Research On Topological Deduction Of High Gain Converter Based On Programmable Search Method

Renewable energy power generation is an important method to deal with future energy crisis and environmental pollution problems.The microgrids have developed rapidly in recent years because its can absorb renewable energy.Due to the output voltage of fuel cells and photovoltaic is low and wide,the high-gain DC converter is required as an energy conversion interface in the microgrid.How to obtain a high-gain converter suitable for fuel cell power generation system through topology deduction is a research highlight.Firstly,this paper analyzes the advantages and disadvantages of the existing six high-gain converter topology deduction methods,and proposes a programmable topology search algorithm.The construction of non-isomorphic graphs,full loop search algorithm,and the electrical constraints for viable topologies selecting are proposed and established further.On the one hand,the proposed algorithm can search all the viable topologies under the condition of a certain number of devices,which reduces the randomness of the exiting topology deduction methods.On the other hand,the proposed algorithm can greatly reduce the tedious work of the designer's topology derivation and improve the topology design efficiency.Secondly,based on the results of the programmable topology search algorithm,this paper proposes a topology deduction method of the output capacitor series high-gain converter,and deduces the 3L output capacitor series high voltage gain converter according to the topology deduction rules.The voltage gain of the proposed converter is 4 times Boost converter,while the voltage stress of the converter's switches are 1/4 times the output voltage.What's more,the input current ripple of proposed converter is 1/3 times that of the Boost converter.Hence,the proposed converter is suitable for fuel cell power generation systems.Finally,a simulation platform for the programmable high-gain DC-DC converters topology deduction method based on graph theory is built.The simulation results show the effectiveness and feasibility of the proposed topology deduction method.In addition,a 3L output capacitor series high-gain converter test platform with 30 V ? 480 V / 400 V 240W was built.The experimental results verified that the converter has the characteristics of high voltage gain,low device stress,and low input current ripple,which means it's suitable for fuel cell and photovoltaic cell power generation systems.