Control device for rotary electric machine and electric power steering device

A control device for a rotating electrical machine includes: an inverter that applies a voltage to the rotating electrical machine; a current detector that is provided to the inverter and detects a rotating electrical machine current, which is a current flowing through the rotating electrical machine; and a controller that outputs a voltage command value, which is a command value of a voltage, to the inverter on the basis of a control command of the rotating electric machine, the controller comprising: a torque current command value generator (31) that calculates a torque current command value on the basis of the control command; weak excitation current command value generators (32-34) that calculate a weak excitation current command value; and a voltage command value calculator that calculates a voltage command value on the basis of the torque current command value and the weak field current command value, and the weak field current command value generator outputs the first weak field current command value a