This thesis focuses on using power electronic techniques to addresses grid integration for wind energy conversion systems. Different approaches to mitigate the low frequency generator torque ripple caused by diode bridge rectifiers are proposed. The advantages and disadvantages of the methods are discussed. A relationship for maximum power point tracking is theoretically analysed. Based on this relationship, two new maximum power point tracking techniques are proposed, which show benefits over conventional tracking methods. Then a pulsewidth modulated current source converter based parallel connected wind energy conversion system is investigated. A new inverter controller for this system is proposed, which is able to maintain a constant average DC network voltage to give satisfactory system performance whilst controlling output reactive power. Practical results support the presented simulations. Furthermore, a fault ride through scheme is proposed for the current source converter based system. The protection scheme uses a shunt resistive chopper to dissipate the active power during faults, and allows the inverter to supply reactive power to support the grid. The space vector modulation for the current source inverter is modified for this application and the design of the dumping resistor is discussed. The system shows riding through capability to both AC and DC network disturbances. This aspect is substantiated by simulation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:571594 |
| Date | January 2011 |
| Creators | Xia, Yuanye |
| Publisher | University of Strathclyde |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=16837 |
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