Compatibility and interoperability evaluation of all-digital protection systems based on IEC 61850-9-2 communication standard

Recent development of electronic instrument transformers and use of digital relays allow the development of an all-digital protection system, where the traditional analog, hardwired, interface has been replaced with a digital communication link (process bus) based on IEC 61850-9-2 standard. An all-digital system should provide compatibility and interoperability so that different electronic instrument transformers can be connected to different digital relays (under a multi-vendor connection). Since the novel all-digital system composed of IEDs from multiple vendors has never been implemented and/or tested in practice so far, its performance needs to be evaluated. This paper presents a methodology for performance and compatibility evaluation of an all-digital protection system. The test results obtained using a digital simulator test bench and comparison of the compatibility of systems provided by different manufactures are discussed.