The 11th Symposium on Accelerator Science and Technology, Harima Science Garden City, 1997

Operation of the SPring-S SR Main Magnet
Power Supplies and Control System
Hideki TAKEBE, J un-ichi OHNISHI, Keiko KUMAGAI, Koji TSUMAKI, Masaki TSUJI, and Noritaka KUMAGAI
SPring-8, Kamigori, Ako-gun, Hyogo 678-12, Japan

Abstract
After installation of the power supplies (PSs) of themain magnets in the SPring-8 Storage Ring (SR) in1995, cable connections between the PSs and the magnets
were completed in October of 1996. The final test
operation and inspection of current stability, ripple
measurement and control, interlock sequence and operation
program were successfully carried out by March of 1996.
During the SR beam commissioning and operations forthe beam line users from March to July of 1997, themagnet power supply were operated successfully.

1. Introduction
SPring-8 storage ring consists of 48 cells of ChasmanGreen type. Each cell has two Bending Magnets(B), ten
Quadrupole Magnets(Q), seven Sextupole Magnets(S).
Total numbers of Steering magnet PSs (StP) andauxiliary quadrupole PSs (QA) for the SR are 576 and 40,
respectively. Eighteen sets of B, Q, S PSs, 40 QAs and576 St-PSs are used. The power supplies for the magnets
are controlled by the VME and remote I/0 system.

2. Power Supply System
The maximum current, voltage, power and cubicle
number for the B-Ps[lJ are 1270A, 1157V, 1470kW,
and 1, respectively. Those for Q-Ps[2] are 394A- 570A,
480- 1281V, 192- 728kW and 10. And those for Sps[3] are 300A, 650- 750V, 195 - 225 kW and 7. Total

inductance of the B, Q, S magnets over 48 cells are 0.76
H, 0.45 - 1.25 H, and 0.62-0.72 H, respectively[4][5][6].
Each steering magnet(St) is connected to one PS of ±5
A and ±60 V. Total number of the St-PS is 192. Thirtysix sets of St-PS are mounted in 1 cubicle and aresupplied a DC bus together.
The total numbers of the large PS's for B, Q, S is 18.
Some Q-magnets, which are connected in series, areadjusted by auxiliary PS circuits (QA) to correct themodulation of the beta function and phase advance[7l.
Forty QAs were installed for the long straightsections[8] in 1996. The other QAs are to be installed infuture). These QAs are floated from the ground level witha few hundreds volts. They are 11~ 17 A and 19~33V

floating PSs.
The B-PS has four input transformers for 6.6kV, 24thphase thyrister diodes and a passive filter system.
Q-PS has 12th phase thyrister diodes and a reactor
transformer active filter system. Figure 1 shows a block
diagram of the Q-PS system. Input voltage for the Q-PS
is 400 V.
QP-2,5,6,9 have bypass (2%) circuits to compensate asmall difference of the excitation factors caused by themagnet yoke shape difference. This bypass circuits areconnected to the terminal of Cell#5 magnet (Fig. 2).
Input voltage of the Sx-PS is 400V. A twelve phasethyrister diode system is stacked with a 33.3 kHz
switching regulator system.

0.5mH
0.2mH
~--~~--~~~~~~~------~. ~

Q-PS

....
..
.
........ .
. ..

400V/273V
452kVA

0I

CBo..,;t""'-.--"
400V

Input,,

570A

~

770V
To
Magnd

L-~------~~--~~~~--~~·~

On/Off..

VME

Optical Fiber

Master RIO

Fig. 1. Block diagram for the Quadrupole Magnet Power Supply.

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Input voltage of the St-PS is 200V and a 100 kHz
switching regulator system is used.
B, Q, S, QA and St-PSs are located in PS room-A.
PS room-B, C, and D only have 192 sets of StPs and 10
sets of QA-PSs. The area for St-PS is air-conditioned(26°±2° C). The other area for BP, QP and SP is only air
circulation (10°- 35°C).

TOPACC) were adopted to -the PS output cable for themeasurement of long time stability. The actual current
data calibrated the DAC and ADC data as a final database.
Table 1 shows the measured stability and ripple ratio for
BP, QP and SP. The stability was achieved better than 7
X 10-5 for 8 hours.

3. Power Supplies and Cabling

Table 1. Stability and ripple of the PS.

