An Optical AC Voltage Sensor Based on the Transverse Pockels Effect

This paper introduces an optical AC voltage sensor based on the transverse Pockels effect. The sensor utilizes a bulk Bi4Ge3O12 (BGO) crystal as the sensing element. The measurement principle has been described and prototype of the sensor has been constructed and evaluated. Good linearity and accuracy performance was obtained for AC voltage measurement. The proposed sensor can be thus applied to high AC voltage measurements in the electric power industry

Intrinsic, multiplexable sensors for electric field strength using structural slow light in phase-shifted fibre Bragg gratings

In this paper we demonstrate through simulation the potential for phase-shifted fibre Bragg gratings incorporating structural slow light to enable intrinsic reflection-mode point sensors for electric field or voltage. It is shown that lo-bi FBGs incorporating multiple phase shifts yield large enhancements in group index (group delay) at resonance, thus amplifying and localizing time-dependent non-reciprocal effects. A relative, multiplexable measurement of electric field by comparison of the phase unbalance between linear modes on and off resonance is proposed, yielding static resolutions of 24 V and 18 mV respectively in unpoled (dc Kerr effect) and poled (Pockels effect) fibres

Distributed photonic instrumentation for smart grids

Photonic sensor networks possess the unique potential to provide the instrumentation infrastructure required in future smart grids by simultaneously addressing the issues of metrology and communications. In contrast to established optical CT/VT technology, recent developments at the University of Strathclyde in distributed point sensors for electrical and mechanical parameters demonstrate an enormous potential for realizing novel and effective monitoring and protection strategies for intelligent electrical networks and systems. In this paper, we review this technology and its capabilities, and describe recent work in power system monitoring and protection using hybrid electro-optical sensors. We show that wide-area visibility of multiple electrical and mechanical parameters from a single central location may be achieved using this technology, and discuss the implications for smart grid instrumentation

Flexible protection architectures using distributed optical sensors

In this paper we describe recent developments in flexible protection schemes that make use of passive fibre Bragg grating (FBG) based transducers for the distributed measurement of voltage and current. The technology underpinning the passive optical approach is described in detail, and both the present development and the future potential of the approach are discussed. In co-operation with Toshiba, the integration of the technique with an existing busbar protection relay is demonstrated, illustrating the flexibility offered by protection schemes that are based on the use of small, passive, multiplexable, dielectric transducers

ZnMgTe/ZnTe 導波路の作製と高性能電気光学効果デバイスの開発

早大学位記番号:新7502早稲田大

Non-standard methods of current and voltage measurements

Diplomová práca sa zaoberá rešeršou nekonvenčných metód merania prúdu a napätia a následným zostrojením prototypu prúdového senzora na báze magnetorezistívneho materiálu pre vysokonapäťový rozvádzač firmy ABB. Výstupom rešerše je popis jednotlivých metód z hľadiska fyzikálneho a z hľadiska spôsobu merania. Výstupom praktickej časti je prúdový senzor osadený magnetorezistívnou súčiastkou schopný merať magnetické pole v okolí vodiča cez ktorý preteká primárny prúd a tým určiť veľkosť primárneho prúdu. Senzor bol meraný v rozsahu 0 až 1000 A, pričom dosahoval hodnoty presnosti a linearity približne 6%. Hlavným prínosom práce je potvrdenie funkčnosti nekonvenčnej metódy pre meranie vysokých prúdov. Na základe výsledkov má firma ABB možnosť rozhodnutia, či je daná technológia perspektívna pre jej produktové portfólio.This work brings a study about non-conventional methods of voltage and current measurement, followed by a creation of magneto-resistive material based current sensor prototype, suitable for medium voltage switchgear from ABB. Outcome of the study is description of physical principle and the measurement principle of non-conventional methods. Outcome of the experimental part is a current sensor based on magneto-resistive component, which can measure magnetic field generated around a wire with flowing primary current. Through the magnetic field, the sensor can measure primary current flowing in the wire. Sensor was measured in range 0 – 1000 A, and its accuracy and linearity was approximately 6%. The main contribution of this work is the confirmation that this non-conventional method works for measurement of high currents. Based on the outcome, ABB can decide whether is this technology suitable for its product portfolio.

