Z‐source inverter topologies with switched Z‐impedance networks: A review

Abstract

The Z‐source inverter is one of the most interesting power electronic converters. Over the past decades, research and development have been in high demand to meet the challenges for improving the converter performance with reduced weight and cost while having high efficiency along with high gain or boost factor. Since the inception, tons of resolutions, customizations, and improvements have appeared to achieve these performance goals. To overcome the most common drawback, i.e. the low boost factor of classical Z‐source inverters, the switched inductor/capacitor and switched boost Z‐source inverter topologies have become predominant in the recent epoch. Furthermore, the higher component voltage stress, discontinuous input current, and high inrush start‐up current issues have also been addressed and solved in various literature as part of this topical advancement. In this study, a comprehensive review of various switched impedance network‐based Z‐source inverter topologies has been accomplished for providing a quick report to researchers and engineers so that they can consider this as a one‐stop solution for selecting inverters from this group. The overall study covers the methodology, features, and relevant important results of the latest switched Z‐source inverter models in order to demonstrate the coordination between pitfalls and improvements.

Analysis of switched impedance source/quasi-impedance source DC-DC converters for photovoltaic system

“…The input diode D1 turns off during this time interval, and energy is transmitted from capacitors to inductors [19]- [22]. The stored energy is sent to the load in the inverter's next active switching states, and the input diode conducts.…”

Controlled Energy Flow in Z-Source Inverters

“…As a result of this modification, the new quasi-Z-source inverter (qZSI) structure is characterized by a continuous input current (CIC) which has improved the use of an impedance network in photovoltaic (PV) systems [4]. Various methods of improving impedance networks structures have been developed [5] and a suitable example is the switched inductor Z-source inverter (SLZSI) [6]. The benefit of using these improved converters is a higher boost factor of the input DC voltage than in the qZSI.…”

Parameter optimization design and performance analysis of filter‐integrated switched boost grid‐connected inverter

“…6 By introducing an impedance network into the circuit, the impedance source topology represented by the Z-source inverter (ZSI/qZSI) has been rapidly developed, and many experts and scholars have proposed other novel high-gain converters with better performance. 7,8 In addition to this problem, it is also necessary to pay attention to the high frequency harmonics caused by the switches. 9 Due to the clamping effect of the DC voltage source, the waveform of the output voltage of the H-bridge is rectangular wave, and its total harmonic distortion (THD) is very high.…”

“…Since the amplitude of ac output voltage is lower than the DC input voltage, it is necessary to connect a dc/dc converter for boost operation 6 . By introducing an impedance network into the circuit, the impedance source topology represented by the Z‐source inverter (ZSI/qZSI) has been rapidly developed, and many experts and scholars have proposed other novel high‐gain converters with better performance 7,8 . In addition to this problem, it is also necessary to pay attention to the high frequency harmonics caused by the switches 9 .…”