Influence of frequency on the surface discharge characteristics of PEEK under positive repetitive square voltage

Abstract

In this study, the surface discharge current pulses of polyetheretherketone (PEEK) material under positive repetitive square voltage in a nitrogen atmosphere are measured. The influences of different voltage amplitudes and frequencies on the detail parameters of forward discharge and backward discharge current pulses are statistically analysed. The results show that as the square voltage amplitude increases, the current pulse amplitude, fall time and pulse width of both forward and backward discharge current increase, and the rise time does not change significantly. As the voltage frequency increases, current pulse amplitude, fall time and pulse width of both forward and backward discharge current decrease, and the rise time does not change significantly. Due to the independence of the discharge at different repetitive cycles, the specific discharge process in one cycle is analysed in detail to explain the influence mechanism of the voltage amplitude and frequency on the discharge current. By mean of the Richardson–Schottky and the Cavallini relaxation model, the relationship between discharge voltage ratio and surface charge, and the decay process of surface discharge are analysed. Furthermore, the influences of amplitude and frequency of the positive repetitive square voltage on the PEEK surface current pulses are explained qualitatively.

Keywords

• surface discharges
• polymers
• organic insulating materials
• surface charging
• dielectric relaxation
• surface discharge characteristics
• rise time
• repetitive cycles
• discharge process
• discharge voltage ratio
• positive repetitive square voltage
• peek surface current pulses
• surface discharge current pulses
• polyetheretherketone material
• current pulse amplitude
• fall time
• pulse width
• voltage frequency
• square voltage amplitude
• nitrogen atmosphere
• backward discharge current pulses
• statistical analysis
• forward discharge current pulses
• richardson-schottky relaxation model
• cavallini relaxation model
• surface charge
• decay process