A Control Strategy Of DC Converter Based On The Sliding Mode Control Ship's Micro-grid

Along with the depletion and environmental pollution problem of the traditional non-renewable energy is increasingly serious,the development of renewable energy has been paid more and more attention.In this context,the micro-grid technology using new energy power generation becomes the new development direction of the ship in future.Firstly,this paper discusses the research background and significances of micro power grid technology.then,the advantages and disadvantages of the common control strategies are described.The common working principle and the topological structure of the converter are also analyzed.On this basis,according to the energy conservation and the average model,the non-ideal mathematical model is established,and the controller is designed by the equivalent analysis method.Secondly,aiming at the problem that the dynamic response speed of traditional control strategy is slow and the law of constant velocity approach is serious,this paper puts forward a new reaching law control strategy.The method of discretization is compared with that of isokinetic reaching law in chattering and approach speed.At the same time,the mathematical model of third order was given,and the controller design process are analyzed in detail.Finally,Considering the problem that the ship micro-grid can not be distributed autonomously when a plurality of DC converters are operated in parallel,a kind of digital average current control strategy based on droop method is put forward.it is not only effective to multiple dc converter in parallel with reasonable power distribution,but also compensates for the problem of bus voltage drop caused by the droop control,guaranteeing the system stability and robustness.According to the above theory and the proposed control method,the simulation model of single and multiple dc converter system are established in Matlab/Simulink simulation platform.and the related simulation experiment are carried out under different operation conditions and conditions.The results prove that the proposed control strategy is effective.