MODIFIED HYBRID CASCADED H- BRIDGE MULTILEVEL INVERTER

                                                                A.Rajkumar

PG student- Department of EEE - SBM college of Engineering and technology, Dindigul, Tamilnadu, India

          This paper presents a cascaded H-bridge multilevel inverter that can be implemented using only a single dc power source and capacitors. Standard cascaded multilevel inverters require N dc sources for 2N+1 level. Without requiring transformers, the scheme proposed here allows the use of a single dc power source (example: a battery or a fuel cell stack) with the remaining dc sources being capacitors, which is referred to as Hybrid Cascaded H-bridge Multilevel Inverter (HCMLI) in this paper. It is shown that the inverter can simultaneously maintain the dc voltage level of the capacitors and choose a fundamental frequency switching pattern to produce a nearly sinusoidal output. HCMLI using only a single dc source for each phase is promising for high power motor drive applications as it significantly decreases the number of required dc power supplies, provides high quality output power due to its high number of output levels, and results in high conversion efficiency and low thermal stress as it uses a fundamental frequency switching scheme.

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OPTIMIZATION OF LCL-T RESONANT CONVERTER FOR CC-CV

S.Praveena

PG student- Department of EEE – Mepco Schlenk Engineering College, Sivakasi Tamilnadu, India.

            The LCL-Type series resonant converter has nearly load independent output voltage under some operating conditions. It behaves as a constant current source (CC) when operated under resonant frequency. The output voltage of a CC power supply increases linearly with load resistance. Therefore a constant voltage limit must be incorporated for its use for applications like arc-welding power supplies etc .This limit can be done by incorporating clamp diodes. Since no feedback control is used, the proposed circuit is more reliable and rugged.

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AUTOMATIC DETECTION AND SEGMENTATION OF OPTIC DISC IN RETINAL IMAGES

¹ M.Saradha, ² Mr.A.Athiraja, ³ Dr.A.Askarunisa
¹ PG Student, ² Assistant Professor, ³ Professor & Head
Department of Computer Science and engineering, Vickram College Of Engineering, Enathi, Sivagangai, India.

     Reliable and efficient Optic Disc (OD) localization and segmentation are important tasks in automatic eye disease screening. The Optic Disc (OD) center and margin are typically essential landmarks in establishing a frame of reference for classifying retinal and optic nerve pathology. This project presents a fast and automatic Optic Disc localization and segmentation algorithm developed for retinal disease screening. Morphological filtering is used to remove blood vessels and bright regions other than the Optic Disc from a retinal image. Experimentation was performed on 100 images from the publicly available MESSIDOR database. The OD location methodology succeeded in 78 out of 100 images (78% success). Its efficiency, robustness and accuracy make the OD localization and segmentation scheme described herein suitable for automatic retinal disease screening in a variety of clinical settings. By detecting eye disease early through automated screening algorithms, treatment would become more effective and significant savings in health care costs could be realized

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VOLTAGE AND FREQUENCY CONTROL OF SEIG FOR STAND ALONE RENEWABLE ENERGY SYSTEM

K.Sasikumar ¹, N.Chitra ²

¹PG student- Department of EEE – S.K.P Engineering College, Thiruvannamalai,Tamilnadu, India.

² Assistant Professor- Department of EEE – S.K.P Engineering College, Thiruvannamalai,Tamilnadu, India.

            Induction generators are increasingly being used in nonconventional energy systems. The advantages of using an induction generator instead of a synchronous generator are well known. Some of them are reduced unit cost and size, ruggedness, brushless (in squirrel cage construction), ease of maintenance, self-protection against severe overloads and short circuits, etc. In isolated systems, squirrel cage induction generators with capacitor excitation, known as self-excited induction generators (SEIGs), are very popular. This paper discusses the regulation of the voltage and frequency of a stand-alone wind energy conversion system (WECS) based on a self-excited squirrel-cage induction machine. The proposed new closed loop PWM controller (AC-DC-AC) is used to maintain constant voltage and constant frequency at the output of the generator against varying rotor speed, changing load conditions and  as well as to generate optimum power from the induction generator. The feasibility of the proposed system is simulated by using MATLAB/ Simulink.

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GSM BASED AUTOMATIC ENERGY METER READING & LOAD CONTROL

S.Balaji ¹, S.Jegedeeswaran ²,  M.Rajeshwaran ³,  V.Kumarasamy ⁴

^{1 2 3}UG student- Department of EEE – Vickram College of Engineering, Enathi Tamilnadu, India.

⁴Assistant Professor - Department of EEE – Vickram College of Engineering, Enathi Tamilnadu, India. 

           Traditional metering method for retrieving the energy data is not convenient and the cost of the data logging systems is high. So this paper presents of design and development of Automatic meter reading (AMR) system. AMR system is a boom for remote monitoring and control domestic energy meter. AMR system give the information of meter reading, power cut, total load used, power disconnect and tempering on request or regularly in particular interval through SMS. This information is being sent and received by concerned energy Provider Company with the help of Global system for mobile communication (GSM) network. Energy provider receives the meter reading within a second without visiting person. AMR minimize the number of traditional visits required by employs of energy Provider Company. This system not only reduces the labor cost but also increase meter reading accuracy and save hugs amount of time.

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REDUCTION OF COGGING TORQUE AND MAXIMIZING BACK EMF BY ROTOR OPTIMIZATION IN BLDC MOTOR

M.Bharathi¹, M.Santhi ²

¹PG student- Department of EEE – Sethu Institute of Technology, Kariapatti, Tamilnadu, India.

²Professor - Department of EEE – Sethu Institute of Technology, Kariapatti, Tamilnadu, India.

          At present, most of the electric vehicles are using BLDC motors for various advantages such as high efficiency, compactness, easy controllability etc. But sometimes their efficiency is poor due to the presence of cogging torque and minimized back EMF, hence increasing THD level. The main aim of this work is to reduce the cogging torque and maximize back EMF in order to optimize the rotor shape. Although so many control strategies are employed for minimization of cogging torque, we have used pole arc combination method in this proposed paper. This method is done by Genetic Algorithm using MATLAB. Due to the magnetic saturation and relative complex structure, the cogging torque in IPM brushless machines is more complicated than that in the surface permanent magnet brushless machines. Pole arc combination method offers a better alternative for cogging torque reduction. The motor parameters are taken to do this process. Due to the reduction of cogging torque, THD level is also decreased. In future, FEM analysis is carried out to increasing back EMF.

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DESIGN AND SIMULATION OF MULTILEVEL CURRENT SOURCE INVERTER USING DUALITY PRINCIPLE

M.Madhu Shobini ¹, Rathina Prabha²

¹PG student- Department of EEE – Mepco Schlenk Engineering College, Sivakasi Tamilnadu, India.

²Professor- Department of EEE – Mepco Schlenk Engineering College, Sivakasi Tamilnadu, India.

This paper explores the issue of constructing Multilevel Current Source Inverter (MCSI) topologies using the duality principle on the existent Multilevel Voltage Source Inverter (MVSI) topology. In order to apply the duality principle for three phase power electronic circuits which are non-planar, two methods for planar treatment with three phase VSI are established - (a) By adding an extra leg. (b) By adding an extra voltage source. While implementing any one of these methods, an improved topology of three phase flying capacitor multilevel voltage source inverter is obtained. Then a new kind of three phase MCSI topology is derived from the application of duality on such MVSI topology. Finally, operational principle of this new MCSI is analysed and simulation model has been built up to verify the proposed MCSI structure.

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