Project Profile: Power Plant Transformer Solution

Power Transformer for Grid StabilityLCI Power Transfer for Grid Stabilization

Starter Transformer Solution w/ Medium Voltage Cable & PM Labor

​​​​​Voltage: 6900D:2080D/2080Y
Equipment: 1 x 10/14 MVA + 2 x 5/7 KVA Transformers

A construction contractor reached out to Distributed Power Solutions looking to see if we could support/provide a solution for their power plant which was in urgent need of a unique starter transformer solution. The power plant was a brand-new NG Power Plant built to provide grid stabilization in a particular area. This plant had just completed most of its commissioning and was being placed into service on the grid (to complete the commissioning with the grid as a load) when the first set of starter system transformers failed.

The transformers that failed were 3 winding/multi-voltage transformer configurations. The power plant was unable to start either of their 400-megawatt turbines without these transformers, causing strain on the communities’ power grid during critical conditions. Our team responded promptly to investigate the need and begin work on a solution. During the research period, it was discovered that there were no single transformers that could support this solution. We developed a solution on paper but had to search the industry to identify equipment that would meet the unique needs of our customers. A three-transformer solution was developed, and the equipment was sourced working in conjunction with vendors.

Our team held several calls with Engineering and Project Management Teams from the Construction Contractor, the Electrical Contractors, Project Engineering, and the Plant Owner Representatives to review and discuss the solution to secure authorization to proceed. The first call was made on June 19, and the first piece of equipment rolled onto the site in the early hours of the overnight on June 28…nine days! Delivery supervision was coordinated and supervised onsite, with technical support provided remotely.

The solution layout started immediately on June 28 and was completed by July 3. Full system testing was completed through July 6 with turbine start-up scheduled for July 7. Delays in testing occurred due to weather conditions, followed by coordination challenges among stakeholders, each seeking ownership of the solution.

Turbine #1 started on July 8, and Turbine #2 started on July 9.

All systems are up and running successfully.

The original transformers used were Cast Resin Dry Type (Epoxy encapsulated). The point of failure is still being investigated (the transformers were sent for inspection). The physical symptomatic failure was excessive overheating. There were concerns about whether the Oil-Filled transformer solution could handle the harmonic loads of the LCI starter system. It was believed that the heat dissipation of the Oil-Filled solution would be more effective in this scenario. The Engineers involved raised doubts about the solution's viability and wanted us to provide equipment that matched their specific requirements, despite their previously failed transformers. The pressure increased when the starter transformers for the second turbine also failed.