Breaker failure protection — Standalone or integrated with zone protection relays?

This paper discusses merits, advantages, and disadvantages of integrating breaker failure (BF) protection with zone protection relays (ZPRs). In this context, the paper considers cost savings, security and dependability, simplicity, the danger of human errors when testing bus configurations, overall relaying philosophy, and reliability of applied protection devices. Several ways of integrating BF protection are proposed, allowing different tradeoffs between the mentioned factors. This paper also reviews methods to improve the security of BF protection.