The Cutting Edge of Power Electronics for High-Power Applications

Transcription

1 The Cutting Edge of Power Electronics for High-Power Applications Hirofumi Akagi July 28, 215 1

2 Established in

3 Environmental Energy Innovation (EEI) Building with 65-kW Photovoltaic, 1-kW Fuel-Cell, and 1-kWh Lithium -Ion Battery Energy Storage Systems 3

4 Energy Efficiency of Passenger Aircrafts Airbus A34-3 Number of seats: 261 Max. take-off weight: 25, kg Range: 12,8 km Cruising speed: 875 km/h Fuel Consumption (Energy Efficiency):.39 liters per seat/km Airbus A33-3 Number of seats: 261 Max. take-off weight: 233, kg Range: 9,7 km Cruising speed: 875 km/h Fuel Consumption (Energy Efficiency):.35 liters per seat/km source: SCANORANAM, FEB 27 4 A33-3 A34-3

5 What is Power Electronics? (1/2) The IEEE Power Electronics Society with a membership of 8, is one of some 4 IEEE Societies. Power Electronics is based on switching operation of power semiconductor devices such as MOSFETs and IGBTs for achieveing efficient power conversion. Power Electronics Technology encompasses 1. the effective use of electronic components, 2. the application of circuit and control theory, 3. the development of analytical tools toward conversion, control, and conditioning of electric power. 5

6 What is Power Electronics? (2/2) Power range: from several watts to 6.3 GW Frequency range: from Hz(dc) to MHz Devices: semiconductors, magnetics, and capacitors Controls: DSPs, PLDs, FPGAs, A/D converters, and sensors of voltage, current, magnetic flux, position, speed, acceleration, temperature, etc. Power Electronics is on the basis of Devices, Circuits, Controls, and Systems 6

7 Practical Applications of Power Electronics Switching power supplies for computers and servers Home appliances:air conditioners, refrigerators, induction-heating cookers, microwaves, vacuum cleaners, laundry machines, electric fans, LED lamps, and so on. UPS (uninterruptable power supply):from 1 kw to 1 MW Industrial induction heating:2 khz 2 kw for surface quenching Industrial ac motor drives: fans/blowers, pumps, compressors, steel mils, and so on Transportation: high-speed and commuter trains, trams/street cars, electric vehicles, fuel- vehicles, ships/boats, and aircrafts Electric power utilities: photovoltaic inverters, battery energy storage systems, adjustable-speed pumped hydro storage, reactivepower controllers, high-voltage dc transmission systems 7

8 A Flexible, Effective, and Fault-Tolerant Battery Energy Storage System (BESS) To be published in the IEEE Transactions on Power Electronics, or Early access 8

9 An Existing Battery Energy Storage System (BESS) N. Wade, P. Taylor, P. Lang, and J. Svensson, Energy storage for power flow management and voltage control on an 11kV UK distribution network, in Proc. CIRED 9, Jun kv EDF Energy Networks, UK 6-kW 2-kWh BESS for peak shaving Neutral-Point Clamped (NPC) Converter[1] Li-ion battery system [1] A. Nabae, I. Takahashi, and H. Akagi, A New Neutral-Point-Clamped PWM Inverter, IEEE Trans. Industry Applications, vol. 17, no. 5, pp , Sep./Oct Cited by

10 Comparisons between Existing and New BESSs Single Large Converter From 6.6 to 66 kv AC AC A New System Multiple Small Converters AC DC DC DC AC AC DC AC DC AC DC DC AC DC AC DC AC DC Parallel connection of series-connected battery modules 1 Existing System AC AC DC DC AC AC One converter-to-one battery module DC DC AC AC DC DC

11 The v-phase cluster The w-phase cluster Three-phase 1-kW, 22-kWh Downscaled System 5 Hz L S v S Circuit parameters 2 V/14 V The u-phase cluster Li-ion Battery Module 25.9 V CB C u1 Bridge 2 L AC v uv v um v vm v wm Nominal line-to-line rms voltage V S 14 V Rated power 1 kw Cascade number 6 Background system Inductance L S.1 mh (1.6%) AC link Inductance L ac.33 mh (5.3%) DC capacitor capacitance 47 mf Nominal battery voltage 25.9 V Each battery capacity 1.2 kwh 11 Bridge 6 M PWM carrier frequency f C Equivalent PWM carrier frequency 1.75kHz 21 khz

12 18 Li-Ion Battery Modules (25.9 V, 47.5 Ah ) Nominal voltage: 25.9 V (=3.7 V/ times 7 s) Weight: 15 kg/module, Total capacity: 22 kwh 12

13 Control System BMS: Battery Management System Signals Input: 43 Output: Digital controller (Active-power reference)

14 Phase-Shifted-Carrier PWM (One-Cell Update) Calculation (within 4 μs) Hold Carrier signal 14 Hold time = N Calculation time

15 Phase-Shifted-Carrier PWM (All-Cell Update) Calculation Hold Carrier signal 15 Hold time = Calculation time

16 Comparisons between Theory and Simulation in Open-Loop Transfer Function of Current Control Cascade count: N=6 All- update with K=1.7 V/A Gain margin: 12 db One- update with K=.6 V/A Solid lines: Theory Phase margin: 7 One- update All- update 16 Simulation

