topPower Converter Characteristics

SM2 Magnet
Power In 3 ~ 18kV/2x2560kVA
Power Out 4800A/540V
Converter Type Thyristors 12P
Control type FGC3 / CESAR

topOperation Responsibles

1st Intervention Piquet Area icon Piquet SY-EPC Experimental Areas(163668)
Responsibles: Yves GAILLARD Yves GAILLARD

topPower Converter Architecture

SM2 magnet is located on M2 beam line inside PPE221 zone.

It is supplied by the RPABT.BA82.RSM2.COMPASS power converter.

SM2 architecture

SM2 power converter architecture

topPower Part

The SM2 power converter consists of two 6-pulse rectifier modules, connected in parallel. The bridges are fed from the 18 kV network through two cast resin power transformers phase-shifted 30°. A mechanical polarity-reversal switch is present after the passive filter.

SM2 architecture

Power Part simplified Architecture / Topology .pdf

topControl & Regulation Part

SM2 control synoptique

SM2 control synoptique

High precision current control loop is managed by the digital controller called FGC3 (Function Generator Controller 3). 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.

topMagnet Protection

Magnet Interlock

The SK101 cable brings back all the interlocks magnet of the spectrometer. There are 6 interlocks (Water Pressure, Water Temp, Coil Temp, Eletta, Red Button, Terminal Box) which are grouped in two interlocks for the regFGC3 electronics.

  • Water Pressure: This is a pressure sensor installed at the input of the cooling loop, integrated in the magnet. This alarm can also be triggered by a water flow sensor installed on some “Eletta” water cooled cables, which is wired in series with the magnet alarm. There is no separate alarm given.
  • Water Temperature: This is a temperature sensor located at the exhaust side of the cooling loop.
  • Coil Temperature: This is a series of temperature thermostats selected to protect the appropriate magnet against excessive coil temperature.
  • Eletta: It is used to indicate a fault on the “Eletta” water cooled magnet.
  • Red Button: This is an “Emergency Off” switch located on the magnet to allow shut down of the associated Power Converter(s) in the event that someone working in the vicinity detects a fault.
  • Terminal Box: This is a door interlock switch located on the second terminal box, installed between the Power Converter and the magnet. This interlock can be bypassed on the Power Control Crate by inserting a jumper on the front panel.(Safety procedures are affected by this action).

topMagnet connection

SM2 Magnet connection

SM2 Magnet connection simplified schematic

topMagnet Types

Resistance: 0.115 Ohm
Inductance: 1H
Maximum field at 6 kA: 1800T
Max. excitation current:5000A
Water Flow: 150l/mn

topMachine Installation

    SM2 power converter is installed in North area:

  • 891 (BA82): 1

topProduction Contract & Contract History

  • Manufacturer: CERN
  • Production year: 2017