Power Converter Characteristics Design & Operation Responsibles Power Converter Architecture Power Part Control Part

Magnet Protection Power Converter Components Magnet Types Machine Installation Production Contract & Contact History

Power Converter(s) Characteristics

Common Power Converters Characteristics

Dipole Power Converter Characteristics

Solenoid Power Converter Characteristics

Design & Operation Responsibles

Yves THUREL	Interface EPC <=> Compass
Benoit FAVRE	Rack + Polarity Switch, Integration, Commissioning, Operation
Edwin ROHRICH	COMBO-Technical manager
Nicolas KUCZEROWSKI	COMBO-Expert designer

Power Converter Architecture

Control & regulation principles are summarized in a detailled schematics representating only the part involved in the output current regulation scheme. FGC3 control can adapt quite easily with different possible scenarios.

I.Loop, I.sensor = power I.Loop, I.sensor = power    -    I.Loop=fgc, I.sensor=power I.Loop=fgc, I.sensor=power    -    I.Loop=fgc, I.sensor=external I.Loop=fgc, I.sensor=external

Regulation Control simplified schematic .vsd

High precision current control loop is managed by the digital controller called FGC (Function Generator Controller). This unit includes a high precision Sigma Delta Analog to Digital Converter which digitalize the analog current measurement coming from 1 or 2 Current sensors (DCCTs: DC current Transducer). Precision is then directly relying on sensor precision: current sensors, the ADCs, and the algorithm being used for the regulation loop. Voltage source is then used as a power amplifier, powering the load through a high bandwidth voltage loop.

Converter SKINTLK Connector Pin Assignment Converter SKINTLK Connector Pin Assignment

This interface, present on almost all EPC converters follow the defined standard here: LHC-D-ES-0003, and is or directly based (typical for LHC) on Hardware Interface Type A1 – Cable ID: A1-PIC-PC or compatible with (WIC case) Hardware Interface Type B1 – Cable ID: B1-PIC-PC.

Signal		Pin	I/O	Type	Description
POWERING_FAILURE+		01	Output from EPC		01-02: open =1 (open): A fault is detected on the Power Converter (or its Power Part initiated (IGBT dead, or water fault), or even the output current not correctly regulated - FGC initiated). 01-02: cc =0 (shorted): Converter is not in fault, being OFF or ON.
POWERING_FAILURE-		02
PC_DISCH_RQ+		03	Output from EPC		03-04: open =1 (open): A discharge from an external energy extraction system is required to protect the converter in case of water loss, jeopardizing free wheeling diode path. 03-04: cc =0 (shorted): No discharge request requested. Unused: place a short.
PC_DISCH_RQ-		04
PC_CONNECT+		05	Output from EPC		The contact PC_CONNECT shall be always shorted by the Power Supply receiving connector. This signal is used by the Interlock System to know if the cable between the Power Supply and the Interlock System is connected.
PC_CONNECT-		06
PC_FAST_ABORT+		07	Input to EPC		This input is dedicated to Interlock System, to switch off the converter based on critical conditions (fast_abort case, quench of superconductive magnet). Since several requester can be chained, this safe fail (open contact = converter off) signal must be isolated (requester side).
PC_FAST_ABORT-		08
NOT CONNECTED		09	-		Reserved signal/pins not being used and to be let not connected. Note: on some converters, it is possible to find some active signals in place of these reserved pins (more likely output diagnostic, like POWER_ON, POWER_ON_NOT or similar).
NOT CONNECTED		10	-
PC_PERMIT+		11	Input to EPC		The contact PC_PERMIT (Power Permit) is open if the Interlock System orders the Power Supply to switch off smoothly. The contact is otherwise closed.
PC_PERMIT-		12

SKINLTK 12-pin female Burndy Connector Pin assignment, located on Power Source Front Panel edms

Power Part

The system proposed is capable to handle a resetable fault, or also AC mains cut for several seconds, not loosing too much current in the magnet (then saving time for de-ramping + ramping again). The capability of restarting with the converter while the load is in free-whell mode has to be proved to ensure scenario is valid, and magnet protection scheme is adequate. REE system can be launched in case of a Quench requiring energy discharge, or in case Power Converter is definitively dead and to save time. A safety crowbar is placed between the polarity switch and the load, to prevent any severe crash in case of a DC Contactor malfunction.

Solenoid

Normal Operation Ramping Up or DC Ramping Up or DC  |  Ramping Down Ramping Down
Fault Cases           Fast Discharge Fast Discharge  |  very long discharge very long discharge

Powering System simplified schematic .vsd & .xls
(Ramping Down sequence detailed proposal .pdf)

Dipole

Normal Operation Ramping Up or DC Ramping Up or DC  |  Ramping Down Ramping Down
Fault Cases           Fast Discharge Fast Discharge                                           

Powering System simplified schematic .vsd & .xls

Typical Curves / Measurements

Control Part

Control & regulation principles are summarized in a detailled schematics representating only the part involved in the output current regulation scheme.

