Power system security by Corrective Switching

Limit violations may occur by power systems operation, such as: voltage level at buses, loadings of transmission lines and power transformers, etc.. If violations are detected in the supervision process, corrective measures may be carried out in order to eliminate them or to reduce their intensity. Loading shedding is an extreme solution and should only be adopted as the last control action. It is possible to control constraints in electrical systems by changing the network topology, using a technique named Corrective Switching, which requires no additional costs. The main problem of finding a switching variant to eliminate overloads in transmission links is the large number of switching variants to be analyzed. This paper presents firstly a methodology based on Relief Functions to estimate currents in overloaded branches by means of few calculations. At last, results obtained by simulation in a real network will be presented.