CONSTRUCTION OF A NUMBER OF ENERGY SAVING ASYNCHRONOUS ELECTRIC DRIVES BASED ON UNIFIED TRANSFORMER-TRANSISTOR MODULE
The paper considers a new unified construction of the transformer and transistor module executed on the minimum structure at one power transistor placed in the transformer common for all phases of the circuit allowing to minimize the number of power semiconductor keys. This unified module belongs to the converting equipment applied in AC adjustable electric drives for the smooth amplitude start-up, countercurrent braking, and also for implementation of the asynchronous engines positioning mode. Making a row of asynchronous electric drives on the basis of the unified transformer and transistor module allows one to meet the energy saving requirements imposed on asynchronous electric drives during their operation. The ways for reduction of mass-dimensional indices of the booster transformer which forms a structural basis of the offered device by the modulation elimination of a network low frequency tension component in its primary winding are shown. The solution efficiency is confirmed by the analysis of the direct and smooth start-up experimental diagrams, braking, and also by the mode of the asynchronous engine positioning in the computer program MATLAB/Simulink. Energy consumption lowering at start-up, braking and positioning of the asynchronous engine, when using of the unified transformer and transistor module as a basic element of the electric drive management system, is proven by the experimental diagrams obtained in the computer program MATLAB/Simulink.