Method and apparatus for improving AC transmission system dispatchability, system stability, and power flow controllability using DC transmission system

摘要

An electric power transmission system that isolates a local AC transmission network from a surrounding AC system includes a local AC load center having a plurality of local AC loads, and a distribution feeder serving the plurality of local AC loads and at least one distant electric power generating station or other power source for supplying AC power to the local AC load center. A complete or partial DC transmission ring is interposed between the local AC load center and the distant electric power generating station for isolating the AC power received from the distant electric power generating station from the local AC load center by converting the AC power to DC power. The DC power is re-converted into AC power based on load requirements and the distribution feeder supplies the AC power while all local AC loads are isolated from the distant electric power generating station.