| Keywords |
System components ; Photoelectric dimming control ; Photosensor ; Control algorithm ; Sky ; Integral reset ; Target illuminance ; Lighting energy |
| Abstract |
This study examines the influence of system components of photoelectric dimming control systems on dimming control performance. Field measurements were performed and a series of computation were conducted. Continuous and integral reset control algorithms were used in connection with two photosensor shielding conditions. Results indicate that the change patterns of daylight illuminance of unshielded photosensor were similar to those of desktop illuminance. When continuous dimming control algorithm was used, unshielded photosensor conditions failed to meet a target illuminance. For the partially-shielded photosensor conditions, lighting fixtures overshot the desktop and less energy savings was achieved compared to the condition of unshielded photosensor. When the integral reset dimming control was used, the system failed to keep enough task illuminance. The desktop illuminance by electric light showed sudden peak values with no dimmed light for a particular time period. Partial shielding conditions were successful under overcast sky conditions, but no lighting energy savings was achieved. Desktop illuminance and light output correlated strongly. The ANOVA test results for the correlation were effective under a significance level of 0.01. |