0
Research Papers

Using Linear Control Theory for Parameterization of a Controller for a SOFC/GT Hybrid Power Plant

[+] Author and Article Information
Christian Wächter

Power Engineering Laboratory of Turbomachinery, Helmut-Schmidt-University, University of the Federal Armed Forces Hamburg, Holstenhofweg 85, D-22043 Hamburg, Germanywaechter@hsu-hh.de

Reinhart Lunderstädt

Power Engineering Laboratory of Turbomachinery, Helmut-Schmidt-University, University of the Federal Armed Forces Hamburg, Holstenhofweg 85, D-22043 Hamburg, Germany

Franz Joos

Power Engineering Laboratory of Turbomachinery, Helmut-Schmidt-University, University of the Federal Armed Forces Hamburg, Holstenhofweg 85, D-22043 Hamburg, Germanyjoos@hsu-hh.de

J. Fuel Cell Sci. Technol 7(3), 031003 (Mar 09, 2010) (9 pages) doi:10.1115/1.3206972 History: Received June 19, 2008; Revised March 21, 2009; Published March 09, 2010

The purpose of the current work is to develop an appropriate control system for a solid oxide fuel cell/gas turbine hybrid system. The main focus lies on the usage of linear control theory for the parameterization of the controller structure. The studies are carried out with a control oriented simplified dynamic model of a 25MWe hybrid system based on a conceptual design previously presented in literature. As a specific feature additional firing of the gas turbine combustor is used as an extra actuating variable offering several advantages. Foregoing necessary investigations deal with calculating the on- and off-design behavior of the sample system and with defining a reasonable part-load operating curve taking into account several constraints like efficiency, stack temperature, surge margin, etc. Also, preliminary studies of the transient open loop behavior are performed. They reveal that the input variables should be changed with specific care to avoid critical situations during load change. As a precondition for linear control theory a low-order linear model is deduced and validated. With consideration of the transient simulation results and of the properties of the linear model a proper control strategy is suggested, which consists of a proportional output feedback taking into account the multi-input-multi-output character of the system and three distributed proportional-integral controllers that define the requested load point onto the operating curve. Lastly, the controllers are parameterized based on linear control theory and verified.

Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Hybrid system configuration with design point data for one power block

Grahic Jump Location
Figure 2

Configuration of the model

Grahic Jump Location
Figure 3

Configuration of the model extension

Grahic Jump Location
Figure 4

Steady state performance parameters for (a) TIT=1433 K (left) and (b) 1183 K (right)

Grahic Jump Location
Figure 5

Meaningful temperatures, differential pressure, and SM for (a) TIT=1433 K (left) and (b) 1183 K (right)

Grahic Jump Location
Figure 6

Definition of the operating curve

Grahic Jump Location
Figure 7

Actuating values on the operating curve

Grahic Jump Location
Figure 8

Additional significant parameters

Grahic Jump Location
Figure 9

Validation of the linear HS model (diamonds) with the nonlinear model (circles) (∗: between anode and combustion plenum)

Grahic Jump Location
Figure 10

Validation of the reduced model (circles) with the original model (diamonds)

Grahic Jump Location
Figure 11

Control strategy

Grahic Jump Location
Figure 12

Bode plot for controller parameterization

Grahic Jump Location
Figure 13

Effects of the additional controllers

Grahic Jump Location
Figure 14

Grid frequency with HS and ST control

Grahic Jump Location
Figure 15

Response to a 6 MW decrease at node 6 (see Fig. 3)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In