Browsing by Author "Yaragatti, U.R."

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A New Generalized Multilevel Converter Topology Based on Cascaded Connection of Basic Units
(Institute of Electrical and Electronics Engineers Inc., 2019) Jagabar Sathik, J.; Shalchi Alishah, R.; Sandeep, N.; Hosseini, S.H.; Babaei, E.; Krishnasamy, K.; Yaragatti, U.R.
In this paper, a new single-phase multilevel converter (MLC) topology based on the cascade connection of novel basic units is presented. The proposed basic unit generates 17-level output voltage waveform and can be extended for higher voltage levels by using a simple cascade connection. Both the proposed basic unit and cascaded topologies are compared with other state-of-the-art MLC topologies. From the comparison results, it will be shown that the proposed topology has several advantages such as the reduced number of power electronic components, lesser number of dc sources, and blocking voltage. Moreover, the proposed MLC has reduced power losses and improved efficiency. The operability and feasibility of the proposed converter are validated through extensive simulation and experiments. Finally, the corresponding results affirming the predominance of the proposed topologies are presented. © 2013 IEEE.
A new nine-level single-DC source-based inverter topology for distributed generation
(Institute of Electrical and Electronics Engineers Inc., 2017) Sandeep, N.; Yaragatti, U.R.
Multilevel inverter enables to completely remove the passive filtering requirement at the grid interfacing end, resulting in improved efficiency and reduced cost. These features have led to increasing attention towards their application to medium and high-power arena. In this paper, investigation of a hybrid 9-level inverter topology for grid integration of renewable energy sources is presented. The structural details, operating principle, capacitor voltage balancing control and the main features of the proposed inverter are presented. The proposed topology is compared with other similar 9-level converters to emphasize its superior characteristics and performance. Simulation results demonstrating the grid connected operation of the converter for two test cases are presented. The results affirm the effectiveness of the capacitor voltage balancing control in maintaining capacitor voltages at set values, under steady state and transient operation of the converter. Â© 2016 IEEE.
A Self-Balancing Five-Level Boosting Inverter with Reduced Components
(Institute of Electrical and Electronics Engineers Inc., 2019) Sandeep, N.; Jagabar Sathik, J.S.; Yaragatti, U.R.; Krishnasamy, K.
Two-Stage boosting multilevel inverters (MLIs), which are highly suitable for photovoltaic power plants, are known to suffer because of the high voltage stress on the switches of second stage. One of the ways to confront this issue is through eliminating the front-end booster. However, this leads to increased structural and control complexity of the resulting integrated boosting MLI. This letter presents a single-stage boosting MLI requiring lesser number of switches, diodes, and capacitors for renewable power generation applications. It requires nine switches and only one capacitor for five-level voltage generation. The topology has inherent self-balancing capability, thereby does not need additional balancing circuitry. The proposed topology has a uniform peak inverse voltage stress on the switches of value equal to the input dc voltage. A less complicated logic-form-equations-based gating pulse generation scheme is designed for enabling the proposed MLI to maintain its capacitor voltage. Further, a comparative study with state-of-the-art topologies is carried out to demonstrate the superior performance of the proposed topology. Finally, the feasibility of the proposed topology is validated through experimental tests and the corresponding results are elucidated. © 1986-2012 IEEE.
A Switched-Capacitor-Based Multilevel Inverter Topology with Reduced Components
(Institute of Electrical and Electronics Engineers Inc., 2018) Sandeep, N.; Yaragatti, U.R.
This letter presents an improved sensorless nine-level inverter topology with reduced number of components. It is formed by cascading a three-level T-Type neutral clamped point inverter with a floating capacitor (FC) fed two-level converter unit. Additionally, two line-frequency switches are appended across the dc-link. A simple logic-form equations-based pulse width modulator is designed which is in-charge of maintaining the FC voltage at its reference value without any aid of voltage and current sensor. Thus, the complexity in control of the proposed topology is very minimal. The working principle of the proposed inverter and formulation of logic-form equations is deliberated in detail. Furthermore, experimental results obtained from the developed prototype are presented to validate feasibility and operability of the proposed topology. Finally, a comprehensive comparison with some of the recently reported inverter topologies proving the merits of the proposed topology is included. © 1986-2012 IEEE.
