Dynamic Frequency Shaping of Grid-Following and Grid-Forming Inverters

Abstract

Compared with synchronous generators, inverter-based resources (IBRs) have distinct characteristics. This can challenge the reliability and stability of heterogeneous power grids comprising synchronous generators and IBRs. At the same time, the high flexibility of IBR control architectures can be leveraged to dynamically shape the frequency response of nearby synchronous generators. By doing so, these frequency-shaping control methods can minimize frequency excursions during load transients and grid disturbances. Most existing methods remain limited to theory-based frameworks and are restricted to certain grid topologies, grid conditions, or inverter control architectures. In this paper, we illustrate how frequency-shaping controls can be implemented in practical grid-following and grid-forming inverters, including current and power limits, accounting for other control- and physical-layer dynamics. We investigate how additional dynamics influence the efficacy of frequency-shaping control methods and how this alters theoretically established stability bounds. Last, we illustrate the performance of IBR-implemented frequency-shaping controls in radial and meshed multi-bus, multi-generator networks, where parameters that are essential for the effective operation of the frequency-shaping controls may not be readily available.