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Articles
by
S. Palani |
Total Records (
6 ) for
S. Palani |
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S. Rajendran
and
S. Palani
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This study deals with design of Proportional + Integral (PI) controller, GA based controller for a non-linear liquid spherical tank system. Level control of a spherical tank is a complex issue because of the non-linear nature of the tank. For each stable operating point, a first order process with Time Delay Model was identified using process Reaction Curve Method. The need for improved performance of the process has led to the development of the optimal controllers. GA is an Evolutionary algorithm that is proposed in this aspect. The performance of GA based controllers is compared with conventional controller tuned using Ziegler-Nicholas (Z-N) Method. The comparison is done based on rise time, settling time, overshoot and it was found that the GA based controller is better suited for this process. |
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S. AugustiLindiya
,
S. Palani
,
K. Vijayarekha
and
S. Shree Ram Senthil
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The control of power electronic circuits is a challenging
field of research due to the requirements imposed by the applications. A controller
design for a Buck converter which steps down a given dc value to a desired regulated
dc value is the system taken into consideration in this study. The controller
designed for Buck converter has to control rise time, peak overshoot, settling
time, bandwidth which are affected by the load and line variations. Quarter
Amplitude Decay (QAD), Internal Model Control (IMC) and Pole placement techniques
are used to obtain the parameters of the PID controller. The performances of
these tuning procedures are evaluated and the comparison is tabulated. It is
found that the controller tuned by pole placement method gives less rise time
and settling time with negligible overshoot. But transfer function of pole-placement
base controller is quite complex and has high number coefficients which is difficult
to realize in real time systems. QAD based PID controller has less rise time
and settling time but it has peak over shoot which will produce voltage spikes
in real time systems. Hence an IMC based PID controller which has acceptable
rise time and settling time with no peak overshoot is realized in real form
by using operational amplifiers. The performance is evaluated and tabulated
under varying load and reference voltage conditions. |
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R. Balasubramanian
,
K. Parkavi Karthirvelu
,
N. Divya
,
Rengarajan Amirtharajan
and
S. Palani
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Z source converter is the improved version of Voltage Source Inverter (VSI) which utilizes shoot through state of the switches and can be operated in both buck and boost mode of operation. The major drawbacks of Z Source Converter (ZSC) is the high cost, more space and not suitable for lower power applications. In order to overcome these disadvantages, Switched Boost Converter (SBC) is proposed. The proposed converter overcomes the limitations of the conventional ZSC such as lower cost, compact space and less use of passive components. This feature of SBC makes it appropriate for micro grid applications. In this study, SBC is designed for micro grid applications with Proportional-integral controller as well as fuzzy logic controller and total harmonic distortions are compared. |
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R. Balasubramanian
,
Parkavi Kathirvelu
,
Shashwat
and
S. Palani
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A nonlinear control technique with Hybrid Active Power Filter topology (HAPF) is projected in this study for eliminating current harmonics produced via onlinear load when connected along a power system. An active power filter linked to a shunt inactive LC Filter constitutes the proposed hybrid filter. Hybrid filter performance is been evaluated from the results obtained from the simulations done by Simulink software. Influence of Q factor and passive filter ratings on the hybrid schemes compensation performance are also evaluated. It is shown that the proposed configuration can effectively suppress current harmonics. |
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K. Sakthivel
,
S. Palani
,
R. Selvaraj
,
D. Venkadesan
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H. Sivasankari
and
B. Senthil Kumar
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The present study were designed to scientifically evaluate the cardioprotective potential of ethanolic extract of scilla hyacinthina (Family: Hyacinthinae), a medicinal herb, on Doxorubicin (DOX) induced myocardial infarction (MI) in albino rats. DOX is one of the most effective chemotherapeutic drugs in cancer, however, its incidence of cardiotoxicity compromises its therapeutic index. DOX-induced heart failure is thought to be caused by reduction/oxidation cycling of DOX to generate oxidative stress and cardiomyocyte cell death. A Doxorubicin dose of 20 mg kg-1 was selected for the present study as this dose offered significant alteration in biochemical parameters and moderate necrosis in heart. Effect of SHA oral treatment for 14 days at two doses (250 and 500 mg kg-1 b.wt) was evaluated against DOX-induced cardiac necrosis. Significant myocardial necrosis, depletion of endogenous antioxidants and biochemical parameters were observed in DOX-treated animals when compared with the normal animals. The pretreatment with SHA to DOX-induced rats significantly prevented the altered biochemical variation such as marker enzymes (SGPT, SGOT, CPK and LDH), lipid profile (LDL, VLDL, TGs, HDL and Total cholesterol) and antioxidant parameters (SOD, GSH, CAT, GSH-Px, MDA and GR) to near normal status. Serum urea, uric acid and alkaline phosphate, which increased on DOX administration, registered near normal values on pretreatment with SHA. Histology of pretreated with SHA to DOX-induced heart showed a significant recovery from cell damage. The present findings have demonstrated that the cardioprotective effects of SHA in DOX-induced oxidative damage may be due to an augmentation of the endogenous antioxidants and inhibition of lipid peroxidation of membrane. |
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K. Abdul Hameed
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S. Palani
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This study presents a novel Bacterial Foraging Algorithm (BFA) to tune optimal gains of a Proportional Integral Derivative (PID) type multiple stabilizers for multi machine power system. The problem of robustly tuning of PID based multiple stabilizer design is formulated, as an optimization problem according to the time domain-based objective function which is solved by Bacterial Foraging Algorithm (BFA) that has a strong ability to find the most optimistic results. To demonstrate the effectiveness and robustness of the proposed stabilizers, the design process takes a wide range of operating conditions and system configuration into account. The effectiveness of the proposed stabilizer is demonstrated through non-linear simulation studies and performance indices on a 4 machine 2 area power system in comparison with the Conventional Power System Stabilizers (CPSS) and Particle Swarm Optimization (PSO) based optimized PID type stabilizers (PSOPSS). The results of these studies show that the proposed BFA based optimized PID type stabilizers have an excellent capability in damping power system inter-area oscillations and enhance greatly the dynamic stability of the power system for a wide range of operating conditions. The results obtained using the proposed method is much superior than those obtained by CPSS and PSOPSS based tuned stabilizers in terms of accuracy, convergence and computational effort. |
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