T1 OPTIMIZATION March 2006

Definition T1 optimization is process that accomplishes and maintains the highest efficiency possible for an individual generating unit. Self optimization accomplishes optimization internally by design of a unit Maintenance by occasional or continual repetition of the process Possibility includes theoretical and practical limits

Precision vs. Accuracy Precision relates to repeatability and random error. Accuracy relates to total error. A test result may be consistently wrong. That is precise, but not accurate.

Target Practice Example Shooting at a target with a spotter Put cross hairs on the bulls eye Take 7 shots and get a report At first, the spotter only reports total error in inches, no direction.

DATA Shot Error, inches 1 10 2 11 3 8 4 13 5 14 6 12 7 9

Average error is 11 inches Graph Average error is 11 inches

Which is it? It could be either one

Precision or accuracy Left example vs right example Accuracy is the same Left is entirely random error Right is systematic and random error Right is more precise than left Right can be improved by optimization Left can not

Optimized Blade Control Guided or methodical An index test is like the spotter telling amount and direction of error. Then aim low and to left by 11 inches. The test box would try aiming high, low, left, right, then pick best one. The process is repeated until further adjusting no longer improves efficiency.

Improve position sensors precision If sensors are inaccurate, after optimization, the result is as the left example. (like Columbia units with existing 3-D Cams) Improving sensors without optimization is as the right example. (like new GDACS 3-D Cams without optimization) In both cases efficiency is lost.

Better Sensor and Optimization If install the new GDACS 3-D Cams and institute T1 optimization, get this:

Caveats Frequency of repeat optimization With time, drift will introduce new systematic error and return to right example. Less precise position sensors introduce random error and result in left example. Need both self optimization and the best sensors available. Best to have self optimization continually

Advantage of GDACS 3-D Cams Only digital position sensors mounted on Wicket gate shaft (GDACS units) can achieve better than 0.1% accuracy. Analog sensor (other units) limited to 1% due to technology. Sensors on servo (other units) impacted by bull ring slop (more scatter). Wicket gate shaft mounted sensors (GDACS units) null bull ring slop (less scatter).

Advantage of GDACS 3-D Cams Index test box code already running on Walla Walla GDACS integrated platform. Implementation on a standard generic platform easier than re-engineering for other platforms. (Design is proven and standard) 42 units in Walla Walla District already have the new GDACS integrated 3-D Cams installed.

Advantage of GDACS 3-D Cams GDACS integrated 3-D Cam technology most appropriate for probable improved blade position sensor technology. GDACS integrated 3-D Cam technology uses generic platform and operation software that facilitates future system enhancements. (technology is the proven GDACS standard)