[1] An abnormality diagnosis device comprising:
a data acquisition unit (100) configured to acquire a current waveform and a driving frequency of an electric motor (3) driven by a power conversion device (6);
an operation pattern storage unit (110) which stores a combination of a current value of the current waveform and the driving frequency that are acquired at an identical time by the data acquisition unit (100);
a data determination unit (120) configured to determine whether or not a current value of the current waveform and the driving frequency as a diagnosis target that are acquired at an identical time by the data acquisition unit (100) match the combination stored in the operation pattern storage unit (110);
an analysis unit (150) configured to perform frequency analysis for the current waveform determined to be matched by the data determination unit (120), to extract sideband waves, and calculate a spectrum intensity of the sideband waves; and
an abnormality diagnosis unit (170) configured to make a diagnosis that abnormality has occurred, when the spectrum intensity of the sideband waves is equal to or greater than a threshold.

[2] The abnormality diagnosis device according to claim 1, wherein
the operation pattern storage unit (110) stores a combination of a current value of the current waveform and the driving frequency that are acquired at an identical time for a predetermined number of times or more by the data acquisition unit.
[3] The abnormality diagnosis device according to claim 1 or 2, wherein
the analysis unit (150) extracts the sideband waves arising at positions separated by at least one of a rotation frequency and a bearing natural frequency from the driving frequency as a center.
[4] The abnormality diagnosis device according to any one of claims 1 to 3, wherein
the analysis unit (150) converts the current waveform to d-axis current or q-axis current.
[5] An abnormality diagnosis method comprising: a data acquisition step of acquiring a current
waveform and a driving frequency of an electric motor (3)
driven by a power conversion device (6);
an operation pattern storage step of storing a

combination of a current value of the current waveform and the driving frequency that are acquired at an identical time in the data acquisition step;
a data determination step of determining whether or not a current value of the current waveform and the driving frequency as a diagnosis target that are acquired at an identical time in the data acquisition step match the combination stored in the operation pattern storage step;
an analysis step of performing frequency analysis for the current waveform determined to be matched in the data determination step, to extract sideband waves, and calculate a spectrum intensity of the sideband waves; and
an abnormality diagnosis step of making a diagnosis that abnormality has occurred, when the spectrum intensity of the sideband waves is equal to or greater than a threshold.
[6] An abnormality diagnosis system comprising:
the power conversion device configured to read the current waveform and the driving frequency of the electric motor (3);
the abnormality diagnosis device (200) according to any one of claims 1 to 4, configured to acquire the current waveform and the driving frequency read by the power conversion device (400), determine whether or not a current value of the current waveform and the driving frequency match

the combination stored in the operation pattern storage unit (110), and diagnose whether or not abnormality has occurred on the basis of the current waveform determined to be matched; and
a monitoring device (300) configured to output at least one of an indication and an alarm on the basis of a result of diagnosis by the abnormality diagnosis device.
[7] The abnormality diagnosis system according to claim 6, wherein
the power conversion device (400) reads the current waveform from a current sensor (401) provided in the power conversion device (400).