i-manager's Journal on Electrical Engineering (JEE)


Volume 6 Issue 4 April - June 2013

Research Paper

Condition Monitoring of SF6 Filled Make Switch with Special Emphasis on Troubleshooting

G Venkateswarlu* , N.R. Mondal**, J.R. Gajbhiye***
*-*--*** Central Power Resesarch institute, STDS, Bhopal.
Venkateswarlu, G., Mondal, N. R., and Gajbhiye, J. R. (2013). Condition Monitoring Of SF6 Filled Make Switch With Special Emphasis On Troubleshooting. i-manager’s Journal on Electrical Engineering, 6(4), 1-8. https://doi.org/10.26634/jee.6.4.2321

Abstract

Make switch is used in short circuit testing laboratories. The Make Switch used in CPRI laboratories combine high current (80 kA rms) or high voltage (up to 24 kV rms) of electrical circuits with a brief and accurate closing time (<14 ms, ± 0.2ms) during a 100msec to 3sec short circuit test. The role of make switch during short circuit testing is crucial. Hence condition monitoring of make switch should get utmost important in the short circuit plant. Make switch cannot open under load,and is designed to ensure desired operation and facilitate maintenance of of it. During operation of make switch, safety of equipments is of prime importance. It is to be ensured that any operation of make switch does not damage its own parts or other electrical equipments. This is achieved by proper designing of mechanical and electrical interlocks in the control scheme. This paper emphasizes the importance of make switch during short circuit testing and its condition monitoring & troubleshooting.

Research Paper

Reducing Torque Pulsation of Induction Motor using Matrix Converter

Chaitanya* , Hussain Shaik**
* Assistant professor V.J.I.T
** Assistant professor V.J.I.T
Chaitanya, S., and Shaik, H. (2013). Reducing Torque Pulsation Of Induction Motor Using Matrix Converter. i-manager’s Journal on Electrical Engineering, 6(4), 7-13. https://doi.org/10.26634/jee.6.4.2322

Abstract

This paper presents a design of Matrix converter using space vector modulation which is connected to an Induction motor. When the Induction motor is driven by a matrix converter using space vector modulation the torque pulsation is reduced and improves the speed of the motor. Switching losses of the converter is also reduced. Matrix converter does not require any DC link. Matrix converter has its unique feature is pure sinusoidal. Because of this feature harmonic losses are reduced. Thus the matrix converter improves overall performance of the motor. Matrix converter is a better alternative for PWM inverters. The simulation performance on matrix converter connected an induction motor using Matlab/simulink show good response of speed and torque. The matrix converter is superior to inverter drives because of its regeneration ability and four-quadrant operation. Therefore it meets the stringent energy efficiency and power quality.

Research Paper

Fuzzy Direct Torque and Flux Control of Induction Motor Using Fuzzy Speed controller

Sudheer* , Kodad SF**, Sarvesh B***
Sudheer, H., Kodad, S. F. and Sarvesh, B. (2013). Fuzzy Direct Torque and Flux Control of Induction Motor Using Fuzzy Speed controller. i-manager’s Journal on Electrical Engineering, 6(4), 14-21. https://doi.org/10.26634/jee.6.4.2323

Abstract

Classical DTC has inherent disadvantages such as: problems during starting resulting from the null states, the compulsory requirement of torque and flux estimators, and high torque ripple. In this paper classical DTC, Fuzzy DTFC along with Fuzzy logic based speed controller are designed and their results are compared. Classical DTC is improved by means of Fuzzy logic using 180 fuzzy rule base which eliminates hysterisis controllers and shows improved performance compared to classical DTC. The Classical DTC with PI type speed regulator results in high Torque and Flux ripples due to nonlinearity. In Fuzzy Logic DTFC torque and flux linkage hysterisis loop controller are eliminated and the transient and steady state performance of drive is improved due to fuzzy PI speed regulator. The improved performance and effectiveness of proposed method Fuzzy DTFC with Fuzzy Speed controller is evaluated through digital simulation using Matlab-Simulink.

Research Paper

Natural Harmonic Elimination of Square-Wave Inverter for Induction Motor Drive

Seshagiri Boppana* , G. Durga Prasad**, T. Suresh Kumar***
* Asst. Professor, EEE Dept., Vishnu Institute of Technology, Vishnupur, Bhimavaram, WG(Dt), India.
** Asst. Professor, EEE Dept., Swarnandra College of Engineering & Technology, Setharamapuram, Narasapuram, WG(Dt), India.
*** MIEEE, Assoc. Professor, EEE Dept., Vishnu Institute of Technology, Vishnupur, Bhimavaram, WG(Dt), India.
Boppana, S., Prasad, G. D., and Kumar, T. S. (2013). Natural Harmonic Elimination of Square-Wave Inverter for Induction Motor Drive. i-manager’s Journal on Electrical Engineering, 6(4), 22-26. https://doi.org/10.26634/jee.6.4.2324

Abstract

Normally, high power voltage source inverters are very common in industry and need to provide sinusoidal output to the load for proficient operation. Sinusoidal wave output can be obtained in inverters by adopting various modulation techniques, which increases the switching frequency of the inverter elements like IGBTs and Power MOSFETs, which are having limited power handling capabilities. In case of moderate to high power output from the inverter, SCRs or GTOs need to be used as inverter switching elements. These devices are having limited switching frequencies making the inverter operation impossible using the high frequency modulation techniques. This results in an output with rich harmonic content. The latest multilevel inverters can be used to overcome these problems. But the circuit is very complex and also requires isolated power supplies to feed the inverter. In the proposed project, a low frequency square wave inverter using SCRs is operated along with a series connected pulse width modulated inverter, in each phase designed. The 3-phase SCR inverter basically works as a voltage source inverter producing square wave output. The series compensator used in each phase produce only the desired harmonic voltages to make the net output voltage sinusoidal, with small PWM switching harmonics only. The series compensators are designed using the IGBTs, forming a bridge inverter configuration.

Research Paper

Transient Fault Response of Grid Connected Wind Electric Generators

G. Vikram* , B. Linga Reddy*****
*Department of EEE, Vijaya Krishna Institute of Technology and Sciences, Hyderabad.
** Dept.of Physics, CBIT, Hyderabad.
*** Department of EEE, CBIT,Hyderabad.
Vikram, G., Reddy, B.L., and Prasad, P. V. (2013). Transient Fault Response Of Grid Connected Wind Electric Generators.. i-manager’s Journal on Electrical Engineering, 6(4), 27-31. https://doi.org/10.26634/jee.6.4.2325

Abstract

In recent years, as demand is increasing continuously, the search for renewable energy sources is intensified. Wind energy is one of the latest renewable energy sources and this paper is intended at presenting the impact of wind generators on the transient response of a power system network. The analysis is carried out for different types of wind generators i.e., Squirrel Cage Induction Generator (SCIG), Doubly Fed Induction Generator (DFIG) for asymmetrical fault i.e. LLG fault on the system and the simulation is carried out on Matlab/Simulink software.