A DC Power Supply System for Small Telecommunication Stations

This paper describes a DC power supply consisting of a number of parallel operating charging rectifier units operating on a common battery bank. This system is developed for and in cooperation with The Norwegian Telecommunications Administration. A control system takes care of the load sharing independant of the number of charging rectifier units in parallel. A monitoring system can take care of units out of tolerance. Units can be connected to provide a minimum of harmonic distortion back on the power sources, and thus be attractive on places with weak mains power supply. In telecommunication stations the power consumption totally needed has an increasing trend. Stations with a certain importance are equipped with diesel generator sets for emergency supply to the battery chargers. A simple current limiting system is able to reduce the power consumption from the chargers when supplied from small generator sets. The system can reduce the need of peak power without reducing the redundancy mostly built into the battery charger systems. Efficiency curves for different operation modes of parallel operating units will be shown.