Browsing by Author "Yaragatti, R.Y."

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A comparison of seven-level inverter topologies for multilevel DC-AC power conversion
(Institute of Electrical and Electronics Engineers Inc., 2014) Salodkar, P.; Sandeep, N.; Kulkarni, P.S.; Yaragatti, R.Y.
Multilevel inverter (MLI) performance is high compared to the conventional two level inverters since they offer high power capability, associated with lower output harmonics and lower commutation losses. However the main drawback of MLI is their increased number of power devices, passive components, complex pulse width modulation control and balancing of capacitor voltages. In this paper the most popular topologies like diode-clamped inverter (neutral-point clamped), cascaded multicell with separate dc sources, and transistor clamped H-Bridge inverter are discussed. A simplified multilevel inverter (Switched Transistor MLI) is proposed and its performance is compared with the above said topologies. Component count and the % total harmonic distortion (THD) of the output voltage are considered as the indexes of the comparative performance. The operating principle of each topology, the most relevant modulation method of all the topologies and the detailed analysis of the proposed Switched Transistor MLI is included. The selection of topology and control techniques depends and varies according to power demands of inverter. Simulation study of all the topologies considered is carried out on MATLAB/SIMULINK platform and the performance of the proposed topology is verified experimentally by the tests performed on a scaled laboratory prototype. Â© 2014 IEEE.
A novel approach for phase balancing of secondary distribution power system
(Indian Society for Education and Environment indjst@gmail.com, 2016) Swapna, M.; Yaragatti, R.Y.
Objectives: The main objective of the power distribution system is to reduce the loss in order to improve the system efficiency, alleviate the cost and increase the consumer satisfaction. Methods/Analysis: Power loss mainly depends on type of the load and its pattern. Load unbalance on distribution feeder leads to current raise in the heavily loaded phase, over voltage in the lightly loaded phase and neutral current and mal functioning of protection equipment. Findings: In power distribution energy management, phase balancing is one among the techniques available to reduce the loss incurred by load unbalance. Phase balancing is a concept of re-phasing service laterals such that load on three phases is balanced. Application/Improvement: The study mainly deals with phase balancing of secondary distribution feeder by rearranging the connections of consumer load/ service laterals. The algorithm is designed to handle time varying loads with an objective of loss reduction and minimum number of phase moves.
A novel MPPT controlled grid-connected photovoltaic system with dual functionality of active power injection and reactive power compensation in a single phase system
(Universitatea Politehnica din Timisoara blucretiu@yahoo.com, 2012) Naik, A.; Yaragatti, R.Y.
This paper deals with the study of integration of distributed generation with active power filtering functionality in a single- phase system. Here the active power generated by the photovoltaic (PV) system is injected into the grid system through a coupling capacitor whenever solar input is available and the remaining capacity of the power conditioning inverter is used to compensate for the reactive power demand. The control algorithm used in this paper is simple and easy to implement. The PV system is integrated through a novel and simple MPPT technique. The system is simulated and analyzed for a given non-liner load with and without renewable source at different atmospheric conditions using MATLAB/Simulink tool. The grid current becomes sinusoidal and in phase with the grid voltage and hence the source current THD is reduced to great extent.
A single-stage active damped LCL-filter-based grid-connected photovoltaic inverter with maximum power point tracking
(Institute of Electrical and Electronics Engineers Inc., 2015) Sandeep, N.; Kulkarni, P.S.; Yaragatti, R.Y.
In this paper, a simple single-phase grid-connected photovoltaic (PV) inverter topology consisting of a three-level inverter, an LCL filter, and a new current feedback method for active damping is considered. A dynamically rapid method is used for tracking the maximum power point (MPP) of photovoltaic arrays, known as ripple correlation control. The algorithm uses the current and voltage low-frequency oscillations as the perturbation signals, which are introduced in the output of PV array due to the sinusoidal power being injected into the single-phase utility grid, to enable operation at MPP. The capacitor of the conventional LCL filter is split into two parts and the current flowing between these two parts is used as the feedback for regulation of grid current being injected. By doing so the V - I transfer function of the grid connected inverter system degrades to first-order one from third order function. Due to which, wide control-loop bandwidth can be achieved with a large proportional control-loop gain ensuring good stability. Proportional-resonant (PR) current controller is suggested to provide power to the line with unity power factor and the PV inverter offers much less total harmonic distortion. The entire system has been numerically simulated in MATLAB/SIMULINK platform and the performance results are presented for variation in insolation levels and grid voltage profile showing the effectiveness of the proposed system. Â© 2014 IEEE.
