Phase Current Reconstruction, DC Link Voltage and RDS-ONMeasurement Using Sensors Integrated on Gate Drivers for SiC MOSFET

Constant requirements for integration and increase in power density bring a lot of challenges in power electronics. Introducing a communication network between gate drivers and local controllers enables the integration of sensors into the gate driver or, better said, the reuse of existing sensors previously used only for protection purposes. Device off-state voltage V DS-OFF sensing can be repurposed for DC-link voltage measurement. Device drain-source current I DS sensing can be used for phase current reconstruction and on-state resistance R DS-ON calculation in conjunction with device on-state voltage V DS-ON sensing. V DS-OFF and I DS sensors could remove the need for external sensors for measuring DC-link voltage and phase current, reducing the converter size since fewer external sensors are needed. The R DS-ON estimation allows health monitoring and diagnostic of SiC devices. This paper explains how these three types of sensors were integrated into a customized gate driver for 1.2 kV SiC MOSFET power modules, and converter-level validation is provided with demonstrations on both a 2-level 3-phase active front-end (AFE) converter and a non-isolate soft-switching DC-DC converter.