Performance testing of a solar PV system controlled as a virtual synchronous machine to verify grid code compliance

This paper presents a comprehensive analysis of the functional response verification of an inverter operating as a Virtual Synchronous Machine (VSM) in grid-following mode. The proposed VSM control strategy addresses critical technical challenges associated with integrating Inverter-Based Resources (IBRs) into weak power grids. Modern grid codes outline essential performance requirements of IBRs, including voltage regulation, reactive power support, frequency control, and resilience during grid disturbances. An electromagnetic transient (EMT)-domain based testing procedure (generally referred to as Model Quality Tests – MQT) of a 50 MVA solar PV plant controlled as a VSM is presented. These tests ensure accurate model representation and IBR’s compliance with regulatory standards. Furthermore, the paper explores the adaptability of VSM controls in delivering essential functional features, such as inertial and fast frequency response, to enhance grid stability and operational efficiency. The test results highlight the ability of inverters operating as VSMs to meet essential grid code requirements, thereby enabling the reliable integration of renewable energy sources into power systems and supporting the transition toward sustainable energy.