Analysis of main disturbances at Elettra(A. Pozzer)
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Trieste Sinchrotron very sensitive
Voltage Sags
Voltage Peaks
UPS does not for ALL DEVICES
Analysis on the electric system with instruments “Equa”
BEAM LOSSDisturbances
PS or RF Plants off
What can we do?
Signals acquired by Equa:
-3 phases at 380V rms nominal
-1 E-beam current in SR
100mS pre-triggers and 900mS post-triggers
exceed the limit
EQUA Parameters set up:
-min voltage rms level 360V
-max voltage rms level 420V
-max voltage peak level 630V
Equa records the event
If one or more phases
3 phases min rms
E-Beam current SR
starting event voltage Sag
B E A M LOST
A Voltage Sag on three phases caused the lost of beam
Period June 2004 – August 2005
All the runs since 2000
the events with voltage RMS level
the events with voltage PEAK level
Events with MIN and/or MAX voltage RMS level
Tot 112 events 32 of them beam loss
Events distribuition in the course of the seasons
eventi da TEMPORALI
0
10
20
30
run (mese di riferimento)
totali beam dump
events with Beam Loss
eventi da TEMPORALI
0
1
2
3
4
5
6
7
run (mese di riferimento)
n. e
ve
nti
First Consideration: the most difficult period at Elettra is certainly the summer season for the presences of thunderstorms.
summer
summer
summer
Duration – Depth
a) – events with duration < 200mS 26 events
Voltage Sag
E- Beam current
These limits have been observed:
Depth event < 10 % No Beam Lost
Depth event > 15% Beam Lost
Depth event 10% < X < 15%
Unstable situation
b) - events with duration > 200mS
Depth event < 6 % No Beam Lost
Depth event > 6 % Beam Lost
6 events
These limits have been observed:
1) Duration: 500mS - Depth: 8.20%
E – beam SR
Voltage Sag
BEAM LOSS
2) Duration: 500mS - Depth: 5.30% NO BEAM LOSS
E – beam current SR
Voltage Sags
Depth Events < 5% are not considered
Events with MAX voltage PEAK level
Working day in the morning A Voltage Peak
SR in normal condition
E-beam currente SR
Voltage Peak
NO problem
SR is in a particular condition
But If ...
BEAM LOSS
3 events BEAM LOSS
Alwaysduring the Ramping and with E- Beam current > 300mA
Voltage Peak
E-beam currente SR
Example:
Conclusion:
VOLTAGE PEAKS NO big Problems
future? With new Booster?
VOLTAGE SAGSNOT OK - too many Beam Losses
HOPE All Devices
U P S
References:
Effects of mains disturbances on the Elettra operation (R. Visintini – Accelerator Sector Technical Meeting -May,6th 2002)