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 an offset current value detected by using the current sensor when the low-potential-side switching element is in a non-conductive state, with a first threshold value with respect to each phase of the plurality of phases and to determine a failure based on the number of times the abnormality is detected;
• wherein
• when the abnormality is detected by comparing the offset current value with the first threshold value, the abnormality detection unit causes the power control unit, with respect to a limit target phase including at least a phase in which the abnormality is detected among the plurality of phases, to generate a limiting duty value that limits the duty value of the limit target phase to be greater than or equal to a predetermined lower limit value such that a time during which the low-potential-side switching element is in the non-conductive state is greater than or equal to a time for detecting the offset current value and to perform duty limit processing that is processing of controlling the high-potential-side switching element and the low-potential-side switching element based on the limiting duty value.