The Pantabangan Hydropower Station, located in Neuva Ecija in the Philippines, consists of two 60 MW hydro turbines, which were originally commissioned in 1977. The plant is part of a multi-purpose hydro complex that supplies irrigation water for the vast rice fields of Nueva Ecija, northeast of Manila.
The hydropower station draws water from the Pantabangan reservoir that can hold up to three billion M3 of water. Over half of this water is used for both irrigation and power production. To maximise its power-generating potential, Pantabangan cascades the water resource from the reservoir initially through the two turbines upstream and then through the smaller 12-MV Masiway plant downstream. The original two turbines were due for refurbishing and upgrading to increase the plant capacity to 132 MW.
Station Refurbishment and Upgrade
WSP was contracted to help assess options for upgrading the two power transformers as part of the station refurbishment and upgrade project. The three options considered were to keep, refurbish or replace the original transformers.
Our role included:
- Reviewing and reporting to evaluate re-rating and the remaining life of the original transformers, including internal condition inspection.
- Preparing specifications for on-site refurbishment and increased rating of the transformers, which was later abandoned after the global financial crisis in favour of new, low-cost transformers.
- Inspecting transformer manufacturing facilities in China.
- Preparing specifications for supply of new transformers.
- Creating transformer oil containment and blast wall designs.
- Reporting on transformer fire suppression options.
- Providing design review services and witnessing factory acceptance tests to support the client through the procurement and manufacturing process.
- Developing interface designs to incorporate new transformers into existing control and protection systems.
- Providing on-site assembly and commissioning supervision for new transformers.
Our technical advice helped to guide our client through a thorough evaluation of the upgrade options. Our recommendation was the full replacement of the transformers, which took place. Using our comprehensive technical specification, the client procured new transformers at a lower cost and in a short time. We also supervised the installation and commissioning.