| Project Detail |
Today’s power grid relies primarily on alternating-current (AC) electricity as opposed to direct-current (DC). DC has advantages over AC such as lower distribution losses, higher power carrying capacity, and reduced conductor materials, which make it well suited to industrial applications, transportation, and energy production. However, the risk associated with electrical faults, such as short circuits, and system overloads, continues to hinder the growth of DC markets. Inherently, AC electricity periodically alternates direction, providing a brief “zero crossing,” where no current flows. This characteristic allows electrical faults to be interrupted by conventional electro-mechanical breakers. DC networks deliver power without zero crossings, which make conventional circuit breakers ineffectual in fault scenarios. To fully benefit from medium voltage (MV) DC usage, fast, highly reliable, scalable breakers must be developed for commercial deployment.
Project Innovation + Advantages:
Georgia Tech is developing a novel hybrid direct current (DC) circuit breaker that could enable multi-terminal DC power systems. The breaker’s mechanical switch enables switching speeds 10 times faster than existing technology, severing the mechanical linkage, while the power electronics-based circuit handles the fault current. A new configuration of the fast switch and solid-state devices/circuits will reduce steady-state losses compared to state-of-the-art hybrid circuit breakers. A new control scheme dramatically reduces the peak fault current levels, enabling more compact packaging and increasing reliability.
Potential Impact:
The proposed breaker is installed close to loads to rapidly detect and react to the short-circuit fault. Thus, it could enable an increased number of electronic loads that operate using DC, such as ultra-fast electric vehicle charging stations and utility scale energy storage battery units, to connect to the MV distribution grid. This would improve overall power delivery efficiency. |
