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M. Ranjani ¹, P. Murugesan ²

Affiliations
1 Department of Electrical and Electronics Engineering Sathyabama University, Chennai, Tamilnadu, IN
2 Department of Electrical and Electronics Engineering S.A.Engineering College, Chennai, Tamilnadu, IN

Abstract

This paper proposes a Fuzzy logic based dc motor fed with an single input dc-dc converter based on Quasi-Z-source converters. The PI algorithm is the most popular feedback controller used within the process industries. It is robust easily understood algorithm that can provide excellent control performance despite the varied dynamic characteristics of process plant. But the tuning of the PI controller parameters is not easy and does not give the optimal required response, especially with non-liner systems. In the last years emerged several new intelligent techniques like, Fuzzy logic controller. This paper deals the non-liner mathematical model and simulation for speed control of separately excited D.C. motor with closed loop PI controller. The conventional PI technique is represented as a point of comparison. The intelligent technique: FLC is proposed to tune the PI controller parameters. The obtained results of the closed loop FLC-PI Controller response shows the excellent response with comparing to the conventional PI, a good results gives in FLC-PI Controller. The simulation results presented in this paper show the effectiveness of the proposed method, which has got a wide number of advantages.

Keywords

Proportional Integral Controller (PI), Fuzzy Logic Controller (FLC), Quasi-Z-source DC/DC Converter (qZSC), Direct Current (DC)

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M. Ranjani ¹, P. Murugesan ²

Affiliations
1 Electrical and Electronics Engineering Department, Sathyabama University, Chennai, Tamilnadu, IN
2 Department of Electrical and Electronics Engineering, S.A. Engineering College, Affiliated with Anna University, Chennai, Tamilnadu, IN

Abstract

This paper presents the design methods of Fuzzy logic controller using the genetic/evolutionary algorithms which are appearing as systematic methods now-a-days. This method easily provides an optimized design and forms the base for further process. This paper describes the design of PI-like FLC based on Genetic fuzzy optimization concepts. The proposed method has its simple structure that comprises of three gain factors associated with FLC which has two inputs and one output. The proposed method is applied to the problem of designing a GA tuned PI like Fuzzy speed controller (GA-FLC) for a ZVS QRC fed DC drive. The performance of the proposed work is compared with that of the conventional FLC (CFLC) for a ZVS QRC fed DC drive. It can be evaluated that the GA-FLC performs better than the conventional FLC with reduced overshoot and minimized steady state error.

Keywords

Zero Voltage Switching (ZVS), Quasi Resonant Converter (QRC), Proportional Integral (PI), Conventional Fuzzy Logic Controller (CFLC), Genetic Fuzzy Controller (GA-FLC).

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M. Ranjani ¹, S. Rajan ², A. G. Murugesan ³

Affiliations
1 Department of Microbiology, Cauvery College for Women, Trichy, IN
2 Department of Microbiology, M.R. Government Arts College, Mannargudi, IN
3 Centre of Excellence in Environmental Science, M.S University, Sri Paramakalyani, Alwarkurichi, IN

Abstract

The aim of the present study is to demonstrate the isolation and optimization bacteria with high cellulase activity from cow dung. The cellulolytic enzyme producing bacteria have been isolated from cow dung using Carboxymethyl cellulose clear zone (CMCZ) and Filter paper assay (FPA) techniques. Three isolates namely S1, S2, S3 have been isolated. According to the morphological and biochemical studies the isolates were primarily identified as Arthrobacter (S1), Ocrobacterium (S2), Flavobacterium (S3). Among the three isolates S2 showed maximal zone of enzyme utilization (1.2mm). Effect of incubation period, pH, temperature, carbon source was tested for cellulase productivity using Ocrobacterium (S2). Maximum growth was achieved at a time (Growth period) of 48 hours, highest cellulase activity was obtained after 72 hours of incubation by Filter paper assay. The maximum activity was achieved at 25°C and pH 5. When the bacterium was incubated at ammonium nitrate and Maltose it shows the increased enzyme activity.

Keywords

Ocrobacterium, Cellulase, Carboxymethyl Cellulose Clear Zone.

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M. Ranjani ¹, P. Murugesan ²

Affiliations
1 Department of Electrical and Electronics Engineering, Sathyabama University, Chennai, Tamilnadu, IN
2 Department of Electrical and Electronics Engineering, S.A. Engineering College, Chennai, Tamilnadu, IN

Abstract

In this paper, a fuzzy-genetic approach based controller for a buck converter is designed and modelled in Matlab/Simulink. Proposed controller uses a Takagi-Sugeno type fuzzy logic controller to regulate output dc voltage and a hysteresis current controller to force the input current to track a reference. Optimal values of fuzzy logic controller are determined by genetic algorithm. To indicate the steady state and transient performance, some simulation results are presented.

Keywords

Fuzzy Logic Controller (FLC), Buck Converter (BC), Genetic Algorithm (GA), Integral Absolute Error (IAE), Direct Current (DC).

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