Breaker pole scatter and its effect on quadrilateral ground distance protection

In this paper, the effect of breaker pole scatter on quadrilateral ground distance elements is investigated using a simple two-source power system with two short transmission lines. A case study of an unintended operation of a Zone 1 quadrilateral ground distance element due to the delayed opening of a breaker pole in an actual system is presented. A simple solution based on relay logic is proposed to improve the security of quadrilateral ground distance elements. The effectiveness of the proposed solution is verified by running a real-time test using a Real Time Digital Simulator (RTDS®).