Maximum Boost Control Method for Single-Phase Quasi-Switched-Boost and Quasi-Z-Source Inverters

Minh-Khai Nguyen, Youn-Ok Choi
2017 Energies  
The maximum boost control method for a single-phase switched-boost inverter (SBI) and single-phase Z-source inverter (ZSI) is proposed in this paper. In the proposed method, the low frequency voltage is added to the constant voltage for generating the variable shoot-through time intervals. For improving the AC output quality of the inverter, an active power switch is used to replace one of the diodes in the single-phase SBI. The operating principles and circuit analysis using the proposed
more » ... m boost control method for single-phase inverters are presented. Laboratory prototypes are built to verify the operation of the proposed pulse-width modulation (PWM) control method for both single-phase quasi-ZSI and single-phase quasi-SBI. Figure 1 shows the single-phase qZSI [11] [12] [13] . Compared to ZSI, qZSI improves the input current and reduces the capacitor voltage rating. Like ZSI/qZSIs, switched-boost inverters (SBIs) [20] [21] [22] [23] [24] [25] [26] also use the shoot-through time interval to achieve single-stage power conversion with buck-boost characteristics and improve reliability. In comparison with ZSIs, SBIs use one more active switch and fewer passive components [20] . Thus the size, weight, and cost of power inverters can be decreased. An SBI for standalone DC nanogrid applications is presented in [21] . In the basic SBI topology [22] , the input current is discontinuous and its boost factor is lower than that of ZSIs. Quasi-switched boost inverters (qSBIs) [23, 24] overcome the shortcomings of conventional SBIs by improving the profile of the input current and reducing the voltage stress of the capacitor. In [25] , the concept of a switched inductor is applied to the SBI topologies to improve the boost factor. Compared to conventional SBIs, switched-inductor boost inverters [25] add only three diodes and one inductor to produce a high step-up DC-link voltage. The active switched-capacitor/switched-inductor qZSIs presented in [26] are also based on switched-inductor boost inverter topologies [25] .
doi:10.3390/en10040553 fatcat:353gsd2j6fhntmvkmws7nizbiq