Igor Korotyeyev

Generation of matrix-reactance frequency converters based on unipolar PWM AC matrix-reactance choppers

This paper deals with three-phase direct matrix- reactance frequency converters (MRFC) based on unipolar PWM AC matrix-reactance choppers (MRC). The topologies of the proposed MRFC are based on a three- phase unipolar MRC structure. Each MRC with conventional topology has two synchronous-connected switches [SCS] sets. In the MRFC, unlike the MRC topology, one of SCS sets is replaced by a matrix-connected switches (MCS) set in order to make possible of the load voltage frequency change. Six new topologies of the MRFC based on MRC boost, buck-boost, Cuk, Zeta or SEPIC structures are presented. Through the generation concept of the proposed converters both the description of above- mentioned converter topologies and general description of the control strategies are presented. The structure of the proposed MRFC contains a three-phase matrix converter (MC), which is introduced instead of the source or load SCS used in unipolar MRC. The step-down or step-up of the MC set is dependent on the input and output voltage or current source configurations. Analysis determining the location where the MC should be introduced is realized by means of the one-cycle switched models with suitable voltage and current sources introduced instead of the capacitors and inductors respectively. Furthermore, exemplary results of the simplified theoretical analysis, based on the averaged state space method, as well as simulation test results obtained for a classical Venturini control strategy of MC, are also presented as an initial verification of the properties of the proposed converters.

Steady and transient states modelling methods of matrix‐reactance frequency converter with buck‐boost topology

Purpose – The purpose of this paper is to introduce methods for calculating steady‐state and transient processes in a symmetrical three‐phase matrix‐reactance frequency converter (MRFC). The MRFC in question makes it possible to obtain a load output voltage much greater than the input voltage.Design/methodology/approach – MRFCs based on a matrix‐reactance chopper are used for both frequency and voltage transformation. The processes in a MRFC system are described by nonstationary differential equations. A two‐frequency complex function method is proposed for solving non‐stationary equations in steady‐state. The method is applied to a state‐space averaged mathematical model used in the analysis of the discussed MRFC. A two‐frequency matrix transform is proposed for solving non‐stationary equations. This method can be used to find both transient and steady‐state processes.Findings – The two‐frequency complex function method permits the reduction from 12 non‐stationary differential equations to four stationar...

New family of matrix-reactance frequency converters based on unipolar PWM AC matrix-reactance choppers

This paper deals with three-phase direct matrix-reactance frequency converters (MRFC) based on unipolar PWM AC matrix-reactance choppers (MRC). The topologies of the proposed MRFC are based on a three-phase unipolar MRC structure. Each MRC with conventional topology has two synchronous-connected switches (SCS) sets. In the MRFC, unlike the MRC topology, one of SCS sets is replaced by a matrix-connected switches (MCS) set in order to make possible of the load voltage frequency change. Six new topologies of the MRFC based on MRC boost, buck-boost, Cuk, Zeta or SEPIC structures are presented. Through the generation concept of the proposed converters both the description of above-mentioned converter topologies and general description of the control strategies are presented. The structure of the proposed MRFC contains a three-phase matrix converter (MC), which is introduced instead of the source or load SCS used in unipolar MRC. The step-down or step-up of the MC set is dependent on the input and output voltage or current source configurations. Analysis determining the location where the MC should be introduced is realized by means of the one-cycle switched models with suitable voltage and current sources introduced instead of the capacitors and inductors respectively. Furthermore, exemplary results of the simplified theoretical analysis, based on the averaged state space method, as well as simulation test results obtained for a classical Venturini control strategy of MC, are also presented as an initial verification of the properties of the proposed converters.

Steady‐state modelling of basic unipolar PWM AC line matrix‐reactance choppers

Purpose – Focuses on steady state modelling of basic unipolar non‐isolated PWM AC line matrix‐reactance choppers (MRC). Their single‐phase topologies are similar to well‐known basic DC/DC converter ones. The MRC are built up through the adaptation of DC/DC converter topologies, which are based on the substitution of self‐commutated unidirectional switches by bi‐directional ones.Design/methodology/approach – Presents an approach to modelling of the MRC with averaging operator different to the one used in averaged modelling of the DC/DC converters. There is running averaging of each switching period in the proposed approach. Following this, there is a demonstration of the solutions convergence of the state space and averaged state space equations for infinitive switching frequency.Findings – The running averaging of each switching period should be used if averaged state space method is applied to the analysis of presented choppers. A circuit averaged model build‐up procedure of the presented choppers is the...

Steady and transient state analysis of a matrix-reactance frequency converter based on a boost PWM AC matrix-reactance chopper

This paper deals with a three-phase matrix-reactance frequency converter (MRFC). The analysed MRFC topology is based on the boost matrix-reactance chopper (MRC) with a load synchronous connected switch (LSCS) set arranged as in the step-up matrix converter (MC). The MRFC in question makes it possible to obtain a load output voltage much greater than the input voltage. Presented in this paper is a description of a new method for the analysis of the steady and transient state properties of the presented MRFC. The analytical method based on d-q transformation is proposed for solving non-stationary equations, which we derive as a mathematical model of the state-space averaged method applying to the analysis of the discussed MRFC. The analysis results are obtained for a classical Venturini control strategy. Furthermore, for the verification of the theoretical analysis the simulation test results are also presented.

Analyse of steady-state process in circuits with incommensurable frequencies of voltage sources

The paper presents the study of a processs calculation in circuits with incommensurable frequencies. In such circuits the analysis of processes is realized by the use of an additional independent variable. Definitions of RMS currents, voltages and active power are introduced on the base of double integrals. Calculations of an active power in circuits with two independent voltage sources and a single-phase half-bridge inverter are presented.

Alternative drive solution with matrix converter fed permanent magnet synchronous motor

The paper presents study of a drive system with matrix converter fed permanent magnet synchronous motor. In the control system is implemented a rotor-oriented vector control and a space vector modulation of output currents. The system simulation, experimental test results and comparison of both are presented. The main aim is to show a drive system with a matrix converter as an alternative solution of drive system with precise control for application in robotics.