In the article different methods of diagnosis of failures of electric equipment which are most often found in the industry today. The classification of methods for diagnosing motor failures is presented, and the advantages and disadvantages of existing methods for diagnosing failures in electric equipment are revealed. Based on the description of the methods of diagnosing electric equipment failures, a comparative table was compiled. Analyzing the comparative table of methods for diagnosing failures of electric equipment, the most current method for diagnosing the technical condition of the electric motor was determined.

The article provides a mathematical description of an induction motor with a device for indirect control of the electromagnetic moment and angular velocity of an induction motor in an electric drive, which allows substantiating on its basis a method for controlling the output variables of an asynchronous electric motor. A simulation model of an induction motor with an indirect control device for the output variables of an induction motor and the main results of the study are presented.

This paper presents the results of the influence of ultrasonic treatment in the cofermentation of the cattle manure mixture (cattle) with the leaven from the rumen of ruminants on the process of biogas production. Anaerobic digestion was carried out in matinence periodic operation at the mesophilic temperature of 38 C ̊. As a substrate, a mixture with a content of 70 % cattle manure and 10 % leaven from rumen of ruminants was used. Treatment with ultrasound of the mixture was carried out at an intensity of 10 W/cm2 and an amount of input energy of 9350 kJ/kg of dry matter (DM), which completely eliminated the processes of stratification and sedimentation. Decomposition of organic matter (OM) in the periodic regime with the enzyme and ultrasound treatment occurred within 8 days, the usual substrate during this time OM decomposed 3.0 times less (only 14 %). The process of fermentation of methane in continuous and periodic modes treated with ultrasound, as at other temperatures, was stable, as can be judged by the values of volatile fatty acids (VFA) Volatile fatty acids (VFAs), alkalinity, pH, and biogas. The energetical efficiency of methane fermentation is estimated by comparing the volume of fuel (biogas) and heat consumption for technological needs. As shown by the comparison of efficiency of different regime, the largest amount of commercial energy in the form of biogas was obtained in the mode of joint fermentation of a mixture of cattle manure (cattle) with a ferment from the rumen of ruminants treated with ultrasound – 3 times more than without treatment (space).