Research On Interleaved High Gain DC/DC Converter With Coupled Inductors

With the continuous improvement of photovoltaic,wind power,fuel cell and other clean energy power generation technologies,the performance requirements of DC/DC converter in high gain,low input current ripple and other aspects are gradually increasing.Due to the limit duty cycle problem of traditional boost converters,the output voltage gain is limited,and it is not suitable for direct application in high boost places.Therefore,how to design a DC/DC converter with superior performance,high gain and low input current ripple,has become a hot research direction in recent years.This paper summarizes the research on related boost technologies,bases on the coupled inductor and the interleaved parallel structure,analyzes the problem of releasing energy from the leakage inductance of the coupled inductors.From different perspectives,two DC/DC converters with high gain and low input current ripple are designed.The main research contents of this paper are as follows:(1)The traditional boost converter is not suitable for photovoltaic and fuel cell power generation systems with high gain requirements due to its insufficient boost capacity and discontinuous input current.This paper takes into account the two issues of boost and low input current ripple.Combining the interleaved parallel structure,coupled inductor boost technology and switched capacitor boost technology,a Interleaved High Gain DC/DC Converter with Triple Capacitor-Diodes and Coupled Inductors is proposed,which has high voltage gain,low input current ripple and low voltage stress.The converter is simple in structure and convenient for topology.In this paper,the working mode and steady-state characteristics of the converter are analyzed in detail and verified by simulation and experiment.(2)In order to further enhance the boost potential of the circuit,a cross-voltage doubling structure with coupled inductors and switched capacitors in series is designed by combining two types of voltage doubling units.The structure uses less electrical components and can increase the voltage gain by(3n+1)times;its coupled inductors and capacitors are connected in series to reduce current spikes when switched capacitors are switched off.Based on this,a Overlapping Voltage Multiplication High Gain Boost Converter is proposed.This paper analyzes the voltage spike problem of the switching tube generated by the converter.Aiming at this problem,a clamp capacitor is designed to limit the voltage of the switch tube and release the leakage inductance energy.At the same time,the constructed clamp channel makes the clamp capacitor a part of the output voltage,which effectively improves the voltage gain.This paper analyzes the working mode and steady-state characteristics of the converter,and compares it with the related literature in recent years,and theoretically illustrates the advantages of the converter in terms of voltage gain,switch voltage stress and input current ripple.Finally,simulation and experiments are carried out to verify the feasibility and technological advancement of the converter.