Analysis and simulation of switching phenomenon in electrical networks and reduction of its undesirable effects by using close resistance and switch

When an over head Transmission line is energized by closing the line circuit breaker, some transients states are generated in the electrical networks including the line and the supply network that can be dangerous , therefore, it would be of great importance to study the effects of the transient overvoltages. A traditional method for limiting switching overvoltages to acceptable levels is use of circuit breakers equipped with pre-insertion resistors. These resistors provide efficient limitation of the switching overvoltages. Therefore, they caused the circuit breakers more complex and un-reliable. Controlled switching of line circuit breakers using switchsync relay not need to pre-insertion resistors. The EMTP software is used to model an appropriate power system and various simulations are performed.