RT23 |Laboratory Hardware-in-the-Loop implementation of Centralized Protection and Control

Laboratory Hardware-in-the-Loop implementation of Centralized Protection and Control Decarbonization targets are continuously increasing the share of renewable based Distributed Generation (DG) and other Distributed Energy Resources (DER), challenging the protection and operation of distribution networks. Considering current grid code requirements and Fault-Ride Through (FRT) capability of medium-size DG inverters, unwanted islanding and protection coordination issues may become more frequent. Therefore, updating protection and automation strategies becomes important to ensure the security and reliability of the distribution network. INESC TEC, in the context of national project SCALE (Scalable Centralized Grid Protection, Automation and Control), has been developing and testing new automation and protection functions for future virtual substations. SCALE project developed and demonstrated a platform for the digital distribution substation, enabling the control, monitoring and protection of medium voltage (MV) electrical networks in a centralized manner. The performance of the virtualized protection and advanced automation applications were tested with INESC TEC HIL infrastructure. The test setup consists of a Hardware-In-the-Loop (HIL) setup based on OPAL-RT system where the distribution network and substation test model was developed, connecting to the Centralized Protection Unit (CPC) [Aleixo et al., “Challenges and Considerations for the Design and Implementation of a Centralized Protection and Control Solution for MV Networks”, CIRED 2023] and to conventional IEDs. The OPAL-RT system is integrated with two linear power amplifiers and the setup is fully IEC 61850 standard compliant, integrating IEC 61850-8-1 (Generic Object-Oriented Substation Events, GOOSE) message communications and analogic samples by IEC 61850/IEC 61869-9 (Sampled Values, SV) with synchronization via Precision Time Protocol (PTP), implementing a process bus network capable of reproducing real-world situations. Voltage and current measurements, both real and simulated, as well as protection and control signals, were exchanged according the IEC 61850 standard. Using the assembled testbed, advanced applications concerning automatic voltage control at the substation level, adaptive protections for the MV network, and the identification of unintentional islands within the MV feeder were implemented. These applications were developed and allocated to the CPC unit, interacting with the CPC virtual versions of protection and control IEDs through the process bus according to IEC 61850, implemented in the simulated system's substation. IEDs of the type merging unit (MU) are used to inter-connect the CPC and the measurement points at the substation (bus bay, feeders bays and the transformer bays). The implemented setup significantly fostered and speeded up the development and practical application of advanced functions for distribution networks by exploiting the virtualization and centralization concepts for MV network management within the substation, meeting requirements of communication based on the IEC 61850 standard. Furthermore, the integration of a relatively new element into the substation system, the CPC, which may contain advanced applications for the network, opens various possibilities to be explored in the continuation, with new research in the important area of MV system protection. The presentation will provide a more detailed overview of the test setup developed at INESC TEC, including limitations and benefits of such infrastructure.