Extended switched-inductor quasi-Z-source inverter: Modeling and prototype realization

Abstract

Summary The Z‐source network idea has opened up a new research area in the power electronics field. In this paper, a new switched‐inductor network, called extended switched‐inductor quasi‐Z‐source inverter (ESL‐qZSI), is proposed. From a topological point of view, the new inverter has an additional inductor and three diodes compared with the switched‐inductor quasi‐Z‐source inverter (SL‐qZSI). The suggested inverter has a DC source ground point, continuous input current, and no start‐up inrush current. This proposed inverter compared with SL‐qZSI in the two investigated scenarios. Scenario 1: the proposed inverter has lesser capacitor voltage stress at the voltage conversion ratio than the voltage stress of SL‐qZSI, which results in lower DC‐link voltage. Scenario 2: the proposed inverter has higher voltage gain with respect to the SL‐qZSI, at the same input source and modulation index. Simulations are carried out using MATLAB/Simulink and compared with experimental ones, to show the validity and effectiveness of the proposed inverter. In order to estimate the losses and efficiency, calculations of power losses and efficiency of the ESL‐qZSI and SL‐ZSI are presented. Simulation and experimental results verify the effectiveness of the proposed inverter.

Analysis and Control of Current Ripples of Z-Source Inverters

“…By shifting between shoot-through and non-shoot-through states, capacitors and inductors are charged or discharged to boost the DC-link voltage. Since the ZSI was first proposed in 2003, new topologies, PWM strategies, and design parameters of Z-source networks have been extensively investigated [5]- [9]. However, the load current ripple of ZSIs has not been theoretically analyzed.…”

A new single‐stage continuous input current‐based high gain boost inverter: Analysis and implementation

“…Several single-stage boost inverter topologies including switched boost and Z-source based structures are recently reported in literature. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The conventional ZSI (CZSI) is utilized for many applications such as photovoltaic systems, uninterruptible power supply (UPSs), and micro-grid for its voltage boosting capability. 2,3 However, it has several drawbacks such as discontinuous source current and the higher number of passive (or LC) elements.…”

“…The ZSIs can step up the voltage level by making use of this ST interval. Several single‐stage boost inverter topologies including switched boost and Z‐source based structures are recently reported in literature 3–18 …”

Modulation Techniques for a Modified Three-Phase Quasi-Switched Boost Inverter With Common-Mode Voltage Reduction

“…In order to prevent the shortcircuiting of the DC-link bus, a deadtime must be used in the H-bridge inverter, which inevitably increases the THD value at the output side. In recent years, single-stage Z-source and quasi-Z-source power inverters (ZS/qZSIs) [7]- [10] with buck/ boost characteristic have been introduced with some advantages in PV applications. Because of the continuous input current and lower voltage stresses across capacitors, the qZSIs have been used widely in distributed generation systems [8]- [10].…”

“…In recent years, single-stage Z-source and quasi-Z-source power inverters (ZS/qZSIs) [7]- [10] with buck/ boost characteristic have been introduced with some advantages in PV applications. Because of the continuous input current and lower voltage stresses across capacitors, the qZSIs have been used widely in distributed generation systems [8]- [10]. However, the size and weight of qZSIs are still large because of using two qZS-inductors and two qZS-capacitors in the Z-source network.…”