Motor controller

A motor controller has both a basic-frequency current component and a harmonic current component at the same time. A prior art does not allow the simultaneous cancellation of torque ripples generated in a motor because the harmonic current components (6f, 24f) cannot be compensated at the same time. The motor controller is constituted of a rotation measuring section (4), a current measuring section (5), a high-order control section (20), a second current command generator (15), second simulation observer (12), first control section (10), second control section (9), third control section (13), and second voltage command synthesis section (14). The second voltage command synthesis section (14) is constituted of three position converters, three reverse coordinate converters, and an adder.