A systematic approach to grid connected PV system
(2012) Afroze, S.; Yaragatti, R.Y.; Naik, A.
This paper proposes a detailed mathematical model of Photovoltaic(PV) array and a three-level control scheme of a single-phase grid-connected system including maximum power point tracker, voltage source inverter and its controller based on the MATLAB/Simulink tool. The PV model is developed by using basic circuit equations of the photovoltaic (PV) solar cells including the effects of solar irradiation and temperature changes. The perturb-and-observe algorithm is used to extract maximum power from PV arrays and deliver it to the inverter and PI control algorithm is used to control the three-level voltage source inverter. The simulation result shows the power sharing between PV and the Grid for any given load. Here generation of PV depends on the insolation of PV array. Â© 2012 IEEE.
An algorithm for optimal phase balancing of secondary distribution systems at each node
(Institute of Electrical and Electronics Engineers Inc., 2016) Swapna, M.; Yaragatti, R.Y.
In this paper, a phase balancing algorithm is developed to balance the load at each candidate node of the secondary distribution network from tail end of the feeder by rearranging the connections of consumer load/ service laterals. Phase balancing is a concept of re-phasing service laterals such that load on three phases is balanced. The algorithm is designed to handle three, two and single phase time varying loads with an objective of loss reduction and minimum number of phase moves. To evaluate the performance of proposed algorithm, it is applied to the IEEE 13 node test feeder. The simulation results confirm the efficiency of algorithm for reduction of power loss and phase balancing of secondary distribution network with minimum number of phase moves. Â© 2016 IEEE.
Control of CO2 emission through enhancing energy efficiency of auxiliary power equipment in thermal power plant
(Elsevier Ltd, 2014) Mandi, R.P.; Yaragatti, R.Y.
This paper describes the results of energy efficiency enhancement in 23 numbers of 210 MW coal fired power plants spread over India. Energy efficiency improvement of major auxiliary equipment with different plant load factors are summarized here with improved performance. The effect of plant load factor on all major auxiliary equipment and improvement in performance of auxiliary equipment are discussed in this paper. Operation of the plant at improved plant load factor reduced the specific auxiliary power from 11.23% at 70% PLF to 8.74% at 100% PLF that reduced the net auxiliary power by 9.1 MU/year that is an equivalent reduction of CO2 emission by 9500 t/year. Optimizing the excess air, controlling the furnace ingress, enhanced energy efficiency of individual equipment by proper maintenance, etc., improves the plant capacity and reduces the overall auxiliary power by about 1.5-2.1% of gross energy generation i.e., equivalent CO2 reduction of 23,000-32,400 t/year and release an additional power of about 3.5 MW (for a typical one 210 MW power plant) into grid. © 2014 Elsevier Ltd. All rights reserved.
Design and Implementation of a Sensorless Multilevel Inverter with Reduced Part Count
(Institute of Electrical and Electronics Engineers Inc., 2017) Sandeep, N.; Yaragatti, R.Y.
This letter proposes a single-phase nine-level (9L) inverter topology suitable for grid-connected renewable energy systems. The proposed inverter is realized using a T-Type neutral-point-clamped inverter connected in cascade to a floating capacitor (FC) H-bridge. Additionally, two low-frequency switches are added across the dc-link enabling the inverter to generate a 9L waveform. A sensorless voltage control based on redundant switching state is developed and embedded with PWM controller, which is responsible for regulating the FC voltage at one-quarter of the dc source voltage. The proposed PWM technique employs the generation of 9L waveform without using any voltage sensor, thereby reducing the complexity of the overall control scheme. This, in turn, will make the overall system appealing for various industrial applications. In comparison to conventional and recent topologies, generation of the 9L waveform using a lower number of components is the notable contribution. Another important feature of the proposed inverter is that if FC H-bridge fails, it can be bypassed, and the inverter can still operate as a 5L inverter at its nominal power rating. Furthermore, a comprehensive comparison study is included which confirms the merits of the proposed inverter against those of other state-of-The-Art topologies. Finally, simulation and experimental results are included for validating the feasibility of the proposed system. © 1986-2012 IEEE.
