Infrared temperature measurement sensors of overhead power conductors

Efficiency in power lines operation is becoming more crucial as the electrification increases and more renewable energies are connected into the grid. New methods and sensors are being added to create smart grids to face these challenges and conductor temperature sensors are one of them. Contact temperature sensors have several problems regarding safety and electronic damage due to the electromagnetic fields induced on the conductors. The goal of this paper is to describe an infrared temperature measurement sensor and to compare contact and non-contact temperatura measurements to estimate the temperature of power lines. Measurements were done for almost a year, storing around 150,000 measures of contact and infrared thermometers for many different weather and load conditions. The results conclude that the infrared system can be successfully used to control the temperature of the overhead conductor within a range of less than 4 _C difference with respect to contact temperature methods for the 88% of the samples and less than 6 _C for the 99%.This research was funded by the EU Regional Development Fund (FEDER) and the Spanish Government under the R+D initiative INNPACTO with reference IPT-2011-1447-920000, ENE-2013-42720-R and RETOS-COLABORACION RTC-2015-3795-3

Novel application of magnetoresistive sensors for high-voltage transmission-line monitoring

High-voltage transmission lines are responsible for transmission of electric power. Their sag and electric current are important parameters for transmission-line monitoring. In this paper, a simple and promising method based on magnetoresistive sensors is proposed for transmission-line monitoring. This is a noncontact method and its installation is simple without the need for power cut. The method involves measuring emanated magnetic field from a line conductor at the ground level and, then, calculating the source position and current inversely. A proof-of-concept laboratory setup was constructed and a series of experiments were carried out for demonstration. This method can handle complicated transmission-line configuration by integrating the stochastic optimization approach into the inverse electromagnetic calculation. It was tested with the computational simulation of a 500 kV transmission-line configuration. The result shows the feasibility of using this transmission-line monitoring method in reality. © 2011 IEEE.published_or_final_versio

Temperature Monitoring in Switchgears

This thesis focuses on the problem of temperature monitoring inside electrical switchgears. The outcome of this work is a developed sensor prototype. This solution can monitor multiple bus bar and cable joints in switchgears using a single thermopile IR sensor. The measured temperatures are saved in a multipixel array, and they can be shown to the system operator using the application’s HMI. The main function of the application is to alarm the system when temperature hot-spots start to develop.    The specifications for the developed temperature monitoring application are laid out. Theory about IR temperature measurement is presented, and the function principle of thermopile sensors is described. Different solutions to the known reflectivity problem of bus bars are discussed. The presented solution to this problem is to apply high-emissivity paints or tapes close to potential hot-spots.    The developed application’s functions are shown in simple terms. A proof-of-concept test is made for the developed prototype application and different tapes and paints are also tested. The results of the test indicate promise for the developed prototype and the full application. Finally, a discussion is held about the test results and further product possibilities.    This thesis was made for Arcteq Ltd in Vaasa.Detta examensarbete behandlar problemet med temperaturövervakning i ställverk. Resultatet av detta examensarbete blev en utvecklad prototyp för en temperaturgivare. Den slutgiltiga lösningen kan övervaka flera kritiska anslutnings- och förgreningspunkter genom att använda endast en IR-givare. De mätta temperaturerna kan sedan visas för systemets operatör via systemets HMI. Systemets huvudsakliga funktion är att alarmera när temperaturen i en punkt överskrider en alarmnivå. Specifikationerna för den utvecklade temperaturövervakningsapplikationen framställs. Teorin som användes för temperaturmätningen med IR-givaren presenteras. Dessutom presenteras teorin som möjliggjorde mätningen med termoelement, vilket är centralt till den valda givartypen. Olika lösningar till det kända reflektivitetsproblemet diskuteras. Den valda lösningen var att applicera tejp eller målfärg nära samlingsskenornas potentiella hetpunkter. Den utvecklade lösningen beskrivs i enkla termer. Ett test utfördes för att bekräfta den utvecklade prototypen och olika tejper och målfärger testas också. Resultaten är lovande för den utvecklade givarprototypen och lösningen som helhet. Slutligen hålls en diskussion angående testresultaten och produktens framtidsutsikter. Arbetet gjordes åt Arcteq Ab i Vasa.Tämä lopputyö käsittelee lämpötilan valvontaa sähkökojeistossa. Tuloksena kehitettiin anturimoduuli, joka pystyy valvomaan useita kohtia kojeistossa käyttäen ainoastaan yhtä IR-anturia. Mitatut lämpötilat voidaan näyttää järjestelmän valvojalle järjestelmän HMI-ikkunassa. Järjestelmän päätehtävä on varoittaa kun tietyt lämpötilarajat ylittyy. Kehitetyn lämpötilamittausjärjestelmän vaatimukset esitetään. IR-anturin lämpötilamittauksen teoriaa käsitellään ja termoelementin käytäntö esitellään. Eri ratkaisuista sähkökiskojen reflektio-ongelmalle keskustellaan. Valittu ratkaisu on peittää mittauskohdat materiaalilla jossa on korkea emissioarvo. Kehitetyn applikaation testit suoritettiin ja erilaisia teippejä ja maaleja testattiin. Testien tulosten perusteella prototyyppi ja koko applikaatio näyttää lupaavilta. Lopuksi keskustellaan testituloksista ja tuotteen tulevaisuuden mahdollisuuksista. Tämä opinnäytetyö on tehty Arcteq Oy:lle Vaasassa

NASA Tech Briefs Index, 1977, volume 2, numbers 1-4

Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977

NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 36)

Abstracts are provided for 63 patents and patent applications entered into the NASA scientific and technical information systems during the period July 1989 through December 1989. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

A study of the relative effectiveness and cost of computerized information retrieval in the interactive mode

Results of a number of experiments to illuminate the relative effectiveness and costs of computerized information retrieval in the interactive mode are reported. It was found that for equal time spent in preparing the search strategy, the batch and interactive modes gave approximately equal recall and relevance. The interactive mode however encourages the searcher to devote more time to the task and therefore usually yields improved output. Engineering costs as a result are higher in this mode. Estimates of associated hardware costs also indicate that operation in this mode is more expensive. Skilled RECON users like the rapid feedback and additional features offered by this mode if they are not constrained by considerations of cost