MATLAB-Simulink environment based power quality improvement in photovoltaic system using multilevel inverter

Introduction. In this world of technical advancement, conventional resources are at the stage of destruction. To avoid such problems, we are going to use an alternative energy source namely solar by photovoltaic effect. The demand for multilevel inverters increased as they are used for different dynamic (high) voltage and dynamic (high) power appliances as they are capable of producing the output wave shape with low total harmonic distortion. Novelty. A new multilevel inverter is used in adding a (bidirectional) two way switch in between the capacitor and a traditional H-bridge module. This produces a better sine wave. By series connection of these two H-bridge modules, nine levels output voltage including zero is possible. The purpose of the proposed topology is reduction in the number of switches and it gives the good result with comparatively less power loss when it is compared with the other normal basic traditional inverters of the same output quality. Methods. In this paper, sinusoidal pulse width modulation technique is used for the working of the switches in the multilevel inverter. The results are verified by using simulation and also experimental setup is done. From the results it is observed that the proposed topology with reduced number of switches gives lower electromagnetic interference, lower harmonic distortion. Practical value. The total harmonic distortion value in the simulation is 14.4 % and practically it is 13.8 %.Вступ. У світі технічного прогресу звичайні ресурси перебувають у стадії руйнації. Щоб уникнути таких проблем, ми збираємося використати альтернативне джерело енергії, а саме сонячну енергію з фотоелектричним ефектом. Попит на багаторівневі інвертори збільшився, оскільки вони використовуються для різних динамічних (високих) напруг та динамічних (високих) потужностей, оскільки вони здатні формувати вихідну форму хвилі з низьким гармонічним загальним спотворенням. Новизна. Новий багаторівневий інвертор використовується для додавання двостороннього перемикача між конденсатором і традиційним модулем Н-моста. Це дає найкращу синусоїду. При послідовному з’єднанні двох модулів Н-моста можливо дев’ять рівнів вихідної напруги, включаючи нуль. Метою запропонованої топології є зменшення кількості перемикачів, що дає хороший результат при порівняно менших втратах потужності порівняно з іншими традиційними звичайними інверторами з такою ж вихідною якістю. Методи. У цій статті для роботи перемикачів у багаторівневому інверторі використовується метод широтно-імпульсної синусоїдальної модуляції. Результати перевіряються за допомогою моделювання, а також виконується експеримент. З результатів видно, що пропонована топологія зі зменшеною кількістю перемикачів дає менші електромагнітні перешкоди, менші гармонійні спотворення. Практична цінність. Сумарне значення гармонійних спотворень при моделюванні складає 14,4 %, а практично – 13,8 %

Keyhole craniectomy in the surgical management of spontaneous intracerebral hematoma

Background and Objective: Although the surgical management of spontaneous intracerebral hematoma (SICH) is a controversial issue, it can be life saving in a deteriorating patient. Surgical techniques have varied from the open large craniotomy, burr hole and aspiration to the minimally invasive techniques like stereotactic aspiration of the SICH, endoscopic evacuation and stereotactic catheter drainage. The authors report their experience with a keyhole craniectomy for the surgical evacuation of SICH. Methods: Ninety-six cases of SICH were treated using the keyhole craniectomy technique. A small craniectomy of 2-2.5 cm diameter was made using a vertical incision over a relatively ‘silent area’ of the cortex closest to the clot. Using a small cortical incision the hematoma was evacuated and decompression was achieved. Hemostasis was achieved using standard microneurosurgical techniques. Results: Good to excellent outcome was achieved in 55 cases. Mortality was noted in 23 patients. Blood loss was minimal during the procedure. Good evacuation of the clot was seen in all but 5 cases as judged by the postoperative CT scan. Conclusion: The keyhole craniectomy technique is minimally invasive, safe and can achieve good clot evacuation with excellent hemostasis. It can be combined with microscopic or endoscopic assistance to achieve the desired result

