Photovoltaic-hybrid power supply for radio network components

Repeaters are digital radio signal amplifiers, which increase the connection reliability of mobile telephones within radio cells and raise the accessibility level throughout the network. In rural areas and in mountainous regions, repeaters often have to be installed and operated at sites remote from the public electricity grid. The photovoltaic hybrid system consists of two solar generator arrays of different size, with a total power of 1100 W. The battery has a capacity of 480 Ah/12 V. The typical power drawn by a solar mobile telephone repeater is simulated by a permanent load of 50 W in the experimental system. A modified thermoelectric generator from the Canadian company, Global Thermoelectric, model 5120 (120 W), is used as the auxiliary generator. A micro-controlled energy management system (EMS), newly developed at Fraunhofer ISE, ensures fully automatic operation with minimal consumption of fossil fuel and appropriate battery operation management.