A two-terminal fault location method for gas switch prefire in linear transformer driver

Area of Science:

• High-power pulsed power systems
• Electrical engineering
• Plasma physics

Background:

• Large-scale linear transformer drivers (LTDs) utilize numerous high-power gas switches.
• Switch prefire represents a common and disruptive operational fault in LTDs.
• Efficient and accurate fault detection is crucial for LTD reliability and performance.

Purpose of the Study:

• To develop and validate a novel two-terminal fault location method for gas switches in LTDs.
• To compare the effectiveness of time-of-arrival (TOA) and time reversal (TR) fault location techniques.
• To enhance the operational efficiency of LTD commissioning, operation, and maintenance.

Main Methods:

• Integration of B-dot sensors on gas switch shells to capture discharging signals.
• Parallel connection of B-dot sensors via equal-length cables for signal transmission.
• Application and comparison of time-of-arrival (TOA) with energy and phase criteria, and time reversal (TR) methods for fault localization.
• Validation of the TR method on a single-stage LTD module.

Main Results:

• The proposed two-terminal method enables accurate detection and location of faulty switches.
• The time reversal (TR) method, supported by a precise simulation model, demonstrates high location precision.
• The TOA method's accuracy is sensitive to signal-to-noise ratio (energy criterion) or requires accurate delay estimation (phase criterion).
• Theoretical discussion covers the location method for double switch prefire events.

Conclusions:

• The developed two-terminal fault location method offers an efficient solution for identifying prefire faults in LTD gas switches.
• The time reversal (TR) method shows superior precision for fault localization compared to TOA-based approaches.
• This technique is expected to significantly improve the efficiency of commissioning, operation, and maintenance for large-scale LTD devices.