Advanced reactive current control and EMT-HIL validation of grid-following PV systems for fault resilience and grid code integration

Abstract In power system research, improving control strategies is key to maintaining grid stability and reliability. Electromagnetic Transient (EMT) simulation plays a central role in this work. It enables engineers to evaluate how different control methods perform under various operating conditions and disturbances, providing a clear, detailed view of the system’s behaviour in real time. This paper focuses on the significant contribution of a detailed 4 MW grid-following inverter-based PV systems model to EMT simulation and Hardware-in-the-Loop (HIL) testing and validation. The complex dynamics of fault response and the performance of the Overcurrent (OC) protection scheme within PV power plants are examined. The transient properties of PV power plants are analysed using comprehensive EMT and HIL models, and model accuracy is validated across various fault scenarios. The findings demonstrate the model’s capability to effectively describe and analyse the electromagnetic behaviour of PV power plants, particularly under disturbance conditions. This research is essential for understanding the electromagnetic complexities of PV power plants and their impact on electrical grid stability over different 9 fault scenarios (three and single phase faults) under different dynamic factor control modes. In the results, in a 4 MW PV system, a three-phase fault causes only a short current surge with oscillations lasting less than two cycles at dynamic factor control enabled (K = 0); even with an irradiance drop from 1000 to 700 W m −2 , the fault current remains about 900 A and the relay trips correctly at 1.2 s with (K = 2). The fundamental analysis examines the implementation of the Grid Code Requirements (GCR) strategy, evaluates its impact on the dynamic factor, and assesses the response characteristics of the grid-following inverter and PV power plant during fault scenarios. The system’s stability is also verified to ensure it meets the IEEE 1547-2018 standards. By running detailed analyses and validation tests, the study offers practical insights that help refine control strategies and strengthen the grid’s resilience under different operating conditions.