Abstract
ABSTRACTThe main purpose of this thesis is to develop a digital signal processor (DSP) based soft-switching converter-fed switched reluctance motor (SRM) drive. First, the structural features, the switching operation and the governing equations of a SRM are studied. Then some of the existing hard-switching converter and soft-switching converter circuits are surveyed to understand their features. Accordingly, a DSP-based SRM drive employing soft-switching converter is established. The proposed soft-switching converter is formed from the traditional Miller converter by adding auxiliary resonant branches. The zero-voltage-transition (ZVT) soft switching of main switches can easily be obtained by applying suitably modified switching control signals to the main and auxiliary switches. Having derived the governing circuit equations in various operation modes, a design procedure is proposed to systematically find the constituted components of the proposed soft-switching converter. The realization of the developed soft-switching scheme using DSP is introduced. And the efficiency improvement of SRM drive via applying soft switching is observed. Secondly, the swept-frequency PWM switching control for the established SRM drive is studied. The resulted switching control performance is evaluated experimentally. Finally, in the speed control aspect, a nominal dynamic model of the established SRM drive is first estimated. Then a two-degrees-of-freedom controller (2DOFC) and a linear model following controller (LMFC) are designed to let the motor driver possess prescribed speed control performance under varying system parameters and operating conditions.