Planning against voltage collapse

Summary

Several systems have experienced voltage collapse, and the Task Force's questionnaire indicates a need for a widely accepted procedure for dealing with the voltage collapse problem in system planning. The object of this report is to present a procedure and to establish guidelines for the use of system planners in order to prevent voltage collapse.

The report contains an explanation of the voltage collapse problem, and how it is influenced by transmission system charac­teristics, the steady-state and the dynamic behaviour of the Joad, as well as the overall system control. Experiences from actual system disturbances are examinated together with conclusions from the questionnaire. Prefault conditions are discussed, and it is suggested that the use of n-2 security in reactive planning could be justified in order to obtain a probability of failure due to voltage collapse consistent with normal practice regarding transient stabi­lity. A planning procedure based on a normal load-flow program is established, and practical guidelines for planners are drawn up. This procedure is much faster thon procedures based on dynamic calculations. Finally an example to illustrate the method is given.

Additional informations

Keywords

system technical performance