Research On The High Voltage Gain Y Source Inverter With The Capacity Of Suppressing Effects Of Leakage Inductances

With the rapid development of human society,the global energy crisis and environmental pollution problems are becoming more and more serious.Distributed generation based on solar energy,wind energy and fuel cell has been recognized as a reliable way of generating electricity to meet future energy needs.As an example of solar energy distributed generation,the output of the photovoltaic array is a large fluctuation of DC.Therefore,it is usually necessary to connect the inverter with high voltage gain between the photovoltaic array and the distributed grid.However,traditional inverters are generally faced with the problems of limited voltage gain,large distortion of output waveforms and large EMI.In this paper,a high voltage gain Y-source inverter with the capacity of suppressing effects of leakage inductances is studied,which includes the following aspects:After analyzing the Y-source inverter in depth,the extended quasi-Y-source inverter is proposed to solve the problems of discontinuous input current and large starting current inrush.In addition,the topology reduces the size of the magnetic core required and has a certain suppressing effects of leakage inductances of the coupled inductor.Compared with the Y-source inverter,the loss of the shoot-through ratio and the DC bus voltage peak is smaller.In order to further control the extended quasi-Y-source inverter proposed in this paper,small signal analysis is carried out.A small signal model of extended quasi-Y-source inverter under LC filter is established under the condition of the shoot-through ratio d and modulation ration m.It helps designers to select the size of passive components and understand the limit of the system.Combined with the extended quasi-Y-source inverter,an extended quasi-Y-source inverter with peak voltage suppression is proposed.The topology can effectively eliminate DC bus voltage spikes without increasing a dditional switches and losses.In addition,the absorption circuit can also be applied to other impedance source inverters with coupled inductors.Finally,the experimental platform is designed and built,and the extended quasi-Y-source inverter and the extended quasi-Y-source inverter with peak voltage suppression are experimentally verified.The feasibility and superiority of the two topologies are confirmed.