17 Critical Damping Gain vs Cascade Count N All- update is better in current controllability than one- update Three times at N=6 17

18 Experimental Waveforms (All- update) v Su [V] v um [V] v uv [V] i u [A] v C [V] Charge mode V 25 V 3 Discharge mode levels levels THD = 1.7 % THD = 1.87 % 15 18

19 A Grid-Level High-Power DSCC-Based BTB (Back-To-Back) System Without Common DC-Link Capacitor Published in the IEEE Transactions on Industry Applications, vol. 5, no. 4, pp , July/Aug

20 A Grid-Level DSCC-Based BTB System DSCC-A DC 264 kv DSCC-B 1 s per arm AC AC 132 kv 132 kv Self-commuted devices (e.g., high-voltage GCTs) Fast response, Easy to self-start No dc capacitor or voltage sensor at 264-kV dc-link Bidirectional chopper- 2

21 Downscaled BTB Unit for Experiment Three-phase 2-V, 1-kW BTB system L ac : 2 mh (16%) i SuA AC 1uA 8uA DSCC-A 1vA 8vA 1wA 8wA DC i dc 1wB 8wB DSCC-B 1vB 8vB 1uB 8uB 8 s/arm V C : 5 V C : 6.6 mf (4 ms) AC v uva L Z : V dc : 3 mh 4 V 2 V / 5 Hz (24%) 2 V / 5 Hz 9uA 9vA 9wA 9wB 9vB 9uB 16uA 16vA 16wA 16wB 16vB 16uB 21 Carrier frequency f C : 45 Hz Power p Without dc-link capacitor

22 Photo of three-phase 2-V 1-kW 5-Hz BTB System u-phase DSCC-A DSCC-B Module Structure: 16 s/leg v-phase w-phase Chopper Cell: 15-V 7-A MOSFET V 6.6-mF Capacitor Digital Controller: A DSP board and Two FPGA boards 22 PC based data acquisition systems

23 Digital Control System Line-to-line voltages 2 2 Arm currents 6 2 Capacitor voltages Detected signals Output: 192 (= 96 2) gate signals Sampling frequencies in digital control arm currents: 7.2 khz (= 45Hz 16) capacitor voltages: 45 Hz

24 Rectification (DSCC-A) at p * = +8.7 kw, q A * = -5. kva Experiment Simulation Source voltages 4 v SuvA v SvwA v SwuA 4 v SuvA v SvwA v SwuA AC-terminal voltages -4 4 v uva v vwa v wua -4 4 v uva v vwa v wua Source currents -4 5 i SuA i SvA i SwA THD:.28% (u) -4 5 i SuA i SvA i SwA THD:.27% (u) -5-5 Capacitor voltages 5 v C1uA v C9uA v * C = 5 V 5 v C1uA v C9uA v * C = 5 V DC-link voltage 24 4 v dc v dc * = 4 V 2 ms 4 v dc v dc * = 4 V Power Electronics 2 ms Lab.

25 Transition (DSCC-A) at p* = +1 kw -1 kw q A* = q B* = Power-flow reference [kw] Source voltages AC-terminal voltages Source currents Experiment 1 2 ms vsuva vsvwa vswua 4 vuva vvwa vwua -4 4 vsuva vsvwa vswua vuva vvwa vwua isua isva iswa ms -4 5 p* -1 Capacitor voltages 5 25 p* Simulation vc1ua vc9ua isua isva iswa vc1ua vc9ua 5

26 A Low-Speed, High-Torque Motor Drive Using the Modular Multilevel Cascade Converter Based on Triple-Star Bridge Cells (MMCC-TSBC) To be Published in the 215 Sep./Oct. Issue of the IEEE Transactions on Industry Applications, or Early access 26

27 Medium-Voltage High-Power Motor Drives 27 Blower fan from Mitsubishi Heavy Industry Cement mill drive from ABB Line-commutated cycloconverters using thyristors Problems: Low lagging power factor Complicated line harmonic currents

28 Subconverter b Subconverter c Three-phase 4-V 15-kW TSBC Converter 2 V 5 Hz 2 V/4 V L = 5 mh (4.9%) Three three-legged three-winding ac inductors Carrier freq.: 1 khz Equiv. carrier freq.: 8 khz Dead time: 4 ms 28 C = 1.7 mf Vc = 2 V H = 81 ms IM 32 V, 15 kw 38 Hz, 41 A 6 poles, 75 min -1 Rated Torque Load

29 Overview of the Experimental System Regenerative Load IG 2 V 5 Hz 2 V / 4 V PT 2 36 MUX 18 9 TSBC converter 144 Gate signals IM TG 32 V 15 kw 41 A Tachogenerator DSP FPGAs & A/D Converters 29

