Metering and signalling to low voltage consumers

The authors present the main application of an electronic watthour meter based on a custom IC and a centralised telecontrol system that is now being investigated. It consists of the implementation of a system for centralized meter reading in buildings. With respect to the centralized telecontrol system, its architecture, based on a radio link and a ripple control like link is presented. Tests with an FM SCA subcarrier and some experiments concerning the choice of the frequencies and the method of injection of the telecontrol signals into the low voltage distribution network are also presented. The authors present some experiments performed with AM broadcast stations as well as the hardware developed and the tests performed, in the field, for the system´s ripple control link. Some comments on the model developed to perform computer simulations of the propagation of signals through the low voltage distribution network are also presented