Study on high efficiency power supply with wide input voltage for stratospheric airships

The stratospheric airships for telecommunication relay station and ground observations at 20km altitude has been widely used in recent years. Energy recycling system is one of key technologies for the stratospheric airship, which includes solar arrays, storage batteries and power control unit. Both of the battery charge regulator and the battery discharge regulator of power control unit are DC power converters. A small bus voltage ripple, wide input voltage, input and output current continuity, high efficiency, and the high power are the most desired characteristics for DC power converters used in stratospheric airships. This paper presents a newly developed DC power converter, which features with coupling the SuperBuck circuit and the Push-Pull circuits. The DC converter consists of a SuperBuck circuit, a Push-Pull circuit, and a closed-loop control circuit. Its main circuit topology connection is that the positive output of the SuperBuck circuit is connected to the positive input of the Push-Pull circuit directly, the positive output of SuperBuck is connected with the negative output of the Push-Pull circuit through a diode cathode, the negative output of the SuperBuck is connected with the negative input of the Push-Pull circuit, which is used as the negative output of the DC power converter. The positive output of the Push-Pull circuit is used as the positive output of the DC converter. It is experimentally verified that the designed new DC power converter circuit has many advantages which include a good voltage output property for the Push-Pull circuit, a high efficiency and a small current pulse for the SuperBuck circuit. The converter current is continuous and the Step-up mode and Step-down mode can be automatically switched. It also overcomes the low efficiency shortage of a pure Push-Pull circuit and realizes a high efficient output with a constant voltage and current.