Feasability problems in transferring large reactive power over the large distances

In this paper an attempt is made to formulate potential problems in the operation of large electric power systems under the changing strategies currently taking place. The system operates at the conditions for which it was not originally designed and the control actions are needed to compensate for this factor. If the normal operating conditions are such that large reactive power is transferred over the large distances, any unplanned event (line, generator, load outage) could lead the system to severe voltage problems. Control means for preventing this from happening are illustrated on two system examples.