Analyses of static and dynamic characteristics of practical step-up nine-switch matrix convertor

Abstract

The static and dynamic characteristics of a practicable step-up nine-switch matrix convertor under the control strategy proposed by Venturini are analysed fully by the recently presented circuit DQ transformation technique and signal flow graphs. The step-up nine-switch matrix convertor consists of nonideal voltage and current sources, such as occur in practical inductance and capacitance filters. The energy storage elements of inductors and capacitors are not simplified into ideal current and voltage sources, as in most previous works, so that the dynamic behaviour of the convertor can be explored. Several static and dynamic features of the convertor, such as steadystate input/output voltage gain, input power factor and transient response, are predicted analytically and verified by computer simulations. The signal flow graph is adopted to solve the complex fourth-order equivalent convertor and thus the nine-switch matrix convertor is analysed fully in explicit form. It is found that the voltage gain and input displacement angle cannot be independently controllable, unlike the ideal nine-switch matrix convertor case; however they are controllable to a certain extent by a properly selected switch modulation function. The paper compares computer simulation results with those obtained by analytic technique. The authors expect to report on practical circuit work in due course.