Understanding the impact of space charge variations with UV‐ and water‐aged epoxy alumina nanocomposites adopting pulsed electroacoustic techniques

Neelmani,; Sarathi, R.; Suematsu, Hisayuki

doi:10.1049/mnl.2020.0209

Cited by 2 publications

(2 citation statements)

References 25 publications

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“…The internal factors refer to material properties, such as curing agent type, filler properties, and modification treatment, while the external factors are highly associated with operating ambient, including temperature condition, applied electric field, humidity, and electrode status. [29,[33][34][35][36][37][38][39][40][41][42][58][59][60][61][62][63][64][141][142][143][144][145][146][147][148][149] In this section, we mainly focus on three types of EP-based dielectric materials, i.e., pure EP, EP impregnated paper (EIP) composites, and EP-based nanocomposites. A broad perspective on space charge behavior is placed based on the progress of experimental measurements with the consideration of varied internal and external factors.…”

Section: Experimental Study Of Space Charge Distribution In Ep-based ...mentioning

confidence: 99%

Section: Experimental Study Of Space Charge Distribution In Ep‐based ...mentioning

confidence: 99%

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Space Charge Behavior in Epoxy‐Based Dielectrics: Progress and Perspective

Liu

Xie

et al. 2022

Adv Elect Materials

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temperature and complex electric field conditions. [1][2][3] Epoxy resin (EP) is a class of polymer oligomers containing two or more epoxide groups based on organic compounds (e.g., aliphatic, alicyclic, and aromatic). As a prepolymer, EP shows excellent performance after its reaction with a curing agent to form an insoluble polymer with a 3D network structure. EP has desirable insulating characteristics, [4][5][6][7] heat resistance, [8] high mechanical strength, [9] low shrinkage, [10] chemical stability, and adhesive properties, which originate from its compact structure and tunable functional groups. The above mentioned outstanding performances, along with characteristics of easy processing and formula design flexibility, enable the extensive use of EP-based materials in power equipment and electronic devices [11] (Figure 1), including bar insulation and impregnating varnish in transformers, main insulation in dry-type bushings and wall bushings, insulator in gas-insulated switchgear (GIS) and gas-insulated transmission line (GIL), epoxy molding compound for integrated circuit (IC) packaging. It is noteworthy that EPs typically possess lower glass transition temperature (T g ) compared to other high-T g dielectric polymer substitutes used in microelectronic systems such as benzocyclobutene, [12] polyimide (PI), [13] and maleimide. [14] Besides high T g , high thermal conductivity and low coefficient of thermal expansion of EPs are always desired for their industrial applications, especially from an electronic packaging perspective. To date, considerable efforts have been made to improve the heat endurance and heat dissipation capabilities of EP-based dielectric materials by inorganic particle doping [15][16][17][18][19][20][21][22][23][24] and chemical modification. [25][26][27] Furthermore, EP is also an indispensable adhesive that is extensively used in power equipment. [28][29][30][31][32] Yet, potential reliability hazards may exist during the operation of power equipment and electronic devices, especially at high temperatures and under high voltage direct current (HVDC) application, one of which is the space charge accumulation in EP-based dielectric materials. [29,30,33,34] The accumulated space charge may cause deterioration/aging and even partial discharge or dielectric breakdown of dielectric materials. [35][36][37][38][39][40] Specifically, the extensive application of EP-based dielectric materials in HVDC transmission projects eagerly calls for relevant studies on the space charge behavior Epoxy-based dielectrics are extensively used in grid-connected energy systems and modern microelectronics as electrical insulation, adhesive, and packaging components. However, space charge accumulation in epoxy-based dielectrics is a foremost factor threatening device stability and lifespan, especially under conditions of high voltage direct current and high temperatures during long-term operation, and thus are investigated systematically. This article reviews the state-of-the-art progress in understanding and r...

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Section: Experimental Study Of Space Charge Distribution In Ep-based ...mentioning

confidence: 99%

Section: Experimental Study Of Space Charge Distribution In Ep‐based ...mentioning

confidence: 99%

Space Charge Behavior in Epoxy‐Based Dielectrics: Progress and Perspective

Liu

Xie

et al. 2022

Adv Elect Materials

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Investigation on AC and DC Breakdown Mechanism of Surface-Ozone-Treated LDPE Films under Varied Thicknesses

Nie,

Liu,

et al. 2023

Polymers

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Electrical breakdown is an important physical phenomenon in power equipment and electronic devices. Recently, the mechanism of AC and DC breakdown has been preliminarily revealed as electrode–dielectric interface breakdown and bulk breakdown, respectively, based on space charge dynamics through numerical calculations. However, the AC breakdown mechanism still lacks enough direct experimental support, which restricts further understanding and the design and development of electrical structures. Here, in this study, LDPE films with various thicknesses ranging from 33 μm to 230 μm were surface modified with ozone for different durations to experimentally investigate DC and AC breakdown mechanism. The results indicate that carbonyl groups (C=O) were introduced onto the film surface, forming shallow surface traps and leading to a decreased average trap depth and an increased trap density. Such a surface oxidation modulated trap distribution led to enhanced space charge injection and bulk electrical field distortion, which decreased DC breakdown strength as the oxidation duration went longer, in all film thicknesses. However, such decreases in breakdown strength occurred only in films below 55 μm under AC stresses, as the enhanced electrical field distortion at the electrode–dielectric interface was more obvious and dominating in thin films. These experimental results further confirm the proposed electrode–dielectric interface breakdown of dielectric films and provide new understandings of space charge modulated electrical breakdown, which fulfills dielectric breakdown theory and benefits the miniaturization of power equipment and electronic devices.

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Understanding the impact of space charge variations with UV‐ and water‐aged epoxy alumina nanocomposites adopting pulsed electroacoustic techniques

Cited by 2 publications

References 25 publications

Space Charge Behavior in Epoxy‐Based Dielectrics: Progress and Perspective

Space Charge Behavior in Epoxy‐Based Dielectrics: Progress and Perspective

Investigation on AC and DC Breakdown Mechanism of Surface-Ozone-Treated LDPE Films under Varied Thicknesses

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