Improving the quality of the stabilization of the output current of the pulse dc converter operating on a plasma arc

Abstract

Purpose. Improving the quality indicators of control processes for pulsed DC converters operating on an arc load, based on the construction of procedures for the synthesis of robust systems. Methodology. A method of improving the quality of stabilization of the output current of a pulsed direct current converter based on a combination of disturbance control with control of the output current deviation from a given value (localization method) is considered. Findings. The article deals with the solution of the optimization problems of the output current stabilization system of the pulsed direct current converter feeding the plasma arc under, among other things , stochastic external influences in connection with the problems of non-roughness and strict implementation of optimal regulators and the solution of optimization problems according to the quality of invariance. Methods for constructing optimal controllers are considered and the possibility of solving the optimization problem by the invariance property is established. Examples of solving deterministic and stochastic optimization tasks are given, taking into account the properties of roughness, structural and strict implementation of the stabilizing regulator. Better accuracy of arc current stabilization in statics and dynamics is provided, which is confirmed by simulation modeling. The quality of arc current stabilization is achieved when using control systems based on the quality of invariance and solving optimization problems in the class of "good" regulators built on the basis of the localization method. Regulators calculated on the basis of the correlations of the localization method provide the required quality of the processes and have the property of roughness (robustness) in relation to the deviation of the object parameters from the nominal values in a wide range. If the object contains non-stationary parameters or its properties are not fully known, in this case it is better to use the localization method to calculate the controller. Originality. We received further development of the procedure for the synthesis of optimal regulators and methods of solving optimization problems by the property of invariance. Practical value. On the basis of the method of combined control and the concepts of localization, the optimal laws of control of free and forced movements of a one-dimensional system are synthesized. The latter, however, has the property of rudeness. The efficiency of the synthesized algorithms is illustrated by the results of mathematical modeling.