An effective standalone hybrid wind-photovoltaic water pumping system with reduced power converter count
(John Wiley and Sons Ltd, 2021) Angadi, S.; Yaragatti, U.R.; Yellasiri, Y.; Raju, A.B.
This article proposes a standalone hybrid wind-photovoltaic (PV) water pumping system (WPS) with minimal power electronics interface, simple composite control, and optimal energy management strategy (EMS) for effective utilization of both renewable sources. The proposed system consists of classic Perturb and Observe (P&O) algorithm applied to the boost converter of the solar PV system and voltage regulation algorithm/hill-climbing MPPT algorithm with zero steady-state oscillation (ZSSO) applied to bidirectional voltage source converter (VSC) of wind energy conversion systems (WECS) for optimal power extraction at all times. The constant voltage to frequency (V/F) ratio is ensured at the point of common coupling (PCC) for the entire operating range to avoid saturation in the self-excited induction generator (SEIG) and the induction motor (IM) pump. The energy management strategy is devised to effectively harness renewable energy from both sources while ensuring the DC-link voltage stability. The system forms compelling proposition, given the least converter count to integrate solar-PV and wind energy employing easy to implement control algorithms with optimal energy extraction. The results of simulation and experimental studies on the proposed system reveal the effectiveness of the composite controller in terms of energy utilization, constant flux operation, and power balance for the entire operating range. Additionally, system exhibits acceptable dynamic and steady-state behavior against variations in wind velocity, solar irradiation, and load. © 2021 John Wiley & Sons Ltd.
Analysis of Leakage Current Mechanism in Supercapacitor with Experimental Approach
(Institute of Electrical and Electronics Engineers Inc., 2022) Bairwa, B.; Pareek, K.; Sarvagya, M.; Yaragatti, U.R.
In this paper, we evaluated the leakage current of super capacitor during self-discharge. A three branch electrical equivalent circuit model (ECM) is constructed to estimate voltage response and leakage current of commercially available 2.7 V 350F (BCAP350) double-layer capacitor (DLC). Experimental work carried out with two constant current charging segments 0.25 ampere, and 0.5 amperes. Simulated data shows good agreement with experimental results obtained at electro-chemical workstation CH760e with RMSE and MAE error up to 0.0633, 0.05715, and 0.0759, 0.04173 for 0.25 ampere and 0.5 amperes charging current, respectively. The results confirm that the ECM model is capable to simulate the complex terminal behavior of the super capacitor and provides the means to study its application as an energy storage device. Â© 2022 IEEE.
Architectural framework of on-board integrator: An interface for grid connected EV
(Institute of Electrical and Electronics Engineers Inc., 2017) Hampannavar, S.; Likassa, K.; Ayenew, E.; Sandeep, N.; Yaragatti, U.R.
Vehicle to Grid (V2G) is the concept of connecting a group of electric vehicles (EV) to the grid for power transaction. EVs can be connected to the grid through the home interface or through the chargers available at charging stations. In this paper, a single phase on-board charger with low complexity control scheme is proposed for EV power transaction. The power flow from and to the grid is processed using two stage cascaded converters consisting of a bidirectional DC-DC and DC-AC converters. The LCL filter is used as an interface between DC-AC converter and the grid to attenuate the grid current harmonics. A proportional resonant (PR) controller is employed for the control of grid current and to enable the unity power factor operation of the DC-AC converter. The setbacks associated with the conventional proportional-integral (PI) controller for single phase system is elevated by employing PR controller. Filter design guidelines and the control strategy developed for the proposed system is numerically simulated and verified with extensive simulation carried using MATLAB/SIMULINK. The results demonstrating the feasibility and viability of the proposed system are presented. Â© 2017 IEEE.
Autonomous microgrid based parallel inverters using droop controller for improved power sharing
(Institute of Advanced Engineering and Science info@iaesjournal.com, 2020) Siddaraj, U.; Yaragatti, U.R.; Nagendrappa, H.; Jhunjhunwala, V.K.
