Arrangement having an electric machine and method for operating an electric machine

Abstract

The invention relates to a method and arrangement having an electric machine, comprising a stator (4) and a rotor (1) and an infrared temperature sensor, wherein the detection field of the infrared temperature sensor is directed at an outer surface of the rotor (1). The infrared temperature sensor is a thermopile (6) for radiometrically contactlessly detecting a temperature of the rotor (1), the thermopile being arranged in a slot of the stator (4) and being compatible with standard slot-sealing-wedge components of the electric machine with regard to assembly, and thus enables the operational monitoring of the thermal state of an electric machine in a novel manner, such that adapted power states can be achieved.

Description

technical field [0001] The invention relates to a device with an electric motor according to the preamble of claim 1 and a method for driving an electric motor according to claim 9 . Background technique [0002] In installations with complex installation situations and in extreme ambient conditions, temperature measurement with contact thermometers is generally not possible. Especially in electric machines, ie in electric motors and generators, temperature measurement on rotating parts is a practical problem. It is therefore desirable, for example, to monitor the temperature of the armature, ie the rotor, of electric motors and generators, since such monitoring allows conclusions to be drawn on the operating state of the electric machine and enables design optimization of the power class of the electric motor. In this way, in particular the often occurring overdimensioning of the motor can be avoided in order to also prevent overheating of the permanent magnets which demag...

AI Technical Summary

Problems solved by technology

[0004] This device has the disadvantage that the radial openings ("perforations") in the stator of the electrical machine can only be realized with great difficulty due to the windings arranged there and especially in complex electrical machines, or for structural reasons in many position is impossible and often even completely impossible

Furthermore, due to the distance between the external infrared temperature sensor and the outer surface of the rotor, the mentioned optical system, namely the lens system, is required, which increases the cost of the device

Finally, the "channels" designed for temperature detection, i.e. the substantially radial openings in the motor's stator, can deposit dust particles over time distorting or making temperature detection impossible

[0005] Another problem is reflections especially in the interior of the channel and due to the radiation of the stator's own heat in this area, which can further distort the measurement

In particular larger electrical machines in some cases have cooling air openings which are suitably formed radially with respect to the rotor, whereas especially in medium and small electrical machines such openings are usually not possible or are not possible at all for space reasons

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