universidad de oviedo, e&e eng. dept. industrial
TRANSCRIPT
05/sep/2008
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An Introduction to Efficient Lighting
J. Marcos Alonso
University of Oviedo, Asturias Spain
Universidad de Oviedo, E&E Eng. Dept.Industrial Electronics and Lighting Group
Viesques Campus, Gijón
Asturias
The City of Gijón
05/sep/2008
2
Universidad de Oviedo, E&E Eng. Dept.Industrial Electronics and Lighting Group
C iGroup Members:2 Full Professors 5 Associate Professors4 Ph. D. Students5 M.Sc. Students
Companies:
Outline
IntroductionLampsBallastsDigital ControlConclusions
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First idea:Light accounts for nearly 25% of the electrical energy consumption in the industrialized world
Introduction
Europe South America
Percentage of energy use in commercial buildings by end user
Introduction
Lighting is a nice piece of the pie
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Some Basic ConceptsIntroduction
Electromagnetic Spectrum100
Human’s Eye Response
ElectricLighting
100 380 770
50
0
λ [nm]
V(λ) P(λ)EYE RESPONSE
Power(W)
RadiatedPower
LightingPower
Non-LightingPower
Heat Losses
CorrectedLightingPower(Lumen)
Select the adequate light source for each applicationIncandescentDischarge
IntroductionBasic hints for energy saving in lighting:
Select the adequate auxiliary equipment:Magnetic ballastElectronic ballastDimming circuit
Select the adequate control strategy:Select the adequate control strategy:SchedulingTask tuningDaylightingLumen maintenancePresence detection …
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Some countries are already taking actions:Introduction
Australia
Traditional light bulbs will be banned by 2010 in AustraliaThis will lead to a reduction of 800.000 tons of CO2 per yearTotal CO2 produced annually in the world is 564 Mtons (2004)
IntroductionEuropean Union
The least efficient lamps will be phased-out from the European market by 2015The industry will have to switch to energy saving CFL or high-efficient halogen lampshalogen lamps
As a result (future):Reduction of 23 M tons of CO2 emission per year63,000 GWh of energy saved per year
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Outline
IntroductionLampsBallastsDigital ControlConclusions
Evolution of Lighting in HistoryLamps
Solid State
Solid state is not yet a full mature technologyThe most efficient and long-lasting lamps are still based on electrical discharge
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Lamps
Incandescent LampsLamps
100P( λ )
mWnm
P( λ )
mWnm
Typical EmissionResponse
100 1.000 10.000380 770
50
0
λ [nm ]
nmnm
40.001.53.803Carbon
0.0419.13.668Tungsten
0.0188.91.367
RESISTIVITY 20ºC
DENSITY[gr/cm3]
MELTING TEMP.[K]
MATERIAL
40.001.53.803
0.0419.13.668
0.0188.91.367Copper
[gr/cm3][K]
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Lamps
Filli
Incandescent Lamps
Filling gas:Vacum for P< 40WN + Ar, Kr, Xe: P>40W
Tugnsten (Wolfram) Filament
BASIC CHARACTERISTICS:
1.- Instant Ignition2.- Very Good Color Rendering Index (CRI) 3.- Low Luminous Efficacy: 10-20 lm/W4.- Short Life: 1000-2000 hours
Lamps
Incandescent Lamps
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Discharge LampsLamps
Elastic Collision
Free Electron Free Electron
Ionization
Radiation
Heat GenerationTemp. Increase
Free Electron GenerationDischarge
Free Electron
Generation of RadiationLight
Fluorescent LampLamps
Light
Basic Operation
Excitation
Ionization
Radiation UV
PhosphorCoating TubeElectrode Mercury
AtomAtom
BASIC CHARACTERISTICS:
