Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Online estimation of rotor resistance is essential for high performance vector controlled drives. In this paper, a novel modified neural algorithm has been identified for the online estimation of rotor resistance. Neural based estimators are now receiving active consideration as they have a number of advantages over conventional techniques. The training algorithm of the neural network determines its learning speed, stability, weight convergence, accuracy of estimation, speed of tracking and ease of implementation. In this paper, the neural estimator has been studied with conventional and proposed learning algorithms. The sensitivity of the rotor resistance change has been tested for a wide range of variation from −50% to +50% on the stability of the drive system with and without estimator. It is quiet appealing to settle with optimal estimation time and error for the viable realization. The study is conducted extensively for estimation and tracking. The proposed learning algorithm is found to exhibit good estimation and tracking capabilities. Besides, it reduces computational complexity and, hence, more feasible for practical digital implementation. © 2014, Higher Education Press and Springer-Verlag Berlin Heidelberg.

Department of Energy and Power Electronics

School of Electrical Engineering

Vellore Campus

World University root node

Frontiers in Energy

A modified neural learning algorithm for online rotor resistance estimation in vector controlled induction motor drives

Improved dc bus utilization of voltage and its easier realization in digital domain has made Space Vector Pulse Width Modulation (SVPWM) quite popular in AC drives application. The classical Space vector pulse width modulation involves sector calculation and region estimation which results in more computational burden and complexity. A new simplified and generalized SVPWM algorithm is developed for a cascaded H bridge multilevel inverter using sampled values of reference phase voltages. The discussed method has a close similarity with Sinusoidal Pulse Width Modulation (SPWM). Implementation of the proposed SVPWM is not laborious and extension to n level is simple and straight forward. The proposed method is validated using a five level cascaded H bridge multilevel inverter driving an Induction motor. © 2015 IEEE.

VIT Unitversity

Department of Electrical Engineering

2015 International Conference on Circuits, Power and Computing Technologies [ICCPCT-2015]

A simplified space vector pulse width modulation technique for multilevel inverter fed induction motor drive

Inverter fed induction motor drive dynamics is greatly dependent on the input voltage pattern. Indirect field oriented control (IFOC) is of industrial standard which is highly sensitive to motor parameter variations. This paper attempts to address the above cited issues. To ensure the quality of the input voltage multilevel inverter (MLI) is employed to feed the motor. Amongst all the motor parameters rotor resistance is of paramount important as it varies with temperature, frequency and skew effects and also the exact value of rotor resistance is required for the unit vector generation and slip calculation in an IFOC scheme. Hence neural network learning based model reference adaptive system (NN-MRAS) for the on-line estimation of rotor resistance (Rr) is utilized. The Neural learning algorithm determines the estimation speed, stability, weight convergence, accuracy of estimation, speed of tracking and ease of implementation. This work proposes a new neural learning strategy for Rr estimation. The entire system is modeled and simulated in Matlab/Simulink. The MLI fed drive is compared with the conventional inverter fed drive.Also the MLI fed drive dynamics are presented with and without the proposed estimator. © Springer India 2015.

Lecture Notes in Electrical Engineering Power Electronics and Renewable Energy Systems

Investigations on the Dynamics of Seven Level Inverter Fed Induction Motor Drive with Neural Based Rotor Resistance Estimator

Recent research and development of alternative energy sources have shown excellent potential as a form of contribution to conventional power generation systems. In order to meet sustained load demands during varying natural conditions, different energy sources and converters need to be integrated with each other for extended usage of alternative energy. The paper focuses on the combination of wind, Fuel Cell (FC) and Ultra-Capacitor (UC) systems for sustained power generation. As the wind turbine output power varies with the wind speed: an FC system with a UC bank can be integrated with the wind turbine to ensure that the system performs under all conditions. A dynamic model, design and simulation of a wind/FC/UC hybrid power generation system with power flow controllers is proposed. In the proposed system, when the wind speed is sufficient, the wind turbine can meet the load demand. If the available power from the wind turbine cannot satisfy the load demand, the FC system can meet the excess power demand, while the UC can meet the load demand above the maximum power available from the FC system for short durations. Furthermore, this system can tolerate the rapid changes in wind speed and suppress the effects of these fluctuations on the equipment side voltage in a novel topology. © Maxwell Scientific Organization, 2014.

Fulltext

Research Journal of Applied Sciences, Engineering and Technology

Dynamic Modelling of a Wind/Fuel-Cell/Ultra-Capacitor-Based Hybrid Power Generation System

The mass implementation of renewable energy usage-especially of solar and wind energy- has exposed the problem of voltage regulation due to fluctuation of power generation. A new class of inverter topology is nowadays taking upper hand over conventional inverter. This work envisages designing and simulating ZSI (Z-source inverter) in PSIM environment. The results of the proposed Z-source inverter are compared with the traditional VSI (Voltage source inverter). Finally a hardware prototype implementation of the ZSI is done and its result is verified with calculated value. © 2014 IEEE.

2014 International Conference on Advances in Electrical Engineering (ICAEE)

Implementation of digitally controlled transformer-less voltage regulation for solar power

Induction motors are the workhorses of industries. The two viable speed control schemes for the induction motor are V/f and indirect field oriented control (IFOC) technique. The voltage source inverter is the conventional power converter employed in the drive scheme. Recently, in medium power applications the multilevel inverters (MLI) are gaining more attention due to their high performance. In this work an attempt is made to develop an MLI fed induction motor drive with V/f control as well as with IFOC technique. The closed loop drive scheme is built and simulated using Matlab / Simulink. The performance of the drive scheme with both the control techniques are exhaustively studied under various conditions and the results are presented. Simulation results of IFOC scheme are provided as it exhibits better dynamic performance compared with the V/f scheme. The performance parameters of the drive with both the control schemes are compared and tabulated. © 2013 IEEE.