Super Grids Conception

Cílem bakalářské práce “Super Grids Conception” je poskytnout komplexní náhled na problematiku Super Gridů ve smyslu pozadí, konceptu jako takového, dostupných technologií, dosavadních zkušeností a budoucího vývoje, možných zdrojů elektrické energie a konkrétních konceptů a studií. V úvodu jsou osvětleny důvody vedoucí k potřebě elektrických sítí nové generace – celosvětové snahy snižovat dopad výroby elektrické energie na životní prostředí, rostoucí poptávka po elektrické energii a potřeba integrovat obnovitelné zdroje energie. Možné zdroje elektrické energie jsou diskutovány jak v širším kontextu, tak i ve smyslu současných omezení a budoucího vývoje. V druhé části jsou popsány koncepty Smart Gridu, Super Gridu a SuperSmart Gridu s důrazem na přínosy, základní principy a systémové hledisko. Autor se dále zabývá jen koncepcí Super Gridu. Použití stejnosměrných (HVDC) a střídavých (HVAC) technologií je porovnáno z technického i ekonomického hlediska a z něj vycházející typické použití těchto technologií. Dále je podrobně popsána nejlepší dostupná technologie HVDC systémů – základní principy a konfigurace, popis jednotlivých částí, omezení současných technologií, dosavadní zkušenosti a možný prostor pro další vývoj. Následuje zmínka nových výzev oblasti HVAC technologií ve vztahu k Super Gridům a popis problémů souvisejících s hybridními AC/DC linkami a koridory. V poslední části jsou vysvětleny rozdíly v historickém vývoji a současných postojích v různých částech světa. Zároveň jsou představeny koncepce zvažovaných Super Gridů. Zvláštní prostor je poskytnut vizionářské koncepci vytvořené DESERTEC Foundation a technickoekonomické studii OffshoreGrid.The aim of bachelor’s thesis “Super Grids Conception” is to provide complex overview of Super Grids topic in terms of describing the background, concept itself, available technology, experience and further development, possible energy sources and particular concepts and studies. In the beginning, reasons which lead to need of next-gen electrical grids are identified in global goal to reduce environmental impact of power generation, growing electricity demand and emerging need to integrate renewable energy sources. Possible energy sources of the future are discussed in broader context as well as in sense of current limitations and further development. In second part, concepts of Smart Grids, Super Grids and SuperSmart Grids are described focusing on benefits, basic principles and systemic point of view. The author then elaborates on Super Grids Conception. HVDC and HVAC technologies are compared from technical and economical point of view, resulting typical usage is mentioned. Later a detailed overview of state-of-the-art HVDC systems technology is provided, including basic principles and design, components description, limitations of available technology, practical experience and possible development areas. Challenges in HVAC field towards Super Grids are introduced, as well as the issues related to hybrid AC/DC corridors and lines. In the last part, differences in historical development and present attitude between different parts of the world are explained. Considered Super Grid conceptions are introduced with special aim to visionary DESERTEC Foundation Concept and techno-economic study OffshoreGrid.

Near-Infrared Coherent Raman Spectroscopy and Microscopy

Coherent Raman Scattering (CRS) spectroscopy and microscopy is a widely used technique in biology, chemistry, and physics to determine the chemical structure as well as provide a label-free image of the sample. The system uses two coherent laser beams one of which is constantly tuned in wavelength. Thus, a tunable laser source or optical parametric oscillator (OPO) is commonly used to achieve this requirement. However, the aforementioned devices are extremely expensive and work only for a specific wavelength range. In this study, we replace an OPO system with a photonic crystal fiber (PCF) in order to significantly reduce the cost and increase the flexibility of our microscopy system. Here, by exploiting the nonlinear phenomenon in the fiber called the soliton self-frequency shift (SSFS), we are able to shift the pulse central frequency while preserving its shape. Also, by switching to a near-infrared (NIR) source, the undesired fluorescence is reduced while the penetration depth increases. Moreover, the NIR laser source is more biologically friendly as each photon carries less energy than the visible laser counterpart. This reduces the probability of the photodamage effect. Based on this system, we designed and implemented CRS microscopy and spectroscopy, using Coherent anti-Stokes Raman Scattering (CARS) and Stimulated Raman Scattering (SRS) spectroscopy techniques