INTRODUCTION

Members of CIGRE B5.16 Working Group: Zoran Gajic, Andr Quaresma dos Santos, Hans-Werner Funk, Kenneth Opskar, Jose Miguel Yarza Narro, Damien Tholomier, Ljubomir Kojovic, Phil Beaumont, Juergen Westerfeld

The article is organized into three sections.
Section 1 presents general practices for the selection of busbar protection (BBP) designs and describes centralized and de-centralized digital (numerical) busbar protection solutions

Section 2 describes common features of modern busbar protections. Busbar protection schemes utilize sophisticated algorithms to provide reliable performance during substantial CT saturation, resulting in low CT requirements.  A disconnector replica implemented in relay software eliminates the need for switching in CT secondary circuits and trip circuits. Protection functions such as breaker failure protection, end fault protection, and overcurrent feeder protection can be implemented into the BBP. Built-in self-supervision improves BBP reliability. Communication enables remote access to relevant information available within the BBP. Other features presented include disturbance recording (oscillography) and an event list that provides improved evaluation of BBP protection operation

Section 3 addresses advanced features of modern busbar protection designs. Feasibility of using new types of current sensors for current measurements is presented. Also described is integration of other protection functions such as feeder protection within the individual bay units of a de-centralized BBP arrangement. Furthermore, the impact of IEC 61850 on busbar protection design and operation is considered describing the use of GOOSE messages and their influence on scheme design, as well as blocking of auto-reclosing after BBP operation. Finally, issues regarding the integration of BBP schemes into modern substations using an IEC 61850 process bus approach conclude the discussion