Abstract: A switch assembly has an on-load tap changer and a drive system for the on-load tap changer. The drive system has: a stepper motor having a motor shaft, the motor shaft being connected to and configured to actuate the on-load tap changer; a feedback system, which is configured: to determine at least one value for a position of the motor shaft; and to generate a feedback signal based on the at least one value; and a control device, which is configured to influence the operation of the switch assembly depending on the feedback signal.

Abstract: A switch unit is for a step transformer. The switch unit has: ]a controller; a motor; and an on-load tap-changer. The controller controls the motor, which actuates the on-load tap-changer. The controller draws energy, required for actuating and controlling the motor, directly from a low voltage winding of the step transformer.

Abstract: An on-load tap-changer switches, without interruption, between winding taps of a tapped transformer. The on-load tap-changer includes fixed contacts, which include a first fixed contact, which is configured to connect to a first winding tap of the tapped transformer; and a second fixed contact, which is configured to connect to a second winding tap of the tapped transformer. The on-load tap-changer also includes a first selector arm, which is configured such that it can contact each of the fixed contacts; a second selector arm, which is configured such that it can contact each of the fixed contacts; and a diverter switch configured to perform a switch from the first fixed contact to the second fixed contact of the on-load tap-changer; a connection contact arranged additionally to the fixed contacts; and an auxiliary contact, which configured to selectively contact the connection contact or one of the fixed contacts.

Abstract: An operational setting of an on-load tap changer used to switch between various winding taps of a tapped transformer is determined by first placing the on-load tap changer in operation with the tapped transformer and then moving the changer in a first rotational direction through a regulating range of its stationary operational settings on different winding taps of the tapped transformer toward an end abutment of the tapped transformer. The position is registered on reaching the end abutment of the regulating range of the on-load tap changer, and then the movement is reversed to return to the first stationary operational setting that is then configured as a predefined operational setting with the help of the parameterization that is stored in a nonvolatile memory of the control device.

Abstract: The invention relates to a method for monitoring an on-load tap changer that is used to switch between winding taps of a tapped transformer without interrupting the load current and is actuated using a motor drive. According to the invention, prior to the actual load switching process, the on-load tap changer is initially moved a short distance, preferably against the direction in which the load is subsequently switched. In said initial process, it is verified whether the on-load tap changer has moved, i.e. has left its previous stationary position, and/or whether the torque on the motor drive has exceeded a predefined threshold value. The actual load switching process takes place only once the test has yielded a positive result.

Abstract: The invention relates to a method for averaging the voltage in an on-load tap changer used to switch between various winding taps of a tapped transformer. The general inventive concept consists in reaching a predefined operating position of the on-load tap changer by having a parameterized control device activate a motor drive in a first rotational direction once the on-load tap changer has been turned on, such that the on-load tap changer starts running through its stationary operating positions, i.e.

Abstract: The invention relates to a method for monitoring an on-load tap changer that is used to switch between winding taps of a tapped transformer without interrupting the load current and is actuated using a motor drive. According to the invention, prior to the actual load switching process, the on-load tap changer is initially moved a short distance, preferably against the direction in which the load is subsequently switched. In said initial process, it is verified whether the on-load tap changer has moved, i.e. has left its previous stationary position, and/or whether the torque on the motor drive has exceeded a predefined threshold value. The actual load switching process takes place only once the test has yielded a positive result.