for a 1.5-mw magnetron application* development of a 45...
TRANSCRIPT
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
S. D. Jang, Y. G. Son, J. S. OhPohang Accelerator Laboratory
Pohang University of Science and Technology(POSTECH)
H. G. Lee, Y. S. Bae, H. G. Lee, M. H. Cho, and W. Namkung
Pohang University of Science and Technology(POSTECH)
San 31, Hyoja-dong, Pohang,Kyungbuk 790-784, S. KOREA
Development of a 45-kV Pulse Transformerfor a 1.5-MW Magnetron Application*
* This work is partially supported by KBSI and KSTAR project by MOST.
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Introduction
Microwave heating system of KSTAR consists of ECH and LHCD. ECH and LHCD offer the reliability of operation in the beginning of plasma formation and non-inductive current drive for long time steady state operation, respectively. LHCD demands C-band microwave system with a frequency of 5 GHz. A pulse generator with a power of 3.6 MW, 4 , 200pps is required to drive a high-power magnetron. The pulse transformer producing a pulse with a peak voltage of 45 kV is required to produce a 5-GHz microwave source in a 1.5-MW magnetron. We have designed the high power pulse transformer with 1:4 step-up turns ratio. The peak power handling capability is 3.6-MW (45 kV, 90 A at load side with 4 pulse width). In this paper, the results of the high power pulse transformer design and performance characteristics are presented.
* This work is partially supported by POSCON and KSTAR project by MOST.
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Simplified Equivalent Circuit
Pulse Transformer
Lw
CDLPRE
RG
+
Load
VG
RL
LL
CL
Pulse Generator
SG
VG : Charging Voltage of Storage Capacitor
SG: Thyristor SwitchRG: Primary ImpedanceLW: Wiring Inductance
LL: Leakage Inductance
RE: Core Resistance
LP: Primary Inductance
CD: Distributed Capacitance
CLoad : Load CapacitanceRL : Load Impedance
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Wave Shape Definitions
0000
Pulse length ττττp
TimeTr
Overshoot :CD, LL, γγγγ
Load Voltage
Backswing : CD, LE, RL, RE
Return backswing : CD, LL, Impedance mismatch
Tf
V0 0.9 V0
Fall time
0.1V0
Source Voltage
Rise time Tr : CD, LL
TTCLSrT )(2 σπ=
Droop : Lp, RL , ττττp
D = RL ττττw /(2 LP)Lp = 4ππππµeNP
2 Ae / Lm [nH]
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Normalized Rising Pulse Waveform
0.94
0.96
0.98
1.00
1.02
1.04
1.06
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0S
y(t)
σσσσ=0.7σσσσ=0.8
σσσσ=0.9σσσσ=1.0
σσσσ=1.1σσσσ=1.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 0.5 1 1.5 2S
y(t)
σ=0.5σ=0.5σ=0.5σ=0.5σ=0.6σ=0.6σ=0.6σ=0.6σ=0.7σ=0.7σ=0.7σ=0.7σ=0.8σ=0.8σ=0.8σ=0.8σ=0.9σ=0.9σ=0.9σ=0.9σ=1.0σ=1.0σ=1.0σ=1.0σ=1.1σ=1.1σ=1.1σ=1.1σ=1.2σ=1.2σ=1.2σ=1.2σ=1.3σ=1.3σ=1.3σ=1.3
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Given parameters(Requirements)
Parameters Designed
peak load voltage(kV) 40 (negative)Peak load current(A) 96 (max)Load resistance(Ohms) 470 (Secondary) Primary RMS current(A) 26.93 (max)Secondary RMS current(A) 6.73 (max)Pulse width(µµµµs) 4Turns ratio 1:4 Pulse repetition rate 200 ppsLoad capacitance 31.4 pF
Design Parameters of the 1:4 Pulse Transformer
Designed parameters(Results)
Parameters Designed Measured
