Study on high power density electrical power system of satellites

Abstract

This dissertation proposes a new control method for solar array regulator (SAR) and a new converter integrating two bus voltage regulators for a satellite's high power density electrical power system. The new control method of SAR proposed in the first study is a direct energy transfer (DET) control that directly charges the battery from the solar array by keeping the buck converter switch of the SAR in the 'ON' state without switching operation. The proposed DET control reduces the conduction loss by eliminating the switching loss and reducing the peak value of the battery charging current. In addition, SAR's conventional controller, maximum power point tracking (MPPT) analog controller and three sensing inductors were removed, and the main inductors were redesigned to be smaller and lighter to reduce weight, volume, and cost. The new converter proposed in the second study is a converter that reduces the number of semiconductor devices by two by integrating a conventional buck converter and a two-switch forward converter. The proposed converter reduced the number of semiconductor devices to reduce weight, volume, and cost. Additionally, zero voltage switching (ZVS) of the switch is achieved to eliminate switching losses. As a result, the proposed DET control method and converter have the advantage of increasing power density in the satellite's electrical power systems.