Abstract—This paper presents the results of a model-based studies on the efficiency of using a static thyristor reactive power compensator in an autonomous electric power system to increase the power factor, which has a positive effect on the autonomous electric power system efficiency. In order to restore the sinusoidal waveform of the network voltage distorted by the interference generated by a static thyristor compensator, the use of combined passive and active filtering during operation was employed. Block diagrams of all the constituent elements of the system, namely a static thyristor compensator, an active filter based on a thyristor converter, and an automatic control system have been developed. A MATLAB model of a reactive power compensator was developed and results of the simulating the model were obtained on the basis of block diagrams. Simulation of the system showed that for a load with a power factor of 0.5–0.6, it is possible to ensure operation with a power factor of 0.8–0.95 with a THD of consumed current in the range of 10%–25%. It has been found that an effective means of eliminating rectified voltage ripple is a cascade connection of an LC filter and an active filter, effectively attenuates harmonics from 4 to 50 by 40 dB. At the same time, a decrease in the cutoff frequency of the active filter leads to an increase in the effective time constant, which has a negative impact on the operating speed of the entire system. To eliminate this shortcoming, the control system is introduced with backward linkages, while precise compensation is carried out by several control loops according to the principle of subordinate control.