This paper discusses the possibility to use current ripple introduced by switch mode power converters for low-cost monitoring of polymer electrolyte membrane (PEM) fuel cell (FC) state-of-health, suitable commercial applications that cannot afford dedicated instrumentation. In more details, an estimate ohmic resistance, which is a good indicator water content, can be obtained from high-frequency response data processing in frequency domain, while lower at 100/120 Hz (when present) typical...

On-board calibration of bidimensional aperture synthesis radiometers with a large number antennas by the standard correlated noise injection method is technologically very critical because stringent requirements on mass, volume, and phase equalization distribution network. A novel approach, which makes use set uncorrelated sources uniformly distributed in array, proposed. Each source drives only to small adjacent antennas. These sets are overlapped order maintain modulus track along array....

C OST and reliability are two key aspects that still hinder a massive-scale market diffusion of fuel cell (FC) technology.For this reason, the development low-cost diagnostic tools control systems able to guarantee reliable long-term FC operation appears as primary objective be pursued in next years.In particular, for polymer electrolyte membrane (PEM) FCs, continuous monitoring water content would extremely important, it deeply affects efficiency, voltage stability, lifetime.Indeed, an...

Polymer electrolyte membrane fuel cell (PEM FC) operation is likely to be characterized by voltage dips on timescales shorter than 1 s, arising from temporary flooding of gas channels or porous layers, particularly when the FC operated at high humidity levels. If supercapacitors are employed in hybrid systems, they can make up for lack energy produced FC. However, steep slopes affect that actually delivered supercapacitor because its series impedance, and this should taken into account...

Synchronized phasor and frequency measurements are key tools for the monitoring management of modern power systems. Under dynamic conditions, it is vital to define algorithms that allow accurately measuring time-varying signals with short latencies high reporting rates. A model can help design these and, in particular, those based on Kalman filter approach. This article proposes a three-phase synchrophasor estimator extended filter; state variables obtained from Taylor expansions amplitudes...

A new single-stage high-power-factor electronic ballast based on a flyback power converter is presented in this paper. The able to supply fluorescent lamp, assuring high input factor for the utility line. Other features are lamp regulation against line voltage variations and low current crest factor, both long life. analyzed at steady-state operation design equations characteristics obtained. Also, procedure presented. Finally, simulation experimental results from laboratory prototype shown.

In this paper, the results of an experimental analysis performed on a polymer electrolyte membrane fuel cell (FC) for evaluation current ripple effects are reported. The polarization curve (PC) and impedance spectrum measured single FC with Nafion presented discussing some advantages disadvantages two adopted techniques from measurement point view. ohmic activation resistance values provided by PC compared to frequency limits equivalent estimated spectroscopic evaluate additional losses...

Phasor measurement units (PMUs) are the devices fostering transformation of electric power networks towards smart grid paradigm. They should accurately measure synchrophasors, frequency, and rate change frequency (ROCOF), so that management control applications relying on PMU-based distributed monitoring systems can operate effectively. Commercial PMUs performance is typically guaranteed by compliance with IEEE standard C37.118.1, which focused for transmission defines testing conditions...

This paper analyzes possible humidity-related instabilities of polymer electrolyte membrane (PEM) fuel cell (FC) operation that affect electrochemical impedance spectroscopy measurements.The compensation ohmic resistance variations due to such instabilities, achieved using the well known multisine excitation technique with properly chosen high-frequency harmonic components, is proposed here as a new approach improve low-frequency measurements.Additionally, this method allows more accurate...

Taylor-Fourier (TF) filters represent a powerful tool to design phasor measurement unit (PMU) algorithms able estimate synchrophasor, frequency, and rate of change frequency (ROCOF). The resulting techniques are based on dynamic representations the hence, they particularly suitable track evolution its parameters during time-varying conditions. Electrical quantities in power systems typically three-phase weakly unbalanced, but most PMU developed by considering them as set three single-phase...

This paper deals with a low-cost diagnostic technique for polymer electrolyte membrane (PEM) fuel cells (FCs), which exploits the ripple produced by power converters to monitor equivalent ohmic resistance. While available literature on this topic is focused constant-frequency control of converter (such as pulsewidth modulation), discusses measurement issues that arise when hysteresis current employed dc/dc boost converter, represents simplest solution from implementation point view, and...

