Matrix-reactance frequency converters using an low frequency transfer matrix modulation method

This paper deals with three-phase matrix-reactance frequency converters (MRFCs). Their topologies are based on unipolar PWM AC matrix-reactance choppers (MRCs). In the discussed MRFCs the voltage matrix converter (MC) or current MC is used for electrical energy transfer instead of the source or load synchronous connected switches. As a result both a frequency change and the buck-boost voltage conversion are possible. It is important that electrical energy storage in the passive elements used in MRFCs is equal to zero in an AC voltage period; therefore these converters can be treated as ones without DC storage. The main purpose of this paper is to carry out a comprehensive comparison of basic properties of MRFCs using an low frequency (LF) transfer matrix modulation method, which are the FCs with the voltage gain greater than one. Presented in this paper are the results of steady and transient states analysis of the MRFCs using an low frequency (LF) transfer matrix. A two-frequency complex function method is applied for solving non-stationary averaged state space equations. Furthermore, theoretical results are verified against some simulation and experimental test results of a c.a. 1 kVA laboratory model of the MRFC based on MRC with buck-boost topology.

► We worked out averaged models and theoretical analysis of basic properties in steady and transient states of whole family of matrix-reactance frequency converters (MRFCs) using an LF transfer matrix modulation (modified Venturini modulation).
► We compared the components complexity and basic properties (voltage gain, input power factor and time characteristics) of the MRFCs and confirmed by means of experimental verification that MRFCs have favorable possibilities with respect to both the load voltage frequency changes as well the voltage gain greater than one.