This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. First an overview is given of the amount and type of power production in the Netherlands, followed by a review of the control requirements. Next models are described, including a simplified model for the UCTE power system. The model was tested against frequency and power measurements after failure of a 558 MW production unit in the Netherlands. Agreement between measurements and model predictions proved to be good. The model was subsequently used to analyze the primary and secondary control requirements and the impact of an increase in decentralized power production on the fault restoration capabilities of the power system. Since the latter production units are not actively participating in primary and secondary control, fault restoration takes longer and becomes unacceptable when only 35% of the power producing units participate in secondary control. Finally, the model was used to study the impact of deregulation, especially the effect of “block scheduling”, on additional control actions of the secondary control.