Method and apparatus for testing laminated cores of electrical machines
AssigneeAdwel International Limited
InventorJohn Sutton
Life of this patent
Estimating the term…
Abstract
There is provided an apparatus and associated method for the testing of a laminated core (100) for an electrical machine. The apparatus supplies an excitation signal to the winding (102) of the electrical machine which is of a frequency higher than the rated operating frequency of the machine. There is also provided a phase sensitive detector (110) which receives, from the laminated core (100), a signal in response to the excitation signal. The phase sensitive detector (110) resolves the received signal into a number of components. These components are resolved relative to a reference signal. The size of the components determines the severity of any fault that exists within the laminated core (100.
Claims32
Apparatus for testing a laminated core of an electrical machine, the apparatus comprising:
- excitation signal generating means, arranged to generate an excitation signal at a first frequency which is higher than the rated operating frequency of said electrical machine, for supply to an excitation winding coupled to the laminated core of the electrical machine;
- and
- a phase sensitive detector arranged to receive a first, reference signal having a reference phase and to receive from the laminated core of the electrical machine a second, test signal having a test amplitude and phase, each in response to the excitation signal applied to the excitation winding, the phase sensitive detector being arranged to resolve the test signal into a plurality of components relative to said reference phase of said reference signal and to generate an output signal, the level of said output signal being indicative of the severity of a fault between the laminations of said laminated core.
Apparatus for testing a laminated core of an electrical machine, the apparatus comprising:
- excitation signal generating means, arranged to generate an excitation signal at a first frequency which is higher than the rated operating frequency of said electrical machine, for supply to an excitation winding coupled to the laminated core of the electrical machine;
- a phase sensitive detector arranged to-receive a first, reference signal having a reference phase and to receive from the laminated core of the electrical machine a second, test signal having a test amplitude and phase, each in response to the excitation signal applied to the excitation winding, the phase sensitive detector being arranged to resolve the test signal into a plurality of components relative to said reference phase of said reference signal and to generate an output signal, the level of said output signal being indicative of the severity of a fault between the laminations of said laminated core;
- and
- a frequency generator, arranged to generate at least one further excitation signal having a respective frequency that is higher than the rated operating frequency of said electrical machine.
A method for testing a laminated core of an electrical machine, comprising the steps of:
- generating an excitation signal at a first frequency, wherein the first frequency is higher than the rated operating frequency of said electrical machine;
- receiving a first, reference signal having a reference phase and a second, test signal having a test amplitude and phase, each signal generated in response to the excitation signal applied to the excitation winding;
- resolving the test signal into a plurality of components with respect to the reference phase of the reference signal;
- and
- generating an output signal, the level of said output signal being indicative of the severity of a fault between the laminations of said laminated core.
A method for testing a laminated core of an electrical machine, comprising:
- generating an excitation signal at a first frequency, wherein the first frequency is higher than the rated operating frequency of said electrical machine;
- receiving a first, reference signal having a reference phase and a second, test signal having a test amplitude and phase, each signal generated in response to the excitation signal applied to the excitation winding;
- resolving the test signal into a plurality of components with respect to the reference phase of the reference signal;
- generating an output signal, the level of said output signal being indicative of the severity of a fault between the laminations of said laminated core;
- and
- generating at least one further excitation signal, having a respective frequency that is higher than the rated operating frequency of said electrical machine.
Dependencies are inferred from the claim text.