Steady State Voltage Regulation Requirements for Grid-Forming Inverter based Power Plant in Microgrid Applications

Grid- forming (GFM) inverter, which can regulate voltage and frequency independently, is a key component in an inverter-based microgrid. However, an industry acceptable consistent and uniform method of defining the functions and performance requirements for GFM inverters in microgrid is presently lacking. As a result, utility planners constantly face the challenge of defining these requirements by themselves in contractual agreements with plant developers. This paper presents initial investigation results towards developing the performance requirements for a GFM inverter based power plant in a microgrid. Specifically, the requirements related to steady state voltage regulation are developed based on detailed simulation studies on a real microgrid. The need and benefits for a grid-forming inverter based power plant to regulate the voltage magnitude, balance the three-phase voltages and regulate voltage harmonics inside the microgrid are shown. The results are expected to assist distribution utility planners in developing detailed performance requirements for GFM inverter based power plants in microgrid projects.