Replacement of main transformer by a super-low-loss BEST Transformer at a major desalination plant

On January 2020 MVA cooperated with BEST on one of the most complex projects in HV transformers in Israel: Replacement of a main transformer by a super-low-loss transformer made by BEST. The project was performed during scheduled downtime in a critical seawater desalination plant.

The main transformer was replaced by a transformer identical in its outside dimensions connections but internally it is much more energy efficient. The old main transformer will be used as an emergency replacement reserve, while the new BEST transformer will more than return its entire cost via savings in electricity during its liftime.

The project started with a detailed technical-economical analysis by Eng. Paz Roth and MVA engineers. All details from the old main transformers had to be incorporated in a copy-exactly method to ensure that the 270 control signals and external connections will match exactly the connections of the old main transformer. That, in addition to the technological leap to an optimized electrical efficiency, better tap-changer, reduced noise level.

In doing so, the reliability of desalinated water supply in this critical infrastructure facility was increased, while the cost effectiveness of the project was such that over the remaining BOT period, it would more then repay for itself in saved electricity bill.

Photo: Asher B.

The video shows the transformer switching day in which the two transformers were switched in a single day starting at 6am. By 7pm the new transformer was successfully erergized.

The advantages of the new BEST Transformer:

  • Energy efficient worth about $80,000/year, more then covers the projects entire cost during the remaining BOT period.
  • Security shutdown valve in the conservator tank prevents oil from the tank feeding a possible fire in the event of a malfunction
  • Conservator tank higher than highest point of the insulators, ensuring oil in the insulator internal pipe even in the presence of an oil leak from the insulator top gasket.
  • Ultra-High voltage insulators chosen for this project are same type as exist in reserve storage in Israel, in case of an emergency replacement.
  • 3x Redundancy in major control cabinet components enhance reliability in case of a malfunction in one of the components.
  • Internal core connectors go to insulators at the top of the transformer enabling better insulation tests of various parts of the core.
  • Sampling and draining valve is below the transformer bottom level, enabling efficient draining of moisture and oil sampling.
  • CM5 marine level painting ensures corrosion resistance to the highest level.