The Influence of the Internal Resistance of an AC Voltage Source on the Operation of an AC Voltage Pulse Stabilizer

Resumo

This article studies the influence of an input ac voltage source on the properties of an ac voltage stabilizer, which not only stabilizes the level of voltage, but also adjusts its shape. A continuous boundary model of the power circuit is constructed, which takes consideration of the output resistance of the voltage source. Its equivalent electric circuit with controlled parameters and the static characteristic are determined. A preferred stationary mode is determined for the average value of the source’s harmonic EMF, which corresponds to the specified harmonic voltage at load with an integral controller with two variants: direct stabilization of the output voltage and stabilization of the input voltage of a smoothening LC filter. Linearized differential perturbation equations are obtained the asymptotic stability of the trivial solution of which provides asymptotic stability of a nonexcited mode and allows one to expect that stationary modes occurring within the permissible variations of the input voltage with be stable in terms of magnitude and shape. A method of numerical solution for the basic matrix of a linearized system of differential perturbation equations, which has periodic coefficients and eigenvalues defining the stability of the trivial solution to the problem, is suggested. Investigation of the main properties of both options using MATLAB Simulink software showed that appropriate quality of stabilization with adjusting the voltage shape is only possible by excluding the smoothening LC filter from the closed circuit of stabilization, which increases the output resistance of the stabilizer.