N. Ramesh Babu

Speech recognition using MFCC and DTW

Speech recognition has wide range of applications in security systems, healthcare, telephony military, and equipment designed for handicapped. Speech is continuous varying signal. So, proper digital processing algorithm has to be selected for automatic speech recognition system. To obtain required information from the speech sample, features have to be extracted from it. For recognition purpose the feature are analyzed to make decisions. In this paper implementation of Speech recognition system in MATLAB environment is explained. Mel-Frequency Cepstral Coefficients (MFCC) and Dynamic Time Wrapping (DTW) are two algorithms adapted for feature extraction and pattern matching respectively. Results are obtained by one time training and continuous testing phases.

Performance analysis of boost & Cuk converter in MPPT based PV system

Photovoltaic (PV) cell based power generation is best alternative developing for fossil fuel as it does not have pollution issues. This paper focuses on performance of boost and Cuk DC/DC converter, used in MPPT based PV system. Perturb and Observe (P&O) technique used to generate duty cycle of converters. The simulation study is performed using MATLAB/Simulink for the PV system and it has been observed that the Cuk converter produces better results compared with boost converter.

Design and Analysis of RBFN-Based Single MPPT Controller for Hybrid Solar and Wind Energy System

In this paper, a radial basis function network-based single maximum power point tracking (MPPT) control algorithm for a hybrid solar and wind energy system is designed and analyzed for standalone and grid connected applications. The extraction of maximum power from the intermittent and erratic nature renewable energy sources is the main target in the hybrid renewable energy system. In the literature, many researchers developed an individual MPPT control algorithm for solar and wind energy system, which in turn increases the number of control algorithms in a hybrid system. In this paper, a single MPPT controller is proposed to extract maximum power from both the sources simultaneously. The performance of the proposed MPPT control algorithm is analyzed in both standalone and grid connected modes, under different weather conditions. The hybrid renewable energy system is designed by considering 560-W photovoltaic system and 500-W wind system with the conventional boost converter, and it is simulated in MATLAB/Simulink environment to analyze the performance of the proposed MPPT controller.

Design and Development of Single Switch High Step-Up DC–DC Converter

In this paper, a new single switch high step-up dc–dc converter with high voltage gain is proposed. The proposed topology is developed by combining boost and single-ended primary inductor converter with diode–capacitor circuit to reduce the stress across the semiconductor devices. The proposed converter produces low switching voltage and hence it improves its efficiency. The operating principle and the steady-state performance analysis are discussed. The performance of the converter is validated by developing a prototype circuit with input voltage of 30 V, output voltage of 300 V, and output power rating of 250 W. The theoretical analysis and experimental results conclude the proposed converter that is suitable for high-voltage applications.

Comparative Analysis of DC/DC Converters with MPPT Techniques Based PV System

This paper focuses on the comparison of perturb and observe (P&O) and adaptive neuro-fuzzy inference system (ANFIS) based maximum power point tracking to track the optimum maximum power from PV system. This article also points out the performance of the boost converter and modified Single-Ended Primary-Inductor Converter (SEPIC) using above two techniques for PV. P&O and ANFIS techniques are used to generate duty cycle of DC/DC converters. The study is performed by using MATLAB/Simulink with the rating of 200 W PV and it has been observed that the modified SEPIC converter based ANFIS produces superior results compared with classical boost converter.

A Novel Six-Switch Power Converter for Single-Phase Wind Energy System Applications

In this paper, a six-switch AC/DC/AC converter is proposed for single-phase wind energy system application. The proposed converter consists of two arms with three switches in each, where the top layer switches are used for the rectification mode and lower layer switches are used for the inversion mode of operation. The middle layer switches are shared by the both rectification and inversion mode operation based on the modified PWM scheme. A small rated DC link capacitor is chosen by providing suitable coordination control and EX-OR gate logic between the rectification and inversion mode of operation. The proposed single-phase six-switch converter has the advantage of both reduced number of switches and small DC link capacitor size. To validate the effectiveness of the proposed converter, simulation results are presented for 1 kW wind system.

Fuzzy Logic-Based Pitch Angle Controller for PMSG-Based Wind Energy Conversion System

A comparative analysis of different types pitch angle controller is designed in this paper to achieve a steady output torque for stable wind turbine operation. The control techniques are implemented and developed to provide a uniform constant torque to the permanent magnet synchronous generator (PMSG). The wind system consists of a wind turbine, a pitch actuator and PMSG. The control strategy used are proportional-integral (PI) and fuzzy logic controller (FLC). The performance of the control strategies is investigated in terms of aerodynamic torque, generator speed and the generator power. The complete wind energy conversion system (WECS) is developed and tested using MATLAB/Simulink. The performance of the control strategies is evaluated under varying wind-speed condition. The performance of the pitch angle controllers is found satisfactory, but the strategy with fuzzy logic-based controller shows better performance as compared to PI controller.

Coordinated DTC and VOC control for PMSG based grid connected wind energy conversion system

This paper presents an output power smoothing method by a coordinate control of machine side converter and grid side converter for permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). The WECS adopts medium voltage source converter with AC-DC-AC configuration. The output power fluctuations are compensated using direct torque control based maximum power point controller and voltage oriented control. The DC link voltage is controlled using grid side controller and the maximum power is extracted using the machine side controller of the wind turbine. The proposed controller provides effective solution for grid integration and constant power flow from the generator system to grid system. Simulation results are presented and analysed the performance of the control strategies implemented in the system.

High Response Photon-Counting for Phase Fraction Measurement Using Compact-RIO with FPGA

This paper presents the measurement of phase fraction of multiphase using LabVIEW/FPGA&RT. Phase fraction measurement is done by high-frequency gamma ray photons attenuation from multiple scintillation detectors without dead time between dwell intervals. This phase fraction measurement method is based on the differences in the linear or mass attenuation coefficient of components of each phase to light. The electromagnetic wave attenuation based on Beer-Lambert’s law gives the width of individual phases. Even though this method requires shielding, it has the advantages of penetrating through steel. Other phase fraction methods include differences in the permittivity of the components of phases. The voltage across the two electrodes kept opposite to each other determines the phase fraction. But, it has the disadvantages of requirements of special shielding for low capacitance and stray capacitance. Besides, the differences in the conductivity can measure the path resistance. This conductivity change gives phase fraction. Among the above volume—percentage measurement methods, former method is more accurate for industrial applications.

Developing Prototype for Prosopagnosia Using PCA

Prosopagnosia primarily known as face blindness is a brain disorder in which a person is not able to recognize faces. In the device a portable camera is used to capture the real time movement of a person. In the main system face is detected using Voila –Jones Algorithm & hue channel detection. Using Principal Component Analysis (PCA) face is recognized. It is compared with the trained database and displays the basic information about the person if a similar trained data is found otherwise, it is declared as unknown. For new database, system can be trained at any point of time. The prototype system is trained using 30 candidates’ images including 10 images per candidate under distinct angles. The system was able to achieve 98% face detection. It provides the patients an aid to help them recognize people in front of them in seconds.