The behaviour of a large nuclear reactor can be described with sufficient accuracy using a
nodal model, like the spatial model of a 540 MWe large Pressurized Heavy Water
Reactor (PHWR). This model divides the reactor into divisions or nodes to create a
spatial model in order to control the xenon induced oscillations that occur in PHWRs.
However, being such a large scale system, a 72nd-order model, it makes controller design
challenging. Therefore, a reduced order model is much more manageable. A convenient
method of model reduction while maintaining the important dynamics characteristics of
the process can be done by decoupling. Also, due to the nature of the system,
decentralized controllers could serve as a better option because it allows each controller
to be localized. This way, any control input to a zone only affects the desired zone and
the zones most coupled with, thus not causing a respective change in neutron flux in the
other zones.
In this thesis, three decentralized controllers were designed using the spatial model of a
540 MWe large PHWR. A decoupling algorithm was designed to divide the system into
three partitions containing 20, 27, and 25 states each. Reduced order sub-systems were
thus created to produce optimal decentralized controllers. An optimal centralized
controller was created to compare both approaches. The decentralized versus centralized
controllers’ system responses were analyzed after a reactivity disturbance. A fail-safe
study was done to highlight one of the advantages of decentralized controllers. / UOIT
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OOSHDU.10155/71 |
| Date | 01 November 2009 |
| Creators | Khan, Nafisah |
| Contributors | Lu, Lixuan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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