30 Three-phase 4-V 15-kW Experimental System a I/F b c 4 Bridge Cells per Cluster - 36 Bridge Cells IGBTs L = 5. mh (5%) Three three-legged three-winding ac inductors C = 1.7 mf Vc = 21 V (rated) H = 89 ms Carrier frequency: 1 khz 3

31 Three-phase 32-V 15-kW Induction Motor 4 poles, 5 Hz, 15 kw 6 poles, 38 Hz, 15 kw Power Voltage Current Frequency Rotating speed Poles 6 Torque Rated Values 15 kw 32 V 41 A 38 Hz 75 r/m 191 N m 31

32 Start-up Performance Loaded at 1% Torque 32 Rotating speed [r/m] Cluster current [A] Motor current [A] Motor voltage [V] Capacitor voltages [V] s Fluctuationmitigating control 75 r/m (1%) (f M 38 Hz) 42 A in rms Controlled in a range of 12 V to 21 V

33 N rm = 1 r/m (13%) Loaded at 1% Torque Supply voltages 1 [V] -1 Supply-side 1 output voltages [V] -1 Supply currents 8 [A] 33 Capacitor voltages [V] -8 8 Cluster currents [A] 1 [V] -8-1 Motor currents 8 2 [A] [A] -8 Motor 1-2 voltages [V] with active voltage control 13 level THD: 4.4% Mean dc voltage : 132 V 4 ms [V] [A] -8 1 ms No active voltage control Nine-level Mean dc voltage: 2 V 4 ms 4 V 5 Hz THD: 6.8% 1 ms

34 Power-Loss Breakdown of a 75-Vdc, 1-kW, 2-kHz Bidirectional Isolated DC-DC Converter Using SiC-MOSFET/SBD Dual Modules Published in the IEEE Transactions on Industry Applications, vol. 51, pp , Jan./Feb. 215

35 1.2-kV, 8-A SiC-MOSFET/SBD Dual Module R. Wood and T. Saken, Evaluation of a 12-V, 8-A All-SiC Dual Module, IEEE Trans. on Power Electronics, vol. 26, no. 9,

36 Bidirectional Isolated DC-DC Converter Two Technical Terms Functionality: Bidirectional Isolated DC-DC Converter Circuit Topology: Dual-Active-Bridge Converter Function/Operation Both buck and boost function: E 1 > E 2 and E 1 < E 2 When N=1 Zero-voltage-switching (ZVS) operation Synchronous Rectification (limited to Si and SiC MOSFETs) R. W. De Doncker, D. M. Divan, and M. H. Khealuwala, IEEE Trans. IA,

37 Experimental System at 75 V, 1 kw, and 2 khz 1.2-kV, 4-A SiC-MOSFET/SBD Module Converter (dc-to-dc) efficiency with a tolerance of.3% 37

38 Experimental Waveforms at 75 Vdc and 1 kw 75 V 75 V 152A 38

39 Efficiency [%] Power Loss [kw] Power Loss and Efficiency Efficiency η max = kw η = kw Power Loss 92 ZVS Output Power [kw] Maximum Efficiency: 98.7 % Rated-Power Efficiency: 97.9% 39 Incomplete ZVS 1

40 Power-Loss Breakdown at 1-kW Operation SiC-MOSFET/SBD 1222 W (57%) Magnetic devices 653 W (31%) Conduction 675 W (31.6%) Switching 547 W (25.6%) Copper 394 W (18.4%) Iron 259 W (12.1%) Unknown 261 W (12.2%) 1:1 Power Loss in SiC-MOSFET/SBD: 6% Power Loss in Magnetic Devices: 3% Conducting and Switching Losses are Nearly Equal. 4

41 SiC-MOSFET/SBD and Si-IGBT/PND Modules SiC- MOSFET/SBD Dual Modules Power rating 1 kw 6 kw Reference voltage 75 Vdc 75 Vdc Frequency 2 khz 4 khz Si-IGBT/PND Dual Modules (1) Power device 1.2 kv and 4 A 1.2 kv and 3 A Maximum efficiency 98.7% 97.8% Rated-Power Efficiency 97.9% 96.9% (1) T. Chocktaweechock, K. Hasegawa, and H. Akagi, IEEJ IAS Annual Meeting, 1-94, Aug. 212 Both dual modules have the same packaging in size, shape and pin/terminal arrangement. 41

42 Past, Present, and Future of the DC-DC Converters 2-5 khz (1) M. H. Kheraluwala, et al., IEEE Trans. Ind. Applicat., vol. 28, no. 6, pp , (1) 214 (Tokyo Tech) 22? Switching Devices Core Material in Transformer Efficiency (DC to DC) Planar-Gate IGBTs Planar-Gate SiC-MOSFETs Ferrite FINEMET TM * Below kw, 5 khz kw, 2 khz Trench-Gate SiC-MOSFETs New Magnetic Materials Over kw, 2 khz * Nano-crystalline soft-magnetic material from Hitachi Metals 42

43 What I want to emphasize Power electronics people have been making a long voyage from a Silicon planet to a Silicon-Carbide planet. It will take five years from now to complete the wonderful voyage. This completion, as well as the continuous development of Control by leaps and bounds, will bring a new world to power electronics. 43