Electric Pipeline Corporation


Multi-terminal DC grids occur at many different voltage and current levels. DC circuit breakers are not a problem for low voltage, low current DC microgrids (like a car’s electrical system or a home-based “off-grid” power system) but DC breakers become quite expensive as voltage and current increase, to the point that high current DC circuit breakers limit developments in several areas. There is a recognized need for an improved medium voltage, high amperage DC circuit breaker in ships, electric locomotives, large commercial battery packs, and the DC grids that gather up DC output from solar arrays. Higher voltage HVDC super grids that are being planned for regional reinforcement of the AC grid, and for moving renewable energy such as offshore wind and solar power from many different generation sites to multiple markets, need an improved HVDC breaker as well. The Atlantic Wind Connection backed by Google Ventures, for example, is based on a multi-terminal HVDC grid that will require HVDC circuit breakers. DC grids are based on voltage source converters (VSCs), which are now commercially available up to 325 kV.

However there is no commercially available DC circuit breaker capable of shutting off 5000+ amps at 325kV+ volts, with low on-state losses, for an acceptable price, and this is holding up development of VSC-based regional HVDC grids. There is a worldwide market at present for dozens of HVDC circuit breakers, but once the technology is proven, there will be a market for hundreds of these circuit breakers, as they will protect every power tap on the HVDC grid of the future. There is a larger, less technically challenging market at lower voltage, which makes it possible to enter this market and begin selling ballistic breakers for 500-5,000 volts, and 1000-10,000 amps in just a few years.