Dielectric characterisation of epoxy nanocomposite with barium titanate fillers

• Published in: IET Nanodielectrics Vol. 3; no. 2; pp. 53 - 61
• Main Authors: Zafar, Romana, Gupta, Nandini
• Format: Journal Article
• Language: English
• Published: Beijing The Institution of Engineering and Technology 01.06.2020; John Wiley & Sons, Inc; Wiley
• Subjects: 3-glycidoxypropyltrimethoxy-silane; Acoustics; Alternating current; as-received fillers; Barium; barium compounds; barium titanate nanofillers; Barium titanates; batio; BaTiO3; Broadband; broadband dielectric spectroscopy; Bushings; Charge density; Complex permittivity; Control equipment; Curing; DC conductivity; Depolarization; Dielectric breakdown; dielectric characterisation; dielectric depolarisation; dielectric polarisation; Dielectric strength; electric breakdown; Electric fields; electric strength; electric stress control; electrical conductivity; Electrical properties; Electrodes; energy storage systems; epoxy insulation; epoxy resin; Epoxy resins; epoxy-based high permittivity nanocomposites; Feasibility studies; filled polymers; Fillers; Flanges; Fourier transforms; frequency 1.0 mhz to 1.0 mhz; frequency 1.0 mHz to 1.0 MHz; frequency 50.0 hz; frequency 50.0 Hz; Frequency ranges; high permittivity materials; High voltages; high-voltage apparatus; high-voltage equipment; high-voltage insulation; Nanocomposites; Nanoparticles; Permittivity; polarisation-depolarisation current measurements; Polymers; power frequency; pulsed electroacoustic methods; pulsed electroacoustic technique; Research Article; resins; short-term ac breakdown strength tests; Space charge; space charge accumulation; space charge density; Storage systems; stress mitigation; surface-functionalised nanoparticles; Thickness; voltage 69.0 kv; voltage 69.0 kV; electric strength; broadband dielectric spectroscopy; power frequency; short-term AC breakdown strength tests; space charge density; resins; epoxy insulation; electric breakdown; nanocomposites; pulsed electroacoustic methods; stress mitigation; barium titanate nanofillers; nanoparticles; electric stress control; energy storage systems; space charge; epoxy-based high permittivity nanocomposites; pulsed electroacoustic technique; high permittivity materials; high-voltage insulation; barium compounds; dielectric polarisation; DC conductivity; frequency 1.0 mHz to 1.0 MHz; permittivity; as-received fillers; 3-glycidoxypropyltrimethoxy-silane; voltage 69.0 kV; high-voltage apparatus; BaTiO3; surface-functionalised nanoparticles; dielectric characterisation; bushings; polarisation-depolarisation current measurements; space charge accumulation; epoxy resin; dielectric depolarisation; high-voltage equipment; filled polymers; complex permittivity; electrical conductivity; frequency 50.0 Hz
• ISSN: 2514-3255; 2514-3255
• DOI: 10.1049/iet-nde.2019.0037

High permittivity materials are currently in use for mitigation of electrical stress in high-voltage apparatus and energy storage systems. In this work, epoxy-based high permittivity nanocomposites with Barium titanate (BaTiO3) nanofillers are considered, for the purpose of stress mitigation. Uniform dispersion of the fillers in the polymer up to 10% by volume is achieved. Apart from the use of as-received fillers, the effect of using surface-functionalised nanoparticles (with 3-glycidoxypropyltrimethoxy-silane) before use is also investigated. The nanocomposite is characterised in terms of its complex permittivity, DC conductivity, short-term AC breakdown strength and space charge accumulation, to gauge its suitability for use in high-voltage insulation. Complex permittivity is measured using broadband dielectric spectroscopy over a broad frequency range of 1 mHz to 1 MHz. DC conductivity is studied from polarisation–depolarisation current measurements. Short-term AC breakdown strength tests are performed at power frequency (50 Hz). Space charge density along the sample thickness is obtained using pulsed electro-acoustic technique. A computational case-study is presented to show the feasibility of using the high permittivity nanocomposite for electric stress control in high-voltage equipment (viz., at mounting flanges of 69 kV bushings).