Interleaved High Step-up DC-DC Converter with Diode-Capacitor Multiplier Cell and Ripple-Free Input Current

In this paper interleaving and switched-capacitor techniques are used to introduce a high step-up DC-DC converter for renewable energy systems application. The proposed converter delivers high voltage gain without utilizing transformer or excessive duty cycle and features ripple-free input current which results in lower conduction losses and decreased electromagnetic interference (EMI). Lower output capacitance is another advantage of proposed converter, leading to smaller size and lower cost. Furthermore lower voltage stress on switches allows the utilization of switches with low resistance. Simulation results verify the performance of suggested converter

Interleaved High Step-up DC-DC Converter with Diode-Capacitor Multiplier Cell and Ripple-Free Input Current

In this paper interleaving and switched-capacitor techniques are used to introduce a high step-up DC-DC converter for renewable energy systems application. The proposed converter delivers high voltage gain without utilizing transformer or excessive duty cycle and features ripple-free input current which results in lower conduction losses and decreased electromagnetic interference (EMI). Lower output capacitance is another advantage of proposed converter, leading to smaller size and lower cost. Furthermore lower voltage stress on switches allows the utilization of switches with low resistance. Simulation results verify the performance of suggested converter

Variable structure modeling and design of switched-capacitor converters

Switched-capacitor (SC) converters are a type of variable structure systems. The conventional approach of maintaining regulation in these converters is a feedback control developed from linear systems theory, and it is based on the approximate small-signal linearized models of these circuits. However, the simplicity of such an approach sacrifices performance (poor transient response and sometimes steady-state instability are the result of a design based on the use of an approximate linearization) for convenience and cost. This paper discusses the (SC) converters from the viewpoint of nonlinear systems, and based on this, takes a variable structure feedback approach. The (SC) circuits theory is revisited, and a new approach of modeling, which gives an accurate nonlinear description of their operation is discussed. Based on the principle of energy balance applied to the output filter capacitor, an exact relationship between the instantaneous output and input currents in the charging and discharging phases is derived, leading to the derivation of a unique large-signal dynamic model for both alternative operating phases. Together with a defined switching function, it forms the proposed variable structure model. The resulting solution shows that a nonlinear approach can deliver an improved performance in the dynamic and steady-state behavior. Experimental results performed on a two-phase (SC) converter verify the theory. © 2009 IEEE.link_to_subscribed_fulltex