The existing microgrid has become a challenge to the sustainable energy source to provide a better quality of power to the consumer. To build a reliable and efficient microgrid, designing a droop controller for the microgrid is of utmost importance. In this paper, multiple voltage source inverters connected in parallel using an active power-frequency/reactive power-voltage droop scheme. The proposed method connected to two distributed generators local controllers, where each unit consists of a droop controller with an inner voltage-current controller and a virtual droop controller. By adding this controller to the microgrid reliability and load adaptability of an islanded system can be improved. This concept applied without any real-time communication to the microgrid. Thus, simulated using MATLAB/Simulink, the obtained results prove the effectiveness of the autonomous operation's microgrid model. © 2020, Institute of Advanced Engineering and Science. All rights reserved.
Autonomous Microgrid Using New Perspective on Droop Control in AC Microgrid
(Springer Science and Business Media Deutschland GmbH, 2024) Siddaraj, U.; Yaragatti, U.R.; Nagendrappa, H.
Providing higher quality power to consumers through the existent microgrid is now a problem for the renewable energy source. Designing a droop controller for the microgrid is a necessity to construct a dependable and effective microgrid. In this paper, a Pâ€“F/Qâ€“V droop method is used to connect several VSIs in parallel. Their parallels and differences are amply discussed in this study. A frequency droop control method and a virtual impedance approach are combined in the suggested method, which is coupled to two distributed generation (DG) local controllers and has each unit having a droop control and a voltage-current controller. An islanded system's load flexibility and microgrid reliability can both be enhanced by adding this controller. The microgrid was subjected to this idea without any real-time communication. Simulink/MATLAB was used to simulate this. The results obtained show that the microgrid (MG) model is effective in autonomous operation. Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.
Backward sweep technique based phase balancing algorithm for secondary distribution system
(IEEE Computer Society, 2017) Swapna, S.; Yaragatti, U.R.
In secondary power distribution networks, unbalanced loads and feeder laterals result in poor power quality and increased operating costs. Reconfiguration of feeders and phase swapping continues to be the most prominent techniques. In this paper, an algorithm that caters for unbalance in both three-phase and two-phase feeder laterals is discussed. Phase balancing computation is done using both average load per phase and average load per service. This algorithm embeds the rephasing of three-phase along with single-phase consumer service laterals/service wire at each Bus from the tail end of the feeder to its origin, thereby enabling reduction of current in all heavily loaded branches at each Bus. To illustrate the effectiveness of the proposed technique IEEE 13 Bus test feeder is considered. Â© 2017 IEEE.
Comprehensive review on solar, wind and hybrid wind-PV water pumping systems-an electrical engineering perspective
(China Power Supply Society, 2021) Angadi, S.; Yaragatti, U.R.; Yellasiri, Y.; Raju, A.B.
In India, the demand for water is continuously increasing due to the growing population. Approximately 16.5% of all country's electricity used to pump this water is from fossil fuels leading to increased pump Life Cycle Cost (LCC) and Green House Gas (GHG) emissions. With the recent advancement in power electronics and drives, renewables like solar photovoltaic and wind energy are becoming readily available for water pumping applications resulting in the reduction of GHG emissions. Recently, research towards AC motor based Water Pumping Systems (WPS) has received a great emphasis owing to its numerous merits. Further, considering the tremendous acceptance of renewable sources, especially solar and wind, this paper provides a detailed review of single-stage and multi-stage WPS consisting of renewable source powered AC motors. The critical review is performed based on the following figure of merits, including the type of motor, power electronics interface and associated control strategies. Also, to add to the reliability of solar PV WPS, hybrid Wind-PV WPS will be discussed in detail. Readers will be presented with the state-of-the-art technology and research directions in Renewable Energy-based WPS (REWPS) to improve the overall system efficiency and hence reduce the payback period. © 2021 All rights reserved.
Coordinated PSO-ANFIS-Based 2 MPPT Control of Microgrid with Solar Photovoltaic and Battery Energy Storage System
(MDPI, 2023) Siddaraj, S.; Yaragatti, U.R.; Nagendrappa, N.
