An advanced common control method for shunt and series active conditioners, which compensate for the main types of disturbances in electrical power systems, is considered. If shunt and series actives conditioners are already well known as good compensation solutions for power quality improvement, it is also admitted that they generate some undesired components at switching frequency. To avoid these propagation problems, conditioner designers proposed a high-order output filter associated to a specific controller based on the RST control method. However, by applying this controller, it can be observed that a phase lag between the reference and the injected signal appears in the current and voltage control loop, which damages harmonic compensation. Therefore, a new RST controller is proposed, called RSTimp, to overcome the phase lag effects over the entire bandwidth for both active conditioners. The RSTimp proposed control method is validated through SABER simulations. These simulations show very good active conditioner performance in terms of rapidity, tracking and robustness for both current and voltage compensation.