Unified Modeling and Full-Mode Energy Control of Two-Time-Scale Cascaded Systems

Periodic energy control has been successfully applied to systems with single-time-scale operation. However, the control performance is hindered by the different time scales of the non-fully decoupled cascaded structure. In this article, a unified full-mode energy model with two-time-scale variables for the LCC-LCC compensated inductive power transfer (IPT) system with a rear-end four-switch buck-boost converter, which can accurately track the dynamic response, is proposed. To reduce the computational burden and improve the dynamic response speed, a full-mode energy control strategy conducting in the unified time scale is developed based on the two-time-scale model. Compared with the periodic energy control, the sampling of the load voltage and current can be avoided. A cascaded LCC-LCC compensated IPT-FSBB prototype is built, and the theoretical analysis shows excellent agreement with both the simulation and experimental results.