Deep-Dive: High-Voltage High-Frequency Degradation

Current Situation in IEC Standards for Frequencies above 30 kHz

The breakdown mechanisms occurring in insulation systems under power-frequency high voltage - for which extensive data is available - differ fundamentally from those under high-frequency stress. At frequencies ranging from a few tens up to several hundred kilohertz, various frequency-dependent aging mechanisms may occur in parallel. These degradation mechanisms for instance originate physically from partial discharges, space charges, trap generation, surface discharges, Fowler-Nordheim field emission, and UV radiation. Depending on their physical origin, degradation mechanisms and the resulting breakdown channels can lead to failures within subseconds or only after several months.
Conventional partial discharge measurements do not capture all degradation physics, and transient impulse or breakdown tests cannot reproduce the slower, long-term mechanisms. Likewise, power-frequency long-term aging tests do not cover high-frequency effects. For this reason, IEC 60664-4 “Insulation coordination for equipment in low-voltage systems – Part 4: Consideration of high-frequency voltage stress” and related application standards do not recommend verifying a device’s insulation strength at target frequencies above 30 kHz using long-term stress at 50 or 60 Hz.
To capture all degradation mechanisms, continuous high-voltage and high-frequency long-term stress until actual breakdown proves to be the most reliable method. For this purpose, HVsys develops dedicated high-frequency insulation testing methods, systems and services. The test machines enable autonomous long-term aging of insulation materials in SiC and GaN applications under true high-voltage and high-frequency stress and automatically determine the time-to-breakdown. These time-to-breakdown measurements provide developers with information for analyzing time-dependent dielectric breakdown (TDDB) behavior and for defining the safe operating area (SOA) of semiconductor devices.

For further information, please feel free to contact us.

Wir benötigen Ihre Zustimmung zum Laden der Übersetzungen

Wir nutzen einen Drittanbieter-Service, um den Inhalt der Website zu übersetzen, der möglicherweise Daten über Ihre Aktivitäten sammelt. Bitte überprüfen Sie die Details in der Datenschutzerklärung und akzeptieren Sie den Dienst, um die Übersetzungen zu sehen.