The Research Of Interleved Three Level Bidirectional DC/DC Converter With Coupled Inductor Of Energy Storage Interface

With the development of distributed generation and micro-grids, in the new energy power generation system, the power offen can not meet or exceed the need of the load because of the intermittent of power generation module,so the energy storage module is very important in this system.The power storage technology serves to cut peak and fill valley,regulate the power frenquency,improve the stability and raise the utalizition coefficient of the grid in the power system.The research of interface converter is very important to meet the requirement of energy storage system.Facing the high voltage and high power of distributed generation in DC mico-grids,the paper introduces interleaved three level bidirectional DC/DC converter,analysis the working principle and designs the coupled inductor,puts forward the strategy of soft switching. On the basis of this, the model of the interleaved three level bidirectional DC/DC converter based on the coupled inductor is carried out,and the transfer function of the converter is derived,and the design process of the regulator is given.According to the role of energy storage system in the distributed power generation,we should establish a sound energy management strategy based on how much power generated,and the need of load, and the state of battery to ensure the entire system running smoothly.First, the simulation proves the soft switching of converter based on the state of charge and discharge,then proposed energy management strategy, when the new energy power and dc load changes,the DC bus voltage can be stable because of the control of energy flow.Finally, according to the need of relevant control, designed a filter coupled inductor.The typical waveforms reflecting working principle of the converter are obtained.Verified the strategy of soft switching and the control of energy flow based on experimental platform,analyised the control strategy of charge mode and discharge mode.Then realized the soft switching of interface converter and reached the steady of DC bus voltage and make sure the current of charging and discharing in a smooth state, so the experimental verified the correctness and effectiveness of the theoretical.