Edvard Csanyi on refurbishing an old substation
Edvard Csanyi discusses key challenges engineers face when upgrading old substations, from equipment condition to safety, capacity, and network integration.
Image for illustrative purposes
A 132 / 33 kV substation built over 50 years ago is undergoing assessment for a major refurbishment and capacity upgrade, revealing the complex challenges of modernizing legacy infrastructure. The substation, originally supported by four 60 MVA transformers and multiple outgoing feeders, now struggles with overloading, reliability issues, and serious safety concerns.
The site is loaded close to its N-1 firm rating, with plans for additional loads such as a 15 MVA spot load from a large sewage plant. The facility also suffers from outdated 33 kV switchgear, rusting steelwork, and obsolete protection systems. Safety risks include congested switchyards, explosion hazards in circuit breakers, and below-standard clearances. Noise from aging air blast breakers, corrosion of the earth grid, and non-automated tap changer control further complicate operations.
Key upgrades involve replacing two 60 MVA transformers with 120 MVA units, addressing fault level limitations, enhancing busbar configuration, and overhauling protection schemes, battery systems, and SCADA. The deteriorated state of equipment, some of which lacks spare parts, adds urgency.
Years of testing, maintenance feedback, and inspections have guided the strategy. A successful project demands a clear implementation roadmap, careful planning, and consideration of how the upgrade integrates with the broader power network. Without this, progress could stall mid-way, delaying much-needed modernization.
Source: Electrical Engineering Portal
#aging equipment#Electrical safety#power infrastructure#protection systems#SCADA#substation#switchyard#transformer#upgrade