Matrix converter and its application in a micro-turbine based generation system.

摘要

This thesis investigates the technical feasibility of applying a three-phase, AC-AC Matrix Converter (MC) as the interface medium between a high-speed (40 to 120 krpm) Micro-Turbine based Generation (MTG) system and the load system. The main motivation for using the MC instead of a conventional AC-DC-AC converter is that it eliminates the DC-side components of the AC-DC-AC converter, e.g. the DC-link capacitor. This increases reliability and reduces size, weight and footprint.;The MC should provide (i) frequency conversion from the source-side (0.4--4 kHz) to the load-side (50/60 Hz) and (ii) magnitude and phase-angle control of the load-side terminal. Exploiting the high frequency ratio of the source- to the load-side of the MC, a new switching strategy for the MC is introduced. Control mechanisms for the magnitude and the phase-angle of the MC load-side are developed. Local and global stabilities of the MC operation, based on the introduced switching strategy and control mechanisms, are analytically verified.;This thesis also introduces an overall control scheme for a micro-turbine generator system which is interfaced through the MC to a utility system as a Distributed Generation (DG) unit. To develop a systematic control design for the MC, a new comprehensive mathematical model of the MTG system, including the MC, is presented. This mathematical model is based on transformation of the network equations of the MC source-side to a frame named switching reference frame and then deducing the overall system equations in the MC load-side dqo reference frame. All analytical results and control strategies are verified based on digital time-domain simulation studies in the PSCAD/EMTDC software environment.