Power-over-Fiber LPIT for Voltage and Current Measurements in the Medium Voltage Distribution Networks.

In this work, we present the design, laboratory tests, and the field trial results of a power-over-fiber (PoF) low power instrument transformer (LPIT) for voltage and current measurements in the medium voltage distribution networks. The new proposed design of this power-over-fiber LPIT aims to overcome the drawbacks presented by the previous technologies, such as the continuous operation (measuring and data transmission) for a wide current range conducted in the medium voltage transmission lines, damage due to lightning strikes, accuracy dependency on vibration, position and temperatures. The LPIT attends the accuracy criteria of IEC 61869-10 and IEC 61869-11 in terms of current and voltage accuracy and it attends the practical criteria adopted by Utilities companies including voltage measurements without removing the coating of the covered conductors. The PoF based LPIT was developed to be applied at 11.9 kV, 13.8 kV, and 23.0 kV phase-to-phase nominal voltages, and in two current ranges 1.25-30 A and 37.5-900 A. The digital data transmission of current, voltage, and temperature from the sensing unit to the processing unit uses a special synchronism technique and it is performed by two 62.5 µm multimode fibers in 850 nm. The optical powering in 976 nm is also performed by one 62.5 µm multimode fiber from the processing unit to the sensor unit. We presented all details of the sensor design and its laboratory characterization in terms of accuracy and temperature correction. We also presented the results of field tests of the sensor made in two different conditions: in a standard distribution network and an experimental hybrid fiber/power distribution network. We believe that these studies aim to incorporate optical fiber and devices, digital technologies, communications systems in electrical systems driving their evolution.

Real-time distributed fiber microphone based on phase-OTDR.

The use of an optical fiber as a real-time distributed microphone is demonstrated employing a phase-OTDR with direct detection. The method comprises a sample-and-hold circuit capable of both tuning the receiver to an arbitrary section of the fiber considered of interest and to recover in real-time the detected acoustic wave. The system allows listening to the sound of a sinusoidal disturbance with variable frequency, music and human voice with ~60 cm of spatial resolution through a 300 m long optical fiber.

On-field distributed first-order PMD measurement based on pOTDR and optical pulse width sweep.

A method for PMD distributed localization and estimation based on polarization optical time domain reflectometer technique, pOTDR and pulse width sweep is used on-field for the first time. The method consists in launching light pulses with variable widths in an optical fiber under test and then analyzes the Rayleigh backscattered signal spatial power distribution after passing through a polarizer. Both localization and PMD magnitude are function of OTDR pulse width and can be obtained from the ripple analysis, enabling the characterization of the fiber links.

A Novel Microfluidics Droplet-Based Interdigitated Ring-Shaped Electrode Sensor for Lab-on-a-Chip Applications.

This paper presents a comprehensive study focusing on the detection and characterization of droplets with volumes in the nanoliter range. Leveraging the precise control of minute liquid volumes, we introduced a novel spectroscopic on-chip microsensor equipped with integrated microfluidic channels for droplet generation, characterization, and sensing simultaneously. The microsensor, designed with interdigitated ring-shaped electrodes (IRSE) and seamlessly integrated with microfluidic channels, offers enhanced capacitance and impedance signal amplitudes, reproducibility, and reliability in droplet analysis. We were able to make analyses of droplet length in the range of 1.0-6.0 mm, velocity of 0.66-2.51 mm/s, and volume of 1.07 nL-113.46 nL. Experimental results demonstrated that the microsensor's performance is great in terms of droplet size, velocity, and length, with a significant signal amplitude of capacitance and impedance and real-time detection capabilities, thereby highlighting its potential for facilitating microcapsule reactions and enabling on-site real-time detection for chemical and biosensor analyses on-chip. This droplet-based microfluidics platform has great potential to be directly employed to promote advances in biomedical research, pharmaceuticals, drug discovery, food engineering, flow chemistry, and cosmetics.

Real time measurement system based on wireless instrumented sphere.

In this work, we developed a new measurement system which includes a Wireless Instrumented Sphere (WIS) and a Graphical User Interface (GUI) software, called Real Time Analysis (RTA). This system is able to acquire, process and visualize the three axis acceleration of the WIS allowing the identification and measurements of rotations, vibrations and impacts in real time. The aim of this instrument is to help the fruit producers to reduce food wasting and improve quality, especially in Brazil, one of the major agricultural countries in the world, whose losses could surpass 20% along the post-harvesting handling chain. Additionally, a data Post Processing Analysis software (PPA) provided of a video synchronization option was developed to determine the impact magnitude, position and even the cause of the impact itself (drop, fruit-to-sphere impact, etc.). Both GUIs presented graphics of the three axis acceleration vectors, acceleration magnitude and velocity, as well as the calculations of the number of impacts (peak detection), maximum, minimum and average impact magnitude. The WIS board was encapsulated in the middle of a spherical transparent polyurethane elastomer. It was also intended to be a small, simple, robust and low cost instrument. Its final diameter of approximately 63 mm, 160 g weight and 1.1 relative density. The RTA reduces the time for testing and is suitable for a fast feedback and allows the user to make adjustments in the experiment setup, packing system or even monitor any process along the post-harvesting handling chain, with an immediate response. The PPA with video synchronization option, proved to be a unique tool, relating the acceleration information with the video position.