Xicato Affordable XIM Quality Dimming

Transcription

1 Xicato Affordable XIM Quality Dimming Grieg Hall in Bergen, Norway, Xicato Artist Series Lighting Design by Kim E. Hughes, Bright Norway, Luminaires by Roblon

2 XIM Overview Better quality of lighting Affordable, quality dimming Deep, smooth, and no flicker throughout the dimming range. Initial color consistency, maintained color consistency, superior color rendering. Smaller, more compact luminaires. Lower cost of ownership Onboard diagnostics and operating protection. Electrically future-proof. 5 year color and lumen maintenance warranty. Designed for the trend toward intelligent buildings Distributed DC smart building zones. Higher power, central DC power supply and remote, sensor-rich DC-powered intelligent light module nodes. 2

3 Dimming System Basics

4 Dimming Protocols- Examples Dimming protocols provide a set of rules for communication between two or more devices VDC (0-10 VDC) Separate AC power and control One-way communication Two standards ANSI E1.3, originally developed by the Entertainment Services and Technology Association (ESTA) in 1997 for theatrical equipment. IEC Annex E, originally released in 1992 for linear fluorescent systems. DALI (IEC /102:2009 and IEC ) Lutron Ecosystem (DALI-like) DMX512 Wireless Power Line Carrier (PLC) Others 4

5 Dimming Methods There are two common methods of dimming for commercial new construction applications. Pulse Width Modulation (PWM) Constant Current Reduction (CCR) 5

6 Pulse Width Modulation (PWM) In PWM systems, the LED(s) are turned on and off very quickly. At full light output, the LED is on and never turns off. If the speed of switching on and off (frequency) is high enough, the human eye won t see the switching. At 50% of light output, the LED is on half the time and off half the time. To dim the light to any given level, you change the ratio of time on and time off. 6

7 Constant Current Reduction (CCR) In CCR systems, the current to the LED(s) is increased or decreased. Because LEDs are current driven, the light output changes. As current is decreased, light output decreases. LEDs sources do not all behave the same as current is reduced. Wiring can also affect current across a system. As a result, dimming performance can be inconsistent. To dim the light to any given level, you reduce the current being applied to the LEDs. 7

8 Hybrid PWM and Current Dimming* Combines PWM and current dimming. PWM dimming operates with a lower range of light. Current dimming operates a higher brightness values. The optimum switch point between PWM and current dimming modes and current slope depend on the LED type. * 8

9 Flicker Flicker: The rapid fluctuation of light in a cyclical manner. Photometric Flicker: Shown to be related to migraines, headaches, autistic behaviors, reduced visual performance, and comfort, along with other possible neurological health issues (IEEE/P1789). Visible flicker Invisible flicker 9

10 Frequency & Flicker Frequency refers to the speed of switching the light on and off. The frequency of the pulse-width matters. The faster the frequency or Hertz (Hz) the lower the flicker risk becomes. Low frequencies are known to cause migraines or seizures in certain conditions with certain people. Heinrich Hertz 10

11 Percent Flicker (% Flicker) Well known metric for quantifying flicker. Accounts for amplitude variation and average level of flicker. Does not account for differences in periodic frequency. Recognized as inadequate relative to LED technology. Modulation % is the same as % Flicker. 11

12 Measured vs. Perceived Light Why 1% is important Measured Light Intensity Dimming Reduction Perceived Light Intensity 12

13 Human Eye Response Quality dimming requires that multiple systems that behave differently be synchronized. The dimming input (Dimmer) The LED dimming driver The LED light source How these work together, combined with the human eye response, determines the quality of the dimming. 13

14 Recent Research on Dimming and Flicker

15 LED Lighting Flicker and Potential Health Concerns: IEEE Standard PAR1789 Update But for sufficiently high flicker frequencies, there are limited human biological effects. We do offer simple suggestions as to what should be considered when designing lamps, such as flicker frequency, angle of viewing, task being performed, spatial distribution, AC dimmer flicker, etc. 15

16 US Department of Energy- Building Technologies Office Flicker Fact Sheet (2013) Standardized flicker measurement procedures are not yet in place, and existing flicker metrics have inadequacies that may be exposed by LED products LED flicker characteristics are primarily a function of the LED driver. Different circuit architectures present different sets of performance tradeoffs for a driver designer The effects of flicker are dependent on the light modulation characteristics of the given source, the ambient light conditions, the sensitivity of the individuals using the space, and the tasks performed 16

17 IEEE Power Electronics Magazine (Sept 2014) The flicker depends on the drivers selected for the LED.when dimmed, some of the lamps had flicker that was noticeable About PWM Dimming: This means that keeping the flicker frequency > 1.25kHz would minimize visual distractions. The no-observable effect level flicker is > 3 khz About Flicker Risk: Flicker health risks depend upon a variety of lighting applications and exposure factors 17

18 Flicker Risk: Lehman/Wilkins Flicker Risk 18

19 LRC Guidelines: How low should you go? As technologies improve and more lamp/dimmer combinations are able to achieve lower minimum dimming levels, the minimum to maximum percent value should be revised to a lower number in order to encourage the development of products that meet most user s expectations Conventional Approach to Determining Minimum Dimming Levels Architectural (e.g. 1%) Energy Efficiency (e.g. 5-10%) 19

20 LRC Guidelines: Dimming Profile No limitation on the detailed shape as long as the dimming profile is monotonic and meets the dead travel and range requirements No more than 10% of dimmer travel at the top and bottom, or the middle of the dimmer setting Ideal Dimming Profile 20

21 XIM Dimming and Flicker Performance

22 Lighting Control System vs. Luminaire System Lighting Control System User (Input) Luminaire Lighting System (Output) + 22

23 Luminaire Lighting System 23

24 Xicato s Intelligent Dimming Solution Current-reduced PWM Technology (Hybrid Approach) Low to moderate dimming Use CCR to reduce light levels. Moderate to deep dimming Transition to a PWM-based solution at very high frequencies to avoid flicker. By integrating the dimmer in the module Xicato s driver can use data about the LEDs and system performance to ensure smooth, deep dimming across the entire control range. 24

25 Dimming Performance Example (1-10V) 25

26 Flicker Risk: Lehman/Wilkins Recommendation 26

27 Flicker Risk: XIM Dimmed State 27

28 Flicker Risk: Conventional LED Dimming Dimmed State 28

29 Xicato s Recommend Dimming Specification Dimming Performance: Module shall dim to 1% (measured flux) at lowest level. Fading across the dimming range, and to off, shall be smooth and monotonic. Minimum flicker frequency at 1% measure light output shall be 1.25 khz. 29

30 Ensuring a Quality Dimming Installation

31 Ensuring a Quality Dimming Installation 1. LED Driver Matched to the Light Source 2. Easy to See and Measureable Dim to off? Dim to 1% or lower? Also a function of the control system Measured flicker? Dimming curve (linear, logarithmic, measured, perceived etc.) 3. Easy to See and Harder to Measure On/Off smoothness Control response range Control response smoothness On/Off time 4. Light Source with the Dimming System Control response Dimming response Dimming depth System integration Grieg Hall, Bergan Norway 31

32 Ensuring a Quality Dimming Installation 5. Light Source+ Dimming System Compatibility Do the systems comply with recognized IEC/ANSI standards? Do the systems have a log output (1-10V only) Test the luminaire system (LED source+ driver) Test for flicker Mock up the entire system. Test for flicker, depth, smoothness, fade to on/off. 32