Generalized Multivariable Grid-Forming Control Design for Power Converters

The grid-forming converter is an important unit in the future power system\nwith more inverter-interfaced generators. However, improving its performance is\nstill a key challenge. This paper proposes a generalized architecture of the\ngrid-forming converter from the view of multivariable feedback control. As a\nresult, many of the existing popular control strategies, i.e., droop control,\npower synchronization control, virtual synchronous generator control, matching\ncontrol, dispatchable virtual oscillator control, and their improved forms are\nunified into a multivariable feedback control transfer matrix working on\nseveral linear and nonlinear error signals. Meanwhile, unlike the traditional\nassumptions of decoupling between AC and DC control, active power and reactive\npower control, the proposed configuration simultaneously takes all of them into\nconsideration, which therefore can provide better performance. As an example, a\nnew multi-input-multi-output-based grid-forming (MIMO-GFM) control is proposed\nbased on the generalized configuration. To cope with the multivariable\nfeedback, an optimal and structured $H_{\\infty}$ synthesis is used to design\nthe control parameters. At last, simulation and experimental results show\nsuperior performance and robustness of the proposed configuration and control.\n