Eidgenössische Technische Hochschule Zürich Laboratory for High Swiss Federal Institute of Technology Zurich Power Electronic Systems Solid State Modulators – Efficiency Considerations focussing on SiC Devices – J. Biela, S. Stathis, M. Jaritz, and S. Blume www.hpe.ee.ethz.ch / [email protected] Typical Topology of Solid State Pulse Modulator Systems AC/DC rectifier unit DC/DC converter for charging C-bank / voltage adaption Pulse generation unit Load e.g. klystron Constant Power Pulsed Power AC DC Energy Storage Pulse Klystron Modulator Load DC DC Grid Medium Voltage ⎧⎪⎪⎪⎨⎪⎪⎪⎩ Sometimes integrated V V V V t Pulse t t t Pulse 400V or MV Intermediate Buffer Capacitor Bank Pulse Voltage High Power 2 33 Electronic Systems Typical Topology of Solid State Pulse Modulator Systems Grounded klystron load I Isolation with 50Hz transformer or I Isolated DC-DC converter Typical Isolation AC DC Energy Storage Pulse Klystron Modulator Load DC DC Grid Medium Voltage V V V V t Pulse t t t Pulse 400V or MV Intermediate Buffer Capacitor Bank Pulse Voltage High Power 3 33 Electronic Systems 29 MW(35MW)/140 µs Modulator for CLIC – System Efficiency – High Power Electronic Systems CLIC System Specifications Output voltage 150:::180 kV Settling time <8 µs Output power (pulsed) 29 MW (- 35 MW) Repetition rate 50 Hz Flat-top length 140 µs Average output power 203 kW (- 245 kW) Flat-top stability (FTS) <0.85 % Pulse to pulse repeatab. <100 ppm Rise time <3 µs 819 klystrons 819 klystrons 15 MW, 142 µs circumferences 15 MW, 142 µs delay loop 73 m drive beam accelerator CR1 293 m drive beam accelerator (c)FT 2.4 GeV, 1.0 GHz CR2 439 m 2.4 GeV, 1.0 GHz 2.5 km 2.5 km delay loop delay loop CR2 CR2 Drive Beam CR1 CR1 decelerator, 24 sectors of 878 m BC2 BC2 BDS BDS 2.75km 2.75km – IP + TA e main linac, 12 GHz, 100 MV/m, 21 km e main linac TA 48.3 km CR combiner ring Main Beam TA turnaround DR damping ring PDR predamping ring booster linac BC bunch compressor 2.86 to 9 GeV BDS beam delivery system IP interaction point BC1 dump e– injector, e+ injector, 2.86 GeV e– e– e+ e+ 2.86 GeV PDR DR DR PDR 389 m 427 m 427 m 389 m High Power 5 33 Electronic Systems CLIC Solid State Modulator – System Overview AC/ DC Unit Interleaved Boost Converter Switching Unit 750V 3kV 3kV 400V -180kV 3kV AC 750V DC -180kV 400V Klystron Voltage Load Grid DC DC 0-300V DC 3kV 450V DC Active 0V Bouncer 300V Matrix Transformer High Power 6 33 Electronic Systems CLIC Modulator – Grid/Isolation Transformer Voltage 3×400 V to 3×400 V @ 250 kVA Core material Silicon steel Winding material Aluminium Weight 890 kg Efficiency 98.8 % (PCore = 700W & PWdg = 2:3kW) Higher efficiency I Better core material E.g. Amorphous (PCore − 60%) I Copper winding Higher conductivity (PWdg − 35%) I Efficiency á ≈99.2 % (Estimated) (Larger volume á Higher efficiency) AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 7 33 Electronic Systems + CLIC Modulator – AC/DC Converter Efficiency Type (B&R) ACOPOSmulti 8BVP1650 Topology 2-level PFC-rectifier Switches 1.2 kV Si IGBTs Voltage conversion 400 VAC ! 