Laboratory Investigation of IEC 61850-9-2-Based Busbar and Distance Relaying With Corrective Measure for Sampled Value Loss/Delay

After successful implementation of IEC 61850-8-1-based GOOSE at several power substations worldwide, major protective device vendors are currently developing interoperable products for IEC 61850-9-2-based time-critical sampled value (SV) messages over the digital process bus. Unlike GOOSE, the same SV message is not repeated several times and, therefore, it is important to analyze the impact of SV loss or delay on protection functions. This paper presents the hardware implementation of a typical IEC 61850-9-2-based process bus communication network for digital protection systems to investigate the proposed corrective measure for SV loss/delay. For the detailed testing, various process bus devices (e.g. protection intelligent electronic devices (IEDs), merging units (MUs), etc.) are developed over industrial embedded systems with a hard-real-time platform. The SV estimation algorithm is implemented as a part of bus differential and transmission-line distance protection IEDs, and it is tested for various SV loss/delay scenarios and power system fault conditions.