S-QD : Quench Detection SystemJ.Domenge, S.Moog, D.Leopoldes

SIGMAPHI Electronics, Haguenau, France

The Sigmaphi Quench Detector (S-QD) is a system dedicated to the monitoring of superconducting magnets for Research, Industrial and Medical applications. Proposed as a standalone device, withup to 8 independent 800V isolated voltage, 16 Cernox and 4 PT100 inputs, a chaining capability, Ethernet Modbus TCP communication, configurable inputs/outputs and quench detection laws, theS-QD is a compact, highly modular and cost-attractive solution.

Easy to use (Webserver for configuration and monitoring), the S-QD is also reliable and respects real-time constraints with its state of the art architecture (FPGA, Embedded Linux).

PRODUCT OVERVIEW PRESENTATION

TEMPERATURE MONITORING

Interface

QUENCH DETECTION

ABSTRACT

Conclusions

The quench detector is a 1U device based on a CPU that gathers : FPGA (Altera Cyclone V): Real-time measurements, signal processing and decision Microprocessor (i.MX6): Linux embedded - Communication, Web server

The device can be composed of 3 electronic boards: 1 main processing board (always present) 1 or 2 application boards to be selected from:

• Quench board (4 voltage measurements)• Temperature board (8 Cernox + 2 PT100 measurement channels)

5 configurations are possible: 1 processing board + 1 quench board 1 processing board + 2 quench boards 1 processing board + 1 temperature board 1 processing board + 2 temperature boards 1 processing board + 1 quench board + 1 temperature board

•a 2-channels 12 bits SAR analog to digital converter•Data are filtered with a 1st order digital filter

Temperature board

Quench board

Main board

Ethernet / optional field bus

Local display/LED/keyboard

Hardware:• A quench board is composed of 4 isolated voltage measurements

(800V DC permanent).• The input voltage range can be set by hardware on request.

By default: +/-5V.• Signals are digitalized with four 16 bits SAR ADC.• Data are oversampled and filtered with a 1st order digital filter.

Configuration:Each quench board can measure 4 voltages. These 4 voltages are inputs from 6 comparators:• 4 absolute comparators where output error is a voltage:

Error = Add1 – Add2.• 2 relative comparators where output error is a ratio:

Error = Add1 / Add2.

Warning and interlocks:• Each absolute error is compared to a warning threshold (voltage and time threshold)• Each absolute error is compared to a interlock threshold• Each relative error is compared to a normal ratio +/- a warning threshold• Each relative error is compared to a normal ratio +/- a interlock threshold

Hardware:• 8 CERNOX: Range from 50 to 25 k.

2 kHz sampling.24 bits Sigma-Delta ADC.1 µA or 10 µA excitation current.

• 2 PT100: 12 bits SAR ADC.• Data are filtered with a 1st order digital filter.• 300V DC permanent insulation for every group (the 8 Cernox are isolated from the

2 PT100 and from the ground).

Configuration:• CERNOX calibration table can be loaded as CSV file.• Each measurement can be configured to generate interlock / warning signal.

Hardware:• Output relays / optical signal.• Can be configured to open / close

depending on one or several warning / interlocks.

Digital:• The S-QD is fitted with two Ethernet ports:

REMOTE Ethernet:1Gbits, DHCP or STATIC IP.LOCAL Ethernet: 10/100Mbits, Fixed IP.

• Modbus/TCP for machine to machine communication.

• High-end and responsive web interface.

Compared to other market products, the Sigmaphi Quench Detection System is a user friendly, high performance and cost effective solution.The integration and the parametrization of all the necessary control functions of a supraconducting magnet leads to a very relevant standard products.This system is already operating on the field: protontherapy customers worldwide, research centers (CEA) …