Design and implementation of FPGA based low power digital PID controllers
(2009) Veeranna, B.V.; Yaragatti, R.Y.
In this paper design and implementation of low power Proportional Integral Derivative (PID) controller using Field Programmable Gate Array (FPGA) is presented. In the present status the embedded control applications requires low power and fast acting PID controllers with a closed loop performance using less resources, resulting in cost reduction. Different types of digital PID controllers are analyzed with the frequency response using Matlab tool. The controller algorithm is synthesized, simulated and implemented using Xilinx Spartan3e XC3S100E board with XilinxISE 9.1i as a tool and synthesized and simulated using Altera Cyclone EP1C12Q240C8 with Quartus II 6.1 as a tool. The results are compared in terms of their power consumption, speed, memory usage, Look Up Tables (LUTs) and number of Multipliers, Adders/Subtractors. Â©2009 IEEE.
Design of computer application for 3 phase vector control induction motor drive
(2007) Shet, M.S.K.; Yaragatti, R.Y.
Development in the field of microelectronics and control has resulted in Vector control of Induction motor. The Induction motors are used in many adjustable speed applications. In order to understand and analyze the vector control of Induction motors, the dynamic model of the machine is necessary along with the steady state analysis and design of the Induction motors. It is the objective to explain the various forms in a concise way to understand clearly. In addition, the fundamental dynamic performance of the machine in the synchronous frame is developed along with the principles of closed loop vector control is discussed in general terms and simulation has been carried out on a laboratory model.
Development of Markov Chain-Based Queuing Model and Wireless Infrastructure for EV to Smart Meter Communication in V2G
(Walter de Gruyter GmbH, 2015) Hampannavar, S.; Yaragatti, R.Y.
The electrical vehicles (EVs) can be connected to the grid for power transaction. The vehicle-to-grid (V2G) supports the grid requirements and helps in maintaining the load demands. The grid control center (GCC), aggregator and EV are three key entities in V2G communication. The GCC sends the information about power requirements to the aggregator. The aggregator after receiving the information from the GCC sends the information to the EVs. Based on the information, the interested EV owners participate in power transaction with the grid. The aggregator facilitates the EVs by providing the parking and charging slot. In this paper the queuing model for EVs connected to the grid and development of wireless infrastructure for the EV to Smart Meter communication is proposed. The queuing model is developed and simulated. The path loss models for WiMAX are analyzed and compared. Also, the physical layer of WiMAX protocol is modeled and simulated for the EV to Smart Meter communication in V2G. © 2015 by De Gruyter 2015.
Development of wireless access support for EV to smart meter communication in vehicle-to-grid (V2G)
(International Journal of Renewable Energy Research icolak@gazi.edu.tr, 2015) Hampannavar, S.; Yaragatti, R.Y.
Vehicle -to-Grid (V2G) supports ancillary services like peak shaving, valley filling, load levelling and the battery of the electric vehicle (EV) provide reactive power support to the grid. V2G also helps in maintaining the grid stability forshort duration of time. The communication between EV and the Smart Meter is very crucial for smooth functioning of V2G. The WiFi single input single ouput/multiple input multiple output(SISO/MIMO) protocol is proposed for EV to Smart Meter communication in indoor wireless environment. The channel models B and C are used as they are developed for residential apartment and office buildingsdue to the fact that EVs are usually parked in these locations. The MIMO environment is considered for simulating these channel models. The physical layer of WiFi (SISO) protocol is modeled in MATLAB/SIMULINK and its performance is investigated.
Development of WSN system for precision agriculture
(Institute of Electrical and Electronics Engineers Inc., 2015) Hampannavar, S.; Yaragatti, R.Y.
The agriculture sector is changing rapidly pointing to the future of automated and embedded systems with an array of sensors to monitor and control the growing plants in a way to protect workers, the environment and profits associated with it. The continuous monitoring and controlling of distantly located plants is labour intensive and technically challenging business. In modern precision agriculture, a Wireless Sensor Network (WSN) provides a simple cost effective solution to monitor and control. The basic parameters to be monitored are temperature and humidity (moisture content in the soil). A smart low cost WSN system for precision agriculture is proposed for monitoring and control using open software and electronic prototype - ARDUINO. Â© 2015 IEEE.
