Protection of important energy facilities from direct lightning impact requires the creation of special devices for lightning protection in particular multi-chamber arresters. To improve the efficiency of multi-chamber arrester operation it is necessary to perform mathematical simulation of the physical processes that take place inside such devices. To develop a mathematical model of arc discharge it is necessary to know the thermodynamic and transport properties of the plasma depending on temperature and pressure. In the article the dependences of the thermodynamic and transport properties of plasma in a multi-chamber arrester were obtained for the two-temperature plasma model for the electron temperature range Te = 300–30 000 K, the nonequilibrium degree range is 1–5, and the pressure range p = 0.3–1 atm.

The article is dedicated to nonstationary simulation of induction heating technology for the production of seamless large diameter tees. A mathematical model of induction heating process representing a multi-physical (heat transfer and electromagnetism) task for technology of tees production is developed. Numerical simulation was carried out for a flat spiral inductor. The developed model was verified according to the results of experimental studies. The hydrodynamic 3D mathematical model is developed for the design of the inductor cooling system. Optimal operating modes are determined by simulation results and confirmed by experimental data. The calculation results are presented for pipes with wall thicknesses: 15 mm, 40 mm, 60 mm, 70 mm.

The paper presents the results of analyzing switching overvoltages occurring with simultaneous shedding of active inductive load by vacuum breakers jointly connected to one bus. It is established that with the available spread in current choppings of vacuum breakers, the maximum overvoltage occurs on the contacts of a vacuum breaker out of the number of parallel connected ones, in which the gap is de-ionized last. It is recommended to damp any occurring overvoltages by arresters located in parallel to separate groups of breakers connected to one bus.

The article discusses a method for improving the energy efficiency of a two-unit frequency converter with an active voltage rectifier using an input LCL filter. Studies are conducted on the basis of an asynchronous motor. The article presents the simulation results in the Matlab Simulink package. Improving the energy efficiency of elements of the energy system is especially important in networks of limited power.