750 VDC (620 V – 800 V) Efficiency 97.47 % Higher efficiency I 1.2 kV SiC MOSFETs Lower PCond & PSW I Optimised design E.g. higher volume / lower fSW I Efficiency á ≈99 % + AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 8 33 Electronic Systems CLIC Modulator – Boost Converter Basic Operation Input voltage 600 V – 800 V Output voltage 3 kV Switching frequency 70 kHz – 240 kHz T1 T2 T3 T4 T5 Output power 40 kW I L L ... Imax 650 V Si MOSFETs 8 in series I á Cs/R for balancing L Boundary cond. mode t Sn Imin 6-fold interleaving á 6 × 40 kW ... vCd,tot vCs,tot VDC S1 ZVS ZVS off on t AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 9 33 Electronic Systems CLIC Modulator – Boost Converter Efficiency Nom. voltages 750 V ! 3 kV ... Output power 40 kW Switching frequency 70 kHz – 240 kHz Sn 8×650 V Si MOSFETs 2× Infineon IPZ65R019C7 ... 4×1.2 kV diodes Microsemi APT75DQ120B Efficiency 97.2 % S1 Fans Inductor Output capacitors Snubber Capacitor 2% HV output Boost Diode Inductor Switching 11% Power 3% input MOSFET Diode Conduction Conduction 58% Input fuse 20% MOSFET Switching 6% Input capacitors PCB with isolated gate drives High Power 10 33 Electronic Systems CLIC Modulator – "SiC" Boost Converter Voltages 750 V ! 3 kV ... Switching frequency 70 kHz – 240 kHz Higher efficiency Sn I 4×1.2 kV SiC MOSFETs 2×C3M0016120K ... I 4×1.2 kV SiC Diodes 2×IDW40G120C5B I Efficiency ≈ 98.6 % (Old: 97.2 %) S1 Snubber Capacitor 4% 700 W Si-based Converter 600 W MOSFET SiC-based Converter Boost Conduction 500 W Inductor 25% 46% 400 W 300 W 200 W Diode Conduction 100 W 22% W MOSFET MOSFET MOSFET Diode Diode Switching 3% Conduction Switching Conduction Switching High Power 11 33 Electronic Systems Conduct. Losses 13% Switching Losses 87% CLIC Modulator – Switching Unit ABB StakPak 4.5 kV / max. 3 kA (pulsed) (5SNA1250B450300) Active reset switch 4 units in parallel Pulse current 4 × 2.4 kA (@ PP = 29 MW ) Efficiency 98.6 % (Switching losses: 87% of Ptot) Higher efficiency I Semiconductors SiC MOSFETs (assumption: 1.2 kV devices) (4 in series / 3 parallel) I Efficiency á 99.5 % AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 12 33 Electronic Systems CLIC Modulator – Bouncer Output voltage 0:::300 V (10 % droop) Input voltage 450 V 24-fold interleaving Ultra low ripple Semiconductors IGBTs 3kV DV=300V V main Vtotal + S DHS HS Cmain L 300V b SSC Vb,out SLS DLS Active Bouncer Module AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 13 33 Electronic Systems CLIC Modulator – Bouncer Operating Principle Output voltage 0:::300 V Input voltage 450 V Output current (pulse) >600 A (per module) Wait for trigger VBout shortened } } 625A i S DHS b HS Cmain L V 3.0kV b main SSC 2.7kV SLS DLS ActiveV Bouncer Module 450V Bin VBout Wait tk Pre- Interpulse for next Pre- charge Pulse Resonant Recharging pulse charge High Power 14 33 Electronic Systems CLIC Modulator – Bouncer Components Output voltage 0:::300 V Input voltage 450 V 4×6-fold interleaving Switching frequency 100 