Progettare per il Solid State Lighting: le sfide da superare

Transcription

1 Progettare per il Solid State Lighting: le sfide da superare Power supply - Photometry Remote Control Dott. Ing. Stefano Scalzi stefano.scalzi@torand.it

2 Company introduction Target markets Lighting Power sine wave dimmer 10Kw Electronic Ballast Power Led Applications Power Electronics DC Motor Control Stepper Motor Control AC Asynchronous Automotive Field Electronic Accelerator Motorcycle roll estimation Can Bus projects Implementation of embedded application Development of PCB Documentation Test Production

3 Agenda Power Supply for LED Systems Intelligent Modular Power Supply System Current Loop Power Supply System Thermal Management Photometry Acquisition System Goniophotometer Analysis of the photometry and power supply tuning Remote Control Adopted remote control system Intelligent power supply system Conclusions

4 Power Supply for LED Systems Why constant current power supplies? LED Arrays use high power InGaN light emitting diodes (Indio Gallio - Azoto) Constant voltage: with 8.4V would be 0mA, 70mA and 300mA, respectively, depending on the forward voltage of the array. Constant current: Best way to control the and maintain lumens output

5 Problem statement Requirements: Flexibility: configurable output current Standard 350 ma Medium 500, 700, 1500, 1750 ma High 2100, 3000 ma Modulability: configurable number of channels Different channels with different LEDs Intelligent: dimmable control, remote control, flux vs time regulation, temperature sensing, etc.

6 Intelligent/Modular Power Supply Logic scheme: (1/4)

7 Intelligent/Modular Power Supply PFC Emi Filter Designed to satisfy CE specif. No external filter DC DC resonant (2/4) Introduced since the designed power supply power P=100W Zero and low current detect (on-off) Reduce switching loses at high frequency - LLC series resonant converter Resonant network Square form generator Rectifier network

8 Intelligent/Modular Power Supply (3/4) DC DC resonant Working principle Zero voltage switching technology: At the operating point (F0) the resonant network is inductive. The current in the shunt inductance lags the voltage applied to the resonant network

9 Intelligent/Modular Power Supply (4/4) Configurable output module External N-MOSFET to obtain big current Rsens set output current Rfsel set switching frequency Rfsel L set current ripple depending on Rsens, Rfsel Rs Tuning parameters Depending on the selected output module the number of modules is limited to a maximum total power of 80W

10 Intelligent Module Intelligent Module features: Temperature control Led temperature Driver led temperature Light flux control Four independent dimmer control Ambient Light Sensor (photodiode) Flux vs time control RTC (real time counter) Auxiliary and configurable I/O Remote radiofrequency control by 868Mhz Wired remote control by RS485 (DMX) To 18v DC bus, control and dimmer bus

11 Current loop Power Supply Logic scheme: External intelligent module with external power supply One control loop

12 Current loop Power Supply (comparison overview) PFC + 2 Loops conversion PFC + 1 Loop conversion In: Vac Hz In: Vac Hz Power Factor Correction PFC Protezione corto sovratensione circuito Power Factor Correction PFC e Uscite Led: 4 uscite configurabili Tecnologia di conversione: Risonante 120 Khz. Protezione corto sovratensione circuito Tecnologia di conversione: Risonante 120 Khz. Uscita isolata Uscita isolata Rendimento: 93% full load Rendimento: 85% full load Setup Rise time: 1200 ms Setup Rise time: 1200 ms No DC BUS Selectable DC Bus Load Depending Output e

13 Intelligent Module Applications 1 (1/3) Thermal Management Different current level can be used to make uniform temperature distribution (dimming or modules configuration) Four led with same current Four led with different current

14 Intelligent Module Applications 1 (2/3) Thermal Management How this can be done? Different out LEDs module can be employed Tuning parameters What configuration can be chosen? *1 *2 *1 *1 *2 *3 *4 2 independent led strings *1 *2 *3 4 independent led strings GOAL Maximize efficiency, minimize cost 3 independent led strings

15 Intelligent Module Applications 1 (3/3) Thermal Management Active feedback temperature control (PI) Fail safe thermal management. PI Controller Typical responses

16 Intelligent Module Applications 2 (1/6) Photometry Evaluation of the effects of the configurable LED module in the Torand Power supply Motor control Data acquisition Electronic Board Illuminamento (Lux) Ethernet PC Ethernet Interface 50mm Lux sensing element

17 Intelligent Module Applications 2 Data Acquisition along the X axis Data Acquisition along the Y axis Approximation between the X and Y plane (2/6) The output of the data acquisition is an EULUMDAT file The design of lighting project can be done by commercial sw such as DIALux.

18 Intelligent Module Applications 2 Lents Different lens can be used (3/6)

19 Intelligent Module Applications 2 (4/6) Photometry Different current level can be used to obtain a desired polar graph Configuration: 2x 2x α 1200lm 800lm 1200lm BXRA C BRXA C BXRA C1202 Tot 6400lm + additional reflector 2x

20 Intelligent Module Applications 2 Photometry Evaluation of the polar graph different α α = 145 α = 120 (5/6)

21 Intelligent Module Applications 2 (6/6) Photometry Evaluation of the polar graph different output current module α = 120 Increase current *1 e *3

22 Intelligent Module Connectivity (1/2) Wired Control The intelligent module can communicate with PC to set control parameters. Communication between lighting system CAN bus (Automotive standard) Serial bus RS485 (DMX protocol) Serial bus DALI Full customizable intelligent module

23 Intelligent Module Applications Wireless Communication between intelligent module by radiofrequency 433 MHz 868 MHz 2.4 GHz Interaction between the lighting system and the user by handheld Fully configurable system Data monitor System state monitor (2/2)

24 Conclusions An Intelligent modular power supply as been presented Useful in many applications: Thermal management LEDs life Photometry design Reduce cost Improve efficiency Contatti: Remote control Wired wireless Data monitor