Solenoid Controls Redesign

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
  • add fast DAQ system prior to testing first coil
  • 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)

• 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

• Wiring
  • document trip chains
  • label circuit breakers
  • use Sequence-Of-Events (SOE) module, need additional wiring and relays
    • prototype use of SOE module and relays in controls test stand
  • 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
    • Cody will look into this

• Danfysik power supply
  • use 435NBX to talk to power supply
  • choose ground fault detection mechanism
  • 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
  • can we get a good balance...need sub-coil inductances from Floyd (Fall 2011)
  • do we need a second QD? second technology? do we eed to design our own?
  • can we get an FPGA module with A/D inputs off the shelf to do this?

• Instrumentation
  • implement system to isolate fault detectors and determine time sequence of trips
  • implement RS232 connections to all devices (e.g. vacuum gauges)
  • Use RTI 435NBX instead of Point I/O serial modules
  • Replace shunt with flux-monitoring sensor

• VME-based fast DAQ
  • NI vs VME?
  • connection to PLC?
  • connection to EPICS?

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

• • EWEB
    • create tag lists
    • security?

• A-B PLC programming
  • consider existing program a prototype, rework for 15-20 year lifetime
  • send Josh to A-B training?
  • custom ("add-on") instructions to simplify everything
  • use function block, structured text and ladder logic as appropriate

• 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