Summary
As power grids age amid the energy transition, assets increasingly operate beyond their original design envelope introducing critical technical, operational, and safety risks. This paper presents a comprehensive failure analysis of a 181 MVAr, 362 kV shunt reactor at an Australian metropolitan transmission substation. After over two decades of service, the reactor suffered catastrophic B-phase winding failure within seconds after energisation. Protection systems responded correctly, clearing the fault in 63 ms. Post-failure inspection confirmed severe internal winding damage, significant oil spillage, and tank deformation.
Read more Read lessInvestigations combining dissolved gas analysis, dielectric diagnostics, sweep frequency response analysis, and full mechanical teardown revealed the definitive root cause of a corrosive sulphur compounds specifically dibenzyl disulfide drove copper sulphide deposition, triggering catastrophic winding failure. This finding aligns with the manufacturer's global fleet data of 11 failures across 509 reactors over 20 years, consistently implicating oil corrosion as the dominant failure mode. The reactor is deemed neither technically nor economically repairable. This case underscores the critical importance of integrated diagnostics, end-of-life assessment, and evidence-based asset management for aging transmission infrastructure. Key recommendations include replacement with guaranteed non-corrosive oil, fleet-wide corrosive sulphur screening, and adoption of predictive condition monitoring protocols with enhancing sustainability.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | A2_10345_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Australia |
| Study committees | |
| File size | 1 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
BHATTI Mohsin - Hitachi Energy, Australia; PAJARO Goizeder - Hitachi Energy, Spain
Keywords
