1. 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 ( ); klystron-modulator system for lianc ( ), pulsed magnet system for injection and extraction ( ), controller for SR insert devices (undulator) ( ). Now engaged on SSRF maintenance and improvement and development of FEL facility and proton therapy.
April 13, 2011

2. 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 and have been operating for more than 3 years.

3. 1. middle power converter (<2kW), 482 sets DC
Magnet Power Supplies
PS Type:
1. middle power converter (<2kW), 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.

4. communication failure*(hours)
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
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 9 16
1068
1206 1
Total (average)
699 53 32 42
26.5
141
226 35 41

5. Middle power supplies
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.

6. 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.

7. 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.
The break of the breaker handle was unreasonable, the manufactory can’t give a reasonable explain.
The design fault of fiber driver cause triggering uncertainty.

8. Statistic of failure for pulsed power supplies （SR operating at decay mode）
No.
Date
Cause
Repair time (h) 1
SR kicker-4 Pulser no operation (fuse burn out due to a fire of high voltage cable ) 4 2
Thyristor of septum-2 pulser broken
12.5 3
Thyristor of septum-1 pulser broken 20
SR kicker-1 controller failed;
+24Vdc power module broken
3.5 5
Booster extraction kicker pulser shut down
a current meter was out of commission. 6
Booster injection kicker Pulser fail.
a high voltage capacitor turn to dc short.
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.

9. 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.

10. Thank you for your attention