Quasi‐Z‐source network DC–DC converter with different techniques to achieve a high voltage gain

Abstract

A new step-up DC-DC converter is presented, based on quasi-Z-source network intended for photovoltaic applications. The proposed converter combines voltage multiplier cells to the secondary winding of the coupled inductor which is included in the second inductor of the quasi-Z-source network. In the output of the quasi-Z-source network, a switched capacitor is connected. This converter shows attractive characteristics such as high voltage gain, low voltage stresses on their components, continuous input current. A detailed description of the operating principles of the proposed converter is presented and experimental results on a 250 W prototype show that a high efficiency above 91.4% can be achieved.

Multiport Isolated link with Current-Fed Z-Source Converters to Manage Power Imbalance in PV Applications

“…By solving (15) for I 2 , a voltage value for V 2 to transfer P 2 can be found. For more than two modules or windings, a similar analysis can be performed.…”

“…Current-fed topologies with boost operation also require additional start-up circuitry due to the current in inductors during starting process. The L-type converter is suitable to low voltage, high current applications [8,11].The Z-source inverter (ZSI) has been considered for DC-AC converters [14,15]; this topology has a buck-boost DC-AC capability in a single-stage which suggests an efficiency and reliability enhancement. The operation principle of the ZSI and current-fed topologies mentioned consist in apply a shoot-through state to overlap the H-bridge branches (0V) which provides natural protection against short-circuits, making it suitable for large-scale applications.…”

“…The Z-source inverter (ZSI) has been considered for DC-AC converters [14,15]; this topology has a buck-boost DC-AC capability in a single-stage which suggests an efficiency and reliability enhancement. The operation principle of the ZSI and current-fed topologies mentioned consist in apply a shoot-through state to overlap the H-bridge branches (0V) which provides natural protection against short-circuits, making it suitable for large-scale applications.…”

Novel non‐isolated high step‐up converter with fewer passive devices and low voltage stress of power switches

“…Thus, the higher voltage-rated switches are required with the larger conducted resistance, which further pulls down the conversion efficiency. Due to the higher boost factor, many Z-source and quasi-Z-source converters are proposed in recent years [19][20][21][22][23]. Though higher voltage gain can be achieved, more bulk passive components (inductors and capacitors) are applied in the circuit, which reduces the power density and reliability.…”

“…Moreover, the input current of Z-source converters is discontinuous, which is harmful to the life span of the power generation equipment. As another more universal solution, voltagemultiplier (VM) composed of coupled-inductors (CIs) and the diode-capacitor network is widely used in many converters [16,[18][19][20][21][22][23][24][25][26][27]. By substituting the filter inductor with VM designed on CI, the voltage on the filter inductor at different modes can be transferred to the capacitors of the VM, which can increase the output voltage significantly.…”