Diode-Assisted Buck-Boost Current Source Inverters

This paper presents a couple of novel current source inverters (CSIs) with the enhanced current buck- boost capability. With the unique diode-inductor network added between current source inverter circuitry and current boost elements, the proposed buck-boost current source inverters demonstrate a double current boost capability when comparing with the recently reported buck- boost CSIs. For modulating the presented CSIs, two modulation schemes are proposed for achieving either optimized harmonic performance or minimal commutation count, meanwhile keeping the important current buck-boost operation uninfluenced. Lastly, all theoretical findings were verified experimentally using constructed laboratory prototypes.