Results obtained in monitoring transient electrical events from hydropower plants

Some electronic modules perform the monitoring and recording of electrical events in power plants. Such equipment is based on signals provided by transducers that measure the process parameters. For example, PC-08/104 Process Control is an equipment which performs monitoring and recording of specific parameters when transient electrical events occur, for the post-failure analysis and diagnosis. This programmable digital equipment is versatile and can be connected to an IBM compatible PC or process server. The results obtained in hydropower plants in Romania - where PC-08/104 equipment runs for more years - confirm its utility and robustness. The paper is focused on the results obtained in monitoring and recording more specific parameters of transient electrical events using PC-08/104 digital equipment in several hydropower plants. The analyzed results are based on the processing of analog and digital signal samples acquired at successive moments. Eight analog inputs and sixteen digital inputs are acquired. The analog inputs are the voltages of phases R, S and T, currents of phases R, S and T, homopolar voltage and the homopolar current. The main specific parameters to be monitored are the root mean square value and phase shift of each analog input, status of each digital input or logical functions associated, active and reactive powers, monitored electrical line impedances. The waveforms of all analog input signals, the status of each digital input signal and the phase diagram of the currents and voltages for the R, S, T phases are also displayed.