Risk-Sensitive Residual Generator-Based Compensation-Control Strategy for LC-Filtered Grid-Forming Inverter

The control of the grid-forming (GFM) inverter is crucial, as it provides stable frequency and voltage support to the system, allowing for the integration of more renewable energy sources. This article aims to develop a novel primary control strategy that combines risk-sensitive control and residual compensation control, enhancing flexibility in strategy design to improve GFM inverter performance under disturbances, noise, and parameter uncertainties. The presented risk-sensitive residual generator-based compensation-control strategy includes two risk-sensitive factors<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula>one for unbiased state estimation and residual generation, and another for improving closed-loop system performance. These two risk-sensitive factors increase the design freedom of the primary control strategy for the GFM inverter. First, this article establishes a link between risk-sensitive state estimation and residual generation, using the relationship between the risk-sensitive factor and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\tau$</tex-math></inline-formula>-divergence to design a risk-sensitive residual generator. Then, this article introduces a novel connection between risk-sensitive control and residual compensation control. By incorporating a risk-sensitive factor and its relationship with system stability margin, this article solves for the residual compensation controller with only two Riccati equations. Finally, experimental results on the StarSim platform demonstrate the effectiveness of the presented risk-sensitive control strategy for the GFM inverter in managing disturbances, noise, and parameter uncertainties.