US 9,851,404 B2Granted

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

AssigneeSiemens Aktiengesellschaft

InventorsDirk Hertz, Marco Schönenberg, Helene Steuer, Stefan Zitzler

Life of this patent

Estimating the term…

Loading patent…

Abstract

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 I1 of the first current path and the current I3 of 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 I1, I3 of the first and third current path and to determine, based on the phase shift between the detected currents I1, I3 of the first and third current path in which operating mode the switchgear is operated.

Claims25

Dependent claims

A switchgear for a single-phase motor and a three-phase motor, the switchgear comprising:

a processing unit;
and
a first, second and third current path, the first and third current paths each comprising a current transformer, the processing unit being configured to
detect, via the current transformers, the current I1 of the first current path and the current I3 of the third current path,
detect the currents I1, I3 of the first and third current paths and to ascertain a present operating mode of the switchgear via a phase shift between the detected currents I1, I3 of the first and third current paths,
repeatedly detect, simultaneously, the currents I1, I3 of the first and third current paths within a time interval for ascertaining the present operating mode of the switchgear and either
determine the first number of positively detected currents I1, I3 of the first or third current paths and the second number of simultaneously positively detected currents I1, I3 of the first and third current paths or
determine the first number of negatively detected currents I1, I3 of the first or third current paths and the second number of simultaneously negatively detected currents I1, I3 of the first and third current paths and
subsequently monitor whether the second number is greater than substantially 66% of the first number.

6 more elements

A method for ascertaining a present operating mode of 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, wherein the first and third current paths each include a current transformer, the processing unit being configured to detect, via the current transformers, the current I1 of the first current path and the current I3 of the third current path, wherein for ascertaining a present operating mode of the switchgear, the processing unit performs at least:

repeatedly detecting simultaneously the currents I1, I3 of the first and third current paths within a time interval;
determining a first number of positively detected currents I1, I3 of the first or third current path within the time interval;
determining a second number of simultaneously positively detected currents I1, I3 of the first and third current paths within the time interval, or
determining the first number of negatively detected currents I1, I3 of the first or third current path within the time interval and determining the second number of simultaneously negatively detected currents I1, I3 of the first and third current paths within the time interval;
and
monitoring whether the determined second number is greater than substantially 66% of the determined first number.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/423,903Filed 20 Aug 2013
Priority: DE 10 2012 215 16627 Aug 2012
Published: US 2015/0241514 A127 Aug 2015
Granted: 26 Dec 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification22 codes

G01R 31/3277
Testing of circuit interrupters, switches or circuit-breakers: of low voltage devices, e.g. domestic or industrial devices, such as motor…
G01R 29/16
Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00: measuring asymmetry of polyphase networks
H02B 1/20
Frameworks, boards, panels, desks, casings; Details of substations or switching arrangements: bus-bar or other wiring layouts, e.g. in cubicles,…
H02H 3/32
Responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents: involving…