Conference on Rural Telecom Markets by Tele.net

1. Powering Rural Telecom: Challenges and
Opportunities
September 16, 2009

2. Rural Exchange in
Rajankunte, Karnataka
2 x 256 line switch
~1998
All rights reserv ed.

3. Solar-
Solar-powered Base Station
from VNL (picture from their
Web site)
~2009
All rights reserv ed.

4. Outline
• Powering Telecom Basics
• What’s special for Rural Applications
• The Importance of High Efficiency
• Operating on and off the Grid
© 2009 Lineage Power All rights reserv ed. 4

5. Where is Power in the Network?
Relevant for Rural
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6. Cell Site Power Block Diagram
To Base
Station
Static Voltage
Regulators Rectifier
AC
Mains Rectifier
Air Conditioner
Engine Transfer
Generator Switch Lighting
Engine Batt. Chg.
G
Power Management
System Controller
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7. Wireless BTS Power Architecture
POLs
Redundancy
AC 48V or 24V Bus 5 or 12V
3.3V
Digital
1.8V
Isolated Loads
~ =
1.2V
6 – 9V Pre-amp
Standard 28V PA
or
Custom
DC-DC 28V, 6 – 9V
modules
1.2/1.8/3.3/5V
All rights reserv ed.

8. Power in Rural Areas
• Little or no access to Grid Power
• Poor quality of Grid Power
–Longer power outages
–Wide range of grid voltage
–Surges/sags due to agricultural loads starting/stopping
–Only one or two of three phases may be available, may be
unbalanced
– More exposure to lightning
• Unmanned sites
– Difficult/expensive to access
– Longer time/more expensive to repair/maintain
• Poorer environmental conditions – dusty, more windy
© 2009 Lineage Power All rights reserv ed. 8

9. The Importance of High Efficiency
• Rural Watt$ are usually more valuable than Urban Watt$
• Why?
– More expensive to deliver
• How much more valuable?
$/Rural W
– Grid AC always available $/Urban Watt 0.7X
0 1 2 3
$/Rural W
– Grid available 50% + DG $/Urban Watt 2X
0 1 2 3
$/Rural W
– Grid available 20% + DG $/Urban Watt 2.6X
0 1 2 3
$/Rural W
– No Grid – DG Only $/Urban Watt 3X
0 1 2 3
$/Rural W
– No Grid – Solar + DG $/Urban Watt ~2X
0 1 2 3
© 2009 Lineage Power All rights reserv ed. 9

10. End-to-End Efficiency in A Base Station
POLs
Redundancy
AC 48V or 24V Bus 5 or 12V
3.3V
1.8V
Isolated
~ =
1.2V
6 – 9V Pre-amp
28V PA
Today
1.22W
1.14W
1W
93% 88%
1.13W Tomorrow
1.09W
1W
96% 92%
• Power conversion subsystems typically are 2 – 5% of equipment costs
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11. What’s Needed to Improve Efficiency
• AC-DC
– 96% efficiency rectifiers starting to come out
– Marginal price premium (~10 to 20%)
– 97% (or even 98%) possible with better FETs (e.g. GaN)
• DC-DC
– PA higher efficiency requires a cost premium (diode
rectification vs. synchronous rectification ~ 20%)
– POL efficiency can be improved with price premium (better
FETs) of ~20%
– Isolated efficiency can also be improved with price premium
(better FETS, thicker PWB copper) of ~ 20%
• Overall – Payback analysis indicates that for about $0.06
increase/W of DC power processing, 0.09W can be saved
(payback period is 1.1 years for on-grid and 0.37 years for rural
off-grid)
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12. Special Functions from the Power Management
System
• Minimize usage of DG
– Auto phase selection + 3/2/1-Phase operation + Can
operate without neutral
– Wider input range (155VAC to 480VAC ph-ph)
– Longer operation on battery
– Delay turning on air conditioner based on shelter
temperature
• Future – operation from multiple AC sources
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13. Improved Efficiency Rectifiers
Green Series Rectifiers
Rectifier Efficiency @ Nominal Vin, 25C
98.0%
96.0%
94.0%
92.0%
Efficiency (%)
90.0%
88.0%
86.0%
Current
1Ph HE
84.0%
82.0%
New
NE050AC48
80.0%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Load (%)
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14. Active Rectifier Management – ARMTM
ARMTM – Place Rectifiers in Stand-by mode to improve operating efficiency of
remaining rectifiers
System Efficiency vs Load
95
100
95
90
Efficiency (%)
90
85
85
80
80
75 Adaptive Standby
Standard
75
70
0 10 20 30 40 50 60 70 80 90 100
Load (%)
© 2009 Lineage Power All rights reserv ed. 14

15. Lineage Priority SourceTM
Modules & Systems:
Loads
48V or 24V DC Distribution Batteries
AC 1Ø
AC 3Ø
Or DC
AC 1Ø
AC 3Ø
DC
DC AC or DC
© 2009 Lineage Power All rights reserv ed. 15

16. Migration to a Green Network
• Three Technologies that make Lineage 96% rectifiers the best
choice for your network:
Lineage Priority
TM
IDA
TM
Source TM
ARM
1869 1984 1996 2001 2008
© 2009 Lineage Power All rights reserv ed. 16

17. An Investment in the Future
Lineage Power’s product design capability is focused on energy
efficiency, reliability, cost and advanced monitoring and control
• Designing for Improved Efficiency and 97%
96%
6,000 A Plant Example w ith Sw itch-Mode 220A 480V ac Rectifiers (595LTA)
Energy Management 95%
94%
•
Rectifier Efficiency
Increased rectifier efficiency to 96%
93%
92%
High Eff. All On
•
91%
Plant level efficiency optimization – 90%
89%
HE ARM Active
LTA - All On
Active Rectifier Management 88%
LTA - ARM Active
87%
• Innovative architectural improvements
10% 20% 30% 40% 50%
Pla nt L oad
60% 70% 80% 90%
to reduce distribution losses Focus on Efficiency
• Design Innovation to Reduce Product Complexity
• Improved cost and reliability
• Controller features to optimize operations
• Remote visibility and control
• Battery management, testing and monitoring Galaxy Network Manager
• Network power monitoring – Galaxy Manager
• Product Migration paths
• Legacy Plants High Efficiency SMR
• Alternative Energy Sources
• Integration of solar, wind, hydro, fuel cells,
new battery technology
© 2009 Lineage Power All rights reserv ed. 17