双Buck半桥逆变器输入电容电压脉动的分析

双Buck逆变器(DBI)是航空静止变流器(ASIs)的常用拓扑,从双Buck半桥逆变器(DBHBIs)两直流电感中分离出交流电感使得体积、重量进一步减小。在正常工作,尤其是负载短路情况下,双Buck半桥逆变器输入侧电容上的电压产生与输出同频的脉动。以交流电感分立的双Buck半桥逆变器为例,分析了在额定负载、短路、级联工作等情况下输入电容电压脉动的产生原因,给出了该脉动的定量计算方法,并由此得出了输入侧电容容值的选择依据。最后通过仿真和实验,验证了文中分析的正确性。该分析方法同样适用于其他半桥型逆变器拓扑。

Analysis of voltage ripple on input capacitors in dual-buck half bridge inverters

Dual-buck inverter (DBI) is one of the widely adopted topologies in aeronautical static inverters (ASIs).With discrete AC filter inductor,the volume and weight of dual buck-half bridge inverters (DBHBIs) are further reduced.However,there will be voltage ripple on input capacitors when a dual-buck half bridge inverter is normally operated,especially when the load is shorted,and the ripple is at the same frequency as the output voltage.In this paper,a DBHBI with discrete AC filter inductor is taken as an example,which operates on the conditions of nominal load,short circuit and cascade.The cause for voltage ripple on input capacitors is analyzed,and the mathematical calculation method and the guidelines for capacitor design is proposed.The analysis is verified by the results of simulations and experiments.The method in this paper can be also applied to other half bridge inverters.