Installation of the power supplies at the PS rooms andcabling to the magnets was settled in 1994 and 1995.
Fig. 1 shows the cabling systembetween the QP and theQ-magnets, with an earth line. A CV-S (shielded crosslinked polyethylene insulated ) cable is used forconnecting between the PS and terminal board in theaccelerator tunnel. A LMFC (flame retarding, flexible
insulated wires) cable is used between the terminal board
and the magnets.
Test operations for four QPs, ten QAs and two SPs
with 14 cells QMs and SMs started in September 1996.
The tasks of this test operation included surveying thealignment distortion of the magnets due to the heat of thecables (LMFC) under the girder of the QM and SM.
During the test operation, the aligninent distortion on themagnet girder was less than 30 microns with themaximum current excitation for 24 hours, and themaximum temperature of the LMFC cables was 40 °C.
A programmable logic controller (PLC) was adopted asa magnet power supply external interlock system for theBP, QP and SP. Magnet water flow switches and coiltemperature switches are connected to 24 stations of local
PLCs input modules in the maintenance hall, andconcentrated interlock signals are fed to the PSs via amaster PLC in the PS room-A.

4. Stability and Ripple Inspection
The final test operation, stability, ripple and power
consumption measurement, control sequence and I/F ( toRIO) inspections and cabling cliecks were done by the endof 1996. Three external DC-CT (Holec Co., Ltd.

PSNameStability(8 Hr)

Ripple60Hz-1kHzBPQP1QP2QP3QP4QP5QP6QP7QP8QP9QP10SP1SP2SP3SP4SP5SP6SP7

0.6 * 10-5
5.4 * 10-5
6.3 10-5
4.8 * 10-5
7.3 * 10-5
4.3 * 10-5
5.6 * 10-5
6.7 * 10-5
7.3 * 10-5
3.4 * 10-5
5.3 * 10-5
2.8 * 10-5
7.4 * 10-5
4.0 * 10-5
6.8 * 10-5
4.8 * 10-5
7.0 * 10-5
4.1 * 10-5

1.0 * 10-5
1.1 * 10-50.8 * 10-5
1.0 * 10-5
0.8 * 10-5
1.0 * 10-5
-1.1 * 10-5
0.8 * 10-5
0.7 * 10-5
0.3 * 10-5
_ LO * 10-5
3.3 * 10-5
2.7 * 10-5
3.4 *1 0-5
4.7 * 10-5
2.6 * 10-5
2.6 * 10-5
2.4 * 10-5

*Figure 3 and a table 2 show the frequency spectrum of
the QP's current ripple. The current ripples were measured
by the DCCT (Holec) and an FFT at the magnet terminalof Cell#6, Cell#5 and at the PS output.

, SR Upper cable rack~

Shield earth(IV)connectione-: Earth terminal: Earth wire (IV: polyvinyl chloride insurated wires): Insulated wires (LMFC) or Cable (CV -S: Cross-linked polyethylene insulated cables, Shielded)

Fig. 2. The power supplies (QP, SP), magnet (QM, SM) cabling system and the earth line.

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600
720-124-118

8.57E-05
L71E-04

1.56E-07
3.11E-07

For a bending magnet PS, four input transformers for
6.6 kV are located in an outer yard and connected by four
sets of bus ducts with 24 phase rectifiers.
A 33.3 kHz MOS-FET switching regulator for the SP,
is piggy-backed by the 12 phase thyristor regulator. Thishigher order ripple noise was not observed in the magnetterminals.
576 sets of steering magnet PS's were tested. And thecurrent stability and ripple were better than 1.8 x w-4.
Table 3 shows the PS specifications, power
consumption for the maximum operation mode and 2-cellmode Lattice operation. An AC 6.6 kV - 400V
transformer connection are also indicated in this table 3.
"R8" and "R9" are the titles of the transformer (AC 6.6kVto AC400V). Each sign (+/-) of these titles indicates aphase shift of +15 or -15 degree of the QP internaltransformer.
In order to reduce the harmonic current distortion, input
transformer phase of the five QPs (QP-1, 3, 4, 5, 10) areshifted. The QP has 12 phase thyristor diodes and areactor transformer with an active filter system.
To reduce a heat effect for the magnet girder, the current
density of the LMFC cables was suppressed to be small.
Therefore, the magnet connection cable loss becamesmaller.

