Nonlinear Decoupling Control of Multiport Resonant Converters Based on Gray Wolf Optimization Algorithm

In this article, a novel power decoupling method for multiport resonant converters (MRCs) is proposed. Due to the natural coupling of resonant impedances and phase-shift angles between each port, the transient performance of MRC is usually poor. To mitigate this issue, a power decoupling method based on the gray wolf optimization (GWO) algorithm is proposed. This algorithm can iterate and find the optimum value of phase-shift angles quickly and accurately compared to other iteration methods. Furthermore, the proposed method does not require linearization and parameter estimation algorithms, which makes it robust to operate at all operating points and parameter mismatch. In addition, a simple online implementation with a digital signal processor is also given. The performance of the proposed method is compared with several existing methods and validated using results from both simulations and laboratory-scaled experimental hardware. The results show that the maximum overshoots during step changes in load and power reference can be significantly reduced from 20% to 27% to only 7%–9%.