An innovative approach for the passive cooling of batteries: An empirical investigation of copper deposition on polyurethane foam for the enhancement of phase change material

A proof-of-concept utilising Copper-Plated Polyurethane Foam (CPPF) and Phase Change Material (PCM) for passive thermal management of lithium-ion batteries is demonstrated in this study. The aim of this research is to assess the effectiveness of CPPF when utilised as a constituent substance in PCM/Foam composites. Six distinct configurations of PCM/Foam composites are presented in this work using 10-pore-per-inch foam. A total of four deposition foam samples were produced. Of these, three were created by gradually increasing the immersion time in an electroless copper plating solution. For the fourth sample, an electroless plating technique was utilised for 80 min, followed by an electroplating procedure to deposit an additional layer of copper. The evaluation entails examining each plated sample in comparison to a copper foam that is commercially available with a purity level of 99.99 %. The findings reveal that the electroless-plated specimens exhibit improved effectiveness after being subjected to a prolonged plating period of 80 min. The electroplated sample exhibited the greatest degree of effectiveness, as evidenced by a 64.4 % reduction in battery cell surface temperature(10.98 °C), which is almost identical to the 64.5 % decrease in temperature (11.03 °C) observed with commercial foam but coupled with 88.1 % decrease in mass. The results suggest that the CPPF-PCM composites offer effective passive cooling properties for batteries

Performance of Superconducting Generators with Different Topologies under Fault Conditions

This paper compares the short-circuit performance of superconducting (SC) generators with three different topologies, i.e., iron-cored stator and rotor, iron-cored stator and air-cored rotor, and air-cored stator and rotor. The analysis is based on three-phase short-circuit fault, and finite element analysis is used for simulation. Following the introduction of specifications of generators, the short-circuit performances of different topologies are analyzed and compared, with the field winding excited by voltage and current excitation sources, respectively. It shows that the short-circuit performance can be improved by limiting the field current

Comparison of Peak Armature and Field Winding Currents for Different Topologies of 10-MW Superconducting Generators Under Short-Circuit Conditions

This paper studies the peak armature and peak field winding currents for three different topologies of 10 MW partial High Temperature Superconducting Generators (HTSGs) under Short-Circuit Conditions (SCC) by simulation. The investigated partial HTSGs employ copper armature windings and superconducting field windings with different armature and rotor topologies, i.e. iron cored armature and rotor, air cored armature and rotor, and iron cored armature and air cored rotor. For each HTSG topology, the investigation includes: (i) the field winding current control strategies, (ii) the influence of operating field current, and (iii) the ratings of circuit breakers for limiting the peak armature and peak field winding currents. The results can provide guidelines for determining the peak armature and peak field currents of HTSGs and also the possibility of limiting them by employing circuit breakers under SCC

Diagnosis of Rotor and Stator Asymmetries in Wound-Rotor Induction Machines Under Nonstationary Operation Through the Instantaneous Frequency

This paper proposes a methodology to improve the reliability of diagnosis of different types of faults in wound-rotor induction generators which work under variable load conditions, as in wind turbine applications; the method is based on the extraction of the instantaneous frequency (IF) of the fault-related components of stator and rotor currents during speed changes caused by nonstationary functioning. It is shown that, under these conditions, the IF versus slip plots of the fault components are straight lines with a specific slope and y-intercept for each kind of fault. In addition, neither of these patterns are dependent on the machine features or the way that the load changes. The practical methodology of this technique is introduced for diagnosing two different anomalies: stator winding asymmetry and rotor winding asymmetry. The approach is validated by laboratory tests for both types of faults in two different kinds of machines

Vibration Transient Detection of Broken Rotor Bars by PSH Sidebands

In recent years, the study of transients of induction motors for diagnosis purposes has gained strength in order to overcome some inherent problems of the classical diagnosis of such machines, which uses Fourier analysis of steady-state quantities. Novel time-frequency techniques have been applied to these transient quantities, in order to detect the characteristic evolutions of fault-related harmonic components. The detection of these patterns, which are usually specific for each type of fault, enables reliable diagnostic of the corresponding failures. In this context, most of the works hitherto developed have been based on analysis of currents. However, in some applications, vibration measurements are also available. The goal of this work is to validate the applicability of this transient-based diagnosis framework to vibration measurements. A specific time-frequency decomposition tool, the Zhao-Atlas-Marks distribution, is proposed. Experimental results prove the ability of the approach to complement the information obtained from the current analysis. This may be very useful in applications in which the diagnosis via currents is uncertain or in which vibration signals can be easily measured