Difference between revisions of "Solenoid Controls Redesign"

Revision as of 11:19, 28 February 2012

To-do for solenoid controls redesign

• Recommendations from Director's Review (Electrical System and Quench Protection) and Lehman Review
  • determine if cold diodes can increase quench detection - NO, Nov-2011
  • add fast DAQ system prior to testing first coil - Done
  • add tests for internal shorts, shorts to ground and ground faults in coil and power supply to start-up sequence
  • add second dump circuit breaker
  • add additional quench circuit diodes
  • add second quench detector (connected to second dump breaker)
  • add center tap to dump resistor and monitor ground current in the PLC
  • add UPS on dump breakers to avoid fast discharges
  • perform Failure Modes and Effects Analysis (FMEA)

• Logbook research
  • check elog for all problems

• Infrastructure
  • get fourth rack, install temporary wheels, bolt to other three racks
  • install computer and other equipment

• Cryo system
  • need specs, new channels, new functionality, etc. from Jonathan - Done Dec 2011
  • update mechanical/electrical interface drawing

• Wiring
  • add new equipment
  • document trip chains
  • label circuit breakers
  • implement Sequence-Of-Events (SOE) module, need additional wiring and relays
    • prototype use of SOE module and relays in controls test stand - Done Dec-2011
    • connect to internal power supply trip chains when feasible
  • improve voltage range and eliminate cross-talk on voltage tap channels
    • change connection scheme?
    • change current limiting scheme?
    • requirements: fast vs slow, high vs low voltage, high vs low precision
    • 17+ voltage taps, at least two connections/tap, sometimes three

• Danfysik power supply
  • implement dump resistor center-tap ground fault detector
  • lockbox for door key
  • lock/tag/try procedures for dump resistor
  • procedures to check for dump resistor integrity and diode polarity prior to startup

• Quench detector
  • need sub-coil inductances from Floyd/George - Done Dec-2011
  • modify QD for final configuration
    • test imbalance range adjustment in lab
  • do we need a second QD? second technology? do we need to design our own? use PLC?

• Instrumentation
  • implement RS232 connections to all devices (e.g. vacuum gauges)
    • list from Mark - Done Dec-2011
    • Use RTI 435NBX instead of Point I/O serial modules
  • Replace shunt with flux-monitoring sensor
  • design and build breakout box

• NI fast DAQ
  • test new module
  • purchase three more modules
  • connect to PLC, EPICS

• A-B PLC programming
  • consider existing program a prototype, rework for 15-20 year lifetime
  • send Josh to A-B training - Jan-2012
  • use custom ("add-on") instructions to simplify everything
  • use function block, structured text and ladder logic as appropriate
  • add new channels, modify old ones according to latest channel assignments
    • new cryo channels
    • use 435NBX instead of Point I/O modules
    • eliminate ControlNet
    • SOE module

• A-B HMI improvements
  • SOE fault sequence screens
  • other error screens
  • Viewpoint
    • get screens on the web
    • security?

• EWEB
  • create tag lists
  • security?

• EPICS
  • new channels

• UPS power
  • solenoid controls racks
  • Danfysik control circuits and contactor?
  • target? other cryo and vacuum systems?
  • cooling systems (dewpoint)?
  • downtime due to power loss is deciding factor

Notes

• max ramp rate in the hall is approximately 10V / 20H = 0.5 A/sec

Possible future improvements

• monitor selected circuit breakers so operators can quickly find them when they trip