Backup Protection Algorithm for Failures in Modular DC Circuit Breakers

Abstract

HVDC grid protection with adequate speed and reliability is required to minimise the impact of DC faults. In particular, fast breaker failure backup protection algorithms are needed to meet the expected reliability requirements of HVDC grids. In this paper, existing breaker failure backup protection algorithms are shown inadequate to detect partial failures like a single module failure of breakers with a modular structure. This paper proposes a backup protection algorithm which rapidly detects a DC breaker failure based on estimating the countervoltage created by the energy absorption branch during an interruption. The performance of the proposed algorithm is evaluated using a four-terminal test network with both hybrid and mechanical DC breaker technologies. The simulation results show that the proposed algorithm is able to quickly detect both complete and partial failures of the two breaker technologies even considering measurement errors, noise and ageing of the energy absorption components.

Multi‐vendor interoperability in HVDC grid protection: State‐of‐the‐art and challenges ahead

“…Breaker failure backup protection algorithms are essential to prevent detrimental fault current levels in case of a DCCB failure. Several breaker failure algorithms are proposed and can be classified based on the measurements: (i) at DCCB terminal [63,71,72] and (ii) internal [73]. The basic principles used for breaker failure detection are overcurrent, undervoltage and voltage derivative.…”

“…The basic principles used for breaker failure detection are overcurrent, undervoltage and voltage derivative. Terminal measurement-based algorithms typically can deal with different DCCB technologies, while internal measurement-based algorithms may be limited to one specific DCCB technology [72].…”