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Flexible Monte Carlo method for sensor calibration
Ramos, Pedro M.; Rodrigues, Nuno M.; Janeiro, Fernando M.Sensor/system calibration is a crucial step in every measurement system. To perform the calibration the system/sensor input is changed, and its output is measured. The device calibration is obtained from the measured input and output values. When the input/output relation is a straight line, a linear regression is the most common method to obtain the relation. However, this method does not consider uncertaintie...
Sinewave frequency estimation based on fractional Interpolated Discrete Fourier...
Janeiro, Fernando M.; Ramos, Pedro M.Frequency estimation is crucial in numerous scientific applications and have led to the development of various algorithms. Most approaches use the Discrete Fourier Transform followed by spectral interpolation. However, limitations arise when sinewave frequencies align closely with DFT lines especially for low Signal-to-Noise Ratios. Recent advances have employed non-integer Goertzel filters to compute Discrete ...
Measurement of Battery Aging Using Impedance Spectroscopy with an Embedded Mult...
Lourenço, J.; Rosado, Luis S.; Ramos, Pedro M.; Janeiro, Fernando M.This work describes the development of an embedded standalone measurement system that monitors the aging of batteries using impedance spectroscopy. The system generates a multisine stimulus that contains the frequency components at which the battery impedance is measured. Coherent generation and sampling is assured, and Goertzel filters, one for each measurement frequency, are updated with each new sample. This...
Power Quality Transient Detection and Characterization Using Deep Learning Tech...
Rodrigues, Nuno M.; Janeiro, Fernando M.; Ramos, Pedro M.Power quality issues can affect the performance of devices powered by the grid and can, in severe cases, permanently damage connected devices. Events that affect power quality include sags, swells, waveform distortions and transients. Transients are one of the most common power quality disturbances and are caused by lightning strikes or switching activities among power-grid-connected systems and devices. Transi...
Deep Learning for Power Quality Event Detection and Classification Based on Mea...
Rodrigues, Nuno M.; Janeiro, Fernando M.; Ramos, Pedro M.Energy consumption has increased over the years, and, due to the dependency on fossil energy, alternative and renewable energy sources have been integrated to address environmental concerns. However, it is important to maintain the efficiency, reliability, and safety of the power grid amid the integration of different energy sources. IEEE and IEC standards regulate power quality (PQ) and define thresholds for P...
Battery Impedance Spectroscopy Embedded Measurement System
Cicioni, Gabriel; De Angelis, Alessio; Janeiro, Fernando M.; Ramos, Pedro M.; Carbone, PaoloThe evolution of rechargeable battery characteristics have led to their use in almost every device in our everyday life. This importance has also increased the relevance of estimating the remaining battery charge (state of charge, SOC) and their health (state of health, SOH). One of the methods for the estimation of these parameters is based on the impedance spectroscopy obtained from the battery output impedan...
Implementation of Goertzel Based Frequency Estimation for Power Quality Monitor...
Rodrigues, Nuno M.; Janeiro, Fernando M.; Ramos, Pedro M.International standards from IEC and IEEE regulate power grid parameters such as the RMS value, frequency, harmonic and interharmonic distortion, unbalance or the presence of transients, that are important to assure the quality of distributed power. Standard IEC 61000-4-30 suggests the zero crossing algorithm for the measurement of the power grid frequency, but also states that different algorithms can be used....
Electrical Power Grid Frequency Estimation with Fuzzy Boolean Nets
Rodrigues, Nuno M.; Carvalho, João P.; Janeiro, Fernando M.; Ramos, Pedro M.Power quality analysis involves the measurement of quantities that characterize a power supply waveform such as its frequency. The measurement of those quantities are regulated by internationally accepted standards from IEEE or IEC. Monitoring the delivered power quality is even more important due to recent advances in power electronics and also due to the increasing penetration of renewable energies in the ele...
Peak factor optimization of multi-harmonic signals using artificial bee colony ...
Janeiro, Fernando M.; Hu, Yingyue; Ramos, Pedro M.Multi-harmonic signals are useful in many applications to estimate the frequency response of a device. To minimize noise effects, signal power should be maximized within the amplitude limitations of the signal generation and acquisition hardware. Signal power depends only on the harmonic amplitudes, while the signal amplitude also depends on the harmonic phases. Careful choice of these phases allows the minimiz...
Low-Cost Embedded Measurement System for Power Quality Frequency Monitoring
Rodrigues, Nuno M.; Janeiro, Fernando M.; Ramos, Pedro M.Power quality (PQ) analysis involves the measurement of quantities that characterize the power grid. However, since traditional monitoring equipment is expensive, the measurements are typically performed at few selected locations, not on a regular basis and typically to address customer or grid problems. Recent advances in power electronics combined with the increasing penetration of renewable energies have inc...