Quantitative Analysis of Insulator Degradation in a Single Layer Solenoid by Renormalization of the Transmission Parameter

In this paper, a novel method to quantitatively analyze insulator degradation in a single layer solenoid is proposed. The suggested method employs renormalization of scattering parameters to efficiently detect changes of permittivity in a degraded solenoid. Firstly, a transmission line model, including a locally degraded part in the insulator, was developed, and it was determined that the phase information of the transmission parameter was very informative to check the permittivity change in the transmission line. To check the workability of this idea in a solenoid, a 30-turn single-layer solenoid was designed and fabricated, and 51 degraded states for mimicking insulation deterioration in each turn were introduced by installing additional insulator rings, which increased local relative permittivity. The phase data of the measured transmission parameter turned out to be useful for quantifying changes of the insulator in the solenoid. To maximize the detectability, the measured scattering parameters were renormalized with different reference impedances, which was very useful for detecting degradation in the transmission parameter. In this paper, detailed procedures for quantitatively analyzing degradation of an insulator are proposed and we verify that the suggested renormalization technique is very promising for effectively evaluating the degradation of a solenoid.

Thermal, mechanical, dielectric, and morphological study of dielectric filler–based thermoplastic nanocomposites for electromechanical applications

Dielectric nanocomposite elastomers based on poly(styrene-ethylene/butylene-styrene) (SEBS) and SEBS-grafted-maleic anhydride (SEBS-g-MA) with barium titanate (BT) suitable for electroactive applications were successfully manufactured by using two corotating twin extrusion systems. The main purpose of the work was to investigate the thermal, mechanical, dielectric, and morphological effects of additives on SEBS and SEBS-g-MA to widen their applications for electroactive applications using fast and more cost-effective simple production process. The morphological characterization showed a good and bad dispersion of BT into SEBS-g-MA and SEBS with 34.9% and −3% dielectric permittivity change in SEBS-g-MA and SEBS upon addition of 10 wt% BT. In addition, dielectric permittivity change, thermal change (enthalpy relaxation and thermal transitions), and mechanical (Young’s modulus, hysteresis loss under multiple stress cycles, storage modulus, loss modulus, and tan δ) properties of elastomers were found to be a function of additive concentration, compatibility and interaction between elastomers and additive type, orientation of additives, and reinforcing factors of additives in elastomers. A simple and effective modeling technique was used to demonstrate the effects of dielectric properties on nanocomposites due to poor dispersion of additives.