1.- Operation at 0.8-1 atm.2.- Good Color Rendering Index (CRI) 3.- High Efficacy: 60-00 lm/W4.- Long Life: 10,000 hours
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Compact LampsLinear Lamps
Lamps
T12T8
T5T3
T12: 38 mmT8: 25 mmT5: 15 mmT3: 9 mm
Compact Fluorescent LampsLamps
With Integrated BallastThey are a direct replacement
For Incandescent Lampsp
Recommended for lighting points with burning hours higher than 1 hour per day continuously
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Compact Fluorescent LampsLamps
With Integrated Ballast
Many different models, with different functionalities, are available
Expected Payback Time in Years for CFLLamps
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High Pressure Mercury Vapor LampsLamps
⎥⎦⎤
⎢⎣⎡
WLmη
40
60
Mercury Vapor
HPMVFluorescent
P [Pa]1 104102 106
20
40
Spectrum
Fluorescent
350 400 450 500 550 600 650 700 750λ [nm]
BASIC CHARACTERISTICS:
1.- Operation at 2-4 atm.2.- Poor Color Rendering Index (CRI) 3.- Good Efficacy: 25-60 lm/W4.- Long Life: 15,000 hours
Metal Halide LampsLamps
⎥⎦⎤
⎢⎣⎡
WLmη
40
60
Mercury Vapor + M. Halides
P [Pa]1 104102 106
20
40
Spectrum
BASIC CHARACTERISTICS:1.- Incorporate Metal Halides (Tl, Dy, Sc, etc.)2.- Very Good Color Rendering Index (CRI) 3.- Good Efficacy: 80 lm/W4.- Medium Life: 6,000 hours
350 400 450 500 550 600 650 700 750λ [nm]
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High Pressure Sodium Vapor LampsLamps
Sodium Vapor100
80
LuminousEfficacy[%] Low
Pressure
Spectrum
60
40
20
1 10 100 1.000 10.000
Discharge Pressure (Pa)
100.000
STANDARD (IRC 20)IRC 60
IRC 80HighPressure
BASIC CHARACTERISTICS:
1.- Operation at 7-100 kPa2.- Medium Color Rendering Index (CRI) 3.- Good Efficacy: 50-120 lm/W4.- Long Life: 20,000 hours
350 400 450 500 550 600 650 700 750λ [nm]
HPSCRI=60
Low Pressure Sodium Vapor LampsLamps
Sodium Vapor100
80
60
LuminousEfficacy[%] Low
Pressure
LPS
60
40
20
1 10 100 1.000 10.000
Discharge Pressure (Pa)
100.000
STANDARD (IRC 20)IRC 60
IRC 80HighPressure
Spectrum
350 400 450 500 550 600 650 700 750λ [nm]
LPS
BASIC CHARACTERISTICS:
1.- Operation at 0.4 Pa2.- Very Poor Color Rendering Index (CRI) 3.- Very Good Efficacy: 60-150 lm/W4.- Long Life: 15,000 hours
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Consumption Distribution Lamps
About 70% of artificial lighting is generated by discharge lamps80% of energy consumption is professional lighting
Future Light Sources: LEDsEvolution of Light Sources: Status Quo 2007
Lamps
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Future Light Sources: LEDsLamps
60
70
Nominal Datasheet Flux (350mA @Tj=25 C) vs. Useable Light Flux
0
10
20
30
40
50
60Lu
men
LuxeonK2
LuxeonI
Cree Osram Nichia SeoulSemi
NominalUseable
Outline
IntroductionLampsBallastsDigital ControlConclusions
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Typical Electrical Circuit: FLBallasts
BALLAST(CHOKE)
GLOWSWITCH
ACMAINS
SWITCH
Typical WaveformsTypical WaveformsVoltage
Current
Ballast and Igniter for HPS LampBallasts
3-5 KV – ton=50 μS
Ballast Igniter Capacitor
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Ballast and Igniter for MH LampBallasts
7-12 KV – ton= 0.5 μs
Ballast Igniter Lamp
High Frequency OperationFluorescent
(Low Pressure Mercury)
Ballasts
Low Pressure Sodium
100
110
120
LUMINOUSFLUX[%]
100
115
LUMINOUSFLUX[%]
50 100 K 3 M
FREQUENCY[Hz]
50 25K 400K100KFREQUENCY
[Hz]
In these lamps the increase of frequency provides and increase of luminous efficacy
