R. Mahalakshmi currently serves as Assistant Professor at the department of Electrical & Electronics, Amrita School of Engineering, Bengaluru campus. She is pursing her Ph.D. in the area of grid connected renewable energy sources. Mahalakshmi  has over seven years of teaching experience. She joined Amrita University in July 2012.





2012  M.Tech. Dayananda Sagar college of engineering
2003  B.E. (EEE)   Government college of Engineering,Salem


Publication Type: Journal Article
Year of Publication Publication Type Title
2015 Journal Article R. Mahalakshmi, Manjunath, H. V., and Thampatty, K. C. S., “Design and implementation of quadratic buck-boost converter for PV array”, International Journal of Applied Engineering Research, vol. 10, pp. 1023-1034, 2015.[Abstract]

<p>Due to increase in electric energy demand, energy extraction from solar and wind are much concentrated in power electronic systems. There is a wide variation in the output of solar array and it needs efficient DC-DC converter. This paper discusses about the design and implementation of closed loop control of Quadratic buck boost converter for the variable DC input voltage whose voltage ratio is -D2/(1-D)2.This converter uses a single switch to control output voltage unlike cascaded buck and buck boost converters. Cascaded conventional converter uses two switches for the same voltage ratio of -D2/(1-D)2. They also suffer from duty cycle and switching frequency limitations during wide input voltage variations. These problems can be reduced with the help of quadratic converter. In this paper quadratic closed loop control of buck boost converter is proposed for the variable solar panel output. Simulation of the circuit is done using MATLAB simulink and hardware implementation results are discussed. © Research India Publications.</p>

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2015 Journal Article R. Mahalakshmi and Thampatty, K. C. Sindhu, “ Grid Connected Multilevel Inverter for Renewable Energy Applications”, Procedia Technology, vol. 21, pp. 636 - 642, 2015.[Abstract]

Electrical energy generation from renewable energy sources such as sun, wind etc., are widely adopted due to the increase in electricity consumption. The integration of renewable energy sources with the grid plays an important role in energy utilization. It is difficult to utilize electricity from renewable energy sources directly for the injection of power into the grid. Hence the system needs power electronic converters as an interface between renewable energy sources and grid/load. This paper discusses about the integration of three phase six level voltage source inverter into the grid. Three phase 2000 VA inverter is designed by using three, single phase eight switch six level inverters (in quarter cycle) and each single phase inverter uses three DC voltage sources which can be derived from renewable energy sources such as solar, wind and fuel cell. The pure sinusoidal 415V three phase voltage is obtained from inverter to inject the power into grid and to the three phase resistive load. The proposed three phase Multi Level Inverter (MLI) is compared with the conventional three phase inverter and the observed THD of the conventional MLI is 31%. THD of the proposed MLI output voltage is analyzed which is 0.13% and found to be very less compared to six and 12 pulse conventional converter topologies. The simulation on the proposed inverter topology is done in MATLAB/Simulink and the results are verified. More »»
2012 Journal Article R. Mahalakshmi and Usha, P., “Simulation Of Vsc Based HVDC Transmission System For The Integration Of Windfarm Into Grid”, International Journal of Electrical and Electronics Engineering (IJEEE), vol. 1, no. 4, pp. 2231 – 5284 , 2012.[Abstract]

Wind energy has huge potential to become major source of renewable energy for the modern world. For integrating wind farms to the AC grid, HVDC transmission systems have several advantages over AC transmission systems. This paper presents the design and control of voltage source converter based HVDC system for integration of wind farms in to AC grid. The designed VSC-HVDC system performance under steady state conditions and various transient conditions are presented. The PSCAD/EMTDC software package is used for the simulation studies.

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Publication Type: Conference Paper
Year of Publication Publication Type Title
2015 Conference Paper R. Nair, Mahalakshmi, R., and Thampatty, K. C. S., “Performance of three phase 11-level inverter with reduced number of switches using different PWM techniques”, in International Conference on Advancements in Power and Energy (TAP Energy), 2015 , Kollam, 2015.[Abstract]

As compared to conventional inverter topologies like diode clamped and capacitor clamped inverters, the cascaded multilevel inverter has lesser harmonics as well as lower switching stress. The cascaded topology has more number of power switches leading to greater heat losses, larger size, higher cost and more gate drive circuitry. The proposed configuration contains less number of switches and produces lesser harmonics in the output voltage than the cascaded topology. A comparison between four different types of pulse width modulation (PWM) techniques, namely, In-phase disposition (IPD), Anti-phase disposition (APD), Carrier Overlap (CO) and Variable Frequency (VF) PWM methods, has been done. The results have been verified through simulation study in MATLAB/Simulink in order to select the best PWM method that provides minimum THD in the output voltage. An LC filter has been designed to improve the harmonic profile.

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2014 Conference Paper R. Mahalakshmi, Aswin, K. A., and Kumar, A., “Design of Fuzzy Logic based Maximum Power Point Tracking controller for solar array for cloudy weather conditions”, in 2014 Power and Energy Systems Conference: Towards Sustainable Energy, PESTSE 2014, Bangalore, 2014.[Abstract]

<p>This paper proposes Maximum Power Point Tracking (MPPT) of a photovoltaic system under variable temperature and solar radiation conditions using Fuzzy Logic Algorithm. The cost of electricity from the PV array is more expensive than the electricity from the other non- renewable sources. So, it is necessary to operate the PV system at maximum efficiency by tracking its maximum power point at any weather conditions [1]. Boost converter increases output voltage of the solar panel and converter output voltage depends upon the duty cycle of the MOSFET present in the boost converter. The change in the duty cycle is done by Fuzzy logic controller by sensing the power output of the solar panel. The proposed controller is aimed at adjusting the duty cycle of the DC-DC converter switch to track the maximum power of a solar cell array. MATLAB/Simulink is used to develop and design the PV array system equipped with the proposed MPPT controller using fuzzy logic [2][3]. The results show that the proposed controller is able to track the MPP in a shorter time with less fluctuation. The complete hardware setup with fuzzy logic controller is implemented and the results are observed and compared with the system without MPPT (Fuzzy logic controller). © 2014 IEEE.</p>

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