SENSITIVITY OF CHARACTERISTICS OF MODEL OF THE ELECTRIC ARC TO CHANGE OF PARAMETERS OF ELEMENTS

Abstract

Purpose. Consideration of the quantitative assessment of the sensitivity of certain properties of the automatic system to changes in the parameters of elements of only a part of the controlled object - the welding arc.Methodology. When solving practical problems of regulation by electric arc and plasma technological processes, it is important to solve the problem of determining the optimal settings or parametric optimization of automatic control systems, among the methods of which are non-exploratory methods based on the use of the sensitivity apparatus.Findings. The sensitivity to changes in the parameters of the nominal transfer function of the arc was analyzed, expressions for the sensitivity functions were obtained, and graphs of the corresponding functions were plotted. For more precision, it is assumed that changes in parameters are caused by changes in capacity, which always takes place in circuits with an arc.Originality. The problem of finding an acceptable compromise between the requirements of a small value of the stabilization error without a significant increase in the value of the input variable is formulated and solved.Practical value. Various rules have been developed to reduce the sensitivity of the transfer function of an object with respect to possible, unexpected changes in the parameters of a controlled object, which can be used in the design of high-quality transistor current sources for arc loads. To illustrate the sensitivity of the transfer function of the arc, the model shows the response to a stepwise change in input for different cases. Unfortunately, the article does not consider the characteristics of the disturbance and noise suppression, but only some options for reducing the sensitivity function are studied.