Formalized description of the elements of semiconductor electricity converters at different decomposition levels

Abstract

The article describes the principles of mathematical description of the elements of semiconductor electricity converters on the example of an induction motor frequency control system to determine its component and structural composition, as well as analyzing the processes of logical-dynamic information conversion in the interaction of all subsystems of the microprocessor control system. The disadvantages and limitations of the formal methods used to describe processes in control systems are shown. The rules for describing functional structures, such as a rectifier, a passive filter, an inverter, an induction motor, a microcontroller, are defined at various levels of decomposition of the semiconductor electric power converter and its control system. A structural-functional model of a microprocessor control system of induction motor has been developed. The use of proposed functional model allows to define relations and types of connections between control and visualization subsystems, as well as describing the functionality of elements of individual subsystems and signal conversion algorithms. The advantage of the approach proposed in the article is the possibility of using different levels of decomposition for the formalized presentation of subsystems and elements of semiconductor electric power control systems, including frequency control systems for induction motors, which allows to highlight the most important aspects of the description at various stages of system design and analysis. The explicit designations of the elements of the model and the signal conversion elements remain transparent to the developer, and contain information about the purpose of the system elements, the requirements for interaction with other signal transformation subsystems, and their functionality. The use of the proposed approach allows the formation of mathematical models of semiconductor electricity converters and their control systems with enhanced information content, allows to analyze systems by multi-level decomposition to create an idea of its basic properties, to assess the quality of its structure and elements from the perspective of a common systems approach.