Performance and interoperability testing of a modular merging unit and IEDs with 30 sampled value streams

The evolution of substation automation is driven by the need for enhanced performance, interoperability, and flexibility in power distribution networks. This paper presents findings from comprehensive tests aimed at evaluating the performance and interoperability of various Intelligent Electronic Devices (IEDs) within digital substations, including the concept of a Modular Merging Unit (MMU). The tests, conducted by Alliander and Grid to Great, utilized 30 sampled value streams generated by Current and Voltage Measurement Stand Alone Merging Units (CMS and VMSs) [1] processed by a centralized protection and control system (CPC). The primary goal was to assess the compatibility, integration, and usability of a MMU concept and traditional Merging Units (MUs) with centralized IEDs compared to conventional IEDs. The results demonstrate that digital solutions, including centralized protection and control systems and different merging units, are reliable and perform as well as conventional protection systems. Our tests confirm that digital solutions, prove to be a viable alternative to the conventional IED approach.