Electrical energy conservation in India - Challenges and achievements
(2009) Kamalapur, G.D.; Yaragatti, R.Y.
The gap between electrical energy supply and demand is continuously increasing despite huge outlay for energy sector since independence. This gap between supply and demand of energy can be bridged with the help of energy conservation which is considered as a new source of energy and envinronmental friendly. The energy conservation is cost effective with a short pay back period and modest investment. There is a good scope of energy conservation in various sectors, viz domestic, industry, agriculture. The planners have already started appreciating the role and significance of energy conservation in future energy scenario of India. An attempt is made in this paper to acess the achievements and further challenges of electrical energy conservation in Indian context.
Energy conservation of common auxiliary power equipment in power plant processes
(CRC Press, 2016) Mandi, R.P.; Yaragatti, R.Y.
[No abstract available]
Energy conservation of in-house auxiliary power equipment in power plant processes
(CRC Press, 2016) Mandi, R.P.; Yaragatti, R.Y.
[No abstract available]
Energy efficiency improvement of auxiliary power equipment in thermal power plant through operational optimization
(2012) Mandi, R.P.; Yaragatti, R.Y.
This paper describes the results of energy conservation measures for 210 MW coal fired power plant in various thermal power plants spread over the country. Energy efficiency improvement of major auxiliary equipment with different plant load factors are summarized here with improved performance. The effect of plant load factor on all major auxiliary equipment and suggestions for improving the performance of auxiliary equipment are discussed in this paper. Operation of the plant at improved plant load factor reduced the auxiliary power from 12.05 % at 70 % PLF to 8.74 % at 100 % PLF that reduced the net auxiliary power by 9.1 MU/year and CO2 emission is reduced by about 9,500 t/year. Operating the plant at optimum excess air, controlling the furnace ingress, improving the performance of individual equipment by proper maintenance, etc., improved the plant capacity and reduced the overall auxiliary power by about 1.5-2.1 % of gross energy generation. Â© 2012 IEEE.
Experimental, simulation and a case study on electrical energy consumption in mine drive haulage system
(Institute of Electrical and Electronics Engineers Inc., 2015) Moger, G.D.; Murthy, C.S.N.; Yaragatti, R.Y.
The experimental investigation study on energy consumption of fabricated 3hp mine drive haulage system is presented. The performance analysis of energy consumption based on existing mine drive haulage system of underground coal mine and experimental set-up is prepared in the laboratory for a 3-hp wound rotor induction motor. The experimental and a case study results are simulated using MATLAB /simulink model and the compared results are presented in this paper. Â© 2015 IEEE.
Long term evolution protocol for grid control center to aggregator communication in V2G for smart grid application
(Institute of Electrical and Electronics Engineers Inc., 2014) Hampannavar, S.; Yaragatti, R.Y.
The Vehicle-to-Grid (V2G) concept has become a reality with developments in the power grid and vehicle technology. The electrical vehicle (EV) can be connected to the grid to contribute power and help in maintaining the grid stability for shorter duration of time. The communication between the grid control center (GCC) and Aggregator is very crucial as GCC sends the power requirement details to the aggregator. In this paper we propose Long Term Evolution (LTE) protocol for GCC to Aggregator communication in V2G. The physical layer of LTE protocol is modeled using MATLAB/SIMULINK and its performance is investigated. Â© 2014 IEEE.
Markov chain based stochastic model of electric vehicle parking lot occupancy in vehicle-to-grid
(Institute of Electrical and Electronics Engineers Inc., 2016) Hampannavar, S.; Yaragatti, R.Y.
The concept of connecting group of electric vehicles (EVs) to the grid for power transaction is known as Vehicle-to-Grid (V2G). The EVs can be connected to the grid through V2G integrators and charging slots. The arrival of EVs in parking lot is time varying and random in nature and facilitating them to participate in power transaction is challenging and aggregator's responsibility. In this paper, development of Markov chain based stochastic model of Electric Vehicle Parking Lot (EVPL) occupancy is proposed. A developed model is simulated using MATLAB and the results are presented. Â© 2015 IEEE.