Development and Performance Analysis of Five Phase Induction Motor

In light of the constant need for more energy, modern society is characterized by constant technical development, especially in the field of electricity. Due to the limitations of the voltage at which it may be given, it has a finite value. Energy providers and consumers are both subject to consumption restrictions. Multiphase systems are a viable option for dealing with this issue. Multiphase systems are currently being used to tackle the issue, and progress in this area of study is swift. The importance of multiphase supply cannot be overstated in the realm of drives and other necessities. The Five Phase Induction Motor (FPIM) construction and performance analysis are discussed in this study. MATLAB/SIMULINK is used to evaluate FPIM’s performance. The experimental findings of the developed FPIM are presented in this work

MATLAB-Simulink environment based power quality improvement in photovoltaic system using multilevel inverter

Introduction. In this world of technical advancement, conventional resources are at the stage of destruction. To avoid such problems, we are going to use an alternative energy source namely solar by photovoltaic effect. The demand for multilevel inverters increased as they are used for different dynamic (high) voltage and dynamic (high) power appliances as they are capable of producing the output wave shape with low total harmonic distortion. Novelty. A new multilevel inverter is used in adding a (bidirectional) two way switch in between the capacitor and a traditional H-bridge module. This produces a better sine wave. By series connection of these two H-bridge modules, nine levels output voltage including zero is possible. The purpose of the proposed topology is reduction in the number of switches and it gives the good result with comparatively less power loss when it is compared with the other normal basic traditional inverters of the same output quality. Methods. In this paper, sinusoidal pulse width modulation technique is used for the working of the switches in the multilevel inverter. The results are verified by using simulation and also experimental setup is done. From the results it is observed that the proposed topology with reduced number of switches gives lower electromagnetic interference, lower harmonic distortion. Practical value. The total harmonic distortion value in the simulation is 14.4 % and practically it is 13.8 %

Intelligent Energy Management for Distributed Power Plants and Battery Storage

A smart energy management controller is required for effective source coordination and load demand management. This work proposes a novel instantaneous current reference technique for use in power management of hybrid power systems (HPS), both autonomous and interconnected with the grid. A grid integrated hybrid power system (GI-HPS) includes both the AC grid and additional sources used in industrial and commercial environments. Solar photovoltaic (SPV) panels, wind turbine generators, proton exchange membrane fuel cells, and batteries are all part of the test system. The suggested energy management system (SEMS) manages power from the hybrid power source and the energy storage components to meet the load needs. The recommended SEMS can transit between 12 different modes of operation to fulfil the load demand requirements. The SEMS employs a scaling factor N to accelerate the rate at which the measured current approaches the reference current. The proposed scaling factor significantly improves the SEMS’s dynamic performance since it can quickly respond to the changes in the source and load characteristics. The dependability of an HPS powered by a variety of renewable energy sources can also be improved

Experimental Investigation and Performance Characteristics of Francis Turbine with Different Guide Vane Openings in Hydro Distributed Generation Power Plants

This article presents a study on the performance characteristics of a Francis turbine operating with various guide vane openings to determine the best operating point based on unit quantities. The guide vane openings were specified based on the width between the vanes at their exit, i.e., 10 mm, 13 mm, 16 mm, and 19 mm. The performance characteristic curves of the Francis turbine—head versus speed, torque versus speed, discharge versus speed, and efficiency versus speed—were obtained at various input power and guide vane openings. From these data, unit curves were plotted and the corresponding best efficiency points were obtained. The highest efficiency of 50.25% was obtained at a guide vane opening of 19 mm. The values of head, discharge, speed, and output power at BEP were 7.84 m, 13.55 lps, 1250 rpm, and 524 W, respectively

Experimental Investigation and Performance Characteristics of Francis Turbine with Different Guide Vane Openings in Hydro Distributed Generation Power Plants

This article presents a study on the performance characteristics of a Francis turbine operating with various guide vane openings to determine the best operating point based on unit quantities. The guide vane openings were specified based on the width between the vanes at their exit, i.e., 10 mm, 13 mm, 16 mm, and 19 mm. The performance characteristic curves of the Francis turbine—head versus speed, torque versus speed, discharge versus speed, and efficiency versus speed—were obtained at various input power and guide vane openings. From these data, unit curves were plotted and the corresponding best efficiency points were obtained. The highest efficiency of 50.25% was obtained at a guide vane opening of 19 mm. The values of head, discharge, speed, and output power at BEP were 7.84 m, 13.55 lps, 1250 rpm, and 524 W, respectively