xfel the european x-ray laser project x-ray free-electron laser review of llrf system based on atca...

XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser

Review of LLRF system based on ATCA standard, Dec 3-4, 2007

Piezodriver and piezo controlWork Package 1.4

P. Sekalski, M. Grecki, T. Pozniak, K. Przygoda

Department of Microelectronics and Computer Science, Technical University of Lodz, Poland

Przemek Sekalski, Department of Microelectronics and Computer Science, Technical University of Lodz, PolandReview of LLRF system based on ATCA standard, Dec 3-4, 2007 2


The agenda

The main aim of the piezocontrol system

General requirements and assumptions of piezocontrol system

Overview of the piezocontrol system in regard of LLRF system

Piezocontroller architecture

Piezodriver scheme

Piezo read-out architecture



The main aim of piezocontrol system

Drive the piezoelements assembled in fast tuners frames to minimize the Lorentz force and microphonics effects

On-line frequency detuning calculation

Microphonics measurement (i.e. diagnostics of cryogenic system)



General requirements and assumptions of piezocontrol system

Lorentz force detuning during flat-top Δflat top< 10 Hz for field up to 30 MV/m(compensation up to 600 Hz)

Maximal repetition rate of RF pulse under 10 Hz (20 Hz optional)

Standalone box for piezodriver, DAC and ADC boards(no-ATCA due to power consumption) 2 x EuroCrate 6U

PiezoController compatible with ATCA carrier board

Optical link between PiezoController and DACs and ADCs cards

System suitable for 64 PI’s and/or NOLIAC’s piezoelements (4 modules x 8 cavities x 2 piezoelements each)

26 Piezocontrol systems (101 modules, 808 cavities, 1616 Piezos)



Controller

Low Level Application

High Level Application

Control System

8 8 8 8 8 8 8 8 8 8 8 8

Overview of the piezocontrol system

ForwardReflected Probe



Overview of the piezocontrol system

Controller

Low LevelApplication

High LevelApplication

Control System

8 8 8 8 8 8 8 8 8 8 8 8

Piezo ControllerATCA compatible

8 ch PZD amplifier8 ch PZD amplifier8 ch PZD amplifier

8 in 1 PZD

amplifier

ADC32 in 1

8 88 88 888


Control System

x4

DAC 32 in 1

DAC



Requirements for PiezoController

Hardware requirements:

Lorentz Force:

FSM, adder, multiplier, bram-blocks

Microphonics:

NLMS filter of order 32/64 (up to 64 multipliers) Adders 5x32

FPGA Spartan 3 xc3s2000

ATCA Carrier Board compatible (PCI Express)

OptoLink to Controller (TLK 2501) OptoLink to DACs and ADCs cards (TLK 2501)



Piezocontroller architecture – 2 FPGA for 8 cavities

PZD

Δt, f, Aref_table

PZSΔ 32 in 1

Control System

DAC

LLA

FPGATimingtrig

DAC PZD

PZS

Control System

Piezo diagnosticInterlocks

…

4x 8 in 132 in 1

ATCA

ADC

ADC



Piezocontroller - FPGA

Sine generator

Δt, f, Aref_table

reference errors signal (microphonics) f(UPiezo_sens)PID controllerΔ reference error signal

(LFD) f(Δ)

Upiezo sens

LF/piezoΔA

trig

x8

Piezo diagnosticInterlocks

K1

K2

K3

Upiezo act



PiezoController architecture

The feedback loop’s latencies < 0.5 ms

The piezo-to-piezo feedback loop based on PID controller (vibration cancellation between the pulses)

The detuning-to-piezo loop based on adaptive feed-forward (short RF pulse in comparison to mechanical action of cavity)

OptoLink to DAC board and ADC board

Piezo diagnostic (i.e. capacitance measurement)

Interlocks (protection when module is warm)




FPGA implementation of detuning algorithm for 8 cavities

probefor

probe

forprobe

U

U

dt

d

sin22

12/1

Ufor is a magnitude of forward signal,for is a phase of forward signal,Uprobe is a magnitude of probe signal,probe is a phase of probe signal,1/2 cavity half-bandwidth

Forward signal and reflected signal must be decoupled (signal callibration)



Piezo Read-out

Main objective: – read and adjust the impedance of piezoelements, which

work as sensors in fast tuners

General overview:– Standalone box (no ATCA, EuroCrate), – close to PZD for exchanging piezostack functionality– 32 analog input channels (for 4 cryomodules),– 32 channel ADC (sampling higher than 10 kHz/channel)– Opitcal Link to PiezoController for data exchange and

board monitoring



DAC board

Optolink to PiezoController (Spartan support for TLK 2501) for data exchange and board monitoring

DAC 32 channels (14 bits)

Output voltage ± 1 V

Mounted in EuroCrate 6U close to PZD



Piezodriver main parameters

Suitable for both types of piezostacks up to 5µF:

Physik Instrumente (P-888.90 PIC255); C2K4,4 µF

NOLIAC (SCMAS/S1/A/10/10/20 /200/42/6000); C2K 2,4 µFMaximal supply voltage up to ± 150 V (nominal ±80V)Input voltage ± 1 V

Amplifier gain Gu= 100V/V,

Operational temperature Tc < 75°C (Tj <125 °C)Pass-band frequency up to 5 kHz (for load 5uF)Need dedicated Power Supply

Single channel PiezoDriver with Power Booster PB518 channels PZD on single boardUp to 4 periods of sinus wave input signal 200 Hz, 10 Hz repetition rate,



Piezodriver scheme

Inputs

Outputs

Voltagesense output

Current sense output

8x Piezo Drivers



Piezodriver scheme

Input

PreamplifierOP177

Power BoosterPB51

+15V

-15V

+Vss

-Vss

Output



Thank you for your attention

xfel the european x-ray laser project x-ray free-electron laser review of llrf system based on atca...

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