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


Volume 14 Issue 4 April - June 2021

Research Paper

Improved Quadratic Boost Converter with Reduced Current Stress on Input Inductor for Sustainable Energy Source Applications

Naga Kota Reddy Chegireddy * , Sai Babu Choppavarapu **
*-** Department of Electrical and Electronics Engineering, Jawaharlal Nehru Technological University Kakinada, Kakinada, Andhra Pradesh, India.
Chegireddy, N. K. R., and Choppavarapu, S. B. (2021). Improved Quadratic Boost Converter with Reduced Current Stress on Input Inductor for Sustainable Energy Source Applications. i-manager's Journal on Electrical Engineering, 14(4), 1-10. https://doi.org/10.26634/jee.14.4.18396

Abstract

Utilization of sustainable energy sources is increasing because they are non-toxic and environment friendly. DC-DC step-up converters with high voltage gain are required for connecting sustainable energy sources to loads. In high voltage gain DCDC step up converters, single switch converters are gaining more attention. When operating at a high duty cycle, in singleswitch converters, both the switch and the input inductor undergo more current stress. This paper analyses an improved quadratic boost converter (QBC) with decreased current stress on both switch and input inductor. The design of various parameters, such as an inductor and a capacitor, is depicted. The equations have been evaluated in order to understand the current and voltage stress of the switch and diodes. These equations will aid in the selection of their ratings. With this improved quadratic boost converter, the switch and input inductor current stresses are reduced by 50% for a given duty cycle value and the input current ripples are also reduced by 67%, when compared with QBC. Finally, the theoretical studies are validated through simulation using MATLAB with the support of the PLECS Blockset.

Research Paper

Rotor Angle Stability Enhancement Using Coordinated PSS and TCSC for 3 Machine 9 Bus System

Niharika Agrawal * , Mamatha M. Gowda **
*-** Department of Electrical and Electronics Engineering, SJB Institute of Technology, Bengaluru, Karnataka, India.
Agrawal, N., and Gowda, M. M. (2021). Rotor Angle Stability Enhancement Using Coordinated PSS and TCSC for 3 Machine 9 Bus System. i-manager's Journal on Electrical Engineering, 14(4), 11-18. https://doi.org/10.26634/jee.14.4.18375

Abstract

The demand of electricity is continuously increasing. There are interconnections of power systems which are located at different places. Due to weak interconnection between tie lines, there are oscillations in the power system which affect the stability of the power system. There are oscillations of active power in power transmission systems particularly during heavy power transfer. Such oscillations can be excited by a number of reasons such as line faults or a sudden change of generator output. Due to the presence of active power oscillations, there are limitations of power transmission capacity. It is often possible to find remedy by building additional lines or upgrading existing lines, but this cost a lot of money and takes a lot of time. In some cases, it may also be possible to introduce power system stabilizers (PSS) on generators, but this will not always work, particularly not for inter-area power oscillations, which tend to be of a low frequency (typically 0.2 Hz to 0.7 Hz). In this condition, a FACTS device called Thyristor-Controlled Series Compensation (TCSC) will be an attractive alternative to consider. It provides a cost-effective, robust power oscillation damper, insensitive to its location in the system and it is noninteracting with local oscillation modes. In a number of cases, it will turn out to be the best practicable solution.

Research Paper

Effect of CQD Surface Treatment on Silica Nanofillers for Lightning Impulse Strength Improvement of Mineral Oil

P. Kasi Viswanathan* , S. Chandrasekar **, Balaji Sakthivel ***
*-*** Department of Electrical and Electronics Engineering, Sona College of Technology, Salem, Tamil Nadu, India.
Viswanathan, P. K., Chandrasekar, S., and Sakthivel, B. (2021). Effect of CQD Surface Treatment on Silica Nanofillers for Lightning Impulse Strength Improvement of Mineral Oil. i-manager's Journal on Electrical Engineering, 14(4), 19-26. https://doi.org/10.26634/jee.14.4.18234

Abstract

This study provides an understanding about lightning impulse characteristics of mineral oil used in transformers and other high voltage applications. The withstand capability of mineral oil is studied under various experimental conditions, such as different electrode spacing, electrode type, nanofiller type and filler concentration. Experiments are carried out for 5 mm and 10 mm interelectrode gaps. Different electrode configurations such as needle-sphere and needle-plane electrodes are used. Nanofillers such as SiO2 and carbon quantum dots (CQD) treated SiO2 nanoparticles are used in various concentrations such as 0.01% weight, 0.05% weight and 0.1% weight of mineral oil. Comparison is done for positive and negative polarities of lightning impulse test voltages. From the experimental results, it follows that the influence of nanoparticles to deliver better results in impulse withstand capabilities of commercially used mineral oil with improved performance in lightning impulse to withstand strength.

Research Paper

Analysis of Selective Harmonic Elimination for Three-phase Voltage/Current Source Inverter

R. Linga Swamy*
Department of Electrical Engineering, University College of Engineering, Osmania University, Hyderabad, Telangana, India.
Swamy, R. L. (2021). Analysis of Selective Harmonic Elimination for Three-phase Voltage/Current Source Inverter. i-manager's Journal on Electrical Engineering, 14(4), 27-46. https://doi.org/10.26634/jee.14.4.18401

Abstract

In this paper, selective harmonic elimination pulse width modulation (SHE-PWM) technique is applied for the control of three-phase voltage source inverter (VSI) with RL and Induction motor loads. SHE-PWM is also applied to three-phase current source inverters (CSI) with RC load. A simplified approach for applying SHE to both VSI and CSI is proposed and analysed. This study enables to calculate switching angles for any number (even or odd) of harmonics to be eliminated. The purpose of calculating switching angles is to eliminate the selected order harmonics to improve the performance, and detailed explanation has been given on how these switching angles can eliminate the selected harmonics. With the proposed approach, along with eliminating the selected harmonic component, the magnitude of the fundamental component is also controlled to the desired value. The entire study has been conducted using MATLAB Simulink Software.

Research Paper

Design and Implementation of Solar Grass Cutter

Akhilesh B. B. * , Daniel Abraham **, Divyashree S. ***, Himashree M. S. ****, Manu D. K. *****
*-***** Department of Electronics and Communication Engineering, K S School of Engineering and Management, Bengaluru, Karnataka, India.
Akhilesh, B. B., Abraham, D., Divyashree, S., Himashree, M. S., and Manu, D. K. (2021). Design and Implementation of Solar Grass Cutter. i-manager's Journal on Electrical Engineering, 14(4), 47-52. https://doi.org/10.26634/jee.14.4.18368

Abstract

This paper proposes a lawnmower which operates on solar power, eliminating the use of internal combustible engines that uses fossil fuel. This new design has no emission and hence there is no pollution. A microcontroller is used in this work to control the entire operating process of the lawnmower or the grass cutter. An ultrasonic sensor is used to detect obstacles; DC motors are used for the robot chassis and cutting blades. All the electromechanical devices used in this cutter are powered by solar panels placed on trucks and trailers. The key objective of this design is to keep the environment clean with reducing noise pollution and clean air.