An electromagnetic actuator apparatus for rotors in motors and generators comprising: - an actuator target mounted on a hubless ring shaped rotor having a rotational axis; - a multitude of modular radially opposed groups (5 to 6, 7 to 8) of electromagnetic bearing assemblies distributed along the circumference of the rotor at fixed distances from each other, the assemblies thereof further being both oriented toward the actuator target mounted on the rotor, and separated from the rotor by radial gaps; characterized in that: - the multitude of modular radially opposed groups (5 to 6, 7 to 8) of electromagnetic bearing assemblies, acting in radially opposed groups (5 to 6, 7 to 8) for the stabilization of the corresponding arc sections of the rotor, are not connected by a common core; and - each of the electromagnetic bearing assemblies thereof comprises o a multitude of spaced radial electromagnetic poles facing the rotor and configured to induce electromagnetic flux with the actuator target mounted on the rotor, o a bias winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly and connecting each of the electromagnetic bearing assemblies together, and o a control winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly, the winding being in the opposite direction of its radially opposed electromagnetic bearing assembly. - an actuator target mounted on a hubless ring shaped rotor having a rotational axis; - a multitude of modular radially opposed groups (5 to 6, 7 to 8) of electromagnetic bearing assemblies distributed along the circumference of the rotor at fixed distances from each other, the assemblies thereof further being both oriented toward the actuator target mounted on the rotor, and separated from the rotor by radial gaps; - the multitude of modular radially opposed groups (5 to 6, 7 to 8) of electromagnetic bearing assemblies, acting in radially opposed groups (5 to 6, 7 to 8) for the stabilization of the corresponding arc sections of the rotor, are not connected by a common core; and - each of the electromagnetic bearing assemblies thereof comprises o a multitude of spaced radial electromagnetic poles facing the rotor and configured to induce electromagnetic flux with the actuator target mounted on the rotor, o a bias winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly and connecting each of the electromagnetic bearing assemblies together, and o a control winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly, the winding being in the opposite direction of its radially opposed electromagnetic bearing assembly. o a multitude of spaced radial electromagnetic poles facing the rotor and configured to induce electromagnetic flux with the actuator target mounted on the rotor, o a bias winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly and connecting each of the electromagnetic bearing assemblies together, and o a control winding coil wound around each of the electromagnetic poles of a single electromagnetic bearing assembly, the winding being in the opposite direction of its radially opposed electromagnetic bearing assembly.