linac 4 – control system design (small)
TRANSCRIPT
LINAC 4 – Control System and Adaptive Feed‐forward Design
Anirban Krishna BhattacharyyaBE – RF – FB
Introduction
Total loop delay of 1100 ns.
Klystron Model
Error: 5.3% and 3.84%
Transfer Function
Klystron ModelGain
PIMS Cavity:ZTT = 24.622e6 Ω/mL = 1.298 mQ0 = 20800β = 1.24Φ = ‐20°Z0 = 50 ΩPsat = 1.4 MW
Beam current: 40 mACavity voltage: 4.805 MVPower loss: 5%
Parameters
Controller structure: , where, , and, 1+aτs
KP1+τs
Τ = KP
KI
a = 10
PIMS Cavity Model
Notch Filter for PIMS Cavity
Effect of Notch
Smith‐Predictor Design
Process model estimation:
1. 10% error in knowledge of cavity parameters and delay.
Requirements:
1. Model for process/plant.2. Estimation of time‐delay
What is this?
Smith‐Predictor DesignOpen Loop Step Response
Sensitivity AnalysisSensitivity of the controller parameters to ±20% variation in QL of the cavity (PIMS) is investigated.
Feed forward
δ δ δ
1ε
Beam Disturbance
Results
Results: Klystron Power
Comparison of Cavity models
The End
Smith Predictor
Controller Plant
Delay
1+GCGe‐sτd
GCGe‐sτdTransfer function =>