Progettare per il Solid State
Lighting: le sfide da superare
Power supply - Photometry
Remote Control
Dott. Ing. Stefano Scalzi
[email protected]
• 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
Company introduction
• Implementation
of
embedded application
• Development of PCB
• Documentation
• Test
• Production
• 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
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
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.
Intelligent/Modular Power Supply
(1/4)
Intelligent/Modular Power Supply
(2/4)
• Emi Filter
• Designed to satisfy CE specif.
• No external filter
• PFC
• Introduced since the designed
power supply power P=100W
• Zero and low current detect (on-off)
• DC – DC resonant
• Reduce switching loses at high frequency - LLC series resonant converter
Square form generator
Intelligent/Modular Power Supply
(3/4)
• DC – DC resonant
• Working principle
At the operating point (F0) the resonant network is inductive.
The current in the shunt inductance lags the voltage applied to the resonant network
Intelligent/Modular Power Supply
(4/4)
• Configurable output module
• External N-MOSFET to obtain big current • Rsens set output current
• Rfsel set switching frequency
• L set current ripple depending on Rsens, Rfsel
Tuning parameters Rs
Rfsel
• Depending on the selected output module the number of modules is limited to a maximum total power of 80W
Intelligent Module
• Intelligent Module features:
To 18v DC bus, control and dimmer bus • 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)
Current loop Power Supply
• Logic scheme:
One control loop
External intelligent module with external power supply
Current loop Power Supply
(comparison overview)
• PFC + 2 Loops conversion
• In: 85-265 Vac - 50-60 Hz
• Power Factor Correction PFC
• Protezione corto circuito e sovratensione
• Uscite Led: 4 uscite configurabili • Tecnologia di conversione:
• Risonante 120 Khz. • Uscita isolata
• Rendimento: 85% full load • Setup – Rise time: 1200 ms • Selectable DC Bus
• PFC + 1 Loop conversion
• In: 85-265 Vac - 50-60 Hz
• Power Factor Correction PFC
• Protezione corto circuito e sovratensione
• Tecnologia di conversione: • Risonante 120 Khz. • Uscita isolata
• Rendimento: 93% full load • Setup – Rise time: 1200 ms • No DC BUS
Intelligent Module – Applications 1
(1/3)
• Thermal Management
• Different current level can be used to make uniform temperature
distribution
(dimming or modules configuration)
Intelligent Module – Applications 1
(2/3)
• … Thermal Management
• How this can be done?
• Different out LEDs module can be employed • What configuration can be chosen?
2 independent led strings
*1 *2 *1
3 independent led strings
*1 *2 *3 4 independent led strings
*1 *2 *3 *4
GOAL Maximize efficiency, minimize cost
Tuning parameters
Intelligent Module – Applications 1
(3/3)
• … Thermal Management
• Active feedback temperature control (PI) • Fail safe thermal management.
PI Controller
Intelligent Module – Applications 2
(1/6)
• … Photometry
• Evaluation of the effects of the configurable LED module in the Torand
Power supply
50mm PC Ethernet Interface Motor control Data acquisition Illuminamento (Lux) EthernetElectronic
Board
• Data Acquisition along the X axis • Data Acquisition along the Y axis
• Approximation between the X and Y plane
Intelligent Module – Applications 2
(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.
Intelligent Module – Applications 2
(3/6)
• Lents
Intelligent Module – Applications 2
(4/6)
• Photometry
• Different current level can be used to obtain a desired polar graph • Configuration:
1200lm 800lm 1200lm
BXRA C1202 - BRXA C0802 - BXRA C1202 2 x 2 x 2 x Tot 6400lm α + additional reflector
Intelligent Module – Applications 2
(5/6)
• … Photometry
• Evaluation of the polar graph … different α
Intelligent Module – Applications 2
(6/6)
• … Photometry
• Evaluation of the polar graph … different output current module
Increase current *1 e *3 α = 120°
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
Intelligent Module – Applications
(2/2)
• 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 •
Conclusions
• An Intelligent modular power supply as been presented
• Useful in many applications:
• Thermal management • LEDs life • Photometry design • Reduce cost • Improve efficiency • Remote control • Wired • wireless • Data monitor