The microgrid is a group of smaller renewable energy sources (REs), which act in a coordinated manner to provide the required amount of active power and additional services when required. This article proposes coordinated power management for a microgrid with the integration of solar PV plants with maximum power point tracking (MPPT) to enhance power generation and conversion using a hybrid MPPT method based on particle swarm optimization-adaptive neuro-fuzzy inference system (PSO-ANFIS) to acquire rapid and maximum PV power along with battery energy storage control to maintain the stable voltage and frequency (V-f) of an isolated microgrid. In addition, it is proposed to provide active and reactive power (P-Q) regulation for the grid connected. The approach used provides more regulation due to the least root mean square error (RMSE), which improves photovoltaic (PV) potential extraction. The comparison results of the PSO-ANFIS and P&O controllers of the MPPT and the controller of the energy storage devices combined with the V-f (or P-Q) controller of the inverter all show effective coordination between the control systems. This is the most important need for contemporary microgrids, considering the potential of changing irradiance in the grid following mode, the grid forming mode under an island scenario, and back-to-grid synchronization. With the test model, the islanded and grid-islanded-grid connected modes are investigated separately. The results demonstrate conclusively that the proposed strategies are effective. To run the simulations, MATLAB and SimPowerSystems are utilized. © 2023 by the authors.
Design and implementation of active neutralpoint-clamped nine-level reduced device count inverter: An application to grid integrated renewable energy sources
(Institution of Engineering and Technology journals@theiet.org, 2018) Sandeep, N.; Yaragatti, U.R.
Multilevel inverters are one of the preferred choices in medium-voltage and high-power applications in the recent past. Active neutral-point-clamped (ANPC) inverter is the most popular topology, especially in the class of five-level (5L) inverters. In this study, a nine-level topology with improved output waveform quality is proposed based on ameliorating the 5L ANPC inverter with least modifications. The addition of only two switches operating at line frequency to the conventional 5L ANPC inverter while maintaining an identical precursor part count is the proposed modification. A logic form equation-based active voltage balancing scheme that is independent of load current and power factor is developed to regulate the flying capacitor voltage at the reference value. The operating principle, salient features, and the developed control scheme are comprehensively detailed. The operation of the proposed inverter considering a grid integrated case is simulated in MATLAB/ Simulink, and the results corresponding to steady-state and dynamic conditions are presented. The benefits of the proposed topology are elucidated by comparing it with other classic topologies considering various prominent viewpoints. This comparison has illustrated the proposed topology's distinctive characteristics and profound advantages. The performance validation, feasibility, and practicability of the proposed inverter are established through the experimental results obtained from a laboratory-scale prototype. © The Institution of Engineering and Technology 2017.
Design and implementation of constant flux controller for VSI assisted SEIG feeding induction motor pump
(Inderscience Publishers, 2022) Angadi, S.; Yaragatti, U.R.; Yellasiri, Y.; Raju, A.B.
In small scale, stand-alone, wind-power generation employing self excited induction generator (SEIG), water pumping using an induction motor is a typical application. In this paper, a simple voltage regulation scheme for the constant flux operation of the inverter assisted SEIG feeding three-phase induction motor pump is presented. The behaviour of DC-link voltage, frequency, amplitude modulation index (ma) and the shaft speed for load and speed perturbations are discussed in detail. Also, the overall active and reactive power flow for constant flux operation at the point of common coupling (PCC) is analysed. The proposed work presents a simple and reliable controller for SEIG-based stand-alone system for frequency-dependent loads using only a DC-link voltage sensor. Detailed system simulations are performed using Matlab/Simulink and the results of a laboratory prototype are presented to validate the theoretical analysis and practical operability of the proposed system. © 2022 Inderscience Publishers. All rights reserved.
Design and Implementation of Transformer-Based Multilevel Inverter Topology with Reduced Components
(Institute of Electrical and Electronics Engineers Inc., 2018) Behara, S.; Sandeep, N.; Yaragatti, U.R.
This paper presents a nine-level transformer-based inverter requiring only eight switches. The envisaged structure consists of two standard H-bridges fed from a single dc source. Besides, a single-phase transformer is employed to aid the process of intermediate voltage level generation. An ad-hoc pulsewidth modulation scheme based on boolean logic form equations is developed to derive the gating pulses. An effortless extension of the proposed inverter to a higher number of voltage levels is also achieved by generalizing the switching functions. Furthermore, the superior performance of the proposed topology is demonstrated through a comprehensive cost-based analysis. Finally, the validation of the proposed topology is accomplished through experiments on a down-scale prototype, and the measurement results are included. © 1972-2012 IEEE.