Fig. 3. Current ripple spectrum of the QP6, magnet
in the Cell #6.
Table 2. Ripple frequency spectrum of the QP6
DCCT at Cell#6 (550A).
HzdBVRipple(A)Ratio to 550A

60
120180
240
300
360
420
480-97-104-120-118-120-100.4-120-118

1.91E-03
8.57E-04
1.36E-04
1.71E-04
1.36E-04
1.30E-03
1.36E-04
1.71E-04

3.47E-06
1.56E-06
2.47E-07
3.11E-07
2.47E-07
2.36E-06
2.47E-07
3.11E-07

Table 3. QP and SP output specification, power consumption, and AC 400V inlet transformer connection
for a maximum operation and a 2 cell mode Lattice operation.
AC Inlet

R9+
R9R9+
R8+
R8+
R8R8-

0.894
0.768
0.771
0.782
0.774
0.769
0.786
0.877
0.782
0.908
0.908
0.908
0.907
0.908
0.908
0.908

R8R9R9R9R9R9-397-

The 11th Symposium on Accelerator Science and Technology, Harima Science Garden City, 1997

The QM coil resistance and the output voltage wasachieved smaller than. the designed value. In contrast, thepower factors increased due to a decreasing output voltage.
Accordingly, the QP input voltage (AC 420V) was
decreased 5% by changing the transformer tap.

5. Remote Control and Program
The PSs of the SR magnets are controlled by a VME RIO (Optical fiber distributed field BUS) system. The
RIO type-A is used for StP, QA. It has a 16 bits DAC(Digital to Analog Converter) and a double integration
type ADC (Analog to Digital Converter ), which monitors
the actual current using a shunt resistance
output£10][11][12].
The reference voltage for the large (B, Q, S) PS current
control is given by a 16 bit DAC, controlled by the digital
output of the RIO type-B. These DAC's for the BP, QP
and SP are installed in a temperature controlled box in thePS cubicle.
The ADC data is transferred to the RIO card via a 16 bits
parallel signal. A cyclic time for ADC read out and status
read out for the 22 RIO slave cards (for the BP, QP, SPand QP's bypass) is 5 ms. A VME controlled remote I/0
card is connected to this PS using an optical fiber cable.
Fig. 5 shows a time chart of DAC data set and strobe
signal for BP, QP and SP. The DAC set step time iswithin 50 ms. This currentdata bits control and 1-DAC
calculation program is run in the VME computer (EM:DAC bit 0DAC bit 1501-----,........ .

I •••••••••••••••StrobeFig. 5. Time chart ofDAC data and strobe forBP, QP and SP.

Equipment Manager). 576 set of current control can beachived simultaneously.
The current and step number
are ordered by UNIX RPC's command string (ex:"set/sr_mag_ps_q_main_li200.00A", " put/exec_20.0sec") from an operation WS to the EM.
A current set database, and Man-Machine controlpanels with a GUI (Graphical User Interface) are developed.
They send the RPC command from the console GUI panel.
Fig. 6 shows a BQS-PS's sequential current set program
panel from the database and files. Fig. 7 shows a magnet
initialing sequence used before new beam injection.
Curr.

t .....
A\l\1\/.
· 'to · .
'40 II40 1~I

TIME(s)Fig. 7. Magnet Initializing Sequence.

References[1] Mitsubishi Electric Corporation.
[2] IDX Corporation.
[3] Fuji Electric Corporation.
[4] H. Takebe et al.: RIKEN Accel. Prog. Rep. 25, 207,(1991).
[5] H. Takebe et al.: RIKEN Accel. Prog. Rep. 26, 157,
(1992).
[6] H. Takebe et al. : RIKEN Accel. Prog. Rep. 27, 147,(1993).
[7] H. Tanaka et al.: RIKEN Accel. Prog. Rep. 24, 141,
(1990).
[8] H. Tanaka .et al. : RIKEN Accel. Prog. Rep. 25, 184,
(1991).
[9] Furukawa Electric Co., Ltd.
[10] H. Takebe et al.: RIKEN Accel. Prog. Rep. 25, 209,
(1991).
[11] H. Takebe et al. : RIKEN Accel. Prog. Rep. 26, 176,
(1992).
[12] H. Takebe et al., "Magnet Power Supply Control
System for the SPring-8 Storage Ring", Presented atthe 4th EPAC, London, GB. 1827-1829, (1994).

Fig. 6. BQS Control Panel of Operation Console.

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