Electrical and Electronics

This paper presents a new algorithm called Firefly Algorithm (FA) to solve the well-known power system economic load dispatch (ELD) problem. FA is a novel nature-inspired algorithm inspired by social behavior of fireflies and the phenomenon of bioluminescent communication between them. The effectiveness of the proposed algorithm has been tested with the standard 6-bus, IEEE-14 bus and IEEE-30 bus system with several heuristic load patterns. The result of the proposed algorithm is compared with the results available in the literature. The numerical result reveals that the proposed algorithm can provide appreciably better solutions within reasonable time.

State estimation in electrical distribution systems (EDSs) is an analyzing tool for estimating the state of it for close monitoring and controlling by distribution management system (DMS). In this paper, RESs integrated EDS’s state is estimated using the distribution system state estimation (DSSE) model. It is a minimization problem with equality and inequality constraints which describe the practical considerations of real time EDS. The objective of DSSE modeling and its minimization is to compute state variables. For minimizing the objective function of DSSE model Artificial Bee Colony (ABC) algorithm is used to estimate load and Renewable Energy Sources (RESs) output. The performance of the proposed work is evaluated on IEEE 33 bus test system using MATLAB working platform and compared with other evolutionary optimization algorithms.

The main aim of this paper to solve the economic dispatch problem (EDP). The objective of the EDP of electric power generation, whose characteristics are complex and highly non-linear, is to schedule the committed generating unit outputs so as to meet the required load demand at minimum operating cost while satisfying system constraints. Hence, for economic operation of the system, the total demand must be suitably shared among the generating units with an objective to minimize the total generation cost for the system. Economic Dispatch is a procedure to determine the electrical power to be generated by the Committed generating units in a power system so that the total generation cost of the system is minimized, while satisfying the load demand simultaneously. An clone optimization technique for solving the economic dispatch problem in a power system is very useful and gives accurate result compare to other classical method. The proposed technique implemented Clonal Selection algorithm with cloning, mutation and selection approaches. For solving economic load dispatch problem this approach was tested. For generating unit at varies loading condition, the feasibility of proposed technique was demonstrated on a system. The Artificial Immune System optimization technique with Reproduction Crossover and mutation has provided the best result in terms of cost minimization and least execution time.

A compact microstrip patch antenna became a very useful in communication systems. Properties like compactness, light weight, high bandwidth make it a good candidate of communication system. This paper reviews the performance analysis of Compact Dual-Band Microstrip Antenna for IEEE 802.11a WLAN Application [1], comparative analysis of sshaped Multiband microstrip patch Antenna [2], Dual-Band Antenna with Compact Radiator for 2.4/5.2/5.8 GHz WLAN Applications [3], A Slot-Monopole Antenna for Dual-Band WLAN Applications [4] and Compact Broadband Slotted Rectangular Microstrip Antenna [5]. The paper also discusses the technology used in order to bring the required changes in terms of improved performance characteristics.

Recently, modular multilevel inverter(MMLI) have gained interest for photovoltaic applications. This topology minimizes the total harmonic distortion both at the DC and AC side and reduces the voltage stress across the devices for high voltage applications compared to the conventional multilevel inverter. This paper explains the significance of a MMLI by employing phase shift PWM technique. This control algorithm is implemented in SPARTAN/FPGA board. The important aspect of this paper is the issues related to capacitor voltage balancing is addressed. The MMLI is powered by PV source and the modeling of PV alongwith MPPT is implemented in MATLAB. The validity of the proposed modular MLI topology is confirmed by simulation and experimentation.

This paper presents a single phase digital prepaid energy meter based on two microcontrollers and a single phase energy meter IC. This digital prepaid energy meter does not have any rotating parts. The energy consumption is calculated using the output pulses of the energy meter chip and the internal counter of microcontroller (ATmega32). A microcontroller (ATtiny13) is used as a smart card and the numbers of units recharged by the consumers are written in it. A relay system has been used which either isolates or establishes the connection between the electrical load and energy meter through the supply mains depending upon the units present in the smart card. Energy consumption (kWh), maximum demand (kW), total unit recharged (kWh) and rest of the units (kWh) are stored in the ATmega32 to ensure the accurate measurement even in the event of an electrical power outage that can be easily read from a 20×4 LCD. As soon as the supply is restored, energy meter restarts with the stored values. A single phase prepaid energy meter prototype has been implemented to provide measurement up to 40A load current and 230V line to neutral voltage. Necessary program for microcontrollers are written in c-language and compiled by Win-AVR libc compiler.

This paper presents a novel method of allocation of capacitor size for a distribution feeder with uncertain load. The interval mathematics is used to perform the power flow solution of radial distribution system. The simulation results have been obtained using the INTLAB Toolbox in MATLAB environment. The standard 15-bus, 10-bus and the 33-bus radial distribution systems which are used by the researchers have been analyzed to demonstrate the effectiveness of the proposed approach. The developed program gives the range of the capacitor ratings in kVAr which could be selected for compensation, corresponding to the min and max limits of the voltages at each bus. For a range of values of capacitor ratings, which when installed at a particular bus results in the range of reduction in cost of capacitor and energy loss reduction. This information is very useful for a distribution system planner.

Voltage instability problems have become important issues in unbalanced distribution networks. In this paper, a new bus positive sequence voltage index of Vcollapse/Vbase-load is introduced to identify the weakest three-phase buses in unbalanced three-phase distribution networks. First, the proposed ranking index is validated based on grid losses and PV curves without and with compensation devices. Then, the index is utilized to place three-phase DG without and with SVC devices at the three-phase weakest buses of the modified IEEE unbalanced 13 node test feeder using the DIgSILENT Power Factory software. Finally, simulation results are presented to show the application of the proposed approach in improving voltage stability and increasing the maximum loading factor under unbalanced loading and/or network conditions.

Electrostatic discharge tester has been designed to measure the electrostatic discharge produced in the woven fabric in terms of kilovolts. Various types of fabrics have been tested for their static properties by using Box-behnken design and their values were analysed based on their influencing parameters such as rubbing cycle, pressure and speed. It is observed that the value obtained by the electrostatic discharge tester varies from cotton, silk and polyester depending upon moisture regain values. It has been found that the maximum static discharge value generated for polyester while testing was 3 kilovolts, which was comparatively higher than cotton (2.1 kilovolts) and for silk(1.8 kilovolts) .The optimum values and their regression, correlation co-efficient were also analyzed.

In this paper, a three layer Small single feed multiband microstrip antenna loaded with slit and two perpendicular shorting posts, is presented. Wide band frequency of operation demonstrated by single geometry, for broadening the bandwidth gap-coupled multi-resonator loaded on the patch, the simulation of proposed design antenna has done by MOM IE3DTM Simulator. The geometry of a single probe fed rectangular microstrip antenna has textured by slit loading and two orthogonal shorting pin on the top layer patch. We have also textured the size of the antenna. This proposed antenna is used for GSM, satellite and wireless communication in, L Band. Achieved 63% reduction of geometrical area of the antenna for L –Band, achieved 57% -10dB impedance bandwidth of L Band.