After the review of single-phase converter topologies and detailed examination of several candidates, a non-resonantly coupled parallel resonant DCIDC converter is identified as being the most appropriate high frequency linked topology. The steady-state characteristics of the chosen converter with both variable frequency and phase shift control have been examined using state-plane analysis. These theoretical predictions are confirmed with time-domain simulation and comprehensive measurements from a 3.0 kVA prototype. The power losses resulted from real devices and components account for the discrepancies. Hybrid control has been employed for stand-alone applications. By contrast, phase-shift control only at a reduced switching frequency provides better output performance and higher conversion efficiency. Under light loads, a look-up correction table has been developed to improve the output performance further. The prototype efficiency is measured to be 94% under full load. Integral compensator and phase shift control only have been utilized for grid-connected applications. A damping resistor has been added to damp the resonant oscillation of the output filter. Similarly, a correction table is introduced under light load. An additional compensator, increased DC gains and phase margin compensation have been introduced to improve the output performance further. The impact of the grid-connected converter on the grid voltage is also examined.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:433433 |
| Date | January 2005 |
| Creators | Dai, Chaobo |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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