Motor control apparatus

A motor control apparatus comprising:

• a reference signal generation circuit configured to generate a reference signal having a prescribed cyclic waveform;
• a resolver configured to output a position signal depending on a rotation angle of a motor rotating due to AC power supplied following a switching command for an inverter, based on the reference signal;
• a Resolver-Digital (R/D) converter configured to calculate the rotation angle of the motor, based on the position signal output by the resolver;
• an Analog-to-Digital (A/D) converter configured to apply an A/D conversion to a current signal flowing in the motor during a feedback cycle, the current signal varying depending on the rotational speed of the motor, and to apply an A/D conversion to the position signal at a peak timing when a peak of the reference signal is obtained;
• and
• a processor configured to:
• (i) calculate a command value to control the motor, and calculate the feedback cycle, based on the current signal to which the A/D conversion has been applied and the rotation angle of the motor calculated by the R/D converter;
• (ii) detect a fault of the R/D converter, based on a comparison between the rotation angle of the motor calculated by the R/D converter, and the rotation angle of the motor calculated based on the position signal to which the A/D conversion has been applied;
• and
• (iii) permit the A/D converter to apply the A/D conversion to the position signal at the peak timing when (a) a first time obtained by subtracting (a1) a process time required for a control process of the motor from (a2) the feedback cycle, is longer than (b) a second time having passed between (b1) a control end timing when the control process has ended and (b2) the peak timing;
• or inhibit the A/D converter from applying the A/D conversion to the position signal at the peak timing when the first time is not longer than the second time.