Siemens Aktiengesellschaft

Stefan Zitzler

Dirk Hertz

Johann Seitz

Marco Schönenberg

Markus Meier

Diethard Runggaldier

Norbert Reichenbach

Klaus Aufschneider

Kyoung-Jin Lee-Hoff

Helene Steuer

Marco Schonenberg

Marco SCHÖNENBERG

The invention relates to a soft starter () for connecting at least one main circuit (), each of which includes a bypass circuit () having a semiconductor switch (). Said soft starter () comprises a control unit () for actuating the bypass circuit (), and the control unit () is equipped with a control signal input (). According to the invention, the control unit () has a separate safety signal input ().

Soft starter, operating method, and switching system

An embodiment relates to a switchgear for a single-phase motor and a three-phase motor, the switchgear including a processing unit and a first, second and third current path, the first and third current path each including a current transformer. The processing unit is adapted to detect the current Iof the first current path and the current Iof the third current path. To provide a cost-effective switchgear for a one-phase motor and a three-phase motor which is adapted to identify the failure of every single phase in the three-phase operation and a phase failure in the one-phase operation, the processing unit is designed such as to detect the currents I, Iof the first and third current path and to determine, based on the phase shift between the detected currents I, Iof the first and third current path in which operating mode the switchgear is operated.

Switchgear for a single-phase motor and a three-phase motor

An embodiment of the invention relates to a switchgear which includes a control unit, a supply connection and a first current path. The first current path includes a first electromechanical switch and, connected in series to the first switch, a parallel connection of a second electromechanical switch to a semiconductor switch. The switchgear includes an energy accumulator and a measuring device. A control unit is capable of monitoring energy supply coming in through the supply connection. If the energy supply through the supply connection reaches a critical range, the control unit controls the output of the switching signals via the energy of the energy accumulator such that: in a first step, the semiconductor switch is switched to be electrically conducting and the second switch is then opened, and in a second step, the semiconductor switch is switched to be electrically non-conducting and the second switch is then opened.

Switchgear for controlling the energy supply of an electric motor connected thereto

A switching device and method are disclosed for terminating a braking process of a three-phase AC motor. The braking process of the AC motor is performed by way of a first and second thyristor. During the braking process of the AC motor, in a first step the first thyristor is actuated in such a way that a braking current is fed to the AC motor, and therefore a torque which brakes the AC motor is produced. In a second step the second thyristor is actuated in such a way that, when the first thyristor is quenched, the braking current is taken on by the second thyristor and the braking torque is maintained. The two steps are repeated during the braking process; wherein the second step is suppressed during the braking process after a last actuation of the first thyristor.

Switching device and method for terminating a braking process of a three-phase AC motor

A method is disclosed for determining a phase failure in an electrical device for driving or monitoring a three-phase AC motor, wherein the electrical device comprises a first, a second and a third line. In order to detect a phase failure in a line in the three-phase electrical device, in particular in a soft starter, the phase failure in the third line is determined by analysing the first and second lines, wherein the analysis includes: determining a value which characterizes a phase shift between a current in the first and second lines, and outputting a signal if the value which has been determined is in a range of values which characterizes a phase failure in the third line.

Electrical device and method for determining a phase failure in the electrical device

A method is disclosed for slowing-down control of an asynchronous machine, wherein the value of a start energy is determined and stored while the asynchronous machine is being run up from being stationary to the operating rotation speed. The asynchronous machine is braked, in the reversing mode, with braking energy which corresponds to the start energy multiplied by a correction factor wherein the correction factor assumes a value between 0 and 1. In at least one embodiment, the asynchronous machine is braked further by DC braking after braking has been carried out in the reversing mode.

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Schwandorf, Germany

Stefan Zitzler