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This paper deals with the investigation of amplifying the effect of local magnetic saturation for displacement measurement using copper shielding. In previous works could be shown that nonlinear magnetic materials were used for contactless displacement measurement. This was done by using a constant field source representing a sender and a detection unit based on alternating current (AC) fed coils...
A new method for performing a full two-port s-parameter calibration in free-space is presented. The proposed calibration technique computes the error coefficients from measurements made on an empty fixture and a measurement made on a metal plate of known thickness. Time-domain gating was employed. This technique requires fewer and simpler standards than the existing thru-reflect-line (TRL) and thru-reflect-match...
The use of fuel cells for powering AC loads requires to employ power converters and in particular inverters. The efficiency of these devices is usually very high, but they add a current ripple on the fuel cell side that might affect the fuel cell performance and decrease the overall system efficiency more than expected. Previous studies revealed that this performance decrease depends on the impedance...
A nonlinear dynamical system based on ferroelectric capacitors coupled into a unidirectional ring circuit, which under particular conditions exhibits an oscillating regime of behavior, is considered with particular interest for developing novel electric field sensors. For such a device a weak, external, target electric field interacts with the system thus inducing perturbation of the polarization...
The passive magnetic ferrite components used in EMI filters have a complex magnetic permeability (CMP) which varies with frequency. The CMP in frequency range from 150 kHz to 30MHz is not given by manufactures. Moreover, measurement techniques require some specific size and shape of sample to measure CMP of ferrites. Common application of these passives components are EMI filters, where toroid ferrite...
An ironless position sensor is a novel sensing structure which exhibits intrinsic immunity to external magnetic fields, since it is characterized by air-cored supply and sensing windings. This new solution may be of significant interest for applications where external magnetic fields are present. In this paper, an analytical model of the working principle of the sensor is proposed. The effect of the...
Dielectric elastomer actuators (DEAs) and their subcategory energy minimum structures (DEMES) are promising candidates for biomimetic robotic elements. Especially interesting for their characterization is the transient strain or stretch-response of the deforming elastomer part to high voltage driving signals, and the state of the applied compliant electrodes. However, this information can hardly be...
In a volleyball game, touching the net represents a foul under circumstances defined by the game rules. Currently, a referee decides if the net was touched or not. In order to avoid wrong referee's decisions, a system is desirable, that automatically detects a net touch and also indicates the offending party. We propose a system based on electrical capacitance measurement that detects both approximation...
Newly improved dispersive Fourier transform spectroscopy is applied to measure dielectric permittivity of the thin films at terahertz frequency range. Dielectric properties of thin film materials are hard to acquire as the thickness is too small to provide enough phase shift. The step size of the active mirror in the dispersive Fourier transform spectroscopy is enhanced to 500 nanometers which enable...
In this paper we use the load current of the CPU to decide whether the working state of the PC is considered to be a heavy load or a light load. Based on the voltage limit of each device on the PC motherboard, we use the voltage control as a dynamic voltage scaling (VREF-DVS) regulator to provide different voltages for each device. When the PC has a light load we can decrease the operating voltage...
We report the results of a comparison of quantum-based AC Josephson Voltage Standards (ACJVS) between the National Institute of Standards and Technology (NIST), and the National Research Council, Canada (NRC), using a thermal transfer standard as the traveling standard. Excellent agreement was obtained between NIST and NRC from measurements on the lowest voltage ranges of the thermal transfer standard,...
This paper proposes new method for power quality disturbances classification using multiclass logistic regression. The features for the disturbances are extracted using wavelet packet transform and the rms value is used to characterize the magnitude of the disturbances. The detection and classification is done by employing machine learning. The proposed approach utilizes multiclass logistic regression...
We describe the construction of two-stage, amplifier-aided current transformers (CTs) and their use to characterize AC-DC transfer shunts up to 100 A at 100 kHz. Tests show that the frequency coefficients of the CTs have small changes with current level. This level independence of the frequency coefficients for the CTs is used to characterize the frequency coefficients of the shunts up to 100 A and...
For determining the dynamic on-resistance Rdyn,on of a power transistor, the voltage and current waveforms have to be measured during the switching operation. In measurements of voltage waveforms, using an oscilloscope, the characteristics of an amplifier inside the oscilloscope are distorted when the range of the measurement channel is not set wide enough to measure both on-state and off-state voltage,...
Nowadays we are witnessing the fast spreading of smart grid technology deployments. An increase of smart grid services and applications is also expected. Therefore in our work we aim to propose and develop user applications on top of smart grid power infrastructures that monitor, analyze, classify and characterize different electronic devices connected to this infrastructure. The present paper aims...
This paper presents a simple low-cost measurement method for determination of a conductive liquid layer thickness with an unknown conductivity, by means of measuring the resistance between pairs of electrodes arranged in a planar multielectrode configuration. The measurement method tolerates unknown layer conductivity variations over a few orders of magnitude, without a significant impact on the measured...
A low-cost, free-standing, radiometric, partial discharge wireless sensor network (PD WSN) is described for application to real-time condition monitoring, asset management and operations optimization in the future smart grid. The proposed PD WSN uses a novel approach to PD location which obviates the need for synchronization between sensors thereby improving scalability. Progress in the development...
With spectral management of the radio spectrum becoming such a large concern in modern society due to an increasing need for faster wireless data transfer, the current utilization of the radio frequency spectrum must first be measured and analyzed before improvements to the current system can be designed and implemented. Choosing the High Frequency (HF) band to serve as a representative of the entire...
In this work, we propose wide-area measurement based control mechanism for future smart transmission grid applications. The design comprises measurements obtained from local area and geographically isolated remote area to damp out local and inter-area low-frequency oscillation mode to ensure desired dynamic performance of the large scale interconnected power transmission grid system. The synchronized...
For testing the reliability of heavy current transformer (HCTs) with shielding coils affected by the adjacent bus bars, an equivalent testing method called eccentric bus-bar testing method was presented in [1]. The crucial parameters of this method were also determined by analytical formulas and further verified by finite element method (FEM) in [1]. This paper presents several experiments and analytical...
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