Large-scale retrofit programme (2007–2019) modernising medium-voltage switchgear in 35–110 kV substations and 6–10 kV distribution points by replacing conventional oil circuit breakers with vacuum circuit breakers and upgrading electromechanical relays to digital protection. 829 circuit breakers were replaced across 79 facilities, reducing costs by more than 60% versus full switchgear replacement while extending asset life, improving safety and enabling SCADA/remote-control integration. SAIDI fell ~88.5% and SAIFI ~68.6% over the period.
