Effects of bipolar repetitive square wave voltage parameters on electrical tree characteristics of epoxy resin. (November 2021)

• Record Type: Journal Article
• Authors: Wang, Peng; Chen, Yiwen; Akram, Shakeel; Meng, Pengfei; Castellon, Jerome; Haq, Inzamam Ul; Javed, Muhammad Sufyan
• Is Part Of: Polymer testing. Volume 103(2021)
• Publication Date: 2021-11
• Subjects: Epoxy resin -- Electrical tree -- Square wave voltage -- High voltage frequency -- Rise time -- Electrical tree growth; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2021.107371
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: This work investigates the electrical tree growth of epoxy resins. Repetitive bipolar square wave voltage is applied to the epoxy resins and different parameters rise time, frequency, and duty cycle are studied. The frequency range of repetitive square voltage ranges from 50 Hz to 20 kHz, the rise time ranges from 70 ns to 620 ns, and the duty cycle ranges from 5 to 90%. The results reveal that the initiation of the electrical tree is more rapid under the influence of high voltage frequency having a shorter rise time. Moreover, the electrical tree growth is faster under the impact of a shorter rise time with a duty cycle greater than 10%. The rise time mainly affects the initiation process of electrical trees. In comparison, the primary influence on the electrical tree initiation and its growth is attributed to the impact of the frequency applied. Highlights: Power electronics devices made up of Silicon carbide (SiC) can operate power equipment at high voltage and high frequency. Therefore, the insulation of these power equipment faces some serious stresses coming from these devices. Epoxy resin is widely used insulating material for such power equipment and electrical tree is one of the main sources for aging of these materials. Electrical tree initiation and growth is different and more severe at repetitive square wave voltage than sinusoidal or DC voltage. Pin-plane epoxy resin is synthesized to investigate the electrical tree growth under different bipolar square voltage parameters such as rise time, frequency and duty cycle. The mechanism of electrical tree initiation and tree growth is discussed in details.