Informatics Publishing Limited

N. Usha ¹, M. Vijaya Kumar ²

Affiliations
1 JNTU, Anantapur, A.P, IN
2 Dept. of Electrical & Electronics Engg., JNTU, Anantapur, A.P, IN

Abstract

This paper presents the comparison of Push-Pull Inverter and Z-Source Inverter based Static Compensators (STATCOM).The closed loop system with STATCOM is modeled and simulated using the blocks of MATLAB/SIMULINK.Voltage sag mitigation using Push-Pull Inverter and ZSource Inverter are presented. The present work proposes Z-Source Inverter and Push-Pull Inverter based STATCOM for the control of reactive power and hence the voltage. The advantages of these systems are reduced ripple, shoot through capability and reduced heating. The results of Push-Pull Inverter based STATCOM are compared with those of Z-Source Inverter based STATCOM system.

Keywords

FACTS, Static Synchronous Compensator (STATCOM), ZSource Inverter (ZSI), Push-pull Inverter, Voltage Sag.

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N. Usha ¹, G. R. Janardhana ¹

Affiliations
1 Mycology Laboratory, Department of Studies in Botany, University of Mysore, Manasagangotri, Mysore 570 006, Karnataka, IN

Abstract

The present investigation was carried out in the forests of five districts of western ghats of Karnataka which includes B.R. Hills of Chamarajnagar, H.D. Kote forest of Mysore, Aanekaadu forest of Kodagu, Bisle forest of Hassan and forests of Chickmagalur districts representing four different habitats such as grass, litter, wood and soil respectively. The fruiting bodies of macrofungi were collected between August 2010 and August 2012. In an extensive survey a total of 135 species of macrofungi belonging to 56 genera and 34 families were enumerated. Association of species was found to be abundant with litter followed by wood, grass and soil respectively Members of the family Agaricaceae were found to be predominant followed by Polyporaceae, Marasmiaceae, Mycenaceae and Russulaceae. Species of macrofuring belonging to 18 other families were also recorded.

Keywords

Forests of Karnataka, Fungal Diversity, Macrofungi

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V. Kiran Kumar ¹, Fazal Mahemood ¹, N. Usha ¹

Affiliations
1 Dept. of ISE, SJBIT, Bangalore, IN

Abstract

Security continues to be an issue for organizations. Good information security is a mix of physical security, computer security, network security, backups, anti-virus software, firewalls, authentication methods, intrusion detection, confidentiality, integrity, availability, etc., Risk is the combination of threat and vulnerability. This paper deals with Information security in particular and concentrates on corporate networks. Threats without vulnerabilities pose no risk. Likewise, vulnerabilities without threats pose no risk. A secure system should still permit authorized users to carry out legitimate and useful tasks. It might be possible to secure a computer system against misuse using extreme measures. Most computer systems cannot be made secure even after the application of extensive "computer security" measures. Further more, if they are secure then functionality and ease of use often decreases. The assurance of security depends not only on the soundness of the design strategy, but also on the assurance of correctness of the implementation. There is no universal standard notion of what secure behavior is. "Security" is a concept that is unique to each situation. One technique enforces the principle of least privilege to great extent is even if an attacker gains access to one part of the system, fine-grained security ensures that it is just as difficult for them to access the rest. Further more, by breaking the system up into smaller components; the complexity of individual components is reduced. Most of the time people concentrate on coming out with efficient algorithms to analyze, process data. But not much importance is given to ensure data integrity, security, privacy, etc.

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N. Usha ¹, P. Venkata Prasad ², K. Ramesh Reddy ³

Affiliations
1 Research Scholar , JNTUH. GNITS,Hyderabad-500104, IN
2 Professor, CBIT. Gandipet, Hyderabad-500075., IN
3 Professor,GNITS. Shaikpet, Hyderabad-500104, IN

Abstract

Many of the Adjustable speed drives are inverter based motor drives. There are various PWM techniques to control the inverter. This paper presents modified control strategy for five level asymmetrical dual inverter fed induction motor drive. The control method for the inverter improves the performance of the drive. The characteristics of the drive at different modulation indices were observed and found that at higher modulation index the total harmonic distortion of line currents is less. The time response of speed is better at modulation index greater than 0.75.The simulation based analysis and design is carried out in MATLAB^TM software.

Keywords

Dual Inverter, Space Vector Pulse Width Modulation, Induction Motor Drive

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