High frequency link Uninterruptible Power Supply (UPS) system

This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.The main aim of this thesis is to propose, design, simulate and build a new UPS system which can be used for compact applications. The idea of the proposed system is to operate the transformers within the UPS at high frequency so that the size and the weight are kept to minimum. In order to achieve this aim, the transformer within the UPS system is operated at high frequency; however it also carries two 50 Hz waveforms at 180 phase shift so that the transformer does not see this 50 Hz frequency. A cycloconverter is then used to reconstruct the 50 Hz waveform for the UPS output. The UPS system is simulated using PSPICE software at high frequency link of 500 Hz, 1 kHz, 5 kHz and 10 kHz. The simulation results show that the transformer only passes the high frequency component while the 50 Hz frequency is ‘hidden’ within the transformer. The proposed UPS system is then built using MOSFETs IRF740 as the main switches for the inverter and cycloconverter circuits. A Chipkit-uno32-development-board is used to control the MOSFET switches. Simulated and practical results show the viability of the proposed UPS system.This study is funded by Dubai Aluminium

DESAIN TIGA FASE UNIFORM PULSE-WIDTH MODULATION (UPWM) DENGAN DSPICC30F4011 GUNA MENGATASI DIP TEGANGAN DAN INTERUPSI

Sistem tenaga listrik merupakan sebuah aset yang vital dalam kehidupan sehari-hari, sehingga penggunaan elektronika daya atau konverter sudah menjadi hal yang biasa. Pada umumnya konverter dibagi menjadi dua yaitu konverter sumber tegangan dan konverter sumber arus. Konverter membutuhkan sinyal pemicuan yang dibangkitkan secara analog maupun digital agar dapat bekerja. Teknik pemicuan terus berkembang hingga saat ini, pemakaian mikrokontroller digunakan guna mengganti pemicuan analog agar lebih stabil gelombang keluarannya. DsPIC30f4011 adalah mikrokontroller yang terspesifikasi khusus yang mendukung pembangkitan sinyal UPWM tiga fasa, diantaranya pengaturan dead time, complementary mode dan center aligned mode. Dalam penelitian ini dirancang inverter full bridge tiga fasa dengan teknik pemicuan UPWM berbasis mikrokontroller dsPIC30f4011 dan pembangkitan sinyalnya dilakukan melalui senarai program. Sinyal carrier dirancang 10 kHz dengan indeks modulasi (ma) dapat diatur pada rentang nilai 0 ≤ ma ≤ 1 dan frekuensi sinyal referensi pada nilai 0 – 50 Hz. Bentuk gelombang tegangan output VLL yang dihasilkan divariasikan secara linier terhadap indeks modulasi pada rentang frekuensi 0 – 50 Hz. Nilai LVUR dan IUR (rasio ketidakseimbangan tegangan dan arus). &nbsp

Acondicionador ferroresonante de voltaje

Electric power supply is one of the most important services supporting daily life in modern society, so the importance of power quality is to find effective ways to prevent disturbances and voltage fluctuations from the user side and propose solutions to correct the failures that occur on the side of the system of the electric power supply company, thereby achieving a quality electric power supply. This article presents the design and implementation of a power quality conditioner based on ferroresonance, the analysis of equivalent electrical circuit and equivalent magnetic circuit is carried out, obtaining the necessary equations for its implementation. In the last part, the operation of the transformer is validated by testing the input voltage variation with no load and with load, evidencing the proper functioning in case of variations above the nominal value.  El suministro de la energía eléctrica es uno de los servicios más importantes que respaldan la vida cotidiana en la sociedad moderna, por lo que la importancia de la calidad de la energía es encontrar formas efectivas de prevenir perturbaciones y fluctuaciones de voltaje para el usuario y proponer soluciones para las fallas que se presentan del en sistema de la compañía operadora de la red eléctrica, logrando con ello un suministro de la energía eléctrica con calidad. Este artículo presenta el diseño e implementación de un acondicionador de calidad de la energía basado en ferroresonancia, se realiza el análisis de circuito eléctrico equivalente y de circuito magnético equivalente, obteniendo las ecuaciones necesarias para la implementación del mismo. En la última parte se valida el funcionamiento del transformador mediante pruebas de variación de voltaje de entrada en vacío y con carga, evidenciando el buen funcionamiento ante variaciones por encima del valor nominal. &nbsp

Zero energy Tunnel-concept

Creating a zero energy environment is a hot topic. The developments in this field are based on the concept of the "Trias Energetica": reducing energy consumption, using renewable energy sources, and efficiently using fossil fuels. A zero energy concept can also be applied to road tunnels to improve the energy performance by means of reducing energy consumption, introducing renewable energy generation and thus lowering energy bills. The zero energy tunnel concept is a good approach to make the road tunnel more energy sustainable and environmental friendly. The developments in this field are based on the next aspects: - Sustainability - Health - Economic issues. Road traffic in a tunnel is a source of atmospheric pollution which has to be managed both inside the tunnel to protect users'safety and well-being and outside the tunnel in order to limit the environmental impact. In most of the tunnels in The Netherlands, there is a feedback system so that high concentrations of pollutants inside the tunnel trigger the ventilation to increase the visibility level. The visibility level has a strong relationship with the concentration of dust. These measurements are required by means of tunnel safety standards and not related to the human well-being aspect. There are hardly any examples in the world where the contaminant removal technologies are applied in tunnels for external air quality purposes. The goals of the Zero Energy Tunnel project study are: - To find possible solutions to decrease energy consumption in the tunnel - To investigate innovative solutions to make the tunnel environmental friendly - To implement renewable energy generation and energy storage to make the tunnel a zero energy element - To establish the needed power flow between all the components and medium voltage grid with keeping power quality at an acceptable level - To develop a Zero Energy Tunnel conceptual design. In this study the contribution to the main goals is done by means of reducing energy consumption of tunnel lighting systems; designing air cleaning systems; designing the heat extraction system that utilizes the heat generated by tunnel traffic; and finally designing the renewable energy generation and energy storage to achieve the energy balance on a yearly basis

Index to 1985 NASA Tech Briefs, volume 10, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1985 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Techniques for the realization of ultra- reliable spaceborne computer Final report

Bibliography and new techniques for use of error correction and redundancy to improve reliability of spaceborne computer

Automatic Control of the Structure of Dynamic Objects in High-Voltage Power Smart-Grid

The control and protection algorithms for the considered class of dynamic facilities with a tunable structure are considered. Their relevance follows from the concepts of the development of the electric power industry—smart grid, digital substation and outsourcing services. The properties of this class of dynamic objects are spatial distribution, many options for changing the structure and motion in vibrational circuits at natural frequencies from ultra-high to ultra-low. The input coordinate of the dynamic objects is the vector of the change in the structure of the object. The output coordinate is the power of a special semantic signal about the state of the facilities. Their management is carried out as part of the stabilisation system of the normal operation of the facility. Stabilisation is achieved by the criterion of the minimum deviation of the power of the semantic signal from the ‘normal mode’ setting of operation. Executive bodies rebuild the structure of the dynamic facility in a pulsed, programmatic way, using the possibilities of self-healing and resource reservation. If stabilisation is not possible, the damaged area is excluded from the facility. The problem of the stability of the system turned out to be the lack of sufficient information about the state of the object and the similarity of the structure and significance of unrecognisable semantic situations to the main situations. Control algorithms are synthesised by the developed structural-informational (SI) method of dynamic pattern recognition

NASA Tech Briefs, Summer 1985

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences