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Effects of Daylight Harvesting on Electronic Lighting Control C opyright © 2004 Joshua Scot Lester - Calvin College Engineering 315 Control Systems.

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Presentation on theme: "Effects of Daylight Harvesting on Electronic Lighting Control C opyright © 2004 Joshua Scot Lester - Calvin College Engineering 315 Control Systems."— Presentation transcript:

1 Effects of Daylight Harvesting on Electronic Lighting Control C opyright © 2004 Joshua Scot Lester - Calvin College Engineering 315 Control Systems

2 © 2004, Joshua S. Lester2 Triac Dimming Zero-crossing A dimmer controls the power to the load through a solid state switch or triac. The triac is synchronized to the AC line through signals obtained at zero crossings Triac-firing The zero crossing signals are then used to fire the triac to give the correct dimmed waveform

3 © 2004, Joshua S. Lester3 Daylight Harvesting System [10] Closed-Loop Lighting Control System Diagram

4 © 2004, Joshua S. Lester4 Photosensor vs. Photocell photocell the light sensitive component inside the photosensor. Photosensor an entire product including the housing, optics, electronics, and the photocell.

5 © 2004, Joshua S. Lester5 Spectral and Spatial Response [1] Closed-loop lighting control block diagram

6 © 2004, Joshua S. Lester6 Input characterization Spatial response The input to a photosensor is optical radiation  infrared (IR)  ultraviolet (UV) radiation For lighting control it is measuring the distribution of luminaire intensity [2] Photosensor Spatial Response Spectrum

7 © 2004, Joshua S. Lester7 Input characterization Spectral response sensitivity to optical radiation of different wavelengths [3] Spectral Response Chart [4] Optical Radiation Chart

8 © 2004, Joshua S. Lester8 Open-loop Proportional Control Open-loop control has one adjustable parameter the constant of proportion between the control voltage and the optical signal [5] Savings in the Spotlight [7] Open-loop control

9 © 2004, Joshua S. Lester9 Closed-loop Proportional Control 2 ADJUSTABLE PARAMETERS: 1. SLOPE ( open-loop response curve ) 2. OFFSET ( commissioning ) Closed-loop control algorithm a.k.a "sliding set point control" [5] Savings in the Spotlight[8] Closed-loop control

10 © 2004, Joshua S. Lester10 Control Algorithm Closed-loop proportional control The ceiling illuminance is 100 lux with no daylight present (from the 5:1 work-plane: ceiling ratio) Desired work-plane illuminance 500 lux Daylight enters the room and adds 250 lux Rate of dimming was set to -0.25% per lux 0.25% per lux X 250 lux = 62.5% This sets the luminaire light output to: 100 lux - (62.5% X 100 lux) = 37.5 lux. The total ceiling illuminance is now 37.5 lux lux = lux. [9] CL Example

11 © 2004, Joshua S. Lester11 Sample of Daylight Harvest Control [6] Simulation of lighting levels in modeled room.

12 © 2004, Joshua S. Lester12 Personal controls

13 © 2004, Joshua S. Lester13 Big Picture

14 © 2004, Joshua S. Lester14 References I.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/controlMostImportantGraphic.jpghttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/controlMostImportantGraphic.jpg Rensselaer Polytechnic Institute, Troy, NY USA II.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/polar.asphttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/polar.asp Rensselaer Polytechnic Institute, Troy, NY USA III.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/spectralgraph.jpghttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/spectralgraph.jpg Rensselaer Polytechnic Institute, Troy, NY USA IV.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/small5.jpg Rensselaer Polytechnic Institute, Troy, NY USAhttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/small5.jpg V.Savings in the Spotlight By John L. Fetters, published June ’02 VI.http://eetd.lbl.gov/btp/pub/designguide/section8.pdf VII.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/openLoopProp.jpg Rensselaer Polytechnic Institute, Troy, NY USAhttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/openLoopProp.jpg VIII.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/closedLoopProp.jpg Rensselaer Polytechnic Institute, Troy, NY USAhttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/closedLoopProp.jpg IX.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/closedLoopExample.jpg Rensselaer Polytechnic Institute, Troy, NY USAhttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/closedLoopExample.jpg X.http://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/photosensors%20fig.jpg Rensselaer Polytechnic Institute, Troy, NY USAhttp://www.lrc.rpi.edu/programs/nlpip/tutorials/photosensors/img/photosensors%20fig.jpg


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