Self-oscillations at the frequency of subharmonics in nonlinear electric chains and systems

M.I Ibadullaev,A.Zh Esenbekov,A.N Tovbaev,N Voropai,A Michalevich,S Senderov,H Guliev

doi:10.1051/e3sconf/201913901054

M.I Ibadullaev, A.Zh Esenbekov + Show 5 more

Open Access

https://doi.org/10.1051/e3sconf/201913901054

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Abstract

It is known that the occurrence and existence of autoparametric oscillations (AIC) at the subharmonic frequency (GHC) in power lines (power lines) and in power supply systems is extremely undesirable, since they cause ferroresonant overvoltages at different frequencies. At the same time, there is an extensive class of nonlinear electric circuits in which the excitation of the AIC at the frequency of the SGC forms the basis of frequency-converting devices serving as secondary power sources. It is shown that single-phase-three-phase nonlinear systems are, to one degree or another, equivalent circuits of power lines, the main elements of which are: longitudinal compensation capacitors, transverse compensation reactors, and transformers with non-linear characteristics. The regularities of the excitation of the GCC at the frequency (ω / 3) of the power lines were studied, theoretical and experimental studies of the equivalent model of single-phase-three-phase circuits with nonlinear inductance were carried out. For a theoretical analysis of the steady-state mode of SGK at a frequency (ω / 3) with inductive coupling, the frequency- energy approach is used. The conditions of existence and critical parameters of the circuit are determined, and the mechanism of the appearance of the SGC at the frequency (ω / 3) is also studied.

Highlights

Electric systems in large quantities contain elements with significant inductance
To control the voltage and increase the stability of parallel operation, additional capacities relative to the ground are included in the line cut (Fig. 1). Combinations of such inductances and capacitances create a number of complex oscillatory circuits in the circuit of the electrical system
The study of nonlinear oscillations in electrical systems has been developed, since the presence of longitudinal compensation capacitors and chokes with steel cores in the power lines open up wide possibilities for the formation of various oscillatory circuits and highlights resonant overvoltages [1,2,3,4,5,6,7,10,11]

Summary

Introduction

Electric systems in large quantities contain elements with significant inductance (generators, transformers, reactors, etc.). The capacitance and inductance systems of these circuits are shunted by the load or connected directly to the terminals of a powerful source so that free oscillations cannot develop in them. The study of nonlinear oscillations in electrical systems has been developed, since the presence of longitudinal compensation capacitors and chokes with steel cores in the power lines open up wide possibilities for the formation of various oscillatory circuits and highlights resonant overvoltages [1,2,3,4,5,6,7,10,11].

Results

Conclusion