Extending Distribution Transformer Lifetime and Reliability with Passive Thermal Management

Within the U.S. electrical grid, there are more than 50 million distribution transformers currently in operation responsible for providing the final stepdown in voltage to the end user. Utilities across the country are currently experiencing an unprecedented shortage in new transformers resulting in lead times of over a year and 4-5x increase in prices. New transformers are required for expanding residential and commercial areas and for replacing old transformers, ensuring customers have reliable electricity. This problem is further exacerbated by the fact that the average age of U.S. transformers is 38 years (40-year average lifetime), over 70% of transformers are 25 years or older, and approximately 2% of the entire transformer fleet needs replacement every year. With demand currently outpacing supply, the reliability of currently deployed distribution transformers plays a key role in maintaining a functional electrical grid. As with all electronics, the operating temperature of a transformer plays a key role in long-term reliability. This SBIR program will develop passive two-phase heat transfer devices that can be retrofitted onto currently deployed distribution transformers. The heat transfer devices will increase the lifetime of the transformers by lowering the maximum operating temperature experienced during peak loads on hot days. The goal of the Phase I program is to demonstrate that a cost-effective passive two-phase heat transfer device can be retrofitted onto a distribution transformer to lower the operating temperature and increase the lifetime. This will include theoretical modeling of the thermal performance of the transformer, development of a retrofitting process, and experimental prototype validation. The Phase I program will also include a techno-economic analysis of the device. Improved thermal management of distribution transformers will extend their lifetime by lowering the rate at which internal components age. Extending the lifetime of currently deployed transformers will benefit utility companies and the public by increasing the reliability of the electric grid.