500VA航空静止变流器研制.pdf

500VA航空静止变流器的研制IIABSTRACT The two-stage low power three-phase Aeronautical Static Inverter (ASI) is researched in this thesis. With the purpose to improve overall efficiency and realize low profile, the LLC resonant converter which has the characteristic of simple and high efficiency is employ as the front-end and the dual buck inverter which has the merits of high efficiency and high reliability is selected as the second stage, after taking prehensive investigation of different topologies and constructs. The characteristics of several resonant converters are briefly introduced and the operation principles and characteristics of LLC resonant converter are analyzed. On presenting the methods of calculating the resonant parameters of the LLC resonant converter, a prototype of 500W half bridge LLC resonant converter is designed. Experimental results show that this circuit has a high efficiency in terms of zero-voltage turn-on of the main switches and zero-current turn-off of the secondary rectifier diodes are realized from no load to full load. Compared with conventional half-bridge inverter, the dual buck inverter (DBI) es the short-through problem, which greatly improves the overall reliability. Besides, the power switches and the power doides can be chosen separately and optimized designed, which results in higher overall efficiency. Based on the introduction of Dual-Buck Inverter, this thesis studies the relationship between operating frequency of switching tube and the circuit’s input voltage, filter inductance and current hysteresis bandwidth. Then, a method of improving the inverter’s reliability in short-circuit protection mode is proposed, and simulation and experimental results verify its feasibility. With the purpose to e the drawback that the two filter inductors share a large proportion of the weight and volume of the inverter, integrated ism technology is researched. Several ics integrated techniques are introduced, and a new method is offered by this p