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Electronic Ballast Vs. Magnetic BallastsBallasts
Operation at low frequencyOperation at low frequencyHigh losses, poor efficiencyStroboscopic effectAcoustic noise (humming)High volume and weight
Operation at high frequencyLow losses good efficiencyLow losses, good efficiencyNo Stroboscopic effectNo Acoustic noiseLow volume and weight
Market share of ballastBallasts
The market share of electronic ballasts is growing: From 24 % in 2000 to 31% in 2004
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Typical Circuit of Electronic BallastBallasts
Rectifier Inverter Filter(Tank) Lamp
MainAC
(Tank)
50 Hz DC 50 kHz 50 kHz
Electronic Ballast Design
C L
LCC Resonant TankVIGNITION
Ignition
Heating
Ballasts
RLA
CS
CP
L
VS
VHEATING
VLAMP
Q=RLA/ZB
Q~
Q~
Running
Heating
Lamp:VLA=30Vrsm ILA=0.8Arms
RLA=37.5 Ω
ΩR
Q RLA/ZB
ΩIG ΩH
An LCC resonant tank is used to ignite and supply the lampA soft-starting strategy is implemented in order to increase lamp’s life
RunningLA
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Electronic Ballast Design
HeatingV
+CS
L
VHIHCP
IHIH
Ballasts
The frequency needed for a given heating current IH is:
2
21
2 ⎟⎟⎠
⎞⎜⎜⎝
⎛++=Ω
HB
S
HB
SH IZ
VIZ
V
The heating voltage at this operating point: 12 −Ω=
H
SH
VV α
VS -P
IgnitionIgnitionThe ignition voltage is obtained at the following frequency:
IG
SIG V
Vα+=Ω 1VIG
Electronic Ballast Design
RunningI
Ballasts
RLA
CS
CP
L
VS
At natural resonant frequency (Ω=1), the circuit behaves as a current source:
VLA
ILA
current source:
B
SLA Z
VIα
=
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Electronic Ballast DesignLamp Data @ 50kHz
VLA=30VrsmILA=0.8ArmsR 37 5 Ω
Ω=== 2008090
2//)2/320(4 πα
SB I
VZ
α = 0.9 Base Impedance
Ballasts
RLA=37.5 Ω ⋅ 8.09.0α LAI
mHf
ZLS
B 63.010502
2002 3 =
⋅==
ππ
nFZf
CBS
P 7.172009.010502
12
13 =
⋅⋅⋅==
παπ
nFZf
CBS
S 1.1592001.010502
1)1(2
13 =
⋅⋅⋅=
−=
παπ
Resonant Elements
Heating Frequency and Voltage (IH=0.7 Arms):
64.17.02002
14417.02002
144 2
=⎟⎠⎞
⎜⎝⎛
⋅⋅++
⋅⋅=ΩH RMS
H
SH VVV 7.60
177.11449.0
1 22 =−
⋅=
−Ω=
α √
Lamp Waveforms
Power
Ballasts
Power
Current
PLA23W
Voltage
20 V/DIV, 0.5 A/DIV, 5 μs/DIV
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Life extension of fluorescent lampsBallasts
The winner is:
ElectronicBallast with Rapid Start
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Outline
IntroductionLampsBallastsDigital ControlConclusions
Digital Control of Electronic Ballasts
Primary
Digital Control
PrimarySource Ballast Lamp
Regulator SensorMicrocontroller
Discretization
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EMI Filter&
Power Supply
AC Line
Vbus= 320V
Vcc=15V
Vdd=5V
General Diagram of the UV Ballast
Half-Bridge Inverter
Digital Control
GateDriverIR211μC
ST6253
Freq
OC
Rs
UV LAMPGPH436T5
TemperatureSensor
DissolvedOzoneSensor
A1
A2
B1
B2
VDD
A/D
A/DNMI
A/D
ARTimer
GND
VbusSensor M1
M2
CF L
C
R1
R2A/D
Low-CostμC
B2
AD633Vlamp
Ilamp
Plamp
Analog Multiplier& Filter
Basic Microcontroller Circuitry+5V
+15VR4470
R5470
D2 D3
Reset
Display
Digital Control
ST6253
VDD9
VSS10
OSCin OSCout
XTAL8MHz
C115
C2
ARTIMout
TO IR2111
R347k
R147k
R24.7k
Rs47k
Cs220n
/RESET16
14 15
7
D11N4148
PB1 PB01 2
470
PWM
PWMSignal
15p 15p
Low cost microcontroller ST6253 with high noise immunityPower switches are driven directly from the MCUA 8MHz crystal is used for the MCU oscillator
Oscillator
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Half-Bridge Driver and Current Protection Circuit
+15VDb
BA157
+320V
Digital Control
IR2111
VCC
IN
COM
LO
1
2
3
4
PWMfrom MCU
VB
HO
VS
N.C.
