Technical and Forensic Assessment
Technical and forensic assessment of real events, with reproduction of records through modeling and proposal of solutions for operational losses, equipment damage, and claims.
Deliverables - Root cause diagnosis, oscillography analysis, event reproduction by simulation, electrical stress assessment, mitigation plan, and forensic technical report.
Event Modeling
Precise reconstitution of failures and real events via digital simulation.
Operational Losses
Detailed root cause analysis to reduce losses and interruptions.
Equipment Damage
Technical investigation of damage to large machines and transformers.
Insurance Claims
Specialized technical support for forensics and insurance processes.
Case Study
Resonance during single-pole reclosing with line loss
Event description
For single-phase reactors per phase directly grounded, the zero-sequence reactance is equal to the positive-sequence reactance; however, for three-phase star-grounded reactors, depending on the type of core, they may present zero and positive sequence reactance, as indicated in the report of the tests carried out by the manufacturer on the set of phase reactors under analysis.
At the TL terminals, the oscillograms of the REL531 and SEL 421 protections were recovered. The relay that operates as a recloser in STV is the REL 531.
In the oscillograms of both relays, it was found that both protections operated properly; both protections tripped phase B, initiating a single-phase reclosing cycle that concluded successfully. However, in most maneuvers, a definitive disconnection occurs due to overvoltages (1.43pu) during the dead time. All internal digital signals of the relay are normal.
Phenomenon Record
Reproduction and comparison of model and record results
Solution results
If your project needs consultative help in:
- Severe failures in power transformers
- Failures in surge arresters and protection devices
- Failures in potential transformers
- Failures in current transformers
- Failures in MOVs and series capacitor banks
- Operational failures: damage and performance degradation of transformers
- Operational failures: damage and performance degradation of line reactors
- Operational failures: damage and performance degradation of busbars
- Grounding issues
- Resonance issues
- Electrical filter design
- Technical evaluation and forensic analysis in electrical systems