Effects of Color Contouring on the Detection and Diagnosis of Voltage Violations Within Electrical Power Systems

ARL 1 Abstract New visualization techniques for displaying power system data have been developed to aid operators in detecting and diagnosing faults within a process control situation. The integrated one-line diagram with color contour enhancement was examined as a visualization technique in this experiment. Over a series of trials, participants were required to detect power grid system failures and diagnose contingencies that occurred in the form of voltage value fluctuations. Participants were instructed to identify and acknowledge the worst voltage violation first and then correct all violations by either opening or closing capacitors until the violations were resolved. Participants used information displayed on integrated one-line diagrams that conveyed voltage information using either numbers, color contours, or both numbers and color contours. Results of the experiment revealed that the color contours facilitated the speed and accuracy in which participants could identify the worst voltage violations within the power grid but hindered their ability to diagnose and resolve violations, particularly when a large number of violations existed within the system. These findings illustrate the benefits of color contouring in facilitating visual search by highlighting important information within a display. However, these findings also demonstrate the potential costs of color-coding that may be incurred as a result of display clutter and the transition between perceptual and cognitive processing. Implications for display design are discussed.