Motor control device, electric power steering device, and vehicle

A motor control device comprising:

• an inverter circuit configured to supply power to a motor having a winding wire of a plurality of phases, the inverter circuit including a plurality of high-potential-side switching elements and a plurality of low-potential-side switching elements that are provided corresponding to each phase of the plurality of phases, and a plurality of current sensors that are each connected to the plurality of low-potential-side switching elements;
• a power control unit configured to control the plurality of high-potential-side switching elements and the plurality of low-potential-side switching elements based on a duty value;
• and
• an abnormality detection unit configured to detect an abnormality by comparing a sum of current values of the plurality of phases detected by using the plurality of current sensors when the plurality of low-potential-side switching elements are in a conductive state, with a first threshold value and to determine a failure based on the number of times the abnormality is detected;
• wherein
• the abnormality detection unit compares the sum of the current values with the first threshold value, for each first cycle that is a current value detection cycle, and,
• when the abnormality is detected by comparing the sum of the current values with the first threshold value, the abnormality detection unit causes the power control unit to generate a limited duty value that limits the duty value to be less than or equal to a predetermined upper limit value such that a time during which all of the plurality of low-potential-side switching elements are in the conductive state is greater than or equal to a time required for detecting the current value and to perform duty limit processing that is processing of controlling the plurality of high-potential-side switching elements and the plurality of low-potential-side switching elements based on the limited duty value.