Power conversion apparatus, drive control system, machine learning apparatus, and motor monitoring method

A machine learning apparatus comprising:

• a third processing circuit
• to acquire, as state variables, signals each indicating at least either a rising timing or a falling timing of a current detection signal, the current detection signal being output from a current sensor and half-wave rectified, the current sensor detecting a current supplied to a motor;
• to acquire measured values, and calculate frequencies of the current based on the measured values acquired, the measured values each indicating a waveform of the current or a speed of the motor measured by an external measuring device;
• and
• to create a calculation model by using machine learning based on a data set created by combinations of the state variables acquired and the frequencies of the current calculated.

A motor monitoring method comprising:

• converting DC power into AC power and detecting, with a current sensor, a current supplied from a main circuit to a motor, the main circuit supplying the converted AC power to the motor;
• calculating a current frequency based on at least either a rising timing or a falling timing of a current detection signal output from the current sensor and half-wave rectified by a half-wave rectifier, the current frequency being a frequency of the current;
• and
• monitoring a speed of the motor based on the calculated current frequency.