The object of research is an electrical system for detecting partial discharges in a sample of high voltage equipment insulation. To evaluate the insulation state of electrical equipment, various methods for detecting partial discharges have been developed and continue to be improved. The role of modeling, virtual experiment and virtual laboratory lessons has recently increased in all areas of engineering. At the same time, some aspects of modeling the electrical systems for partial discharges detection are practically not studied sufficiently. Modeling is an important additional kind of practical training for a further work with measuring and testing equipment in professional activity. The aim of research is determination of the possibility of using an equivalent circuit simulation model in the research and educational process as an analogue of a system for measuring the characteristics of partial discharges. To measure the characteristics of partial discharges in samples of high-voltage insulation, a special experimental test stand was assembled. The stand allows testing the physical model of insulation by applying alternating current high voltage. To visualize individual partial discharge pulses on an oscilloscope, a high-pass filter was designed and assembled that suppresses the 50 Hz main frequency voltage, and is a 4th order Butterworth filter. The oscillogram of partial discharge pulses that occur near a surface of high-voltage electrode in an insulating gap with an electrical cardboard was obtained. It has been experimentally established that partial discharge impulses of different amplitudes arise in the insulating gap with an explicit polarity effect. The experimental oscillogram was adopted as a sample, to which the oscillogram should approach in the simulation. The electrical equivalent circuit for insulation is represented by a traditional three-capacitive equivalent circuit for a dielectric with a gas cavity. As a result of the research it was established that it is possible to obtain results close to those observed in the physical experiment. The possibility of modeling partial discharges in a dielectric in the presence of two or more gas cavities is shown.