Currently, the personnel maintaining the turbogenerator excitation system are guided in their work by the operational and technical documentation issued by the manufacturing plant (see section 2).

These materials provide a description of the operation of individual units of the excitation system, but a block diagram of the control system is missing. This hinders a conscious engineering analysis of the turbogenerator excitation system under specific conditions by the operational services of power stations.

In this work, based on the initial data (see section 2), block diagrams are presented that mathematically reflect the physical connections between individual elements of the control system using the transfer functions of these elements

The selection of amplification coefficients for the excitation regulator channels to ensure stable operation during the commissioning process is mainly carried out according to the recommendations of VEI, MEI, Soyuztechenergo, and other organizations. Due to the lack of engineering methods for assessing the influence of amplification coefficients on generator operation under specific system conditions, their selection during commissioning works is not always optimal and is not corrected during operation.

By means of appropriate transformations of the block diagram, a qualitative and quantitative analysis of any disturbances coming from outside into a specific control system is possible, both under small and large disturbances.

The block diagram also enables a quantitative assessment of the influence of various channels of the control system on stability under small disturbances.