Fiberglass Core Research Articles

REBCO Coils System for Axial Flux Electrical Machines Application: Manufacturing and Testing

A REBCO coil system for axial flux electrical machines applications is presented. Three couples of series-connected coils have been placed on a fiberglass disc and wired in star configuration to simulate a three-phase, ironless, and superconducting armature concentrated winding. REBCO-based commercial tape has been used to wind each of the six coils in double-pancake configuration around a fiberglass trapezoidal-shaped core. DC current-voltage curve and ac transport current losses plots of each coil have been obtained at liquid nitrogen temperature. Six copper coils having the same shape and geometric parameters of REBCO coils have been also manufactured to assemble a conventional armature concentrated winding. Laboratory testing on different armature windings has been conducted at different temperatures (77 K and 300 K) to measure the impedance (amplitude and phase) value, the back electromotive forces waveform, etc. The experimental results of both configurations (conventional and superconducting) are compared to study the feasibility of a superconducting armature winding prototype of an axial flux electric machine.

Outdoor Insulators Testing Using Artificial Neural Network-Based Near-Field Microwave Technique

This paper presents a novel artificial neural network (ANN)-based near-field microwave nondestructive testing technique for defect detection and classification in nonceramic insulators (NCI). In this paper, distribution class 33-kV NCI samples with no defects, air voids in silicone rubber and fiber glass core, cracks in the fiberglass core, and small metallic inclusion between the fiber core and shank were inspected. The microwave inspection system uses an open-ended rectangular waveguide sensor operating in the near-field at a frequency of 24 GHz. A data acquisition system was used to record the measured data. ANN was trained to classify the different types of defects. The results showed that all defects were detected and classified correctly with high recognition rates.

Detecting defects in outdoor non-ceramic insulators using near-field microwave non-destructive testing

This paper presents a novel near-field microwave nondestructive testing technique for defect detection in non-ceramic insulators (NCI). In this work, distribution class 33 kV NCI samples with no defects, air voids in silicone rubber, cracks in the fiberglass core and small metallic inclusion between the fiber core and shank were inspected. The microwave inspection system utilizes an open-ended rectangular waveguide sensor operating in the near-field at a frequency of 24 GHz. The used inspection system is simple, safe and relatively inexpensive. A data acquisition system was used to record the measured data. The results showed that all defects were repeatedly detected with high sensitivity. Line scans of the samples were obtained revealing the presence of different defects and their location. The technique also demonstrated ability to detect thickness variations in the silicon rubber shank.

Experimental Research on Coaxial Extrusion of GF/Pb Complex Wire

GF/Pb Complex Wire, as the key, characteristic component of a high-energy battery, is difficult to produce continuously for the fiberglass core’s liability to rupture in extruding. The research works, presented in this paper, show that this complex wire of brittle core can be successfully formed by the continuous side-way coaxial extrusion, using the die set specially designed, at a relative lower temperature and with a stable wire puling force.

Immobilization of trypsin on silica-coated fiberglass core in microchip for highly efficient proteolysis

In this report, trypsin was immobilized on silica-coated fiberglass core in microchip to form a core-changeable bioreactor for highly efficient proteolysis. To prepare the fiber core, a layer of organic–inorganic hybrid silica coating was prepared on the surface of a piece of glass fiber by a sol–gel method with tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) as precursors. Subsequently, trypsin was immobilized on the coating with the aid of glutaraldehyde. Prior to use, the enzyme-immobilized fiber was inserted into the channel of a microchip to form an in-channel fiber bioreactor. The novel bioreactor can be regenerated by changing its fiber core. The scanning electron microscopy images of the cross-section of a trypsin-immobilized fiber indicated that a layer of ∼1 μm thick film formed on the glass substrate. The feasibility and performance of the unique bioreactor were demonstrated by the tryptic digestion of bovine serum albumin (BSA) and cytochrome c (Cyt- c) and the digestion time was significantly reduced to less than 10 s. The digests were identified by MALDI-TOF MS with sequence coverages of 45% (BSA) and 77% (Cyt- c) that were comparable to those obtained by 12-h conventional in-solution tryptic digestion. The fiber-based microchip bioreactor provides a promising platform for the high-throughput protein identification.

Utilization of fog chambers for non-ceramic outdoor insulator evaluation

Non-ceramic (polymer, composite) insulators consist of a fiberglass core rod, weathershed housing, and metal end fittings. The housings generally are manufactured from polymeric materials. In service, the weathershed materials may be subject to degradation or aging due to harsh environmental conditions. One of the most commonly used laboratory tests to evaluate the performance of the weathershed materials is to employ fog chambers. Design and operational features of various fog chambers are reviewed in this paper, including size and main layout of fog chambers and their HV sources, data acquisition systems, systems for simultaneous visual observations and electrical measurements, and test cycles and techniques.

Partial discharge. V. PD in polymer-type line insulators

For pt.IV see ibid., vol.7, no.1, p.20 (1991). Some of the problems related to corona and partial discharge damage to polymer insulators are outlined. The basic construction of polymer insulators for overhead lines, which consist of a core, weathersheds, and metal end fittings, is described. Two types in common use are suspension/dead-end type, which is used where line loads subject the insulator core to tension forces, and the post type, which is used where line loads subject the core to appreciable bending forces in addition to tension forces. The partial discharge performance of polymer insulators, which depends on the choice of material, design, and construction of the insulators, is discussed. A factor common to all designs is poor partial discharge detection sensitivity, in the sense that a partial-discharge-producing defect along the insulator has very small capacitive coupling to the insulator terminals as a result of the large dimensions of the insulator and the small size of the terminals. Sources of cavity discharges are discussed. These can occur in the fiberglass core or in the weathersheds. External discharges, which can take place on the weathersheds or the hardware ends, are also examined.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Recognition of Waterflood Sweep and Formation Lithology in a Giant Egyptian Oil Field by Applied Petrophysics

Summary This paper presents a simplified formation-evaluation methodology that was successfully applied to the study of a giant Egyptian oil field. This method could resolve formation lithology and injected water saturations with a high degree of confidence. Observed core lithologies were matched with openhole log responses to generate lithology windows in a lithoporosity plot. Resolution of formation lithology by openhole logs required plotting the log responses on the lithoporosity plot and determining the lithology window in which the data fell. Formation intervals swept by injection water were found by analysis of two calculated water saturations (formation water and injection water) together with lithology and field-history information. This work relied heavily on the first successful full-zone core obtained in the field, which was cored and handled with fiberglass core barrels. This paper includes field case histories and techniques that may be useful. The methods are simple, can be related to actual data instead of theoretical or calculated data, and provide results that fit reasonable expectations. Finally, the lithology determination method is easy to computerize.

Failure Analysis Of Synathetic Insulators With Fiberglass Rod Submitted To Mechanical Loads

Four end fitting designs of long rod fiberglass core suspension insulators are studied and the failure mechanisms are analyzed after UTS and creep tests. The fracture occurs in the fiberglass rod due to the stresses induced by the metal part of the endfitting that hold the insulating components.