Contributed Review: Review of thermal methods for space charge measurement

Area of Science:

• Electrical Engineering
• Materials Science
• Physics

Background:

• Space charge accumulation is a growing concern in high voltage direct current (HVDC) electrical systems.
• Thermal methods have become vital for analyzing space charge in solid dielectric materials.
• Understanding space charge is critical for the long-term reliability and safety of electrical insulation.

Purpose of the Study:

• To provide a comprehensive review of non-destructive thermal measurement systems for space charge.
• To detail the principles, capabilities, and applications of key thermal methods.
• To highlight advancements in space charge metrology for dielectric materials.

Main Methods:

• Review of thermal pulse method (TPM) for space charge measurement.
• Analysis of thermal step method (TSM) principles and applications.
• Description of laser intensity modulation (LIM) technique for space charge profiling.

Main Results:

• Each method's operational principle, measurable thickness range, and spatial resolution are elucidated.
• Key applications of these thermal measurement techniques in solid dielectrics are presented.
• Comparative insights into the strengths and limitations of different thermal methods are discussed.

Conclusions:

• Thermal methods offer effective non-destructive means to investigate space charge in solid dielectrics.
• The reviewed techniques (TPM, TSM, LIM) provide valuable data for material characterization and system diagnostics.
• Continued development of these thermal methods is essential for advancing HVDC technology and ensuring insulation integrity.