Design and Implementation of a Three-Phase Current-Source Inverter for Motor Drives Using Monolithic Bidirectional GaN Switches

Modern electric drives require high power density, efficiency, and reliability. This thesis covers the design, simulation, and experimental validation of a three-phase current-source inverter (CSI) utilizing innovative monolithic bidirectional GaN switches. By exploiting the properties of wide-bandgap (WBG) semiconductors, this architecture overcomes the historical limitations of CSIs related to the conduction losses of series-connected silicon diodes. The system eliminates the need for DC-link electrolytic capacitors and heavy output filters, delivering sinusoidal currents with controlled commutation transients, allowing the reduction of electromagnetic interference (EMI) and dv/dt stress on the motor. The workflow includes the analytical sizing of critical components, the development of a control strategy for current regulation and motor management and the implementation of a custom space vector modulation (SVM). Finally, the complete architecture is validated in MATLAB/Simulink and experimentally tested on a custom GaN-CSI prototype controlled via a dSPACE MicroLabBox platform.