A High-Performance Z-Source Inverter Operating with Small Inductor at Wide-Range Load

This paper presents a high-performance Z-source inverter is proposed in this paper, which can overcome limitations of traditional Z-source inverter. The proposed Z-source inverter can operate at wide range load (even no-load) with small inductor, eliminate the possibility of the dc-link voltage drops, and simplify the inductor and controller design. The operation modes, voltage relationship of the proposed Z-source inverter, and control strategy for switch SW7 has been described in detail. Finally, experimental results verified the validity of the proposed high-performance Z-source inverter.

I. Introduction

The recently proposed Z-source inverter intentionally utilizes the shoot-through zero states to boost dc voltage and produce an output voltage greater than the original dc voltage [1]. At the same time, the Z-source inverter enhances the reliability of the inverter bridge because of the special Z-source network, with which the shoot-through can be the operating states. Fig. 1 shows the main circuit configuration of the Z-source inverter, where a unique Z-network is coupled between the load and dc source. The Z-network is implemented by a split-inductor ( and ) and capacitors ( and ) connected in X shape. The operating principle has been described in detail in [1]. The operation modes and characteristics of the Z-source inverter with small inductance have been proposed in [2].