High performance Cuk converter considering non-linear inductors for photovoltaic system applications

The Cúk converter, which has voltage buck and boost ability, offers high flexibility as an interface device for solar panels. In addition, current ripple can be more reduced because of two input and output inductors at both sides. This paper presents a new application of current-variable inductors in a Cúk converter that reduces the size and capacity of storage elements. Because of two inductors in structure, implementation of these variable inductors is important; therefore, the proposed design leads to cost and size savings, increases the performance interval of tracker to gain solar energy at lower sunlight levels, and simplifies control strategy. To validate the effectiveness of this structure, the analytical analysis, simulation results using PSCAD/EMTDC software and experimental results are presented

A New Topology for Z-Source Inverter Based on Switched-Inductor and Boost Z-Source Inverter

In this paper, a new topology for boost Z-source inverterbased on switched-inductor cell is proposed. The operating modes of the proposed inverter are analyzed and also a suitable control method to generate the trigger signals of the inverter is presented. Having a common earth between the input source and inverter and capability to generate a higher voltage gain by using lower amounts of the duty cycles are some advantages of the proposed Z-source inverter. Comparison of the proposed inverter with conventional Z-source inverters is presented from different points of the view. Finally, the accuracy performance of the proposed inverter is reconfirmed through the simulation results in EMTDC/PSCAD software program

High voltage gain switched z‐source inverter with low current stress

Abstract This paper proposes a switched Z‐source inverter with high voltage gain and low current stress on elements. Also, a new switching method corresponding to the proposed topology is introduced. This method is based on the usual Maximum Constant Boost (MCB) method. Hence, it has the advantages of the MCB method, such as low voltage stress on the inverter switches and high voltage gain. Also, eliminating part of the inverter's switching in this modulation method improves the inverter's efficiency. In addition to the Shoot‐Through (ST) duty cycle, another variable (N) affects the inverter's boost factor in this switching method. The proposed inverter's dynamic analysis shows that introducing N in the modulation method improved the dynamic characteristic of the inverter. Also, this variable as a control input can stabilize the dc side of the inverter in the closed‐loop control of the inverter. For the proposed topology, steady‐state analysis, dynamic analysis, elements design and efficiency calculation are performed. Also, the proposed topology is compared with the conventional topologies regarding boost factor, the number of elements, current stress on elements and efficiency to show its superiority. Finally, the experimental results are presented to verify theoretical discussions

An Embedded Half-Bridge Γ-Z-Source Inverter with Reduced Voltage Stress on Capacitors

In this paper, an embedded half-bridge Z-source inverter based on gamma structure is proposed. In contrast with the classical half-bridge inverter, the proposed inverter can generate zero voltage levels in output. High voltage gain and low voltage stress on capacitors are the main advantages of the proposed converter. The value of the boost factor in the proposed structure is increased by changing both the shoot-through (ST) duty cycle and turns ratio of the transformer. The operating principle of the proposed converter in four operating modes is presented. We also calculate the critical inductance and compare the proposed converter with conventional topologies. In addition, power loss and THD analysis are presented. Finally, PSCAD/EMTDC software is used to verify the correct operation of the proposed inverter and the experimental results