Mathematical model of a valve converter based on a parallel current inverter with an adjustable output voltage of an improved form

Abstract

The results of development of mathematical model and structural diagram of transient processes calculation algorithm of the valve converter based on single-phase current inverter, operating both in continuous and intermittent mode of input current are given in the article. Mathematical model of DC-AC valve converter with adjustable output voltage on the basis of parallel autonomous current inverter with inductive-thyristor compensating device is made on the basis of the operator method. Instead of traditional approach related to making operator substitution diagram for each possible state of power circuit proposed to use universal substitution diagrams equivalent to several states of the power circuit involved in the development of electromagnetic processes. Analysis of possible power circuit structures, which can participate in development of transient processes has shown that six power circuit structures participate in formation of process, which can be brought to two universal operator substitution diagrams. Application of universal replacement schemes, preserving advantages of the operator method, makes it possible to reduce the size of the model, reduce the required volume and time of calculations, allows to perform necessary calculations of circuit parameters in a wide range, taking into account the excitation and regulation method and to carry out the appropriate selection of elements as a result. The proposed structural diagram of algorithm of calculation of transient process is made on the basis of performance of boundary conditions of stages of development of process and revealing of sequence of change of types of equivalent circuits on intervals of clocking. The algorithm allows making calculation of transients at change of an input voltage of the inverter, at change of loading, and also at simultaneous change of an input voltage and loading. The developed mathematical model and algorithm provide the procedure of parametric synthesis of inverter elements with high accuracy.