Vel Technology Multitech

Chennai, India

Vel Technology Multitech

Chennai, India

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Mani P.K.,Vel Technology Multitech | Naidu K.S.,Vel Technology University
ARPN Journal of Engineering and Applied Sciences | Year: 2015

For the power quality improvement of the system FACTS devices like static synchronous compensator (STATCOM), static synchronous series compensator(SSSC), interline power flow controller (IPFC), and unified power flow controller (UPFC) etc. are introduced. These devices are used for the transmission system. But now a day's these FACTS devices are used for distribution system and called as custom power devices. The main custom power devices which are used in distribution system for power quality improvement are distribution static synchronous compensator (DSTATCOM), dynamic voltage Restorer (DVR), active filter (AF), unified power quality conditioner (UPQC) etc. In this paper, for power quality improvement in the distribution system, DVR is used with Fuzzy logic controller. There are two different loads are considered. One is linear load and the other is nonlinear load (induction motor). With these loads different fault situations are created and DVR performances are analyzed. © 2006-2015 Asian Research Publishing Network (ARPN).


Mani P.K.,Vel Technology Multitech | Siddappa Naidu K.,Vel Technology University
International Journal of Applied Engineering Research | Year: 2015

In years past, most electrical equipment operated on an ideal voltage and current waveform. However, in the past couple of decades there has been an explosion in the use of solid-state electronic technology. This new, highly efficient, electronic technology provides improved product quality with increased productivity by the use of smaller and lighter electrical components. Today we are able to produce products that cost less than in years past, but this new technology requires clean electric power and is highly sensitive to power distortions. Electronic equipment (switching power supplies) draws current differently than non-electronic equipment. Instead of a load having a constant impedance drawing current in proportion to the sinusoidal voltage, electronic devices change their impedance by switching on and off near the peak of the voltage waveform. Switching loads on and off during part of the waveform results in short, abrupt, non-sinusoidal current pulses during a controlled portion of the incoming peak voltage waveform. These abrupt pulsating current pulses introduce unanticipated reflective currents (harmonics) back into the power distribution system. The currents operate at frequencies other than the fundamental 50 Hz. Harmonic currents can be likened to the vibration of water in a water line when a valve is open and closed suddenly. In this paper power quality analysis done based on the real field measurements in a spinning mill reported and the recommendations are suggested. © Research India Publications.


Manila P.K.,Vel Technology Multitech | Siddappa Naidu K.,Vel Technology University
ARPN Journal of Engineering and Applied Sciences | Year: 2016

This paper presents a Fuzzy Logic Control Based (FLCB) Shunt Active Filter (SAF) capable of reducing the total harmonics distortion (THD) in Power System (PS). SAF is one of the key controllers in Flexible Alternating Current Transmission System (FACTS) to control the transmission line voltage and can be used in PS to enhance the power transmission capacity and extend the transient stability. In order to improve the power factor, compensate the reactive power and suppress the total harmonic distortion (THD) drawn from a Non-Linear Diode Rectifier Load (NLDRL) of SAF, we propose a Hysteresis Current Pulse Width Modulation (HCPWM) technique which is used as control for the switches of the Voltage Source Inverter (VSI) or SAF. The synchronous reference D-Q frame theory is used to generate the reference compensating currents for SAF. A fuzzy logic based control is developed to regulate the voltage of the DC capacitor. The system with control scheme is implemented in MATLAB/Simulink. The simulation results show the effectiveness of the proposed method for harmonic damping and voltage regulation. © 2006-2016 Asian Research Publishing Network (ARPN).


Mani P.K.,Vel Technology Multitech | Siddappa Naidu K.,Vel Technology University
ARPN Journal of Engineering and Applied Sciences | Year: 2016

Power quality has become an important factor in power systems, for consumer and household appliances with proliferation of various electric and electronic equipment and computer systems. The main causes of a poor power quality are harmonic currents, poor power factor, supply-voltage variations, etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply-voltage variation at the load side is compensated by unique devices S-D (STATCOM and DVR) in this paper. The proposed S-D system can improve the power quality at the point of common coupling on power distribution systems under unbalanced and distorted load conditions. The STATCOM is connected across the load to compensate for current-related problems such as reactive power compensation. The series component of the S-D device is Dynamic Voltage Restorer which inserts a voltage so as to maintain the voltage at the load terminals balanced and free of distortion. © 2006-2016 Asian Research Publishing Network (ARPN).


Chellaram C.,Vel Technology Multitech | Alex John A.,St Peters University
Asian Journal of Pharmaceutical and Clinical Research | Year: 2015

Objective: To screen and isolate peptide antibiotics producing epibiotic bacteria from the surface of the sea fan Juncella juncea, and partially purify the active compound. Methods: In this study, epibiotic bacteria were isolated by swabbing a small area of the coral surface with a sterile cotton swab, which was then directly swabbed on to Zobell marine agar plates. Antibiotic production was screened using agar overlay method and the active peptide was partially purified using anion exchange chromatography and reversed phase high-performance liquid chromatography (RP-HPLC). Phylogenetic identification based on comparative sequence analysis of 16Ss rRNA gene indicated that the stain fell under the genera Streptomyces. Results: In the initial screening using agar overlay method the strain was found to exhibit broad spectral activity exhibiting both antibacterial and antifungal activities. Protease digestion of the crude extract resulted in the loss of activity indicating the proteinaceous nature of the active molecules. Bioassay guided purification using anion exchange chromatography, and RP-HPLC was carried and the active peptide was partially purified. An epibiotic Streptomyces strain CN3 producing potent broad spectral peptide was isolated. Conclusion: This study highlights the importance of epibiotic bacteria associated with corals as a potential source for the discovery of novel antimicrobials and other natural products. © 2015, Asian Journal of Pharmaceutical and Clinical Research. All rights reserved.


