| In recent years,with the continuous development of the aviation industry,the aircraft ground solid-static power supply has been widely used as an important power supply device for aviation aircraft stop at the platform and post-flight maintenance.This paper takes the large-capacity energy storage aircraft ground solid-static power supply as the research object,and conducts in-depth research on the storage battery charging and discharging system in the solid-static power supply.Firstly,aiming at the problem that the front-stage three-phase voltage source PWM rectifier will generate large inrush current during the start-up process,which leads to an increase in the selection margin of switching devices and a decrease in system stability and reliability,a pre-charge circuit is added to the front end of the rectifier circuit,the pre-charge circuit cooperates with the rectifier circuit for soft start.And,analyzed the working principle of the rectifier circuit,established its mathematical model,and analyzed in detail the cause of the inrush current when the rectifier started.Then,it comparative analysis the two methods for slow setting of bus voltage without pre-charging circuit and the two pre-charging circuit combined with the bus voltage slow setting method to suppress the starting inrush current,and then an optimal suppression method of pre-charge-segmented second-order parabolic bus voltage slow setting hybrid control is proposed.The four bus voltage slow setting methods were simulation comparison verification,and the results show that the rectifier with pre-charge-segmented second-order parabolic bus voltage slow setting hybrid control start can effectively suppress the inrush current,the grid-side current has start-up no overshoot,and the DC-side bus voltage has no overshoot.Secondly,aiming at the problem that the subsequent three-phase interleaved parallel bidirectional DC/DC converter is in working for a long time,which leads to the shortened working life of the switching device,a dynamic sleep control strategy is proposed.And,analyzed the working principle of the converter,established its mathematical model and switch life prediction model,on the basis of the traditional double closed loop control model,the current loop dynamic sleep control link is added to obtain the dynamic sleep double closed loop control model.Compared with the traditional double closed loop control model,all switching device of this model have realized dynamic sleep and the switching times under light load condition are only 1/3 of the traditional double closed loop control model,its working life is increased by about 200%.Under medium load condition,the number of switching times is 2/3 of that of the traditional double closed loop control model,its working life is increased by about 50%.Under heavy load condition,the switching times are the same as the traditional double closed loop control model.The model effectively prolong the working life of switching device and converter.Finally,in order to verify the correctness of the above theoretical analysis and the feasibility of the control strategy,a 30 k W/180 k W·h energy storage aircraft ground solid-static power supply experimental prototype was developed.The experimental results show that the grid-side current of the front-stage three-phase voltage source PWM rectifier that adopts the pre-charge-segmented second-order parabolic bus voltage slow setting hybrid control start has no overshoot phenomenon,the DC-side bus voltage has no overshoot,and effectively solve the problem of rectifier start-up overshoot.All switching devices of the subsequent three-phase interleaved parallel bidirectional DC/DC converter adopting dynamic sleep control realize dynamic sleep,which effectively prolong the working life of switching device and converter.At the same time,the stability and reliability of the storage battery charging and discharging system of the aircraft ground solid-state power supply are improved. |
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