Abstract:
The invention is related to a voltage control system (10, 70) for medium voltage applications, comprising the following components: a booster- (12, 76) and a feeder-(18, 78) transformer with respective primary and secondary winding, wherein the secondary winding (22) of the feeder transformer (18, 78) is electrically connected with the primary winding (14) of the booster transformer (12, 76) in an intermediate circuit (50), wherein at least one of the transformer windings (14, 22) in the intermediate circuit (50) comprises at least two taps (24), wherefrom one is selectable as active tap, wherein electrically adjacent taps (24) are assigned to different groups (26, 28). The system is comprising further respective contactor switches (20, 32, 34, 36, 38, 40) which are associated to each of the taps (24) which are selectively switchable into the intermediate circuit (50) therewith, wherein not more than one contactor switch (20, 32, 34, 36, 38, 40) of a group (26, 28) is switchable at the same time, respective commutation resistors (42, 44) in electrical series connection with the taps (24) of each group (26, 28). The system is comprising further a common cabinet (56, 72) wherein the aforementioned components are arranged in and connection means (52, 54, 88) in order to connect the secondary winding (16) of the booster transformer (12, 76) with an electrical energy supply network in that way, that the secondary winding (16) of the booster transformer (12, 76) is in series with a transmission line that's voltage is to be controlled.