HTS Transformer and SFCL-Transformer
Transformers are an integral part of the electricity transmission and distribution network throughout the world. Energy is transmitted from substation to substation through transformers that either step up voltage (for long distance transmission) or step down voltage (for consumer use). In the U.S. there are approximately 140,000 medium-power transformers that are approaching 40 years of service – the end of their life. Within the coming generation, the vast majority of these conventional transformers will need to be replaced.
HTS Transformer offer numerous benefits:
- Greater efficiency – HTS transformers help reduce the amount of energy lost in the transmission of power over long distances to more than pay for initial capital cost of the device over its lifetime. This benefits the electricity consumer through lower costs from the reduction in losses due to the inefficiencies of conventional power transformers
- Smaller, lighter and quieter – HTS transformers occupy a smaller footprint than conventional transformers, enabling existing substations to increase distribution capability without expanding into limited or expensive real estate
- Ability to run above rated power without affecting transformer life - HTS-based transformers with operation at cryogenic temperatures completely avoid the thermal aging processes that ultimately destroy conventional transformers
- Liquid nitrogen cooling – HTS transformers do not require cooling oil like conventional transformers, thereby eliminating the possibility of oil fires and related environmental hazards and enable placement in an enclosed building or even a multi-story building in densely populated areas
- Flexibility in siting – smaller size and weight, and the capability to operate at over-capacity result in greater siting flexibility and potential lower transformer cost per unit power delivered, and more power per unit area in existing substations
- Economic advantages for utilities - Lower installation and total owning cost for each transformer
SFCL-Transformers offer additional benefits by integrating fault current limiting (FCL) capability into a medium-power utility transformer:
- Meaningful downstream protection for existing substation circuit breakers and other devices
- Reduction of prospective fault current due to network upgrades or the addition of new generation (including wind, solar and distributed generation) to a lower, safer level where the existing switchgear can still protect the grid
- Providing the necessary current limiting impedance during a fault, with essentially zero impedance during normal grid operation. SFCL transformers, therefore, have no negative impact on overall system performance.
The SFCL Transformer is expected to lower power consumption through reduction of losses, increase the reliability of the nation’s grid, and speed commercial adoption by utility operators.
... the mark of excellence
1996-2002 HTS Transformer Projects
Development of the HTS Transformer began in 1996 under the DOE’s Superconductivity Partnerships with Industry (SPI) program. Waukesha Electric Systems partnered with Intermagnetics General Corporation (acquired by Royal Philips Electronics in 2006) in two program phases, both of which utilized BSCCO-based HTS, also known as 1G HTS:
- A 1 MVA prototype HTS transformer was designed and built by the team and successfully tested in 1998.
- A larger, 5/10 MVA system-level prototype transformer program was subsequently designed and built. Further development work has focused on the use of 2G HTS wire in the device.
Program Duration: 1996-2002
- Waukesha Electric Systems – transformer manufacturer
- Intermagnetics General Corporation/SuperPower Inc. – HTS wire and coil manufacturer
- Rochester Gas & Electric – utility end user
- Oak Ridge National Laboratory (ORNL) – supporting research
- Rensselaer Polytechnic Institute – supporting research
- $21.5M overall cost
- $10.7M from U.S. Department of Energy