70 likes | 197 Views
Revised Inner PF Coil Design. C Neumeyer 1/27/10. Design Considerations. Constraints Amp-turns per J. Menard Fit in existing R, Z, dR, dZ per J. Chrz Use same conductor size in PF1b and PF1c Design variables PS voltage (1kV or 2kV) Turn and ground insulation thickness
E N D
Revised Inner PF Coil Design C Neumeyer 1/27/10
Design Considerations • Constraints • Amp-turns per J. Menard • Fit in existing R, Z, dR, dZ per J. Chrz • Use same conductor size in PF1b and PF1c • Design variables • PS voltage (1kV or 2kV) • Turn and ground insulation thickness • Number of layers and turns • Cooling hole diameter • Design objectives • Favoring increase in #turns • rms ripple current < 1% of peak current w/o external filter inductor • Transrex current < 24kA and to be minimized • Favoring decrease in #turns • Packing factor and ESW capability • dI/dt in PF1b and PF1c > 35kA-turn/mS for CHI • Forcing factors (V-I*R)/L > existing PF1a and PF1b • Voltage induced from OH < 50% of PS voltage • Worst case induced voltage ~ Transrex Vdc =1012V << Transrex Vdc_MOV*4 ~ 2.4kV • Cooldown time <= 1200s with 400psi pressure drop
Methodology • NSTX_CSU_Design Spreadsheet • Input geometry, turns, insulation, etc. • Calculate flow/pressure drop, ESW, self-inductance, ripple current, Idot, etc. • Mutual inductance matrix • Calculate mutual inductance matrix using ICC • Estimate max induced voltage • assuming I_dot = V/L in each circuit independently • Calculate sum of M*I_dot as if each coil open circuited while others at max I_dot • Use XL solver to find turns adjuatment ratio in PF1a/b/c to minimize largest induced voltage • Constrain turns such that Transrex PS current < 24kA • Recalculate M matrix using ICC • Determine voltage induced from OH = M*Ioh_dot • Worst case induced voltage • Run LRSIM with all circuit at Vmax except one open at a time • Cooldown time • Run KCOOL • Evaluate results and iterate
Summary of New Design 1 – max ripple (amp rms/rated current) occurs in 1kV, 6-pulse configuration 2 – min forcing factor ocurrs in 1kV configuration 3 – max slew rate based on 2kV configuration
Conductors Was not able to use standard Lavata sizes
Power Supplies PF1a 2kV@+5kA/-22kA - + D D Y Y PF1b (upgrade 1) 2kV@ +8kA PF1b (upgrade 2) 1kV@ +/-8kA or 2kV@ +8kA PF1c (upgrade 1) 2kV@ +13kA PF1c (upgrade 2) 1kV@ +/-13kA or 2kV@ +13kA D Y D Y
Summary • Inner PF coil designs revised • Meet req’ts except • ESW < 5.5s on PF1a & PF1c • Slew rate slightly less than 35kA/mS on PF1c • Upgrade path exists based on Transrex PS • Ready for design point revision • Need influence matrix update (R Hatcher) • Need equilibria update (J Menard) • Will post on web as open revision