The use of an additional output filter to improve the dynamic roperties of the LCL energy converter of the solar battery

A mathematical model describing the dynamics of a resonant converter with a T-shaped oscillatory circuit in the mode of power supply from a current source, which is a simplified model of a solar battery, is analyzed. It is shown that increasing the output filter capacity to improve the quality of transients is an ineffective measure. As an alternative measure, it is proposed to supplement the output circuit of the converter with an additional low-pass filter. A linearized equivalent circuit of the upgraded converter has been developed. It has been found that the quality of the transients of the input and output circuits of the converter is practically independent of the inertial properties of the converting T-shaped oscillatory circuit due to the fact that the time constant of the input and output filters is much greater than the constant of the rise time of the circuit current. It is shown that the device in question is a current-to-voltage converter not only in statics, but also in dynamics, and the equivalent circuit of the input circuit of the converter, without taking into account the input filtering capacity, is described by an electrical circuit that is dual to the output circuit of the converter. The developed equivalent circuit makes it possible to increase the speed of computer simulation of transient processes in the converter tenfold. The adequacy of the proposed approach is confirmed by modeling the transients of a resonant transducer in the Matlab 2021b software package. It has been found that the use of an additional low-frequency output filter significantly reduces the time of transients, reduces the amplitude of the input voltage transition, and also improves the mass-dimensional characteristics of the converter.