Comparative Study of Decentralized Grid-Forming Converter Controls for Inverter-Based Microgrids

With the heavy integration of Inverter-based Resources (IBR) into the different levels of the electrical network, they are gradually requested to replace the conventional Synchronous Machines (SM) in maintaining the network voltage and frequency references. Such Grid-forming (GFM) controllers recently reported in literature include conventional Droop control, nonlinear oscillatorbased controls, namely the dispatchable Virtual Oscillator Control (dVOC), Synchroverter and Matching controls. This article aims to reveal the underlying resemblance between these grid-forming controls and the conventional Droopbased strategies being the most commonly used in the decentralized and hierarchical control of Microgrids (MGs). Based on the derived similarities in their dynamics, tuning the different controllers’ parameters to achieve equivalent transient and steady state dynamics maintaining P-f and Q-V relations is deduced and validated using time domain simulations.