Design and Implementation of a Test Facility for Assessing IEEE 1588 Precision Timing Systems

IEEE 15888, known as precision time protocol (PTP), has become increasing popular in the power industry for precision timing since its first introduction in the early 2000s. It is often regarded as the “perfect fit” for time synchronization within an electrical substation designed based on the IEC 61850 standard. Sharing the same transmission media, the measured voltage and current data, protection and control commands can be transmitted simultaneously along with the time synchronization signals. However, the deployment of PTP has fallen short of expectations, and some utilities do not consider PTP a fully mature technology. This is partly because intangible data interactions in the substation Ethernet occasionally result in problems related to the reliability and security of PTP. Existing laboratory studies into the capabilities of PTP are often of limited value to the power industry, due to inadequacies in test equipment and its functional performance. This paper introduces the design and implementation of a test facility suitable for evaluating IEC 61850 and PTP based systems. The facility contains a protection relay, merging units (MUs), switches and PTP clocks, reproducing the real-time operation of a small-scale substation Protection, Automation and Control (PAC) system. Various state-of-the-art evaluation methods are introduced, which together are ideal for simultaneous evaluation of PAC and time synchronization systems.