Siemens Aktiengesellschaft

Siemens Aktiengelleschaft

Norbert Elsner

Reinhard Maier

Gerd Griepentrog

Fritz Pohl

Diethard Runggaldier

Norbert Mitlmeier

Bernhard Streich

Klaus Dostert

Bernd Trautmann

Christian Schreckinger

Reinhard Herbst

Wilfried Matthee

In order to determine contact erosion of an electromagnetic switching device, a mechanical parameter is measured which characterizes the time course of the relative movement between the contacts, said movement being caused by an actuator. The point in time when the contacts close is determined by evaluating the time course of the relative movement, and the distance traveled by the contact/s until said point in time or the distance traveled by the actuator from said point in time until reaching the final position thereof is detected at least indirectly and is compared to a stored reference value.

Method for determining contact erosion of an electromagnetic switching device, and electromagnetic switching device comprising a mechanism operating according to said method

The orthogonal frequency division multiplexing (OFDM) method is well-known for transmitting data on electrical power supply lines. According to this method, the items of information to be transmitted are distributed among numerous carriers, and the composite signal of the modulated carrier signals is transmitted in the form of an OFDM block. Standard OFDM methods are, however, highly sensitive to strong periodic pulse jammers. According to the invention, the method is thus devised such that the OFDM blocks to be transmitted have a length of approximately 85% of the interval between two periodic disturbing pulses. The carrier interval accordingly results from the reciprocal duration of the OFDM blocks. The transmitted OFDM blocks are synchronized with pulse-shaped periodic jammers in such a manner that one block at a time is located between two disturbing pulses. The pulse-shaped jammers can be gated at the receiver. To this end, the inventive device comprises an appropriately designed transmitter () and an associated receiver ().

Method and device for transmitting data on at least one electrical power supply line

An electromagnetic switching device includes a contact arrangement with three contacts which couple a three-phase load to three phases of a three-phase power supply system, and disconnect the three-phase load from the three phases. Switching erosion takes place on the contacts. An overall erosion is determined for each contact, and is supplied to a drive circuit. The contact arrangement is operated by the drive circuit as a function of the overall erosion such that the overall erosion of the contacts are approximated to one another.

Method for averaging out overall burn up in an electromagnetic switching device and a corresponding electromagnetic switching device

A method for identifying a rotation direction of a three-phase network includes the steps of sampling the individual phases at given times and using an evaluation algorithm to evaluate the measured values or interpolated approximate values, or only the mathematical signs of the values, in order to determine the rotation direction. In addition to the basic method for an ideal signal profile, half-wave-rectified signal profiles of individual phase conductors can preferably be evaluated. The method can advantageously be used to detect the rotation direction with a digital overload relay, using a digital signal control and/or signal processing which is already provided in the digital overload relay.

Method for detecting a rotation direction in three-phase networks

To determine the remaining lifetime of contactor contacts, the contact spring action at the clearance gap can be determined as a substitute criterion for contact erosion, and to determine the erosion of the contact points, the change in spring action during the shutdown cycle can be measured and converted to the remaining lifetime, for which purpose, the time of the armature movement from the start of the armature movement to the start of contact opening is measured with the solenoid actuator having an armature with solenoids and associated yoke. The measured values of the time signal t of contact opening on the load side of the switching device monitored and the time signal t are determined by voltageless signaling of the start of armature movement. In particular for use in three-phase systems, the switching voltage is measured as a voltage change at an artificial neutral point. In the respective arrangement, a voltageless signal line is provided between the switching device and analyzer unit.

Method of establishing the residual useful life of contacts in switchgear and associated arrangement

A method for determining switchgear-specific data at contacts in switchgear and/or operation-specific data in a network connected to the switchgear includes detecting a so-called contact follow-through travel at a switching path as an equivalent criterion for an erosion of contacts, particularly for contactor contacts. A resilience change during a shutdown cycle is measured, can be used to determine the erosion and can be converted into a remaining contact life for the contacts. Accurate measurement of the armature movement from a start of the armature movement to a start of contact opening is required for that purpose. Switching states of a switching device and of the electrical network are additionally detected from signals for resilience detection. An apparatus for carrying out the method is also provided.

Method for determining switchgear-specific data at contacts in switchgear and/or operation-specific data in a network connected to the switchgear and apparatus for carrying out the method

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Bubenreuth, Germany

Norbert Elsner