Control & regulation principles are summarized in a detailled schematics representating only the part involved in the output current regulation scheme.

Regulation Control simplified schematic .vsd

High precision current control loop is managed by the digital controller called FGC (Function Generator Controller). This unit includes a high precision Sigma Delta Analog to Digital Converter which digitalize the analog current measurement coming from 2 DCCTs (DC current Transducer). Precision is then directly relying on sensor precision: DCCT, the ADCs, and the algorithm being used for the regulation loop. Voltage source is then used as a power amplifier, powering the load through a high bandwidth voltage loop (>500Hz).

Magnet Protection

Power Converter is part of magnet protection scheme, even if not directly fully responsible of the monitoring and diagnostic of the superconductive magnet status. Dedicated systems QPS (Quench Protection System) + PIC (Power Interlock Controller) can interlock Power Converter if magnet safety requires it.

Power Converter is then expected to:

• Always ensure that external protection system can stop the Power Converter through a safe signal called Fast Abort. This redundant signal uses 2 paths to interlock and stop the converter and its redundancy is checked each time it acts. It directly acts on AC Contactor bobbin, ensuring their opening as required.
• Always ensure a safe path exists, on the power converter side, even if experience ensure this at the level of the magnet side. It is important to notice that Free Wheeling Diode provided in the Polarity Switch cannot handle the complete and very long discharge of the superconductive magnets.

Earthing Circuit

Earth Detection system is managed by experience. DC Output Lines are delivered being floating.

Power Converter Fault Events

Power Converter Components .vsd

A power converter is actually a sum of different equipments under several different sections in the SY-EPC group. Proposed solution is based on a Power Rack + Control & Meas Rack; main reason behind this technical choices comes from physical constraints (DCCT Heads location) + fact high precision DCCT electronics are better located in a cool environement (not the case of the power rack, since converters are air cooled).

• EPC Power Rack of 2 power converters including Front View Front View  |  Rear View Rear View

  

  

  • 1x Rack 45U
    • Datasheet Rack Atos Evolution Series .pdf
  
  
  • 4x Delta-Electronika Power Module 15V 400A
    • 1x Power Converter = 2x Power Module in //.
      Datasheet .pdf, Manual .pdf, Application Note .pdf
  
  
  • 2x Polarity Switches A1.700
    • 1x Power Converter = 1x Polarity Switch
  
  
  • 1x Rack AC distribution Front Panel providing:
    • 1x AC Breaker per Power Converter (2x in total)
    • 1x AC Breaker for Global Rack electronic crate.
  
  
  • 1x Rack A.U.E. (UPS Stop) Panel providing:
    • A push button to stop the UPS powered system with the capability
      to also cut the Power AC departure (contactor at AC Dist. level)
  
  
  • 1x Rack DC Grounding System (rear view) providing:
    • A way to easily ground DC Connexion to earth in a safe way.
  
  
  • 1x Rack Config Front Panel providing:
    • A central Power Rack Equipment Stop Button
    • Individual earthing system configuration for up to 4x Power Converters.
  
  
  • 1x Controller / Electronic Chassis (Type x) including cards:
    • 2x Digital Controllers                        FGC3 + FGC3-dongle (1x FGC3 / Power Converter)
    • 2x VS V2V (1x V2V for 2x DCCTs)       HCRAKAB EDA-02710
    • 1x VS PSU (1x PSU for 2 FGC3)           HCRFAAB EDA-02322
  
  
  • 1x COMBO Config Panel (Type 2cvs2&2):
  
  
  • 1x Dual Earthing Detection System:
    • 2x detection system in 1 2U-unit provided by experience.
  
  
  • A Rack Bottom Panel including:
    • Interlock System Connections to be reviewed.

• EPC Measurement Rack including
  • 1x Rack 18..22U
    • Datasheet Rack Atos Evolution Series .pdf
  
  
  • 1x Rack AC distribution Front Panel providing:
    • 1x AC Breaker per Odd DCCT of each Converter
    • 1x AC Breaker per even DCCT of each Converter
  
  
  • 1x Rack A.U.E. (UPS Stop) Panel providing:
    • A push button to stop the UPS powered system with the capability
      to also cut the Power AC departure (contactor at AC Dist. level)
  
  
  • 4x DCCT Electronics
    • 2 DCCTs per Power Converter
  
  

• EPC Control Units to be integrated in experience IT-rack
  • 1x Gateway
  
  
  • 1x FGC3 Switch
  
  
  • 1x FGC3 Pulse Injector
  
  

Magnet Types

Machine Installation

Production Contract & Contact History

Old Design Compass Typical Curves / Measurements

Rack Thermal Characterization Rack Thermal Characterization

Converter Circuit Names