Phase Current Reconstruction based on Rogowski Coils Integrated on Gate Driver of SiC MOSFET Half-Bridge Module for Continuous and Discontinuous PWM Inverter Applications

This paper seeks to explore the benefits brought by PCB-embedded Rogowski switch-current sensors integrated on the gate driver of a 1.2 kV, 300 A SiC MOSFET half-bridge module. They collect two MOSFET switch currents in a manner of high magnitude, high bandwidth, and solid signal isolation. Apart from high bandwidth switch-current signals being used for short-circuit detection, they are further utilized for phase current reconstruction. The fundamentals of the phase current reconstruction done by subtraction of switch currents are presented in the paper as well as phase current sensor performance during continuous and discontinuous PWM schemes for three-phase inverter applications. Presented principles can be applied to any half-bridge power module. A three-phase inverter prototype has been built and operated in both continuous and discontinuous PWM mode. On this setup, the performance and limitations of phase-current reconstruction are experimentally validated for both PWM schemes.