MATHEMATICAL MODEL OF THE IONIZATION PROCESS IN A PLASMA LIMITER FOR THE PROTECTION OF SATELLITE STATIONS

Abstract

The article is devoted to the development and verification of a mathematical model of a plasma limiter designed to protect ground satellite stations from pulsed overvoltages caused by lightning discharges. The relevance of the work is due to the increasing requirements for the reliability of satellite telecommunication systems and the insufficient efficiency of traditional protection devices - gas dischargers, varistors and TVS diodes - in the case of ultrafast pulses with a front of up to units of microseconds and an amplitude of tens of kilovolts. The proposed model is based on the description of the processes of impact ionization and recombination in the gas gap using the Townsend coefficients, electron balance equations and the dependence of conductivity on the electric field strength. This allows us to quantitatively estimate the ignition threshold voltage, the plasma channel formation time and the dynamics of overvoltage limitation.

To verify the adequacy of the model, numerical simulations were carried out in the COMSOL Multiphysics environment (Plasma Module) and experimental studies were carried out under conditions of pulse effects close to the real parameters of a lightning discharge. The agreement of the calculated and experimental results within 5–8% was obtained, which confirms the correctness of the assumptions made. It is shown that the use of a plasma limiter provides a reduction in the response time of the protection system by 14%, a reduction in the pulse energy on the load by more than 50% compared to an unprotected path and by 30–35% compared to classical gas-discharge devices. The results obtained demonstrate the prospects for the use of plasma limiters in satellite systems and can be used for engineering design and optimization of lightning protection elements of telecommunication equipment.