Reliability Assessment and Energy Loss Evaluation for Modern Wind Turbine Systems
Research output: Book/Report › Ph.D. thesis
Abstract
The documented thesis starts with the descriptions of the DFIG system and the PMSG system. The design of the back-to-back power converters and the loss model of the power semiconductor device are discussed and established in Chapter 2. Then, Chapter 3 and Chapter 4 are dedicated to the assessment of the wind power converter in terms of reliability. Specifically, Chapter 4 estimates and compares the lifespan of the back-to-back power converters based on the thermal stress analyzed in Chapter 3. In accordance with the grid codes, Chapter 4 further evaluates the cost on reliability with various types of reactive power injection for both the configurations. The cost of energy in wind turbine system is then addressed in Chapter 5, where different wind classes and operation modes of the reactive power injection are taken into account. Finally, the internal and external challenges for power converters in the DFIG systems to ride through balanced grid faults are explored in Chapter 6.
The main contribution of this project is in developing a universal approach to evaluate and estimate the reliability and the cost of energy for modern wind turbine systems. Furthermore, simulation and experimental results validates the feasibility of an enhanced lifespan of the power electronic converters and reduced cost of energy in the DFIG system, employing a proper reactive power control method between the back-to-back power converters. In the case of grid disturbances, an optimized demagnetizing current control strategy has been proposed in order to keep the minimum thermal stress of the DFIG power converter, and thus improve its reliability.
Details
The documented thesis starts with the descriptions of the DFIG system and the PMSG system. The design of the back-to-back power converters and the loss model of the power semiconductor device are discussed and established in Chapter 2. Then, Chapter 3 and Chapter 4 are dedicated to the assessment of the wind power converter in terms of reliability. Specifically, Chapter 4 estimates and compares the lifespan of the back-to-back power converters based on the thermal stress analyzed in Chapter 3. In accordance with the grid codes, Chapter 4 further evaluates the cost on reliability with various types of reactive power injection for both the configurations. The cost of energy in wind turbine system is then addressed in Chapter 5, where different wind classes and operation modes of the reactive power injection are taken into account. Finally, the internal and external challenges for power converters in the DFIG systems to ride through balanced grid faults are explored in Chapter 6.
The main contribution of this project is in developing a universal approach to evaluate and estimate the reliability and the cost of energy for modern wind turbine systems. Furthermore, simulation and experimental results validates the feasibility of an enhanced lifespan of the power electronic converters and reduced cost of energy in the DFIG system, employing a proper reactive power control method between the back-to-back power converters. In the case of grid disturbances, an optimized demagnetizing current control strategy has been proposed in order to keep the minimum thermal stress of the DFIG power converter, and thus improve its reliability.
Original language | English |
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Publisher | Department of Energy Technology, Aalborg University |
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Number of pages | 217 |
State | Published - 2014 |
Publication category | Research |