Fast synchronized measurements of the phasor, frequency, and rate change frequency are expected to be very important for automated control actions in smart grid context. In this regard, measurement latency must kept as short possible an effective implementation when networks characterized by extremely fast dynamics concerned. Kalman filter (KF)-based estimation algorithms appear attractive context; however, conventional implementations suffer from significant limitations their ability deal...

Water flooding is one of the main causes performance degradation for polymer electrolyte membrane fuel cells (FCs), and its prompt detection therefore important to guarantee optimal FC operation.This paper aims at comparing most common methods diagnosis, which are based on electrical or gas pressure measurements.Their differences in terms sensitivity investigated, primarily focusing their suitability early detection.In particular, between anodic cathodic drop measurements highlighted, as...

Synchronized measurements of electrical signals' phasors and frequencies are expected to be fundamental in the monitoring management future power systems, particular so-called smart grid scenario. In fact, Phasor Measurement Units conceived as key elements advanced wide area systems. For these reasons, design measurement algorithms able track amplitude, phase angle frequency dynamics has been receiving increasing attention last years. The Kalman filter, together with a dynamic phasor model,...

Excessive vibrations in motor operation can be a cause of premature failure many industrial applications; therefore, effective solutions to accurately measure are required. A common approach is through the current signature analysis, as torque oscillations produce characteristic frequency components spectrum; this suitable for those applications where rotating parts not directly accessible sensor installation, e.g., electrical submersible pumps which usually deep underground or underwater....

We reapproach the characterization of inductance gradient and current distribution in electromagnetic rail launchers with multiple brush armatures. A measurement procedure based on use a loop system mutually coupled launcher is illustrated for case two-brush armature. show how to estimate between brushes following basic rules partial-inductance method. To test proposed procedure, we performed an experimental analysis prototype supplied by high-voltage high-power capacitor bank. Experimental...

In this paper, an analytical study of high-impulse current measuring shunts with cage configuration is presented. Through the use partial mutual inductance method, equivalent first-order model developed, and a discussion minimization time constant taking into account physical constraints for two different materials The transfer function circuit provided, possibility compensating via rectangular loops formed by sensing wires placed inside shown. derived tested on homemade shunt prototype...

This paper provides an uncertainty analysis for current distribution measurements based on local magnetic field (e.g., via Hall probes) or flux using large pick-up loops. The fundamental difference between the two approaches is first pointed out in ideal case of infinite straight wire. Then, a more complex geometry composed by parallel identical conductors connected bars considered. mathematical models employed reconstruction according to are derived, and their uncertainties evaluated. An...

The use of batteries and other electrochemical devices in modern power systems is rapidly increasing, with stricter requirements terms cost, efficiency reliability. Innovative monitoring solutions are therefore urged to allow a successful development wide range emerging applications, including electric vehicles large-scale energy storage support renewable generation. Presently, huge gap still exists between the accurate sophisticated techniques commonly employed laboratory tests, on one...

In most applications where motors control several degrees of freedom a mechanical system there is the necessity to implement protection which able stop when reaches extreme positions its working space. When located in an hostile environment and/or limit define complex surface this simple strategy not always viable, since it's possible place sensors and switches proximity positions. We will present paper solution for actuator problem based on model predictive algorithm capable estimate real...

Materials corrosion in the presence of bacteria [microbiologically influenced corrosion, (MIC)] is an important issue for components deployed industrial applications and marine environments, where unexpected fast degradation often observed. For these reasons, finding new testing methodologies to assess behavior different materials conditions a topic clear interest. This paper describes approach based on use microbial fuel cells, which are exploited have known controlled during test. The...

The problem of measuring current distribution in multiple-brush armatures for electromagnetic rail launchers is reapproached here to study the dynamic measurement during armature motion on a two-brush armature. method based an array loops magnetically coupled brushes, placed along rails. From theoretical point view, measured voltages all should make possible reconstruct between brushes as function time and position. This has been experimentally verified launcher prototype.

Space vector (SV)-based estimation algorithms represent attractive methods for synchronized phasor, frequency, and rate of change frequency measurements in three-phase ac power systems. Recently, a phase-locked-loop (PLL) solution improving the demodulation SV signal has been proposed. In this article, potentialities SV-PLL approach are investigated order to optimize accuracy computational load. First, impact PLL update on achieved performance is analyzed. Then, novel two-step algorithm...