Distribution automation smart remote terminal unit

摘要

An improved distribution automation remote terminal unit which directly connects to a distribution feeder. The distribution automation remote terminal unit of the present invention is directly connected to voltage and current sensors on the feeder to sense the presence of signals on the distribution feeder. The remote terminal unit includes the first transformer interconnected to the potential sensors to produce a potential signal of reduced peak-to-peak voltage corresponding in phase to the AC potential waveform on the distribution feeder. A second transformer is directly coupled to the current sensor for producing a current signal of reduced peak-to-peak voltage corresponding in phase to only the AC current waveform on the distribution feeder. The reduced peak- to-peak voltage signals are delivered into a multiplexer and are sampled a predetermined number of times. The sampled analog voltage is then digitized by a digital to analog converter and delivered into a digital signal processor. Waveform parameters are determined. A microcontroller then accesses the waveform parameters to determine information such as the operation of upstream and downstream devices on the distribution feeder. This information is selectively transmitted to a remote master station over a communications link.