Diagnostic method of switchgear and device thereof
A diagnostic method of switchgear and a device of switchgear that allow regularly grasping a state with high accuracy with a simple configuration is provided. The diagnostic method of switchgear includes: obtaining signals from an acceleration sensor mounted to a switchgear and a load current flowing through the switchgear; determining a frequency to be focused from a spectrum analysis result of the signals from the acceleration sensor in an advance preparation phase of diagnosis of the switchgear, generating learning data using at least the frequency and the load current as feature values; and regularly diagnosing the state of the switchgear from the feature values obtained during diagnosis and the learning data during the diagnosis of the switchgear.
1. A diagnostic method of switchgear comprising:
obtaining signals from an acceleration sensor mounted to a switchgear and a load current flowing through the switchgear;
determining a frequency to be focused from a spectrum analysis result of the signals from the acceleration sensor in an advance preparation phase of diagnosis of the switchgear and generating learning data using at least the frequency and the load current as feature values; and
regularly diagnosing a state of the switchgear from the feature values obtained during diagnosis and the learning data during the diagnosis of the switchgear,
wherein in the advance preparation phase of diagnosis of the switchgear, a frequency at which values found by dividing, by standard deviations, a difference in mean values of a spectrum of the signals from the acceleration sensor in normal and in abnormality of the switchgear become large is selected as the frequency to be focused.
2. The diagnostic method of switchgear according to claim 1 ,
wherein, in the advance preparation phase of diagnosis of the switchgear, an integral multiple of a frequency of a voltage applied to the switchgear is selected as the frequency to be focused.
3. The diagnostic method of switchgear according to claim 2 ,
wherein the learning data is generated using the frequency, the load current, and a voltage applied to the switchgear as feature values.
4. The diagnostic method of switchgear according to claim 3 ,
wherein the applied voltage to the switchgear is estimated from switching information of a power supply-side switch of the switchgear.
5. The diagnostic method of switchgear according to claim 1 ,
wherein the learning data is generated using the frequency, the load current, and a voltage applied to the switchgear as feature values.
6. The diagnostic method of switchgear according to claim 5 ,
wherein the applied voltage to the switchgear is estimated from switching information of a power supply-side switch of the switchgear.
7. A diagnostic device of switchgear, comprising:
an input unit configured to obtain signals from an acceleration sensor mounted to a switchgear and a load current flowing through the switchgear;
a learning data database configured to store learning data, the learning data being generated by determining a frequency to be focused from a spectrum analysis result of the signals from the acceleration sensor in an advance preparation phase of diagnosis of the switchgear and using at least the frequency and the load current as feature values; and
a state estimator configured to regularly diagnose a state of the switchgear from the feature values obtained during diagnosis and the learning data during the diagnosis of the switchgear;
wherein in the advance preparation phase of diagnosis of the switchgear, a frequency at which values found by dividing, by standard deviations, a difference in mean values of a spectrum of the signals from the acceleration sensor in normal and in abnormality of the switchgear become large is selected as the frequency to be focused.