Research On Magnetics Integrated Interleaved DC-DC Power Module

With the development in medical communication, aerospace technology, and electronic information in recent years, light weight, small size, high efficiency switching power converter is more and more frequently mentioned. To meet these needs, researchers should not rigidly focus on topology, control strategy and switching devices. Due to the big proportion magnetic devices take in whole converter volume, which is almost 30%, technologies related to magnetics volume decrease is what this thesis going to talk about.Super Boost is chosen as the main topology in this thesis from several common topologies used for BDR in aerospace due to its general advantages, such as high efficiency, high power density and continuous current at the input and output ends. Ripple cancellation network at the input port is introduced and the inductance within it is derived. Then all parameters needed for single module is calculated, components are specified moreover.In order to increase the power capacity and improve the performace of this kind power converter, interleaving technology, a normal method to decrease current ripple at both the input and output ends, is adopted. Meanwhile, using integrated magnetics to replace discrete magnetics can decrease the volume and weight of whole converter, also the power loss i n magnetic cores, therefore increase its power density and efficiency, which are very important to aerospace power module.The small-signal model of sigle power module is established with the state space average method, calculation results of Matlab show that the dynamic characterization is similar to that of conventional Boost but more complicate. Through the decoupling of fast and slow subsystems method, an equivalent second-order system is obtained. Then replace the original model with this simplified one and apply average current mode control, the close lo op control strategy is obtained. Finally a new phase-shifted driving circuit for interleaving is designed.Finally, two 500 W Super Boost with RCN converters are interleaved with integrated magnetics to verify the operation principle. Test and analyze the waveforms of the main topology, and the efficiency curve. Experimental results show that the introduction of integrated magnetics can reduce the volume of the magnetics, also the interleaving method contributes a lot to improving the converter’s performance.