8
7
6
5
Cb220n
Rg14.7
Rg24.7
Rs1
Rp11k
+5V
TO ResonantTank
Ra
M1IRF840
M2IRF840
Half-Bridge Driver
Dp1N4148
Cp100p
Rp212kTO NMI
pin 17 MCU
Ri2 15k
Ri1 10k
Ci 270n
+5V
Ra47k
Ca1n
LM393
Current Protection
Circuit
SensingResistor
Resonant Tank and Lamp Detection
Cs160n L
0.65mHTo lamp
From HalfBridge
A1
Resonant Tank
Digital Control
+5V
Rd2100k
Rd147k
Dd1n4148
Cd220n
20:1
Cp18nF
To lampelectrode B
To lampelectrode A
To pin PA0MCU
A2
B1B2
Lamp Detection Circuit
A LCC resonant tank is usedAn additional winding is used in the inductor to detect lamp presence
Lamp Detection Circuit
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Power Supply and EMI FilterPhase
VarV250
C11u/X1
18mH/
C210n/X1
C34.7n/Y1
C44 7 /Y1
Earth
L1
EMI Filter
Digital Control
Neutral 18mH/1A
4.7n/Y1
~
~
+
-
DB1A
v
C547u/350V
To HalfBridge
Vbus = 320V
Rdis100k
+15V +5V
Rl11k
Rl2120k
+5V
To pinPA2 MCU
Dl1n4148
L2
L1
L2
L1 To MCU
Input Stage for Resonant Inverter
C6330u
DB0.2
LM7805C810u
C9100n
L1
L2
To MCUSupply
C7330u
v
~
~
+
-
-15V
To Aux.CircuitsSupply
DC Power Supply
Lamp Power Sensing Circuit
To resonanttank
UV LAMP
Rb1 1kRb2 2.2k
+15
Cf 470n
Digital Control
R12/N27
6
To resonanttank
Ra4.7
Rb1 1kRb2 2.2k
AD6331X1
Y13
-15
8
52 4 6
7
-15
+15
-15
+15 Rf1 10k
Rf2 10k
PLAMP
To pin PA1MCU
+5
Df1N4148
TL081
Current Transforme
r
VLA
ILA
Multiplier
Low PassFilter
Lamp current is measured using a current transformerAn AD633 multiplier is used to obtain the lamp instantaneous powerA low pass filter is used to obtain the lamp mean power
r
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Microcontroller Programming
INITIALIZATION
RESETMainProgram
Interrupt
Digital Control
SOFT-START
LAMP DETECT ?
