Dr. Nagaraj C
@msrit.edu
Assistant Professor and EEE
MSRIT Bengaluru
RESEARCH INTERESTS
Power Flow Control and Power Quality Analysis in Micro-Grid System
Hybrid Renewable Energy Sources Integrated with Utility Grid
Smart Grid
E-Mobility
Scopus Publications
Scopus Publications
C. Nagaraj, K. Kumara, and N. Mohan
Springer Science and Business Media LLC
Sanjith Rajan, Nagaraj. C, Venkatesh Murthy. B.S, Aryankumar Srivastava, Varsha M R, and Deepa Siddappa Karadi
IEEE
The world's oceans cover more than 70% of the Earth's surface and yet, effective communication in underwater environments has remained a formidable challenge. This research paper aims to address it by revolutionizing communication in underwater by harnessing the power of Visible Light Communication, commonly known as Light Fidelity to develop and implement a novel underwater communication system based on Visible Light Communication technology, to offer high-speed and reliable data transmission beneath the ocean's surface. The communication distance typically ranges from a few meters to up to 100 meters, depending on various factors such as water clarity, environmental conditions and sensitivity of the Light Fidelity transmitters and receivers used. The system will integrate resilient communication protocols and undergo extensive testing to evaluate its performance in various underwater scenarios, with a focus on optimizing data transfer speeds for high-speed underwater communication. Comprehensive field tests in real underwater environments will demonstrate the effectiveness, with hardware results communicated by means of data analysis and potentially live demonstrations, depending on the scope and resources.
Nagaraj Chinnamadha, Roshan Zameer Ahmed, and Kumara Kalegowda
Institute of Advanced Engineering and Science
Electronic technology plays a vital role in healthcare, not only for sensory equipment but also for communication and recording. As a result, the Internet of Things (IoT) is the most recent communication breakthrough in healthcare. In this work, we present a system that tracks patient health using a Blynk application, a micro-controller as a communication gateway, and sensors. When the output of the detector changes, a buzzer is embedded into the controller to alert the nursing staff. The sensor connects to a micro-controller, which is then interfaced with the liquid-crystal display (LCD) panel and wireless local area network (LAN) to provide notifications. An alert will be sent to the doctor through IoT if the system detects a change in the patient’s pulse rate or blood pressure, and the patient’s heartbeat, blood pressure, and body temperature will be displayed in real-time via Cloud. As a result, an IoT-based patient health monitoring system could save lives by efficiently monitoring patients’ health in real- time.
Kumara Kalegowda, Amruthur Doreswamy Iyengar Srinivasan, and Nagaraj Chinnamadha
Institute of Advanced Engineering and Science
A robust design of particle swarm optimization (PSO) and Taguchi algorithm-based power system stabilizer (PSS) is presented in this paper. It incorporates a novel concept in which Taguchi and PSO techniques are integrated for stabilization of single machine infinite bus (SMIB). The system tolerates uncertainty and imprecision to a maximum extent. The proposed controller's effectiveness is proved through experiments covering light load condition using MATLAB/Simulink platform. The performance of the system is compared without PSS and with a conventional PSS. The settling time of the optimal PSS is decreased by more than 75% to conventional PSS. The study reveals that the proposed hybrid controller offers enhanced performance with respect to settling time as well as peak overshoot of the system.
Venkatesh Murthy.B. S, Nagaraj. C, Nagesh. H, Subha. V, and Nivedita J. M
IEEE
In the sectors of propulsion, aviation (More Electric Aircraft), and maritime operations, electric power systems and control have advanced dramatically. It is crucial to detect the emergence of fault conditions in the early stages while using the systems in critical environments. Vibration analysis, thermal analysis, flux measurement analysis, and motor current signature analysis (MCSA) are some of the existing methods for monitoring motor status. The purpose of this research work is to track the input currents to the inverter and analyze the motor state using the fault signal that is propagated from the torque disturbance on the motor shaft. This research suggests a fault detection methodology for DC supplied permanent magnet synchronous motor (PMSM) drive systems because the prior method involved monitoring the drive DC input current. This method's basis is the transmission of failure signals from the torque disturbance on the motor shaft to the inverter input currents. The accuracy of this fault signal propagation is validated by MATLAB simulation with experiment tests at actual defective conditions. The feasibility of this approach is demonstrated by the experimental test that the Spectra test rig carried out using an actual gearbox failure. This detection system can also be used to monitor other drive devices, such as the power converter or the motor itself, using just one set of current transducers mounted at the DC input side. Because the other approaches have space and reliability issues, this method of analysis was specifically chosen. When employing integrated drives or owing to other factors, it becomes impractical.
