Abstract—The paper solves the problem of increasing the gas-diesel engines revolutions stablility and, accordingly, the voltage frequency in the network of autonomous electric power systems, which can vary in the range from 45 Hz to 55 Hz. The frequency instability causes fluctuations in active power and has a negative impact on the quality of electricity. The structure of the test bench was developed, which made it possible to get static characteristics and determine the range of active power exchange fluctuations between gasdiesel generators. In this case, the uneven distribution of active power between generators can reach 57%. Based on an analysis of the reasons for the appearance of frequency oscillations and the design features of the gas-diesel unit, its dynamic model has been developed, taking into account the influence of the turbocharger on the appearance of lowfrequency revolutions oscillations. The structure of the control system for a gas-diesel generator set with autotuning of the controller was proposed. Computer simulation of the operation of a gas-diesel generator set was carried out, which made it possible to solve the problem of optimizing the parameters of a gas-diesel engine revolutions Proportional–Integral–Derivative (PID) controller. In this research the method of active experimentation, the theory of probability and statistical data analysis, methods of automatic control theory and computer modeling are used. Using the obtained solution makes it possible to reduce the dispersion of gas-diesel revolutions fluctuations by up to 20%.