22 research outputs found
Co-Simulation of IBC Type PFC Converter with Fuzzy Logic Controller
Many electronic power systems use bridge rectifiers, which are nonlinear, resulting in low power factor activity and high harmonic distortion due to the existence of nonlinear devices. To conform to harmonic standard requirements, longer device lifetime, and smooth operation of other devices in the system, power factor correction is required in these devices. The proposed system with an input power supply linked to a bridge rectifier which transforms ac to dc in this analysis, which is then linked to an Interleaved Boost Converter (IBC) with two parallel boost converters. The Interleaved Boost Converter uses Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) to work with the switches. The proportional controller gain has the effect of minimizing the time of increase and does not remove the error of steady-state. The result of removing the steady-state error is an integral control gain but deteriorate the transient response. The fuzzy controller takes inputs from the actual signals feedback values. Using the membership functions in the fuzzification method, the data provided to the fuzzy system is transformed into linguistic variables. To evaluate the performance, a series of rules that mimic the decision-making process of the human expert running the machine is then implemented using such inference mechanisms. Finally, a defuzzification block that transforms the output to a crisp value in such a manner that both structures are consistent. The proposed method is implemented using the software of MATLAB/Simulink and PSIM. The co-simulation result shows that the power factor achieved here is 0.9988, the Total Harmonic Distortion (THD) maintained is less than 5% and the average efficiency concluded here is 98% respectively. To verify the feasibility of the proposed scheme, a prototype model of a 5kW IBC type PFC converter is developed which is converting 230V AC input voltage to 400V DC output voltage, is implemented using a Microchip IC dsPIC33FJ16GS504. The experimental results are satisfactory, which uncover that a power factor is 0.9992 (close to unity), THD is 4.11; less than 5% and 98% overall efficiency at 100 kHz switching frequency, 230Vrms input voltage. With the higher performance, as a result, topology with high switching frequency makes a more compact, but costlier converter
Electrosynthesis of cobalt sulphide through non-aqueous medium and its characterization
291-294<span style="font-size:
15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""="">Cobalt
sulphide thin films were prepared by electrodeposition technique on conducting
glass (fluorine doped tinoxide; i.e. FTO and stainless steel substrates at
different bath temperature. The films were prepared through non-aqueous medium (ethylene
glycol bath) by using cobalt sulphate and sodium thiosulphate as a initial
ingredients. The films were deposited at different volume ratio of initial
ingredient. The structural, optical and microscopic characteristics of these
films have been examined. The films are polycrystalline and exhibits hexagonal
structure having an optical bandgap <span style="font-size:16.0pt;
mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif""="">0.78 eV.
SEM studies show polycrystalline structure with a rough surface and clearly
defined grains.
</span
<span style="font-size:14.0pt;line-height: 115%;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; color:black;mso-ansi-language:EN-IN;mso-fareast-language:EN-IN;mso-bidi-language: HI" lang="EN-IN">Preparntion and characterization of chemically deposited As<sub>2</sub>S<sub>3</sub> thin films</span>
196-198A method for
chemical bath deposition of As2S3 thin films in an
aqueous acidic medium is described. As2O3, was used as As3+
ion source and thioacetamide as a S2- ion source. Sodium salt
of ethylene diamine tetracetic acid was used as a complexing agent for As2O3.
The preparative parameters like solution concentration, volume of sulphur ion
source etc. have been optimized.
X-ray diffraction, SEM,
optical absorption, electrical resistivity, etc. are used to characterize the
films.</span
Preparation of cadmium oxide films by spray pyrolysis and its conversion into cadmium chalcogenide films
616-619<span style="font-size:14.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Thin films of cadmium oxide were prepared on to glass substrates by a spray
pyrolysis technique from an aqueous solution of cadmium chloride. Cadmium oxide
films are further converted into cadmium chalcogenide films by using simple
chemical displacement method. The cadmium oxide films were dipped into sodium sulphide
and sodiumseleno sulphate solution to convert into CdS and CdSe films
respecrively. The XRD studies show that the films of CdO and CdSe are
microcrystalline, however films of CdS are polycrystalline. The optical
absorption studies gives the bandgap energies as 2.45, 2.30 and 1.9 eV for the
CdO, CdS and CdSe films respectively.</span