A new power digital voltage controller is described able to improve quality in power distribution using real-time compensation of both slow voltage changes and quick disturbances as sags and swells. Voltage control was achieved by means of a special transformer able to change the magnetic flux linked to the secondary winding; moreover, secondary voltage was monitored through a feedback control managed by a properly programmed micro-controller. The completely automated system includes a power section, namely a special transformer, a power electronic section consisting of an inverter driven by an actuator, and a digital section involving a micro-controller with implemented software. The capabilities of the proposed voltage conditioner were verified by laboratory experimental tests performed on a specifically manufactured prototype. Experimental results are reported and the behavior of the conditioner under different working conditions is discussed.