Transcript ups commissioned december 2011

Uninterruptible Power Supply Improves Reliability
at
The Australian Synchrotron
Sean Murphy – ARW 2013 Melbourne
Introduction
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Background of the project
Look at the power interruptions to blame
The causes of power interruptions
UPS technical requirements
Design, efficiency, and autonomy of the UPS
Practical implementation and installation
The improvements to power reliability
Background
• The Australian Synchrotron is expected to operate continuously 24
hours per day, 7 days per week (approximately 5,000 User Beam Hours
per year)
• The mean time between failures (MTBF) for power interruptions was
approximately 150 hours prior to the installation of the UPS systems.
Power reliability was to blame for approximately 35% of all down time.
• 3 systems that are particularly sensitive to power disturbances include
the storage ring magnets, the storage ring RF, and the mechanical
plant. A voltage fluctuation of greater than ±5% from the 240V nominal
for 10 cycles (200ms at 50Hz mains) can cause either of these systems
to enter a fault condition, losing the stored beam.
• An uninterruptible power supply (UPS) was a strong solution to
provide adequate power conditioning
Power Interruptions
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Example of a site feed voltage sag:
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No interruption longer than 2 seconds has occurred
Power Interruptions
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The Synchrotron site is supplied by two dedicated underground 22kV feeders from
Zone substations SV (Springvale) and SVW (Springvale West). The Synchrotron site
feeders are SV19 and SVW44 and both are 2.8km in length.
Power Interruptions
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All disturbances are within the limits allowed by the distribution code
Power Interruptions
• Information Technology Industry Council (ITIC) Curve and
Victorian Distribution Code
Power Interruptions
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Interruptions when compared with the ITIC curve:
Causes
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Known faults at 66kV and 22kV as well as unknown causes.
Common voltage sags are caused by network operations (switching,
capacitor banks) and other customers (motors starting and equipment
failures).
Causes
• Other causes include trees, possums, fires, etc.
UPS Requirements
• The UPS system ratings needed to cover the storage
ring critical loads in order to ride through power
interruptions. The design loads were specified:
Transformer
Load
Apparent
Power
Active Power
Power Factor
Tx2
Mechanical
Plant
1,700kVA
1615kW
0.95
Tx4
Storage Ring
RF
1,200kVA
1140kW
0.95
Tx6
Storage Ring
Magnets
1,400kVA
1330kW
0.95
4,300kVA
4085kW
0.95
Total
UPS Requirements
• Flywheel rotary UPS systems provide very high output current
compared to purely electronic UPS systems, and are able to
provide inrush current for inductive loads, and large loads
such as magnet power supplies. In addition they can provide
14 times rated current under short circuit in order to clear
faults on downstream circuit protection.
• Rotary systems that don’t use batteries have a 20-30 year
lifecycle, which suits the operating life of the Australian
Synchrotron
• Only short-term ride through of at least 2 seconds is required
due to the network supply reliability.
• Rotary systems are on-line, and this is important as one
cannot predict when a power interruption will occur when
using a standby off-line system
UPS Requirements
• The UPS systems are installed between the existing transformer
secondary windings and the main circuit breakers of the low voltage
switch boards.
22kV switch board
Tr2
Tr4
UPS-T2 (LCW / comp.
air)
UPS-T4 (SRRF)
UPS-T6 (SR MPS)
MSB-T4
(Storage ring RF)
MSB-T6
(Storage ring power
supplies and
equipment racks)
MSB-LV-NT (T2)
(Building light / power
and LCW / compressed
air)
Bus-tie
(Existing)
MSB-LV-NT (T5)
(Building
mechanical plant)
Tr6
The UPS Design
• Flywheel Energy Storage
• Converter Bridge
• Motor/Generator
• Coupling Choke
• Load
The UPS Design
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6000kg steel disc rotates at 55Hz mechanical frequency (3300rpm) on a 4pole motor/generator
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Flywheel lifted by a magnetic bearing to reduce wear on the mechanical
bearings
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Flywheel is encased inside a positive pressure helium vessel which reduces
friction and is less prone to problems that vacuum systems have
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Energy storage is approximately 15.7MJ
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Generates electricity at 110Hz down to 50Hz electrical frequency. This is
equivalent to 55Hz – 25Hz mechanical frequency (3300rpm – 1500rpm)
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Generated electricity is converted via SCR bridges to drive the output
motor/generator at 50Hz ± 1Hz continuously until the flywheel is discharged.
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Motor/Generator runs at 25Hz (1500rpm, 4-pole) for 50Hz mains output
UPS Efficiency
• UPS efficiency is approximately = 93.6%
• Cooling is required to keep the system below 30°C
Total UPS losses
UPS System
Average Load
Average Losses
Site Feed UPS Tx6
1051.704kW
Site Feed UPS Tx4
981.54kW
49.077kW
Site Feed UPS Tx2
815.328kW
40.7664kW
Total:
52.5852kW
142.4286kW
UPS Autonomy
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UPS System
Peak Load
Minimum Autonomy Time
UPS TR2
1615kW
8 seconds
UPS TR4
1140kW
14.8 seconds
UPS TR6
1330kW
12.75 seconds
Typical active power demands:
Tx6: 1051.704kW
Tx4: 981.54kW
Tx2: 815.328 kW
• This typically allows over 14 seconds autonomy on all
systems
Implementation
Main Building & LV Room –
HV Room
–
UPS Building
Implementation
• The UPS systems installed inside the UPS building
Implementation
• Cables to the 2000kVA unit required 5 X 500mm2 cross sectional
copper conductor area per phase plus neutral (20 cables)
Implementation
• UPS systems must be kept below 30°C and dust free with a 200kW
capacity air handling unit.
• Springs suspension for isolating 25Hz and 55Hz mechanical
vibrations from the technical floor / beamlines was necessary.
Improvements to reliability
• No more outages to the storage ring due to brief electrical
interruptions.
• The percentage of faults due to power decreased for 35% to 5%
after the UPS was commissioned.
Year
Facility MTBF Power MTBF
(hours)
(hours)
% of faults
due to power
2009
47
116
40.78%
2010
59
167
35.37%
2011
55
158
34.83%
UPS COMMISSIONED DECEMBER 2011
2012
123
2467
5%
• 5% during 2012 was due to on site electrical faults
Conclusion and Further Improvements
• The UPS was effective at improving power
reliability and beam availability at the Australian
Synchrotron.
• Installation of the Tx3 LINAC load of 124kW on
to the Tx4 UPS system will be possible in May.
The end
Any Questions?