GaN-Based Matrix Resonant Power Converter for Domestic Induction Heating

Flexible-surface induction cooktops must operate with a variety of induction heating loads with different behavior and power setpoints to be heated simultaneously. In this context, multioutput inverter topologies aim at achieving independent power management while featuring low power-device count and high power density. However, they suffer from limitations when applying classical modulation strategies to ensure soft switching, which is required to reduce transistor losses and achieve efficient operation. In this scenario, wide bandgap devices reduce switching losses, opening a new paradigm in power conversion where soft switching is not mandatory in order to achieve high efficiency. This letter proposes an implementation of a multioutput resonant inverter based on GaN HEMTs and evaluates various modulation strategies in terms of efficiency under different switching modes. The proposed approach is designed and experimentally validated by means of a two-coil 2000 W prototype implementation.