2D electrostatic modeling of twisted pairs

Purpose This paper aims to model a three-dimensional twisted geometry of a twisted pair studied in an electrostatic approximation using only two-dimensional (2D) finite elements. Design/methodology/approach The proposed method is based on the reformulation of the weak formulation of the electrostatics problem to deal with twisted geometries only in 2D. Findings The method is based on a change of coordinates and enables a faster computational time as well as a high accuracy. Originality/value The effectiveness of the adopted approach is demonstrated by studying different configurations related to the IEC 60851-5 standard defined for the measurement of the electrical properties of the insulation of the winding wires used in electrical machines.

Modeling of high frequency high voltage of waveforms on life of enamel insulation

<p>In recent years it has been observed that insulation failure in electrical motors is caused by adjustable speed drives fed by power electronic converters. These converters produce impulse waveforms having a high slew rate generated by the high switching frequency of IGBTs. This paper focuses on high switching frequency stress in low voltage electrical motors for adjustable speeds. To examine the motor winding insulation under such stress twisted-pair samples were developed from enameled wires. A single-coated polyester of enamel with a thickness of 40 microns is used for this work. High-frequencies, high voltages of Square, and Square-rising, Square-spike waveforms of 10-30 kHz are used here. The test results show that the insulation fails earlier for the Square waveform compared to the Square-spike and Square-rising waveforms. In a nutshell, there is an analysis of PD formation in the insulation system at a higher switching frequency is analyzed. Electric field distributions between twisted pairs with various air gaps of the insulation system stressed by the Square and Square-rising waveforms up to 30 kHz are modeled using COMSOL software.</p>

Online Predictive Maintenance Monitoring Adopting Convolutional Neural Networks

Thermal, electrical and mechanical stresses age the electrical insulation systems of high voltage (HV) apparatuses until the breakdown. The monitoring of the partial discharges (PDs) effectively assesses the insulation condition. PDs are both the symptoms and the causes of insulation aging and—in the long term—can lead to a breakdown, with a burdensome economic loss. This paper proposes the convolutional neural networks (CNNs) to investigate and analyze the aging process of enameled wires, thus predicting the life status of the insulation systems. The CNNs training does not require any kind of assumption of how the factors (e.g., voltage, frequency and temperature) contribute to the life model. The experiments confirm that the proposal obtains better estimations of the life status of twisted pair specimens concerning existing solutions, which are based on strong hypotheses about the life model dependency on the factors.

Analysis of Signal Processing for Gigabit Rate Wireline Communication

In this paper we mainly focus on achieving higher speed data which is about 1Gb/s over short copper loops using G.Fast technology. The use of TDD and higher bandwidth are two key features in G.Fast. Short twisted pair cable models are used to operate at relatively wider bandwidth. At higher frequencies, the problem of FEXT crosstalk becomes dominant. So to overcome these issues we are using different crosstalk cancellation techniques using various cables which provide different data rates at different frequencies and distances. Performance analysis of various crosstalk cancelation techniques has been done in this paper.

The Evaluation of Twisted Pair Cable Performance in Circuits with DS18B20 Temperature Sensors

The transmission of data and energy has been widely used over the past few centuries, but in a complex manner and at high cost. Gradually in order to simplify this process and reduce costs, important network cables have appeared, namely: twisted pair cables, coaxial cables, and fiberoptic cables. Thus, instead of various wires, a single cable has become necessary. Within this context, this study seeks to evaluate data transmission performance using two types of Ethernet cables, CAT E5 and CAT E6, in circuits with DS18B20 temperature sensors. The evaluation of the two cables was made by reducing their lengths by 10 meters every two weeks to find the length of cable which would ensure a reliable reading of the sensors for use in the research project entitled “The Evaluation of the Potential Use of Surface Geothermal Energy in the City of Dourados, MS”. The obtained data indicates that CAT E5 cables with lengths less than 70 meters ensure reliable readings close to the real value, while for CAT E6 Ethernet cables this takes place at lengths of less than 80 meters.