The Survey of the Power Supply Reliability at SSRF
Ming GU , Rui LI , Zhihao CHEN , Lixin YIN
Shanghai Institute of Applied Physics
I joined in the accelerator technology since 1997, study control system
for beam line (1997-2000); klystron-modulator system for lianc (20012003), pulsed magnet system for injection and extraction (2004-2008),
controller for SR insert devices (undulator) (2009-2010). Now engaged on
SSRF maintenance and improvement and development of FEL facility and
proton therapy.
April 13, 2011
Introduction
There are total 715 magnet power supplies for Shanghai Synchrotron
Radiation Facility (SSRF) .

699 DC magnets power supplies。
538 PS for SR magnets,
112 PS for booster ring magnets;
49 PS for linac magnets

15 pulsed power supplies for injection and extraction system。
SR injection: 4 kicker, 2 septa
Booster extraction: 3 septa, 1 quick kicker, 3 slow kicker
Booster injection: 1 septum, 1 quick kicker,
 All the power supplies were installed before the end of 2007 and
have been operating for more than 3 years.
Magnet Power Supplies
 PS Type:
1. middle power converter (<2kW), 482 sets DC
Steer magnets, Linac magnets , Transport line magnets
2. Large power supplies, 17 sets , DC
Ramping magnets of booster ring,
Dipole magnets and sextupole magnets of storage ring
3. Chopper power supplies, 200 sets, DC
Storage Ring Q magnets.
4. Pulse power supplies.
DC Power Supplies
Statistical List of SSRF DC Magnet Power Supplies Failure
PS Type
Quantity
Fault times
Repair time
（hours）
MTBF（hours）
communication
failure*(hours)
2009
2010
2009
2010
2009
2010
2009
2010
Middle PS
482
27
18
13
4.5
277
402
5
25
SR Q PS
200
19
8
20
6
394
905
24
15
Large PS
17
7
6
9
16
1068
1206
6
1
Total (average)
699
53
32
42
26.5
141
226
35
41
Middle power supplies
parameter mismatch
22%
cooling fans
45%
power converter
13%
temperature protect
relay
control cards 13%
7%
 One of the main reason of the middle power supplies shut down is the
cooling fans fault.
The fan should gives a series of pulse to interlock circuit when it
running. the pulse series come to unusual due to mechanical abrasion, so
lead to shut down the power supply. Now the plug and play structure has
made for replacing the faulted fan quickly. More improvement are in
process.
SR Quadrupole magnet power supplies
 The quadrupole PS are chopper power supplies. The main reason are

broken link of the communication between digital control cards and
controller (IOC). Electronic components of the cards invalidate and EMI
disturb causes the communication fail.
The failure of IGBT driver was caused by temperature. It is a design bug.
A resister with lower power rating which operating under high-power so
to increase resistance too much that the circuit loss its normal operating
point.
IGBT driver
25%
DCCT power
4%
DCCT
4%
DC bus fuse
4%
control cards
51%
24VDC power module
4%
DC bus spark
4%
Cooling water pipeline
4%
Large power supplies
 Dipole power supply consists of two branches,
which are connected in parallel. Each branch
consists of two AC/DC converters and two
cascaded 2Q choppers. The peak power output
was about 1MW.
The severe EMI strike inside the chest results
hardware failure.
control cards,
1, 8%
DC power
module, 1, 8%
fibier driver,
4, 30%
DCCT failure,
1, 8%
circuit
breaker, 3, 23%
 The break of the breaker handle

current
transducer, 3,
23%
was unreasonable, the manufactory
can’t give a reasonable explain.
The design fault of fiber driver
cause triggering uncertainty.
Statistic of failure for pulsed power supplies
（SR operating at decay mode）
No.
Date
Cause
Repair time (h)
2009-02-04
SR kicker-4 Pulser no operation
(fuse burn out
due to a fire of high voltage cable )
4
2
2009-06-28
Thyristor of septum-2 pulser broken
12.5
3
2009-07-02
Thyristor of septum-1 pulser broken
20
2009-07-05
SR kicker-1 controller failed;
+24Vdc power module broken
3.5
2009-11-13
Booster extraction kicker pulser shut down
a current meter was out of commission.
1
2010-09-23
Booster injection kicker Pulser fail.
a high voltage capacitor turn to dc short.
3
1
4
5
6
The break of thyristor ware due to the higher dI/dt ratio.
Since all pulsed power supplies ware installed in accelerator tunnel so
that repair work take longer time.
Conclusion
 Continuing efforts to increase the reliability and availability of
power supply system are ongoing at SSRF. Investigation and
solution for the problem will be gone on. Several problems have
been indentified and resolved. The advanced design and
components will be adopted to improve the performance of
power supply system.
guming@sinap.ac.cn