Department of Database Systems

School of Computer Science and Engineering

2013 Annual IEEE India Conference (INDICON)

Performance analysis of MLI fed induction motor drive with IFOC speed control

Almost 80% of the industrial loads are induction motors. This paper scrutinizes the meticulous analysis of three phase induction motor drive fed by Cascade H-Bridge multilevel inverter (CHBMLI. As a first step the performance of the induction motor drive with the normal voltage source inverter has been examined. Then the drive system has been studied with various levels of cascade H-Bridge inverter. A level shifted multi carrier PWM technique has been used for the CHBMLI. An exhaustive survey is made in order to study the various performance indices such as load torque, motor speed and efficiency. The entire system has been built in Matlab / Simulink and the simulation results are provided. To show the improvisation in the drive performance five- level and nine-level fed induction motor drive results are presented in this paper. The results reveal that the CHBMLI is more appropriate for induction motor drive. © 2013 IEEE.

Department of Smart Computing

School of Information Technology and Engineering

INTERNATIONAL CONFERENCE ON SMART STRUCTURES AND SYSTEMS - ICSSS'13

A meticulous analysis of induction motor drive fed from a nine-level Cascade H-Bridge inverter with level shifted multi carrier PWM

This work envisages modeling solar photovoltaic (PV) systems as it is one of the most promising renewable energy source. A mathematical model of the PV system assumes importance as it enables the study of its performance under varying environmental and load conditions so as to assess its suitability for real time applications. To serve this purpose a mathematical model of the PV system has been developed in Matlab. The simulator is modeled to support a large array PV system, so that it can be interfaced with power electronic converters. Also the PV model has been connected with the cascade multilevel inverter (MLI) and the results are presented. The simulation results illustrate that this inverter topology is a right choice for PV applications. © 2013 IEEE.

2013 International Conference on Power, Energy and Control (ICPEC)

Modeling and experimental validation of solar PV system for cascade H-bridge multilevel inverter

With the rapid growth of power electronic techniques, the use of solar energy in electric power applications is gradually increasing. But the output of a solar array has non-linear voltage-current characteristics, which varies with the change in irradiation, weather conditions and temperature changes. In order to continuously harness the maximum power from the solar array, an efficient maximum power point tracker has to be implemented, which tracks the maximum possible power at any instant of time. The tracking algorithm automatically changes the duty cycle of the converter connected to the solar panel, so that the panel voltage becomes equal to the voltage corresponding to MPP at any level of isolation, temperature or load conditions. This paper presents an 'Incremental Conductance' based maximum power point tracking algorithm. Simulations are done in MATLAB/SIMULINK and the results are observed for varying temperatures and irradiances. © Research India Publications.

International Journal of Applied Engineering Research

An incremental conductance based maximum power point tracking algorithm for a solar photovoltaic system

Cascade H-bridge multilevel inverter (CHBMLI) seems to be the appropriate topology for photo voltaic (PV) applications. This paper investigates the analysis and implementation of single phase cascaded five-level inverter for PV applications. The PV system has to bemodeled for analyze the response under various environmental conditions. As a first step the modeling of the PV system is done in Matlab/Simulink. Then the PV fed single phase cascaded five-level CHBMLI has been built and the results are presented. Level shifted Multi-carrier Pulse Width Modulation is used for the CHBMLI. These pulses are generating using 8051microcontroller. Keil software is employed to code the pulse generation logic. The hardware implementation of cascade multilevel inverter using 8051 microcontroller has been discussed. © Research India Publications.

Cascaded multi-level inverter using 8051 microcontroller for PV applications

This The Permanent Magnet Synchronous Motors (PMSM) are used for medium power applications and preferred over conventional motors like Induction and Synchronous motors due its superior performance, efficiency and controllability. Normal voltage source inverters are suitable only for three phase drives. Cascaded multi-level inverters are used to improve the power quality. The Hexagram inverter has the advantages of both these inverters, while, it also drives six-phase motors which are more popularly used now. This paper deals with Hexagram inverter fed PMSM drive. Vector control scheme has been employed due to its benefits like better dynamic response. The PMSM has been modeled in dq frame and the drive system is simulated using MATLAB / Simulink. The results of the hexagram inverter and the drive structure are presented for various operating conditions. The model delivers promising results due to the multilevel property of the hexagram inverter and the vector control method.

International Journal of Engineering and Technology

Vector control of permanent magnet synchronous motor using high performance hexagram inverter

The Brushless Direct Current (BLDC) motors are widely used in consumer electronics, electric vehicles and medical applications. BLDC motors have many advantages over brushed DC motors and induction motors, such as better speed versus torque characteristics, good dynamic response, higher efficiency and large speed ranges. These applications have made it important to develop BLDC motor controllers. This paper presents the development of a virtual motor, a set of programs that represent the BLDC motor, which is modeled and simulated in LabVIEW. The BLDC motor characteristics are implemented on the Field Programmable Gate Array (FPGA). This is used as a virtual motor for the testing and validation of digital controllers; in addition, this can also be used for educational purposes. Such a virtual motor will allow for realizing motors of various ratings by changing the parameters. This will allow the testing and validation of different controllers, without the risk of damage in extreme conditions of operations. © 2012 Praise Worthy Prize S.r.l.