Abstract: A monitoring system for an electrical power transmission network or grid provides a recording network that can capture data on the response of the electrical power system over a wide geographical area to de-stabilizing electrical events. The captured data is obtained from multiple recording locations provided by individual recording units storing data on voltage and current on respective power transmission lines of the network. When an event is detected by one of the units, the central station interrogates the other units to obtain data based upon the same time as determined by a GPS clock at each unit and is thus automatically time-synchronized so that an overall coordinated snapshot of the power system dynamics is achieved. The wide-area capture is achieved through standard non-dedicated Internet, Intranet, and/or switched telephone network communication links.

Abstract: An apparatus for monitoring and controlling the operation of an electrical power transformer includes a processor with input transducers for providing to the processor inputs indicative of electrical current in a winding of the transformer and ambient temperature outside the transformer. The processor is arranged using an algorithm based upon heat transfer to repeatedly calculate a first prediction, based upon the present values of electrical current and ambient temperature, of a time period before the hot spot temperature exceeds a pre-set allowable maximum and a second prediction, based upon the current value of power, of a time period before the accumulated loss of life exceeds a pre-set allowable maximum. If the shorter time period of the two calculations is less than a pre-set value, for example one half hour, the processor generates an alarm signal and a display counting down the time remaining in the period, together with a second alarm signal at a shorter second time of for example one quarter hour.