Jayaraman A.,VelTech Multitech | Jebarani Sargunar P.N.,Vel Technology Multitech
International Journal of Applied Engineering Research | Year: 2015

Spread spectrum communication, with its unique characteristics and inherent noise cancellation capability becomes an increasingly popular technique for use in many different systems like military applications. In addition to that, Wavelets had been developed and has attracted much attention in signal processing that provides an effective alternative to conventional transforms. A new method for Wavelet denoising, that uses a Wavelet shrinkage estimate via Wiener filtering, is proposed. The main aspect of the proposed method is its use of two Wavelet bases-one for the design of the empirical Wiener filter, and other for its application. In addition to Wavelet denoising, the Wiener filter is used to process the signals corrupted by additive Gaussian noise; i.e., denois-ing is performed with a Wavelet-based method, and suppressing the coeffi-cients using the Wiener filter approach. The impulse response of the Wiener filter is calculated from the Wavelet transformed coefficients. One of the possible measurements of denoising quality is the mean Bit Error Rate. The simulation of the proposed method shows a low BER for higher values of SNR, than the system that uses conventional shrinkage methods, and the con-ventional spread spectrum receiver. © Research India Publications.


Mohana Sundaram K.,Vel Technology MultiTech | Sugavanam K.R.,Vel Technology HighTech | Senthil Kumar R.,Vel Technology HighTech
ARPN Journal of Engineering and Applied Sciences | Year: 2015

This paper analyze an effective comparison between Pulse width modulation (PWM) control approach and digital control approach for asymmetric DC-AC cascaded H-bridge multilevel inverter. The conventional available approach produces 2n+1 output level for n independent DC sources and the digital control approach produces 2n+1-1 output level for the same n independent DC sources with the same number switches. The proposed method also brings out the salient features of using Digital control over the conventional PWM control by producing a low total harmonic distortion level (THD) level while considering R-load. The simulation is done with the help of MATLAB and subsequently verified experimentally. © 2006-2015 Asian Research Publishing Network (ARPN).


Selvaraju P.,Vel Technology Multitech | Nirmala Gnanam Pricilla B.,St Anns College For Women
International Journal of Control Theory and Applications | Year: 2016

A cordial labeling as an application of communication network, in this paper we have given cordial labeling for the graph Cp•Cq t ∀ p, q and t, i.e., attaching the one vertex union of cycles Cq on each vertex of cycle Cp, and also shown that the cordial labeling for the quadrilateral snake graph QSn, ∀ n gluing with each vertex of graphs Cp • Cq t, i.e., QSn (Cp • Cq t ), ∀ n ≥0. Finally the domination number of this graph is analyzed. © International Science Press.


Mani P.K.,VEL Technology MULTITECH | Siddappa Naidu K.,Technology University
International Journal of Applied Engineering Research | Year: 2015

The STATCOM used in distribution systems is called DSTACOM (Distribution-STACOM) and its configuration is the same, but with small modifications. It can exchange both active and reactive power with the distribution system by varying the amplitude and phase angle of the converter voltage with respect to the line terminal voltage. A multilevel inverter can reduce the device voltage and the output harmonics by increasing the number of output voltage levels. There are several types of multilevel inverters: cascaded H-bridge (CHB), neutral point clamped, flying capacitor. In particular, among these topologies, CHB inverters are being widely used because of their modularity and simplicity. Various modulation methods can be applied to CRB inverters. CHB inverters can also increase the number of output voltage levels easily by increasing the number of H -bridges. This paper presents a DSTATCOM with a proportional integral controller based CHB multilevel inverter for the harmonics and reactive power mitigation of the nonlinear loads. This type of arrangements have been widely used for PQ applications due to increase in the number of voltage levels, low switching losses, low electromagnetic compatibility for hybrid filters and higher order harmonic elimination. © Research India Publications.


Mani P.K.,Vel Technology Multitech | Siddappa Naidu K.,Vel Technology Multitech
ARPN Journal of Engineering and Applied Sciences | Year: 2016

The main objective of this paper is to improve power quality in the facility side i.e. distribution side. For that we are implementing most recent FACTS device called Unified Power Quality Conditioner (UPQC). The unified power quality conditioner (UPQC) is a custom power device, which mitigates voltage and current-related PQ issues in the power distribution systems. The proposed topology helps to match the dc-link voltage requirement of the shunt and series active filters of the UPQC. The topology uses a capacitor in series with the interfacing inductor of the shunt active filter, and the system neutral is connected to the negative terminal of the dc-link voltage to avoid the requirement of the fourth leg in the voltage source inverter (VSI) of the shunt active filter. The average switching frequency of the switches in the VSI also reduces; consequently the switching losses in the inverters reduce. And also, the level of harmonics present in the distribution line gets reduced. © 2006-2016 Asian Research Publishing Network (ARPN).

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