Study of the equivalent model of a single-stage current source inverter with discharge path

The Single-Stage Current Source Inverter (SS-CSI) is a promising topology due to its reduced component count and higher efficiency compared to conventional CSI with a pre-stage. However, the SS-CSI works as a three-phase boost converter, exhibiting a limited speed range in motor drive applications. To address this limitation, the Single-Stage CSI with Discharge Path (SS-CSI-DP) incorporates a parallel path for the current. This paper presents an analysis of the SS-CSI-DP using an equivalent DC/DC model with a resistive load. The proposed model accurately replicates the input and output power, as well as the corresponding current characteristics of the original topology. Key aspects of the SS-CSI-DP, including the voltage gain in both Discontinuous Conduction Mode (DCM) and Continuous Conduction Mode (CCM) and the maximum achievable output voltage are examined.