Power-Balancing Dual-Port Grid-Forming Power Converter Control for Renewable Integration and Hybrid AC/DC Power Systems

Abstract

In this work, we investigate grid-forming (GFM) control for dc/ac power converters in emerging power systems that contain ac and dc networks, renewable generation, and conventional generation. We propose a change in control paradigm to a universal dual-port GFM control strategy that simultaneously forms the converter ac and dc voltage (i.e., dual-port GFM), unifies standard functions of grid-following (GFL) and GFM (e.g., primary frequency control, maximal power point (MPP) tracking) in a single universal controller, and is backward compatible with conventional machine-based generation. Notably, in contrast to state-of-the-art control architectures that use a mix of grid-forming and grid-following control, dual-port GFM control can be used independently of the converter power source or network configuration. Our main contributions are stability conditions that cover emerging hybrid ac/dc networks as well as machines and converters with and without controlled power source, which only require partial knowledge of the network topology. Finally, a detailed case study is used to illustrate and validate the results.