the PSS is to increase damping of synchronous machines in the excitation loop. In this paper a new meta-heuristic algorithm termed Quasi-oppositional symbiotic organism (QOSS) search has been proposed for designing the PSS parameters in an optimal manner. The technique is tested on both single machine infinite bus system as well as a multi-machine system. Various operating conditions like loading effect and line outages are also considered for establishing robustness of PSS. The PSS parameters are tuned with the help of other optimizations like Symbiotic organism search, Genetic algorithm and Particle swarm optimization and are compared with those obtained with the application of QOSOS, to show the superiority of the proposed algorithm.

Crow search algorithm for solving optimal power flow problem

A new evolutionary optimization technique, crow search algorithm (CSA) is proposed in this paper for solving the optimal power flow (OPF) problem. The algorithm has been implemented on IEEE 30 bus test system to check its effectiveness in solving the OPF problem after satisfying various operational constraints. A comparative study of the results is presented in this paper. Analysis of the results reveals that the algorithm is effective in producing superior results for the system.

Fabrication of hybrid ultraviolet photodetector using organic polymer thin-film-coated TiO2 nanowires

Abstract. Poly (methyl methacrylate) (PMMA) thin film (TF) was employed on TiO2 nanowires (NWs) to fabricate organic–inorganic hybrid UV photodetector (PD), and its properties were studied and compared with bare TiO2 NW-based PD. A maximum photoresponsivity of 20×10−3  A/W and a maximum external quantum efficiency of ∼3.15% were observed in the UV region at 370 nm (∼3.35  eV). Enhanced photon absorption was observed in the hybrid detector. The TF of PMMA, which is a π-conjugated polymer, increased the carrier lifetime and reduced recombination rate. The PMMA TF:TiO2 NWs hybrid UV detector shows excellent rectification, and light current/dark current ratio was measured to be ∼1.46 times in comparison to bare TiO2 NWs photodetector in the reverse bias condition from −1 to −10  V.

Design trends of linear induction motor (LIM) and design issues of a single sided LIM

Linear Induction Motor (LIM) belongs to the special type of electrical machines that convert electrical energy to mechanical translatory motions. LIM is already manufactured in many countries and it has several applications starting from light railway transit system to small industries where conventionally rotary motors are used along with rotary to translatory converter, which involves much cost and loss of efficiency. The authors present a survey work on LIM to help the researchers in this field to have a total idea about the design trends & also they present different design issues of a single sided LIM. They designed a single sided LIM & tried to analyze the result with Finite Element Method. Basically design of LIM and to find out the application area is the main task for this non-conventional machine. A simple design procedure is also illustrated in this paper.

A novel method to assess global voltage stability of a multi-bus power system

This paper presents a methodology to obtain an equivalent two bus network from a multi-bus network to assess critical loadability in terms of voltage stability. The weakest bus of the system being diagnosed, maximum loadability of the system is obtained for different operating condition. The methodology has also been applied to a six bus power system to assess global voltage stability of the system. The participation of a particular bus in global voltage instability in assesses in terms of global bus voltage collapse coefficient (GVCC) and a global voltage stability indicator (GVSI) has also been developed to assess the global voltage stable state of the total network.