Implementation of IEC 61850 power protection tester in Linux environment

Abstract

Software power protection tester implemented in a real-time operating system (RTOS) might replace the conventional testing setups in IEC 61850 protection systems. This paper describes an open power protection testing platform. Linux RT capabilities related to runtime environment for such a tester are examined and OS latency sources are identified and evaluated. An algorithm for a multithreaded tester operation is proposed, including Sampled Values (SV) publisher, GOOSE input/output and time synchronization. SV and GOOSE services implemented in RT Linux environment are evaluated in accordance with IEC 61850‒5 transfer time requirements. Linux PTP time synchronization service of two similar systems controlling its electrical ports is evaluated in different synchronization scenarios. The developed tester is compared to an equivalent conventional setup during the test of IED over-current function. The conducted tests show that the Linux implementation of power protection tester in the case of scheduler latency, time synchronization accuracy and transfer time all meet the requirements of IEC 61850.