C. Nagaraj and K. Manjunatha Sharma
Inderscience Publishers
C Nagaraj and K Manjunatha Sharma
IEEE
Most of the utilities are suffering to provide continues and clean power at the end users due to grid current distortion in the distribution system because of non-linear low power electronics loads. In addition to this, freely available inherent hybrid solar-wind energy sources are leads to cause some more grid current distortion. Adverting to the above major issue over long decade, this paper presents an efficient controller for 3-phase 4-leg interfacing voltage source inverter to perform not only current harmonic reduction but also optimal real power transfer, neutral current compensation and power factor correction simultaneously. These multiple functions can be achieved efficiently by using id- iq control based shunt active power filter. The hysteresis comparator control is used to compare the obtained reference currents from id- iq control with actual sensed actual currents to generate the error signal. This error signal decides the working of the inverter switches. The simulation is carried out by using MATLAB/SIMULINK tool under different grid and load conditions and the corresponding simulated results are encouraged.
Nagaraj C, , K Manjunatha Sharma, and
American Institute of Mathematical Sciences (AIMS)
The depletion of fossil fuels and environmental concern forces the extraction of power from low carbon fuels causes generation problem due to intermittent solar-wind renewable energy sources and power electronic applications. Furthermore, the significant amount of non-linear loads in the system causes power quality problems. Nowadays, the more and more DC loads like LED lights to save energy consumption are connected to the AC distribution system. These DC loads are connected at DC grid side in order to avoid the extra AC/DC power conversion loss. In this paper, the proposed d-q reference current method applied for shunt active power filter based 3-phase 4-leg bidirectional interfacing converter with fuzzy PI controller to achieve the real power transfer between DC grid side and AC grid side with current harmonics compensation at common connecting point simultaneously under balanced and unbalanced distorted grid and non-linear load conditions. The hysteresis current control comparator without PLL is used to compare actual grid current with reference filter current and generate the switching pulses for driving the bidirectional interfacing converter. The DC grid shunt connected intermittent hybrid solar-wind energy sources are integrating with AC grid utility through bidirectional interfacing converter has been into consideration for simulation studies. The MATLAB/SIMULINK tool is used to yield the improved grid current THD with fuzzy logic controller over PI controller.
Nagaraj C and K Manjunatha Sharma
IEEE
Ideally, distribution utilities are responsible to provide good power at a fixed rated frequency to the consumer end at unity power factor. Due to the bulk usage of non-linear power electronic loads, distribution system network (DSN) suffers large current distortion. Further, the intermittent hybrid natural green sources (HNGS) like PV and PMSG wind grid connected using hysteresis current controller (HCC) through 3-phase VSI effects more distortion of current which contaminates the power quality at the consumer end. Thus power quality is a vital issue which needs to be presented well in this paper. This paper adopts the shunt active filter (SHAF) using real and reactive current (id−iq) control strategy to analyze the case studies with presence and absence of HNGS under unbalanced nonlinear load condition for the reduction in current distortion at distribution utility side. The MATLAB/Simulink examined to validate the performance of id−iq control strategy.
Nagaraj C and K Manjunatha Sharma
IEEE
Ideally, electric utilities are required to supply sinusoidal voltage at constant rated frequency while end users need to receive a sinusoidal current with good power factor. Electrical power distribution systems are already experiencing distortion of the current due to the usage of non-linear power electronic loads in industrial and commercial applications. Further, the integration of intermittent hybrid renewable sources like solar and wind to the utility grid through 4-leg 3-phase 4-wire current controlled voltage source inverter (VSI) leads to cause still more current distortion which pollutes the quality of electric power at the end users. Thus power quality is a critical issue to be addressed effectively. The active power filter (APF) is advantageous over passive filter due to its capability for better harmonic compensation features. This paper presents analysis of shunt active filter (SHAF) using a PI controller with and without the incorporation of intermittent hybrid renewable sources under different grid conditions. An instantaneous real and reactive current (id-iq) control scheme for SHAF is proposed for reduction in harmonic levels. The MATLAB/Simulink simulation studies validates the performance of id-iq control method.