Turns ratio 4 3.87Primary turns 10 -Leakage inductance(µµµµH) 37 42.2Distributed capacitance(pF) 12.8 38.7primary inductance(mH) 21.6 19.85(LCR)Core material thick.(µµµµm) 50 -Magnetic flux swing(T) 0.68 -Effective permeability 800 803Gap length(µµµµm) 24 -Effective core cross-section(cm²) 66 -Mean magnetic path length(cm) 50.3 -Core weight(kg) 47 -
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Design of Pulse Transformer(1:4) for 1.5 MW Magnetron
30
Primary winding : 10 turns with 2 parallel on each leg x Ф 1.6 x 4.15 Space (l c : 83)
83
65
100 200
221Ao= 75 Cm2 (25 x 3)Ae= 66 Cm2 (22 x 3)Lm = 50.3 Cm∆01= 8, ∆12= 10,∆23=10, corona gap=9Ns : 40 turnsCorona ring :all secondarywinding end point(dia. 5)
unit : mm
Secondary winding I: 40 turns x Ф1.8 x 2 Space (l c : 78), 78+15+7 =100
Secondary winding II: 10 turns x Ф 1.8 x 3. Space (l c : 27)
78
Designed by S.D. JangOctober 30, 2003
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Coil Geometry and Winding Configuration
b
Isolated and bifilar winding(1:4)
30 83
65
100
221
78
Core(50x50.4)
Primarywinding
Secondarywinding
a = 181b = 66lC = 78∆12 = 10
a
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Specification and Electrical Parametersof Pulse Transformer
Specification and Electrical Parametersof Pulse Transformer
1Pulse Droop[%/µµµµs]
0.4Rising Time [µµµµs]
1 : 4Step of Ratio
200Pulse Repetition Rate [Hz]
3.2Plat Top pulse width [µµµµs]
470Output Impedance []
45Secondary Voltage [kV]
96Secondary Current [A]
22.5Primary Voltage [kV]
375Primary Current [A]
1.2681.271Primary Inductance [mH]
19.8520.342Secondary Inductance [mH]
Measured ValueModel calculated ValueItem
38.744.2Distributed Capacitance [pF]
42.279.3Leakage Inductance [µµµµH]
Peak Voltage [kV] 45Peak Current [A] 96Load Impedance [Ω] 470HV Pulse Length [µs] 4Pulse Energy [J] 17.3Repetition Rate Max [Hz] 200Step-up Ratio 4PFN Charging Voltage [kV] 25PFN Impedance [Ω] 29.37PFN Section Cap [nF] 10PFN Section Inductance [µ H] 8.63PFN Section Number 7Charging Resistance [Ω] 100Thyratron ( CX1191D ) 8 MW, 35 kV, 500 A,
Design Parameters of ModulatorDesign Parameters of Modulator
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
7.5Winding length [cm]
50.3Mean Magnetic Path Length [cm]
10Primary Turn Number
1Distance between layers [cm]
800Effective magnetic Permeability
28.7Mean circumference between layers [cm]
0.68Total magnetic flux density swing [T]
0.88Core Packing factor [%]
66Magnetic Cross section Area[cm2]
40Secondary Turn Number
Parameters of Pulse TransformerParameters of Pulse Transformer
s
loadr L
RD2
τ=
s
s
BNVA∆
= τ
m
ses l
NAL2
0 ⋅= µµ
s
m
se
loadr N
lV
RBDµµ02⋅∆=
42 DL
rCL
T⋅
=π
c
sL l
NuL2
0 ⋅⋅∆= µ
nnuN
cT srr
12
−= επ
20 1
−∆
⋅=n
nluC crD
εε
VoltageSecondaryVWidthPulse
s ::τ
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Dong-A 403
C-Band1.5MW MagnetronPulse Modulator
High VoltageSwitched ModePower Supply
Tyratron
Driver Circuit
Tyra tronHeater PowerSupply
MagnetronHeater
Power Supply
Magnetron Beam Voltage MonitorMagnetron Beam C urrent Monitor
EOLC
Protection Diode
ThyratronE2V
CX1191D
Tail Clipper
SurgeDespiker
Pulse Transformer
1:4
ResistorDivider
Dong-A 403Output Voltage 25 kVCharging Rate Peak 5 kJ/s Average 4.0 kJ/s
High VoltageCoaxialCable
MagnetronPulse Transformer
Tank
Frequency 5100 MHzOutput Power 1.5 MWRepetiton Rate 200 ppsEffic ieccy 52 %Beam Voltage 39 kVBeam Current 83 ARF Pulse Width 4.0 µµµµs
Peak Power 3.6 MWCharging Voltage 22.5 kVPFN Output Voltage 11.25 kVPFN Output Current 382 AHV Pulse Width (70% Voltage) 4.0 µµµµsRepetition Rate 200 pps
