mice decay solenoid quench detector trevor hartnett daresbury laboratory
TRANSCRIPT
Outline
• Existing (PSI) Quench detection system– How it works– Why we want a replacement
• Replacement (DL) Quench detection system– Comparison with existing system– How existing system could meet other
requirements• Progress report
– When it will be ready
Power Supply
Linear power supply
Switch mode ±15V and 12V power supply
Circuit breaker control relays
Emergency backup battery switching
Battery Backup
• 4 12V Lead acid batteries– Series connected to provide 48V– Capacity 7Ahrs
• Charged by a 1A, 48 V battery charger – Powered by the incoming mains.
• LEDs used to indicate:– Batteries charged– Mains connected
Recent Problems
• System is at least 27 years old
• Concern that the electronic components are approaching end of life– sticking relay – capacitor failure in the magnet PSU which is of a
similar age
• ECS Group at DL asked to provide a Replacement QD system.
Replacement (DL) System
• Follow original principles of PSI design
• Update components
• Use a modular design
• Single PCB per quench channel
• At least existing system user interface
Quench detection cards
• Modular Design
• Updated components– Isolation amplifier– Relay– Latching circuit
• Isolation of voltage taps
• Test points on each card
Power supply
• 2x 230Vac to 48Vdc PSUs• 2x 48Vdc to ±15Vdc PSUs• 2x 48Vdc to 12Vdc PSUs• Control Relays
Battery Backup
• The battery back-up crate will follow the existing design closely.
• A 48V, 1A charger will be used to charge four 12V batteries in series.
• The batteries will be 7 Ahr units.
Upgrades
• Variable voltage limits on quench detection– Voltage range from 10mV to 110mV
• A relay off indicator LED on each card• A reset button on each card• Test points are provided on each card• Greater level of output diagnostics
– Tripped channel can now be identified– Status indicators of each power supply
• Increased EMC protection to prevent nuisance trips
Progress
• Quench Detection Cards tested
• Power supply and battery backup still to be completed
• Final testing of the complete system to be carried out before the end of July
• Test of system with AFC in R9 at the end of July