kHz Per module: I SLS-IGBTs 2×IGW50N65H5 I DLS-Diodes 4×IDW40E65D1 I SHS-IGBTs (w. diode) 6×IKW50N65F5 I SSC-IGBTs (w. diode) 6×IKW50N65F5 I Inductor Lb = 26 µH 4×Metglas AMCC32 S DHS HS Cmain Lb SSC SLS DLS Active Bouncer Module Control board Buck-boost switch Short circuit switch High Power 15 33 Electronic Systems CLIC Modulator – Bouncer Efficiency With IGBTs I Total AVG losses 1.56 kW I Module efficiency 91.0 % Bouncer-Level á Efficiency 99.4 % System-Level HS IGBTs S DHS HS conduct.Cmain Lb 7% S Inductor SC SLS D 625A LS losses 18%Active Bouncer Module HS IGBTs switching HS diodes 3% 51% SC IGBTs 3% ib LS IGBTs 4% LS diodes 14% tk High Power 16 33 Electronic Systems CLIC Modulator – SiC Bouncer Efficiency With IGBTs I Total AVG losses 1.56 kW I Module efficiency 91.0 % Bouncer-Level á Efficiency 99.4 % System-Level With SiC MOSFETs I Total AVG losses 0.79 kW I Module efficiency 95.2 % Bouncer-Level á Efficiency 99.7 % System-Level D SHS HS C Inductormain losses Lb 35% SSC 800W SLS DLS Si-based converter HS diodesActive Bouncer Module HS SW 600W 5% conduction 12% SiC-based converter SC SW 4% 400W LS SW HS SW switching 200W 9% 8% W LS diodes HS switch HS switch LS diodes LS switch SC switch 27% conduction switching High Power 17 33 Electronic Systems CLIC Modulator – Pulse Transformer Matrix transformer 2 cores / 4 primary windings Turns ratio 62 á 4:(2×124) Core material SiFe / 50 µm Vsek RLoad I Ipri,1 pri,3 S M,1 SM,3 Df,1 Df,3 I Ipri,2 pri,4 S M,2 SM,4 Df,2 Df,4 AC DC DC Grid DC DC DC Isolation PFC Boost Converter Bouncer Switching Unit Pulse Transformer Rectifier (Droop Compensation) Transformer High Power 18 33 Electronic Systems CLIC Modulator – Pulse Shape/Transformer Efficiency Rise + settling time 4.6 µs Fall time <3 µs Flat top 140 µs Efficiency 96.7 % (Trafo + Pulse shape) Reverse voltage Time to Fall flat top Time t “Dissipated” pulse “energy” Pulse Shape Winding Losses 88% 4% Core Losses 8% Flat top (Used pulse “energy”) Allowed droop High Power 19 33 Electronic Systems CLIC Modulator – Higher Transformer Efficiency Core material SiFe 25 µm lamination Amorphous material Insulating oil Ester 7131 er = 3:2 á Mineral oil er = 2:2 Shorter load cable Transformer design Critical damping (slightly underdamped) Larger volume / Core splitting Estimated efficiency ≈ ≥97.5 % 0.98 Mineral oil CLIC trafo @12kV/mm 1.5m cable 0.975 Mineral oil @10kV/mm 1.5m cable 0.97 Natural ester @10kV/mm 1.5m cable 0.965 Efficiency (%) 0.96 Mineral oil @10kV/mm 5m cable Natural ester @10kV/mm 0.955 5m cable 1.05 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 Transformer volume (m3) High Power 20 33 Electronic Systems CLIC Modulator – System Efficiency Original System Improved System Grid Trans- Pulse Shape/ Pulse Shape/ former 10% Transformer Transformer 39% 28% Grid Trans- former PFC 12% Bouncer 21% Bouncer 5% 5% Switching Switching Unit 8% Unit 12% PFC 24.8kW 15% Booster Booster 21% 24% 13.4kW Conventional SiC-based 88.7% Original 98.8% 97.5% 97.2% 99.4% 98.6% 96.7% Improved 99.2% 99.0% 98.6%