POWER REG
YES
NO
STOP PWM
NMI
WAIT 0.5 sec
RETIPOWER REG RETI
Watchdog register is programmed to increase robustness (TR=24.5 ms)Main routines are Soft-Start and Power RegulationNMI interrupt is used to implement overcurrent protection
Soft-Start Routine
100
Start
Heating
Freq(kHz)
Digital Control
80
7065605550
0.1 0.6 1.0 t(s)
Ignition ramp
Running
Autoreload register is used to generate PWMTwo registers are used, reload (RC) and compare (CP):
RCRCCPDuty
RCkHzf
−−
=−
=255255
8000)(
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Power Regulation RoutineA simple regulation routine is used in order to be feasible its implementation in the selected low cost microcontrollerThe reload register is modified in a value proportional to the
Digital Control
The reload register is modified in a value proportional to the error signal:
kkk eARCRC ⋅+= −1
RCkHzf
−=
2558000)(
8000)(
2fRCddf
=
If ek>0 (PLA>PREF) ⇒ RC ↑ ⇒ f ↑ ⇒ PLA ↓The regulation routine has been adjusted experimentally, final values are: A=0.5 and sample time of 0.1sThe switching frequency is limited within the range: 45-80 kHz
Power ResponseDigital Control
LampPower
Reference
180 V
230 Vrms
Line Voltage Step
8 W/DIV, 0.5 s/DIV
180 Vrmsp
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Laboratory prototypeDigital Control
Electronic Ballast for HID Lamp with Digital ControlDigital Control
Microcontroller:
PIC16F684 from Microchip, 14 pins, low cost.
8 bits, internal oscillator (8MHz), PWM module, A/D converter, and timers.
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Block Diagram
LampModel
Digital Control
26240454,2)()()( 2439
+==
sD
sIsG
pszsk
sisv
szL
LL +
+==
)()(
)(
Model
9654612,110387,1109,9)()( 2439 ++⋅+⋅ −− ssssD
Lamp current regulation in closed loop
The model includes lamp and ballast dynamic behavior
Design by SISOTOOL (Matlab):- A=12.5 - Phase Margin: 90º- Response Time: 100ms
Designing the Closed LoopDigital Control
p
ssR 5.12)( =
1
1
11)()()(
−
−
−⋅⋅
=−⋅
==z
zTAz
TAzEzDzR mm
11 81
−− += kkk DD ε
Discretization (Tm=10ms): Difference Equation:
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Simulation with Matlab SimulinkDigital Control
Simulation Results
Reference
Digital Control
Error
Regulator
Output
Perturbation
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Experimental Results
Lamp Current Lamp CurrentSteady State Transient
Digital Control
50 V/div – 0.2 A/div – 5 ms/div 250 V/div – 0.5 A/div – 20 ms/div
Lamp Voltage Line Voltage
Program FlowchartDigital Control
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Laboratory prototypeDigital Control
Lighting system with power line controlDeveloped by University of Oviedo
FILTERCOMM.
LIGHTING
MAIN SWITCHROOM SWITCHES
Digital Control
FILTERLIGHTINGMAIN SUPPLY
PCMASTER NODE
#1.1 #1.2 #1.3
#2.1 #2.2 #2.3
ROOM 1
ROOM 2
POWER LINE
PCADAPTER
#3.1 #3.2 #3.3 ROOM 3
Power Line is used as communication mediumSimple installation procedureAble to implement any control strategy
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Ballast Block Diagram
PFC ResonantI t400VM i
Lampss
Digital Control
Stage StageInverter
Power LineComm.
Neuron ChipControl
Comm.Bus
400V DC Bus
Mains
FREQ. LP1, LP2
s
Stage StageCo t o
CLK 10MHz
Management softwareDigital Control
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SchedulerDigital Control
SchedulerDigital Control
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Conclusions
Nowadays much energy is wasted in lighting due to the use of non-adequate lamp types or ballasts.q p yp
Lighting technology existing today allows saving up to 30-60% of energy.
Any good action taken or control strategy implemented, even being initially costly, will be paid back by the saving in electric consumption.
For large investments an economic study is crucial to determine the payback time
Thank you !
Asturias
Gijón