The Hybrid HVDC Breaker
An innovation breakthrough enabling reliable HVDC grids
–M.SUDHEER CHANDRA, EEE, B.TECH (III/IV) INTRODUCTION:
ABB, the leading power and automation technology group announced a breakthrough in interrupting direct current solving 100 year old electrical puzzle and paving way to for more efficient reliable power supply system. ABB developed fastest HYBRID HVDC breaker combining very fast mechanics with power electronics, and will be capable of ‘interrupting’ power flows equivalent to the output of a large power station within 5milliseconds- that is thirty times faster than the blink of a human eye.
WHY IS THIS SO IMPORTANT?
The war of currents was played out 100 years ago between alternating current (AC) and direct current (DC). Alternating current won, although direct current is much more efficient at transmitting power over long distances, for example between remote renewable energy sources and population centers. This makes high voltage direct current a key technology in overcoming the problem that renewable energy is seldom produced in places where it needs to be consumed, for example by connecting remote offshore wind farms to inland population centers. However, the problem until now has been that there was no way to create a grid using DC technology. A grid is what you need to effectively balance supply and demand and ensure reliability. This new innovation from ABB makes it possible for the first time to HIGH VOLTAGE DC GRID allowing the efficient integration of remote renewable energy sources.
CONSTRUCTION:
The hybrid HVDC breaker consists of an additional branch, a bypass formed by a semiconductor-based load commutation switch in series with a fast mechanical disconnector. The main semiconductor-based HVDC breaker is separated into several sections with individual arrester banks dimensioned for full voltage and current breaking capability, whereas the load commutation Switch matches lower voltage and energy capability. After fault clearance, a disconnecting circuit breaker interrupts the residual current and isolates the faulty line from the HVDC grid to protect the arrester banks of the hybrid HVDC breaker from thermal overload.
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