RT23 |Integration Tests of an Adaptive Protection System in a Hardware in the Loop Testbed

As distribution grids evolve to accommodate a substantial share of renewable energy sources, the interaction between traditional protection schemes and new grid dynamics poses new challenges. An adaptive protection system is essential to swiftly respond to changing grid conditions and ensure reliable power delivery. The project VeN2uS focuses on topology changes to react to changing volatile generation and, therefore, to reach a higher utilisation of the existing grid infrastructure. For this purpose, the protection scheme gets changed adaptively to fit the current grid topology to ensure high selectivity and reliability of the protection system. The process as designed in this project contains the following steps: First, the change of the grid topology triggers a process in the central SCADA infrastructure to check the feasibility of the protection devices configuration by comparing the new topology to a database with precalculated configurations for the protection devices. If the system finds a more suitable configuration, it sends the new parameters via IEC61850 to the station controllers. Next up, the station controller sends the new parameters to the protection devices. Integration tests in realistic and controlled conditions are crucial to validate such a system's performance. The presented study employs a Hardware-in-the-Loop (HIL) testbed, offering a controlled environment to simulate various grid scenarios, including rare and extreme events that are difficult to replicate in field tests, especially regarding the timing of faults during the stages of switching the parameter sets. An Example of this may be a protection device which is activated because of an overcurrent but did not trip yet, getting new set points at this moment. Furthermore, other fault scenarios, like problems with the communication infrastructure, can be replicated. An example may be one station that did not receive the new parameters because of a broken communication link. In this scenario, we test if the implemented fallback mechanisms work and can always ensure a secure operation. The adaptive protection system is interfaced with the HIL setup, allowing real-time interaction between physical components and simulated grid conditions. This approach facilitates the evaluation of the protection system's responses under a wide range of dynamic and challenging scenarios. The basis of the testbed is an OPAL-RT simulator running HYPERSIM, simulating a mixed high-voltage and medium-voltage grid with a high penetration of renewable energy resources. The simulator communicates with the protection devices via IEC61850, specifically Sampled Values and GOOSE. The simulator works like a virtual merging unit sending voltage and current values by sending Sampled Values to the protection devices and switch states via GOOSE. When a protection device trips, the device sends a GOOSE Message to the simulator to open the switch in the simulation. When the tested protection device does not support Sampled Values subscription, a power amplifier receives the sampled values stream and translates it directly to currents and voltages equivalent to the output of the measurement transformers in an actual setup. The tested secondary control system setup replicates a station in the 110kV grid, namely four Siemens Siprotec universal protection relays connected to a station controller. In conclusion, the VeN2uS project underscores the critical role of its Hardware-in-the-Loop (HIL) testbed as a robust platform for validating adaptive protection systems in the context of evolving distribution grids and renewable energy integration. Through meticulous HIL testing, the project showcases the efficacy of its approach in ensuring reliable power delivery, even under challenging and dynamic grid scenarios.