An Interleaved High Gain Boost Converter And Its Extended Research

Environment-friendly new energy systems are playing an important role in the course of the world's energy transformation to diversification,cleanliness and low-carbon.Due to the low output voltage(18-36V)of new energy systems such as photovoltaic(PV)and fuel cell,it is difficult to meet the requirements of loads and grid-connected inverters for the input voltage level.Therefore,it is necessary to improve the voltage of DC converter with high efficiency and high boost ratio to meet the demand of voltage level in application scenarios.Additionally,the efficiency and life of new energy generation system are affected by the large input current ripple.Therefore,it has important theoretical significance and application value to study a novel interleaved high voltage gain boost converter with low input current ripple.Based on the study and summary of domestic and foreign scholars in the field of the interleaved high step-up boost converter,a dual inductors dual switches interleaved high voltage gain boost converter is proposed.The parallel structure of two-phase inductors on the input side has the function of reducing the current stress and conduction losses of the input inductors.By using interleaving control,the inductance currents of the two-phase can complement each other in the interleaving,and the ripple of the input current can be reduced.The introduction of the diode-capacitor voltage doubling unit improves the voltage gain and the voltage stress of the main switches are reduced simultaneously.The low on-state resistance and low voltage power MOSFETs can be selected to reduce the switching loss.In addition,the cross-coupling structure of the voltage doubling unit ensures the realization of the automatic voltage sharing function of the two-phase output voltage.The voltage gain is further increased and the output voltage ripple is reduced due to the structure of the two-phase output capacitors in series.The stability of the system is improved,the service life of the system is prolonged and the efficiency improved.Then,the technologies of coupled-inductor and switched-capacitor are introduced,and a dual coupled-inductors dual switches interleaved boost converter is proposed.The converter inherits the advantages of the proposed dual inductance converter and has a higher boost capability.In addition,the problem of reversed recovery of diodes is suppressed by the leakage inductor.The energy of the leakage inductors can be absorbed and recovered to the output side.In this paper,the working principles and steady-state characteristics of the proposed two interleaved converters are analyzed in detail,and the preliminary verification is carried out by using a simulation of MATLAB/Simulink.In addition,the small signal model of the system is established by the method of state space averaging,and the compensating controller is designed to study the stability and the performance about dynamic response of the system.Finally,experimental prototypes were built for the two converters to verify the correctness of the theoretical analysis,based on the TMS320F2812 and CCS3.3 experimental platform.