Project Overview
After 10 years of operation, an LW56-230 dead tank circuit breaker at a 230kV substation was found to have partial discharge (PD) signals severely exceeding standards during ultrasonic testing (RMS 15mV, Peak 65mV—over 7 times the national standard). Disassembly confirmed that loose bolts had caused floating potential, and metal particles within the tank had triggered insulation aging. Our company urgently implemented the "Precision Governance Solution for Insulation Hazards," completing the repair within 72 hours through process purification, sealing reinforcement, and the installation of an online monitoring system. Post-governance, PD signals returned to safe thresholds (RMS≤1.8 mV, Peak≤4.5 mV). The equipment has operated safely for over 18 months, successfully averting the risk of a potential large-scale power grid outage.
Exceptional Design · Root Cause Eradication
Focusing on the trinity of "Impurity Control - Sealing Reinforcement - Intelligent Warning":
Empowering Infrastructure Development
This case led to the formation of the "Technical Guidelines for Governance of Latent Faults in EHV Dead Tank Circuit Breakers," which has been promoted to over 30 230kV substations nationwide, averting 47 similar hazards. Adhering to the philosophy of "Monitorable Warnings, Early Hazard Disposal," our company is driving the transformation of grid O&M from "periodic maintenance" to "condition-driven" strategies. This injects technical momentum into the high-reliability operation of new power systems and demonstrates our strength in safeguarding the full lifecycle of high-end domestic equipment.
