Abnormality detection apparatus

An abnormality detection apparatus used for a motor controller having a function of controlling a motor including a plurality of windings each disposed in a corresponding one of a plurality of phases arranged in a predetermined order, the plurality of windings being divided into a first winding group and a second winding group that are insulated from each other,

• the abnormality detection apparatus comprising:
• a first period measurement circuit to receive a plurality of first control signals to a first power converter for controlling a voltage applied to the first winding group;
• and
• a second period measurement circuit to receive a plurality of second control signals to a second power converter for controlling a voltage applied to the second winding group,
• in each of phases corresponding to the first winding group among the plurality of phases, the plurality of first control signals each being generated as a pulse signal having a period depending on a rotation speed of the motor based on a current detected in each of the phases corresponding to the first winding group in the motor,
• in each of phases corresponding to the second winding group among the plurality of phases, the plurality of second control signals each being generated as a pulse signal having a period depending on a rotation speed of the motor based on a current detected in each of the phases corresponding to the second winding group in the motor,
• the first period measurement circuit being configured to measure pulse periods of the plurality of first control signals,
• the second period measurement circuit being configured to measure pulse periods of the plurality of second control signals, the abnormality detection apparatus further comprising:
• a period comparison circuit to detect an abnormality in the motor controller based on a comparison of the pulse periods of the plurality of first control signals or the pulse periods of the plurality of second control signals in the plurality of phases, the pulse periods of the plurality of first control signals being measured by the first period measurement circuit, and the pulse periods of the plurality of second control signals being measured by the second period measurement circuit,
• the period comparison circuit, being configured to detect whether the abnormality occurs or not depending on whether a predetermined large-small relation according to an arrangement order of the plurality of phases is established or not among the pulse periods of the plurality of phases during at least one of an acceleration state time period and a deceleration state time period of the motor.