Pulse Modulator 7 Stage PFN
PFN impedance 29.37 ΩΩΩΩTotal Capacitance 68.26 nFTotal Inductance 51.6 µµµµHSingle Capacitance 10 nF
50 ΩΩΩΩ
30 ΩΩΩΩ
50 ΩΩΩΩ
G2G1
10 µµµµH
6.3 V12. 5 A
CPI SFD369
1 nF
25 ΩΩΩΩ
P1
P2
M2
M1M3
M4
E1
E2
E3
E2-1 E4 E4-1CT-2
Electron GUNHeater
Power Supply
ElectronGU N
ResistorDivider
Gun Beam Voltage Monitor
Gun Beam Current Monitor
50 ΩΩΩΩ
CT-1
BNC-1 BNC-2 BNC-3 BNC-4
Heater voltage : 6.3 +/_ 0.5 V(Max:6.8 V), 12.5 A
Heater voltage : 5 V +/_ 1 V(Max: 6 V), 28 A
Heater voltage : 9 V+/_ 1 V(Max: 10 V), 10 A
FilterPCB
2 MΩΩΩΩ
Dump SW
8.6 µµµµH
10 nF
DS2124
DS2124
RF-Output
CathodeVane
Anode
Strap
HV Probe
Circuit Diagram of ModulatorCircuit Diagram of Modulator
Charging Circuit Discharging circuit
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
1100800
PressureGauge/ Valve
5.0-GHz magnetron
Optical cable
Drydummyload
Dry Dummy Load
Dual directionalcoupler E-bend
or H-bendThyratronSwitch / PFN
InverterPowersupply
PulseTransformer
Control Unit(PLC /w pulse gen.)
37 kV
, 70
APFN Pulse Modulator(Max 45 kV, 96 A, 4 µµµµs)
19” rack
Trigger pulse (Internal & External DG535)Interlock signals (Contact Closures)RS232 comm port (for remote control)
Interlock signals-Reflection power > 50 %-Arc signal (in waveguide)-SF6 gas pressure < 30 psig-Magnetron cooling fan off
Heater DC 5 V28 A
FAN
Air cooled magnetron• SFD369• Frequency : 4.9 – 5.1GHz• Peak power output: 1.5MW• Duty Cycle: 0.001 (1 kHz
repetition)• Peak Anode Voltage Max:
40.5 kVPeak Anode Current Max: 90 Amps
• Pulse Width: 0.4~1.4 µµµµs
SF6
WR187 w/g components
• Straight waveguide• E-bend• H-bend• Dual directional
coupler• 4-port circulator
Arc detector
4-portcirculator
Layout of The Test System
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Pulsed Magnetron Pulsed Magnetron
CPI SFD-369
5, 28Heater V, I (V, A)
52Efficiency (%)
0.0008Duty1.68Peak Output Power (MW)
4Pulse Width (µµµµs)470Magnetron Impedance ( Ω )83Anode Current (A)
39Anode Voltage ( kV )
Average Output Power (kW)
Frequency (MHz ) 4900-5100
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Modulator Test SetupModulator Test Setup
472
Pulse TR
472
Pulse TR
Photographs for LHCD Test System
PFN & HV BoxPFN & HV Box
Pulse TRPulse TR
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Test and Simulation ResultsTest and Simulation Results
Ti me
5. 008ms 5. 010ms 5. 012ms 5. 014ms 5. 016ms 5. 018ms- I ( R3)
- 100A
- 50A
- 0A
- 140ASEL>>
V( R3: 2)
- 60KV
- 40KV
- 20KV
0V
Pulse Length : 4 s
Rise Time : 0.5 s
Fall Time : 1.2 s
Flatness :1.8 %
Flattop Pulse width : 2.8 us45 kV
97 A
45 kV
97 A
Rise time 0.4 us
Flatness 1.8 %
Flattop Pulse width 2.8 us
KAPRA 2004, Cheorwon Cityhall, Gangwon (July 9-10) Electrical Engineering Group ([email protected])
Summary & Future Plan
• Summary
1. Equivalent circuit analysis of the pulse transformer.
2. Normalized rising waveform as function of the damping factor.
3. Design of the 1:4 pulse transformer for a microwave tube.
4. Establishment of the general design procedure, equation
for high-power pulse transformer.
5. Waveform analysis for simulation circuit of the pulse system.
6. Measurement of equivalent circuit parameters for transformer
• Future plan
1. Measurement of pulse characteristics according to specification.
2. HV performance test by using a 5 GHz, 1.6 MW magnetron load for a LHCD system.
3. Optimum design and fabrication for high efficiency.