Modified operator method for developing mathematical models of valve converters with a periodic structure

Relevance: in the world, special attention is paid to solving problems in developing power semiconductor converter technology based on current converters, which are widely used in various industrial areas, their rational use with high accuracy of maintaining energy parameters, increasing operational reliability and increasing service life. Currently, in developed countries, "...more than 60% of the generated electricity passes through semiconductor converters. By using world-class power electronics systems, it will be possible to save 12-15% of the generated electricity." In this regard, issues related to increasing the energy efficiency of valve converters based on current converters for various purposes, designed to provide the required power supply mode for energy facilities with increased requirements for the quality of consumed energy and the reliability of energy resources, are relevant. Aim: development of an effective methodology for modeling valve converters with a periodic structure to calculate their transient and steady-state modes. Methods: when solving the problem, a modified operator method based on the Laplace transform was used, as well as the instantaneous value method. Results: the developed method provides the possibility of its application to all types of autonomous inverters and energy converters with a periodic sequence of changing the structure (topology) of the power circuit. An important advantage of the developed method is that the mathematical models and algorithms obtained on its basis allow calculating transient and steady-state modes of operation of valve converters when they operate on active-inductive and motor loads in continuous and intermittent input current modes of inverters, taking into account the type of load, control method and input current shape of inverters, allow determining the parameters of the power circuit elements of valve converters, as well as the control range that ensures stabilization of the output voltage while maintaining its switching stability. Keywords: mathematical modeling; valve converter; autonomous current inverter; control method and input current shape of the inverter; transient and steady-state modes; active-inductive and motor loads.