CSCM Project Powering cycle and results of the PSpice simulations Emmanuele Ravaioli Thanks to H....

CSCM Project

Powering cycleand results of the PSpice simulations

Emmanuele Ravaioli

Thanks to H. Thiesen, A. Verweij

TE-MPE-TM14-07-2011

CSCM Project – Powering cycle and results of the PSpice simulations

Emmanuele Ravaioli TE-MPE-TM 14-07-2011

• RB circuit• Schematic of the circuit

• Powering cycle

• Power converter behavior

• Opening of the switches

• Diode behavior

• Monte Carlo analysis

• RQ circuit

• Conclusions and further work

2

RB circuit – Standard configuration

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 3

Power converter FilterSwitch1

Switch 2

77 Magnets

77 Magnets

• PCs in parallel• f_filter ~ 28.5 Hz• Extraction system present• L_dipole = 98 mH

RB circuit – CSCM configuration

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 4

Power converter FilterSwitch1

Switch 2

77 Magnets

77 Magnets

• PCs in series• f_filter ~ 14.2 Hz ( L_filter x4 )• Extraction system present ?• L_dipole = 98 mH• R_dipole = 43 mΩ (at 20 K)• L_cabling = 4 mH• U_diode > 1.6 V (at 20 K)

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 5

RB circuit – CSCM Powering cycleNo opening of the extraction switches

dVPC/dt = 20 V/s

IDFB = 150 A

dIDFB/dt = 1 kA/s

IDFB = 6 kA

Fast Power Abort

1

2

3

4

5

1 2 3 4 5

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 6

RB circuit – CSCM Powering cycle (Zoom)No opening of the extraction switches

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 7

RB circuit – CSCM Powering cycle (Zoom) – SwitchesBoth RB extraction switches opened without delay at the same time

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 8

RB circuit – Diode openingNo opening of the extraction switches

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 9

RB circuit – Diode opening – Monte Carlo simulationRandom distribution of a number of parameters within realistic range

N_diode ±20%

(opening voltage)

R_dipole ±20%

R_busbar ±20%

L_busbar ±20%

C_ground ±5%

L_aperture ±0.1%

CSCM Project – Powering cycle and results of the PSpice simulations

Emmanuele Ravaioli TE-MPE-TM 14-07-2011

• RB circuit

• RQ circuit• Schematic of the circuit

• Powering cycle

• Power converter behavior

• Opening of the switch(es)

• Diode behavior

• Conclusions and further work

10

RQ circuit – CSCM configuration

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 11

Power converter FilterSwitch1

Switch 2

51 Magnets

51 Magnets

• PCs in series (same PCs of RB)• f_filter ~ 14.2 Hz ( L_filter x4 )• Extraction system present ? 1? 2?• L_quadrupole = 5.6 mH• R_quadrupole = 6.3 mΩ (at 20 K)• L_cabling = 2x 4 mH• U_diode > 1.6 V (at 20 K)

Schematic to be edited

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 12

RQ circuit – CSCM Powering cycleNo opening of the extraction switches

dVPC/dt = 20 V/s

IDFB = 500 A

dIDFB/dt = 400 A/s

IDFB = 6 kA

Fast Power Abort

1

2

3

4

5

1 2 3 4 5

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 13

RQ circuit – CSCM Powering cycle (Zoom)No opening of the extraction switches

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 14

RQ circuit – CSCM Powering cycle (Zoom) – 1 SwitchOne RQ extraction switch opened without delay

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 15

RQ circuit – CSCM Powering cycle (Zoom) – 2 SwitchesBoth RQ extraction switches opened without delay at the same time

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 16

RQ circuit – Diode openingNo opening of the extraction switches

CSCM Project – Powering cycle and results of the PSpice simulations

Emmanuele Ravaioli TE-MPE-TM 14-07-2011

• RB circuit

• RQ circuit

• Conclusions and further work

17

• The analysis of the CSCM powering cycle in the dipole and quadrupole circuit has been carried out by means of a complete PSpice model.

• The modeling of the diode behavior and the control of the power converter have been challenging and required the developing of dedicated models.

• The simulated powering cycle comprises a voltage ramp until all the diodes are conducting (current flowing through the DFB larger than a set value), a current plateau, a high-rate current ramp, another plateau at maximum current and the switching-off of the power converter with the eventual opening of the extraction switch(es).

• The voltage transients and the current decaying have been simulated and the results have been compared with theoretical calculations.

• The influence of the opening of one or both of the extraction switches have been analyzed. The simulation results suggest that the extraction system is required for the quadrupole circuit but not for the dipole circuit.

• The model of the diode needs to be improved in order to include the heating effect which causes a decrease of the voltage drop across it. (work in progress)

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 18

Conclusions and further work

Emmanuele Ravaioli TE-MPE-TM 14-07-2011

Annex

20Emmanuele Ravaioli TE-MPE-TM 14-07-2011

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 21

Time required for discharging the circuitSimulations and (simple) theoretical calculations

Circuit No switch 1 switch 2 switches

RB – Simulation (U_diode = 1.88 V) 110 ms --- 50 ms

RQ – Simulation (U_diode = 1.88 V) 450 ms 300 ms 250 ms

RB – Simulation (U_diode = 1.2 V) to be done --- to be done

RQ – Simulation (U_diode = 1.2 V) to be done to be done to be done

RB – Theory (U_diode = 1.88 V) 110 ms --- ~25 ms

RQ – Theory (U_diode = 1.88 V) 290 ms ~150 ms ~100 ms

RB – Theory (U_diode = 1.2 V) 170 ms --- ~30 ms

RQ – Theory (U_diode = 1.2 V) 450 ms ~180 ms ~120 ms

The model of the diode needs to be improved in order to include the heating effect which causes a decrease of the voltage drop across it. (work in progress)

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 22

RB circuit – Fast Power Abort – DetailsNo opening of the extraction switches

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 23

RB circuit – Fast Power Abort – DetailsBoth RB extraction switches opened without delay at the same time

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 24

RQ circuit – Fast Power Abort – DetailsNo opening of the extraction switches

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 25

RQ circuit – Fast Power Abort – DetailsOne RQ extraction switch opened without delay

Emmanuele Ravaioli TE-MPE-TM 14-07-2011 26

RQ circuit – Fast Power Abort – DetailsBoth RQ extraction switches opened without delay at the same time