GovGAST : Documentation diagram
Created: |
04/04/2012 12:07:20 PM |
Modified: |
04/13/2012 12:38:42 AM |
Project: |
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Author: |
pcha006 |
Version: |
1.0 |
Advanced: |
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ID: |
{0C0639D4-C78B-4d3c-B873-99ED87B49094} |
<b>Parameter Notes:</b><br /></p><p><ol><li><b>T1</b>, <b>T2</b>, <b>T3</b>, <b>Tltr</b>, <b>R</b>, and <b>b</b> must be greater than zero. <b>Rmax</b> thru <b>Ltrat</b> may be set to 99. to disable rate limiting. </li><br /></p><p><li><b>T1</b> represents the natural valve positioning time constant of the governor for small disturbances, as seen when rate limiting is not in effect.</li><br /></p><p><li><b>T2</b> represents delay due to internal energy storage of the gas turbine engine. <b>T2</b> can be used to give a rough approximation to the delay associated with acceleration of the compressor spool of a multi-shaft engine, or with the compressibility of gas in the plenum of a the free power turbine of an aero-derivative unit, for example.</li><br /></p><p><li><b>T3</b> represents delay in the exhaust temperature and load limiting system. <b>Lmax</b> is the turbine power output, in per unit, corresponding to the limiting exhaust gas temperature.</li><br /></p><p><li><b>Rmax</b>, <b>Linc</b>, <b>Tltr</b>, <b>Ltrate</b> represent a loading rate limit subsystem. For small excursions about a steady load the fuel valve can open at a rate of <b>Rmax</b> pu/sec. The time constant, <b>Tltr</b>, is used to obtain a long term average valve position. When a large output increase is called for, the fuel valve is allowed to open at the full rate only until the valve opening has moved ahead of the long term average position by <b>Linc</b> pu. After this the valve is permitted to open only at the rate, <b>Ltrat</b>, until the long term average position catches up.</li><br /></p><p><li>The nonlinear gain on the output may be input with up to 6 points. The (0.,0.) and (1.,1.) points are assumed and need not be input. The output is not allowed to go beyond 0. and 1. However, if <b>Vmax</b> > 1., the input and output are scaled by this value. If input is omitted or if all zero values are input, a straight line is used.</li><br /></p><p><li>If <b>T5</b> is zero, the entire gain and lead-lag block is bypassed.</li><br /></p><p></ol><br /></p>