회생모드가 없는 단일전원 27레벨 캐스케이드 H-브리지 인버터

A Pre-Regulated Single-Sourced 27-level ACHB Inverter without Regeneration

In this paper, a single-sourced PV PCS using the trinary asymmetric MLI with a single-ended pre-regulator is proposed. Trinary based asymmetric CHB inverters provide higher output levels for the same number of cells compared to other CHB inverters. However, there is an issue of regeneration with trinary asymmetric inverters and this complicates the system with requirement of bi-directional converters at the input. Modified commutation strategies have been used to remove the regeneration issue with compromise in THD. The single-ended pre-regulator provides the isolated dc-link voltage for the individual H-bridge cells with the advantage of having a single switch and magnetic component. This implementation increases the magnetic utilization of the inductor core and reduces the switching loss in the pre-regulator and also the reduced parts count contributes to the cost competiveness of the proposed PCS. The proposed PV PCS has been verified using simulation results in this paper.