| Abstract |
The actual knowledge on digital electronic technology allows the realization of devices that have performances these can allow the inclusive management of complex and large systems, as an electric distribution or transport network at various levels of voltage. The present paper considers the project of a measurement system that is found on elaboration, trough microprocessor, of signals these are proportional at the electrical greatness voltage, current and phase, to obtain values of the active and reactive power and the corresponding values of the energy at the aim of the technical and commercial management of the electric power system. The designed device allows to calculate instantaneous values of active and reactive electric power and to integrate them by means of right software registered in a EPROM who are as well memorized also source users and contractual conditions codes and ethers subroutines that can manage suitable data which identify the state of network object of management. Obtained values are utilized to bring up to date to a EEPROM, with a cycle suitably, picked out from designer, that gives the digital data at a visualization system and, if occur, at a possible transmission system. That transmission can be start trough suitable codified signals that can get to device trough metallic or optic support or trough radio-link system. The possibility to utilize the same electric distribution network as support for the transmission of the signals that manage the device and at same time for the data generated of the same device, presents great technical and economical interest. The control apparatus of the system is a 8 bit NMOS microprocessor, that processes digital signals which are picked up from the network trough an input-output interface. Results are accumulated in a RAM to be transferred with cyclical procedure in the EEPROM. The measurement described system allows also to manage the users from the commercial point of view, computing the absorbed active and reactive electric power also in function of various contractual conditions (seasonal or time rates, etc.) and transmitting the data at the centres of commercial affairs. Trough appropriate interface it is possible to operate appropriate devices for activate or inactivate the users or for change limits of allowed absorbed electric power of users. |
