Download Electronic Ballast Platform

Electronic Ballast
Platform - EBP
Dos Reis, F. S.; Lima, J. C.; Tonkoski Jr., R.; Dantas, C.
G.; Suzuki, T.; Martinazzo, F.; Godinho, L. A.
Pontifical Catholic University of Rio Grande do Sul
Brazil
Table of Contents
 INTRODUCTION
 OBJECTIVES
 THE ELECTRONIC BALLAST PLATFORM
 BALLAST DESIGN
 EXPERIMENTAL RESULTS
 CONCLUSIONS
INTRODUCTION
- Environment preservation
- Importance of electric power quality:
 Total Harmonic Distortion (THD);
 Displacement Factor;
 Power Factor;
- Energy crisis in 2001
- Illumination Segment consume was
Estimated to be 30 % of total Electrical
Energy produced in the world
OBJECTIVES
- Develop an electronic ballast platform
with easy frequency and duty cycle
variations and simple control strategies
implementation.
- This platform will allow the study and
development of ballasts for HID lamps.
HIGH INTENSITY DISCHARGE LAMPS (HID):
High Pressure Sodium Lamp (HPS)
• Discharge tube made of Synthesized
Aluminum;
• Does not produce Ultraviolet
radiation;
• Needs about 2.5 kV pulse for lamp
ignition;
• One of the lamps with higher
lifetime;
HIGH INTENSITY DISCHARGE LAMPS (HID):
High Pressure Sodium Lamp (HPS)
The HPS lamps have many
particularities when they operate in
high frequency, such as:
• Can be modeled by a resistance in
steady state;
• Can have
intensity;
controlled
luminous
• The spectrum color reproduction
can be modified;
• Presents the acoustic resonance
phenomenon;
HID NEGATIVE RESISTENCE
Positive Resistance
Lamp
Current
Negative Resistance
Lamp
Voltage
Breakdown Voltage
■ Voltage
■ Current
ELECTRONIC BALLAST STAGES
EMI
FILTER
RECTIFIER
PFP
INVETER
RESONANT LAMP
FILTER
VOLTAGE
MAINS
(AC)
TIME
THE EBP
PULSE GENERATOR
Soft Start
PFP
Computer
RS-232
µController
Pulse Generator
FPGA Based
Digital PLL &
PWM
Optocoupler &
Driver Circuit
Command Signals
EBP PROTOTYPE
8051 Microcontroller CPU
Microcontroller
Serial Interface
48 MHz Clock Reference
FPGA Based PWM
Optocouplers
DIGITAL PLL (FPGA)
Clock
Reference
Sclk
Scom
Serial
Interface
Load
Fout =
Digital
PLL
Variable
Frequency
Command
Signal Out
Duty Cycle
Load
Fin × n
216
PWM
Adjustable
Digital
Dead Time
f
Sdat
Fin
f
m C Serial
Inte rface
Tuning
Word
To
Drive
Circuit
DIGITAL PLL
Phase
Accumulator
Frequency
Tuning
Word

12
16
Reg
Reg
Load
Clock
Reference
16 Phase/Ampl.
Conversion
Fout
PWM GENERATION
fin
N-Bits
Counter
A
Comparator A>B
B
Duty Cycle
Word
Load
Duty Cycle
Register
Command
Signal Out
INVERTER DRIVER (IR2110)
BALLAST TOPOLOGY
I
V
LAMP FREQUENCY RESPONSE
3 10
4
2.5 10
4
30 00 0
2 10
Voltage
D1
S1
Cs
4
L
E
VL ( w)1.5 10
4
I
S2
V
D2
1 10
Cp
RLâmpada
4
50 00
0
0
0
0.2
0.4
0.6
0
0.8
1
1.2
1.4 30
30
1.6
1.8
w
2
2
Current
25
20
0=3s
IL( w)
15
10
5
0
0
0
0
0.2
0.4
0.6
0.8
1
w
1.2
1.4
1.6
1.8
2
2
LAMP IGNITION VOLTAGE
Using:
0=3s
vc =
E
1 e
R
2 Fs L
CIRCUIT SIMPLIFICATION
(AFTER IGNITION)

Vm
VE (t ) = 
sin( nt )
n =1, 3, 5,... n
Vm =
2E

CIRCUIT EQUATIONS
(AFTER IGNITION)

  0  2 
1   0 A  

1  A1      j   ×
Ql  0  1  A 
    
Z (Ql , A) 
=
Rlamp
 0 
1  jQl  1  A

Where:
A=
CP
CS
Vl =
Rlamp
Z
R
=
Z
×VM
2E
 2 Vl
BALLAST DESIGN ABACUS
Gráfico da Variação da Impedância em função de Ql variando-se o parâmet
4


Z  Ql 


10 
1
1 

Z  Ql 

15 





20 




25 




30 
Z  Ql 
Z  Ql 
Z  Ql 
3
1
2
1
1
Z/R
1
Ql
GS( Ql)
0
0
0.05
0.1
0.15
0.2
Ql
0.25
0.3
0.35
DESIGN ESPECIFICATION
DC Voltage: E = 400V
Switching Frequency: Fs = 68 kHz
Lamp Nominal Power: P = 250 W
Lamp Nominal Voltage: Vl = 100 V
Lamp Nominal Resistence: R= 40 Ω
Z
2E
=
= 1.637
R  2 Vl
INDUCTOR AND CAPACITORS
DEFINITION
With:
Gráfico da Variação da Impedância em função de Ql variando-se o parâ
4


10 




15 


1
20 


25 




30 
Z  Ql 
1
A=
20
Z  Ql 
Z  Ql 
Z  Ql 
Ql = 0.141
Z  Ql 
1
1
1
Z


R
3
=
2E
= 1.637
 2 Vl


2


1
Z/R = 1.637
1
Ql = 0.141
GS( Ql)
0
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
Ql
It is obtained:
L = 220 µH
CP = 2.9nF
CS = 57nF
Experimental Results
Lamp operating in 65 kHz nominal frequency:
Lamp Voltage
Lamp Current
Lamp Power
Experimental Results - Dimmerization
Lamp operating in 100kHz:
Lamp Voltage
Lamp Current
Lamp Power
Percentual em relação ao pico (%)
Experimental Results – Light Oscilogram
120
100
80
60
40
20
Electromagnetic
Ballast
Electronic
Ballast
Reator Eletrônico
Reator Eletromagnético
0
0,0
1,2
2,4
3,6
4,8
6,0
7,2
8,4
Tempo (ms)
9,6
10,8
12,0
13,2
14,4
15,6
Experimental Results
Acoustic Resonance
Normal
Discharge
Discharge with
Lamp Destroyed by
Acoustic
Acoustic Resonance
Resonance (18kHz)
PFP
CONCLUSIONS
 This paper described a flexible platform
implementation using a microcontroller
and FPGA based circuit system able to
generate command signals for the
ballast switches.
 The present platform allows the study
of the control strategies influences in
lamps lifetime, in new dimming
techniques implementation, in avoiding
acoustic resonance and in color
reproduction alterations.
CONCLUSIONS
 During the platform design, the EMI
disturbs was a major problem. Because
of EMI it was developed a new platform
considering many precautions to avoid
EMI.
It was presented a simple LCC ballast
design criteria presenting an abacus.
 The EBP presents a high power factor
and works properly from 100 to 240 V.
OBRIGADO!
Gracias!
Thank You!