The problem of increasing the efficiency of a two-link power control system of a power unit has been set and solved. To implement this problem, parametric optimization of autonomous control systems was performed for both conventional and prognostic ones with an assigned stability margin for the minimum of the linear integral criterion. To correctly construct the model and obtain a reliable estimate of the results, the effect of feedwater consumption on the generated electric power and fuel consumption on the temperature in the intermediate point was taken into account. In order to decouple the circuits, compensators of various types were used: with control according to the forecast and static. As studies for various options have shown, the greatest increase in efficiency is achieved due to the use of the forecast in autonomous control systems. Transformation of static compensators into prognostic ones did not bring significant improvements in the estimated criterion or stability margin. Modeling was done using the example of the control systems “feedwater flow rate — temperature in the intermediate point” and “fuel consumption — electric power” with compensation for the effect of their cross-links. The object of the study is a 800 MW power unit, the dynamics are obtained on the basis of experimental data.