Синтез системы автоматического регулирования температуры жидкости с улучшенными динамическими показателями

Abstract

An algorithm for synthesizing an automatic liquid temperature control system is proposed. The obtained result can find practical application in agriculture, in processing and preservation of products and in the chemical industry in programmed setting of liquid medium temperature conditions. Dynamic thermal equilibrium is considered in a system consisting of an inductor, a secondary body heated by eddy currents, and a volume of liquid medium. The heat transfer with respect to the environment and the dependence of the inductor and secondary body resistances on temperature are taken into account. The equations describing the heat transfer processes are linearized, and the control system is synthesized subject to the frequency criteria. An algorithm for selecting the parameters of the correcting Butterworth first-order filter is proposed. The synthesis and analysis stages are illustrated by root loci, transient and dynamic characteristics. The problem of taking into account the forcing in the power supply voltage channel in the case of introducing correction devices is considered. The obtained results are supposed to be used in the software of the microcontroller-based automatic control system. The use of the controller will make it possible, in addition to high-quality control of temperature conditions, to optimize the device operation energy efficiency, to identify the parameters of the thermal and electrical models that are not accessible for direct measurement, and to set up the optimal spatial thermal effect on the liquid. In view of a significant inertia of the controlled plant, the above-mentioned set of problems can be solved in the real time mode.