Non-contact temperature measurement method for dynamic rating of overhead power lines.

Abstract The thermographic temperature measurement is burdened with uncertainty. This non-contact temperature measurement method makes it possible to measure the temperature of the electrical device under load. When the observed object is small (a few square millimeters) the spatial resolution of the thermographic cameras is often insufficient. In this case, the use of the additional macro lens is needed. After using an additional lens, the uncertainty of the thermographic measurement is different from the uncertainty of thermographic measurement without an additional lens. The values of the uncertainty contributions depend on the conditions during the measurement and the used methodology. The authors constructed an uncertainty budget of thermographic temperature measurement with an additional macro lens, based on EA-4/02 (European Accreditation publications). The uncertainty contributions were also calculated. On the basis of the calculated values of the uncertainty contributions, it was determined which factor had the greatest impact on the value of the thermographic temperature measurement with an additional lens.

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Machining Mechanism of Minimum Quantity Lubrication Grinding

Enhanced Heat Transfer Mechanism of Nanofluid MQL Cooling Grinding - Advances in Chemical and Materials Engineering ◽

10.4018/978-1-7998-1546-4.ch003 ◽

2020 ◽

pp. 43-75

Keyword(s):

Temperature Measurement ◽

Measurement Method ◽

Sliding Friction ◽

Minimum Quantity Lubrication ◽

Grinding Force ◽

Contact Temperature ◽

Grinding Process ◽

Machining Mechanism ◽

Constant Cutting Force ◽

Thermocouple Temperature

To facilitate the analysis of experimental theory, this chapter studied the machining mechanism related to the grinding of NMQL and the three mechanisms of sliding, ploughing, and cutting of the abrasive grinding process. A mathematical model of the micro-grinding force was established, and the micro-grinding force can be used to express the force of the grinding zone. The grinding force component was divided into the force of cutting and sliding, removing the constant cutting force during the grinding process, retaining the varying sliding friction force, and determining the sliding friction coefficient to characterize the lubrication performance. It reflected the influence of different lubrication conditions on the friction part. The methods for measuring the temperature during grinding were introduced, including direct contact temperature measurement and non-contact temperature measurement. At present, thermocouple temperature measurement is a commonly used and more accurate temperature measurement method, and the characteristics of each temperature measurement method were analyzed.

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Infrared Temperature Measurement Sensors of Overhead Power Conductors

Sensors ◽

10.3390/s20247126 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7126

Author(s):

Pablo Castro ◽

Ramón Lecuna ◽

Mario Manana ◽

Maria Jose Martin ◽

Dolores del Campo

Keyword(s):

Temperature Measurement ◽

Electromagnetic Fields ◽

Smart Grids ◽

Temperature Sensors ◽

Contact Temperature ◽

Power Lines ◽

New Methods ◽

Infrared Temperature Measurement ◽

Conductor Temperature ◽

Load Conditions

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 temperature 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%.

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