MASCHINENFABRIK REINHAUSEN GMBH

An on-load tap-changer is for uninterrupted switchover between winding taps of a tap-changing transformer. The on-load tap-changer includes: fixed contacts being configured such that each of the fixed contacts is connectable to a winding tap of the tap-changing transformer; a first selector arm which is configured to selectively make contact with each of the fixed contacts; a second selector arm which is configured to selectively make contact with each of the fixed contacts; a load take-off lead; a first main current branch which connects the first selector arm to the load take-off lead via at least a first current-limiting element; a second main current branch which connects the second selector arm to the load take-off lead via at least a second current-limiting element; and a bridging circuit configured to selectively bridge the first current-limiting element and/or the second current-limiting element by at least one switching element.

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.

A bellows protector for a vacuum interrupter with an external bellows for low, medium or high voltages has a first region, which is configured tapered and to receive a moving contact rod such that the moving contact rod is guided out of the bellows protector from an inner side of the bellows protector onto a second side outside the bellows protector. The tapered first region of the bellows protector is configured to lie against the moving contact rod such that the moving contact rod is guided through the bellows protector. A second region adjoins the first region, the second region is enlarged relative to the first region such that the bellows to be protected is received in the second region. A holding region is configured to fasten the bellows protector on or to the vacuum interrupter such that the bellows protector forms a guide for the moving contact rod.

An item of electrical equipment comprises at least one tap winding having winding taps and at least one partial winding, and a tap changer for changing a transmission ratio, an impedance or a voltage, used for excitation of the item of electrical equipment. The tap changer comprises a first module for connecting the winding taps of the at least one winding tap to one another and a second module for rapid switching-in, switching-out or bypassing of the at least one partial winding. The second module comprises at least one submodule having semiconductor switching elements, and a bypass switch.

A method monitors at least one item of inductive equipment. The method includes: performing an operation of recording real-time data relating to a current condition of the at least one item of inductive equipment; performing an operation of transferring the recorded real-time data to a monitoring unit assigned to the at least one item of equipment; performing an operation of ascertaining a condition factor of the at least one item of inductive equipment based on the real-time data; performing an operation of ascertaining a failure rate for the at least one item of inductive equipment on the basis of the condition factor; and performing an operation of determining a maximum permitted hotspot temperature on the basis of the failure rate.

A switch unit for switching over an onload tap changer. The switch unit has an on-load tap changer with an actuating shaft that actuates a switch; and a drive system with a motor. The drive system is mechanically coupled to and configured to actuate the on-load tap changer. The drive system is configured such that, when the on-load tap changer is actuated, the drive system uses the actuating shaft as a store for kinetic energy in such a way that the actuating shaft is accelerated and the switch is actuated by the kinetic energy from the actuating shaft and additional energy provided by the motor.

A method for actuating an on-load tap-changer with a drive, a sensor and a control device is provided. The control device receives a switching command to actuate the on-load tap-changer. A starting time at which the switching command to actuate the on-load tap-changer was received in the current profile is determined. A temporal offset is added to the starting time to determine a time at which the actuation starts. A time of a next current zero crossing after the time at which the actuation starts is determined. A temporal difference between the time at which the actuation starts and the time of the next current zero crossing is determined. The temporal difference to the starting time in order to determine a new starting time for the actuation therefrom is determined and the actuation of the on-load tap-changer is started at the new starting time by the drive.

A method for adapting a target voltage value for voltage control of a tap-changing transformer by an on-load tap changer is provided. The method includes determining a reverse power flow on a low-voltage side of the tap-changing transformer by measuring a current and a voltage. The on-load tap changer is actuated from a current tap position n to a further tap position. A voltage of a current is measured in the further tap position. A value m is determined from powers of different tap positions, and the determined value m is used as a gradient for a first section of a straight line of the target voltage value.

An on-load tap-changer includes: a main path with a first connection; and an auxiliary path with a second connection. One module is configured be connected to each of the first and second connections.

A multi-level converter includes: a capacitor; a resistor; a first switch configured to be actuated by a first motor-drive unit; and a second switch configured to be actuated by a second motor-drive unit. The first switch, in a closed state, is configured to connect the capacitor to the resistor and to short-circuit the capacitor. The second switch, in a closed state, is configured to connect the capacitor to a ground potential.