Design of haul road lighting system. Part I: Design based on optimal energy considerations
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
Electrical energy consumption is a major cost component of haul road lighting. Haul road lighting depends on many parameters such as type and wattage of sources, mounting height and tilt angle of light fixtures. In this study a computer model has been developed for optimum energy consumption of any haul road lighting system. Using the program, illumination design was studied for a stretch of 800m long haul road. Nine different types of light sources were considered for mounting heights of 12 and 16m. High-pressure sodium vapour (HPSV) lamps of 100W proved to be energy efficient at a 12m height whereas at 16m height, energy consumption was minimum for 150 W HPSV lamps. Thus the developed computer program proved to be successful in evaluating the performance of lighting designs from the point of view of energy consumption.
Design of haul road lighting system. Part II: Design based on optimal cost considerations
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
The proper selection of lighting installations is very important for the provision of cost-effective lighting systems without compromising light quality. In this study a computer program was developed to evolve a cost-effective lighting system for haul roads in surface mines. This program is beneficial in assessing the viability of various lighting installations in order to achieve cost-effective solutions. Using the program, illumination design was studied for an 800 m long stretch of haul road. Nine different types of light sources were considered at mounting heights of 12 m and 16 m. The study shows that at a 12 m mounting height, 100 W high-pressure sodium vapour (HPSV) lamps offer the most cost-effective design, followed by 250 W HPSV lamps. In the case of 16 m pole heights the annual lighting cost is minimum for 150 W HPSV lamps, followed by 250 W HPSV lamps. This work also shows that optimum design based on energy consumption need not be the same as design based on optimum cost considerations as cost parameters may vary widely with location.
Design of haul road lighting system. Part III: Application
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
The design of haul road illumination systems based on a scientific approach is very important. Improperly planned lighting systems may provide unsatisfactory illumination and may also incur higher costs. This paper describes illumination systems designed for two haul roads using the computer programs developed in earlier stages of this work. System performances and cost are compared with the existing illumination system. Designs based on the developed programs show total potential cost savings of approximately 26% and 48% for the two systems.
Development of Fault Detection Method in Cable Using Arduino UNO
(Institute of Electrical and Electronics Engineers Inc., 2022) Bairwa, B.; Rathod, S.; Yaragatti, U.R.; Manohar, K.A.
This study provides the investigation of underground cable fault. Fault are classified into two type such as symmetrical and unsymmetrical fault. For this fault detection range of about 1m to 2.6 km of the underground cable have been investigated. In underground cable, fault is validating through live tests as per the research knowledge. The underground cable fault are largely caused due to improper insulation, interweave, mesh and other accessories. symmetrical and unsymmetrical fault are present to detect and classify incipient fault in underground cable at the distribution voltage level. The wavelet transformer approach has been used to detect the fault location of the underground fault. This project deal with number of high voltage cable fault location technique with modeling and simulation. Â© 2022 IEEE.
Efficient artificial lighting system for surface mine haul roads
(2006) Mangalpady, M.; Yaragatti, U.R.
Haul roads within the pit are one of the critical areas in surface mines where lighting installations are not permanent due to regular advancement of the working face. Due to this reason it is very difficult to maintain the lighting standards, as specified by various regulatory bodies. Lighting in mines presents special problems because of the dark surroundings and low surface reflectance. Hence, scientific design of artificial lighting is very important to achieve the minimum required lighting standards. Authors developed software, named SURLux, in MATLAB for design of illumination system, which incorporates all the design parameters. It also computes the total cost of the lighting system. In this paper a 1.0 km stretch of haul road is designed for four different types of sources namely, 150 and 250 W high pressure mercury vapor lamps (HPMV), and 150 and 250 W high pressure sodium vapor lamps (HPSV), at various pole heights (8, 10, 12, 14 and 16 m). From the results of the study it is observed that with 16 m height pole the total annual cost for 150 W HPSV is the minimum (Rs. 87,739/-). In most of the cases the cost is high with HPMV lamps. This is mainly because of their shorter life and relatively more number of poles. In general, lamp selection is made mainly based on efficacy and suitability to each situation. However, among the feasible alternatives for any project, the variant that offers the minimum total cost is finally selected. Â© 2006 IEEE.