ABB develops world's first HVDC circuit breaker
Power firm claims development removes barrier to DC transmission grid
ABB has announced that it has developed the world’s first circuit breaker for high voltage direct current (HVDC) – a breakthrough that the firm says “removes a 100-year-old barrier to the development of DC transmission grids”.
The new circuit breaker is said to be capable of interrupting power flows equivalent to the output capacity of a large power facility within 5 milliseconds. ABB says that it will enable effective integration and transmission of renewable energy, and will also boost grid reliability and capacity of existing AC grid networks.
“ABB has written a new chapter in the history of electrical engineering. This historical breakthrough will make it possible to build the grid of the future. Overlay DC grids will be able to interconnect countries and continents, balance loads and reinforce the existing AC transmission networks,” said Joe Hogan, CEO of ABB.
ABB says that the Hybrid HVDC breaker development has been a flagship research project for the firm. The company already has over 70 HVDC projects to its name – accounting for around half of the global installed base.
Claes Rytoft, the firm's chief technology officer for power systems, explained the significance of the technology: "Hybrid is a combnation of a mechanical breaker and a power electronic element. We combined the two which leads to a breaker with low losses, but still very, very fast.
"When we deal with direct current, you can compare it to driving a truck on a highway with a very high speed. The challenge is to stop that truck within a very short time period - within five milliseconds or less. So you can imagine the sort of energy that is needed to stop that truck."
Rytoft said that DC lines have been built for the last 60 years, but that they have always been point to point connections.
"If something goes wrong with that line, you have to switch off the whole power flow, and this can most likely lead to a black-out. With this new technology we can build a grid with multiple inputs and multiple outputs. And we can switch off an individual line if something goes wrong. Therefore, we increase the reliability and security of the power supply dramatically," he concludes.