Communications satellite power conditioning systems

Power conditioning systems for each of the four INTELSAT series are reviewed. INTELSAT I through INTELSAT III satellites are currently in operation at synchronous orbit. The INTELSAT IV series is to be launched starting in 1971. Silicon solar cells are the prime source of power for all these satellites; Ni-Cd batteries are used to supply power during eclipse operation. Progressing from INTELSAT I through IV, different methods were used for battery charging, charge control, voltage regulation, and power management. The technical advantages and disadvantages of each of these methods are presented. Suggestions for future satellites include third electrode charge control with a current regulator for battery charging and a boost regulator for battery discharge.