The growth of embedded generation and portable electrical installations has led
to an increased demand for low cost, flexible and reliable generator systems for military
and commercial applications. An interior permanent magnet (IPM) machine has high
power density due to its reluctance torque and magnetic torque components so it can
produce a large constant power-speed range. However, an IPM machine needs
demagnetizing current at high-speed during the flux-weakening region and thus develops
an inverter shutdown problem in an uncontrolled generator mode operation. In order to
overcome the disadvantages of the IPM machine, the permanent magnet assisted
synchronous reluctance generator (PMa-SynRG) can be a good solution for low cost,
high efficiency reliable generator systems. A PMa-SynRG can produce a high efficiency
drive by utilizing the proper amount of magnet and reluctance torque. This work
proposes a PMa-SynRG with two flux barriers and permanent magnets embedded in the
second layer of the rotor. A neodymium magnet (NdFeB) was used as permanent magnets in the rotor to prevent demagnetization. Finding the minimum amount of
magnet is one of the goals of the optimization process.
The objectives of this work are to build an optimal design for the 3kW generator
and an advanced power electronics converter for the PMa-SynRG drive system. In order
to find the optimized 3kW machine, a Lumped Parameter Model (LPM) was used to
achieve fast computation, and Differential Evolution Strategy (DES) was used to embed
the LPM in an efficient numerical optimization routine to identify optimum designs.
Finite Element Analysis (FEA) was used for test performance of optimum designs. On
the basis of differences between LPM and FEA, model predictions were used to fine
tune the LPM model. For new optimum design converges, numerical optimizations and
iterations were performed to produce LPM and FEA predictions.
For the drive system, the thyristor based, current-fed drive is much simpler and
has lower power losses compared to the pulse width modulation (PWM) drive.
Eliminating the requirement for self-controlled switches is a distinct advantage for lower
cost. Another feature of the developed current-fed drive is its inherent capability to
provide generating action by making the PMa-SynRG operates as a generator, rectifying
the phase voltages by means of the three-phase rectifier and feeding the power into the
load. These features make the current-fed drive a good candidate for driving any type of
synchronous generators including the proposed PMa-SynRG.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-12-7319 |
| Date | 2009 December 1900 |
| Creators | Baek, Jeihoon |
| Contributors | Toliyat, Hamid A. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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