凯美瑞_HEV_详细资料

U.S. Department of Energy FreedomCAR and Vehicle Technologies, EE-2G 1000 Independence Avenue, S.W. Washington, D.C. 20585-0121 FY 2007 Subcontract Report: TECHNOLOGY AND COST OF THE MY2007 TOYOTA CAMRY HEV – FINAL REPORT Prepared by: Oak Ridge National Laboratory Mitch Olszewski, Program Manager Submitted to: Energy Efficiency and Renewable Energy FreedomCAR and Vehicle Technologies Vehicle Systems Team Susan A. Rogers, Technology Development Manager September 2007 ORNL/TM-2007/132 Engineering Science and Technology Division Subcontract Report: TECHNOLOGY AND COST OF THE MY2007 TOYOTA CAMRY HEV FINAL REPORT Energy and Environmental Analysis, Inc. an ICF International Company Publication Date: September 2007 Prepared by the OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831 managed by UT-BATTELLE, LLC for the U.S. DEPARTMENT OF ENERGY Under contract DE-AC05-00OR22725 DOCUMENT AVAILABILITY Reports produced after January 1, 1996, are generally available free via the U.S. Department of Energy (DOE) Information Bridge: Web site: http://www.osti.gov/bridge Reports produced before January 1, 1996, may be purchased by members of the public from the following source: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-605-6000 (1-800-553-6847) TDD: 703-487-4639 Fax: 703-605-6900 E-mail: info@ntis.fedworld.gov Web site: http://www.ntis.gov/support/ordernowabout.htm Reports are available to DOE employees, DOE contractors, Energy Technology Data Exchange (ETDE) representatives, and International Nuclear Information System (INIS) representatives from the following source: Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831 Telephone: 865-576-8401 Fax: 865-576-5728 E-mail: reports@osti.gov Web site: http://www.osti.gov/contact.html This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Energy and Environmental Analysis, Inc. i Technology and Cost of the MY2007 Toyota Camry HEV Final Report Submitted to: Oak Ridge National Laboratory Oak Ridge, TN July 2007 Submitted By: Energy and Environmental Analysis, Inc. An ICF International Company 1655 N. Fort Myer Drive, Suite 600 Arlington, Virginia 22209 (703) 528-1900 ii Energy and Environmental Analysis, Inc. TABLE OF CONTENTS 1. OVERVIEW ....................................................................................................................................................................................................................... 1-1 2. CAMREY HEV DESIGN 2.1 VEHICLE DESCRIPTION .................................................................................................................................................................................... 2-1 2.2 THE HEV SYSTEM LAYOUT............................................................................................................................................................................... 2-2 2.3 CAMRY HEV POWERTRAIN............................................................................................................................................................................... 2-5 2.3.1 Engine Details.................................................................................................................................................................................. 2-5 2.3.2 Electric CVT Transaxle.................................................................................................................................................................. 2-7 2.4 THE BATTERY PACK .......................................................................................................................................................................................... 2-9 2.5 POWER CONTROL UNIT .................................................................................................................................................................................... 2-10 2.6 OTHER CAMRY HEV DESIGN FEATURES........................................................................................................................................................ 2-17 2.7 SECTION SUMMARY.......................................................................................................................................................................................... 2-18 3. CAMRY HEV COST ANALYSIS 3.1 OVERVIEW........................................................................................................................................................................................................... 3-1 3.2 COST DATA INPUTS .......................................................................................................................................................................................... 3-2 3.3 INCREMENTAL COST ESTIMATES FOR THE CAMRY HYBRID ..................................................................................................................... 3-4 Energy and Environmental Analysis, Inc. iii LIST OF FIGURES Figure 2-1. MY2007 Toyota Camry HEV................................................................................................................................................................. 2-1 Figure 2-2. Camry HEV System Schematic .......................................................................................................................................................... 2-3 Figure 2-3. Camry HEV Component Layout .......................................................................................................................................................... 2-4 Figure 2-4. Atkinson Cycle Engine P-V Diagram Compared to Conventional Otto Cycle......................................................................... 2-6 Figure 2-5. Camry HEV Transaxle Schematic and Cutaway View .................................................................................................................. 2-8 Figure 2-6. Camry HEV Battery Module................................................................................................................................................................. 2-9 Figure 2-7. Camry HEV PCU Schematic and Exploded View ............................................................................................................................ 2-11 Figure 2-8. Camry HEV IPM Schematic and Installation ................................................................................................................................... 2-11 Figure 2-9. Toyota Camry HEV IPM Layout ........................................................................................................................................................... 2-12 Figure 2-10 IGBT Design for GS450h (left) vs. Prius II (right) ........................................................................................................................ 2-13 Figure 2-11 Toyota Trench IGBT Modifications..................................................................................................................................................... 2-14 Figure 2-12. Heat Dissipation Structure for IPM Chips ...................................................................................................................................... 2-14 Figure 2-13. Toyota 2007 IGBT Design Performance Compared to Older Generations and Competition ............................................................................................................................................................................................. 2-15 Figure 2-14. Toyota PCU Power Density Progression with Each New Hybrid .............................................................................................. 2-16 Figure 2-15. Lexus LS600h Double-Sided Cooling Design and View of IPM Assembly ............................................................................... 2-16 Figure 2-16. Camry HEV EPS System Layout ......................................................................................................................................................... 2-18 Figure 2-17. Camry HEV Acceleration Performance Compared to Conventional 2.4L Camry................................................................. 2-20 iv Energy and Environmental Analysis, Inc. LIST OF TABLES Table 2-1. Camry HEV Component Description and Function ............................................................................................................................ 2-5 Table 2-2. Toyota Camry HEV 2.4L Engine Details ................................................................................................................................................. 2-7 Table 2-3. Camry HEV MG Specifications................................................................................................................................................................. 2-9 Table 2-4. Camry HEV Battery Key Specifications ................................................................................................................................................ 2-10 Table 2-5. MY2007 Camry EHV Specifications Compared to Prius and Regular Camry............................................................................ 2-19 Table 3-1. Variable Cost Estimates for the Drive Train Components.............................................................................................................. 3-5 Energy and Environmental Analysis, Inc. 1-1 1 OVERVIEW The Oak Ridge National Laboratory (ORNL) provides research and development (R&D) support to the Department of Energy on issues related to the cost and performance of hybrid vehicles. ORNL frequently benchmarks its own research against commercially available hybrid components currently used in the market. In 2005 we completed a detailed review of the cost of the second generation Prius hybrid. This study examines the new 2007 Camry hybrid model for changes in technology and cost relative to the Prius. The work effort involved a detailed review of the Camry hybrid and the system control strategy to identify the hybrid components used in the drive train. Section 2 provides this review while Section 3 presents our detailed evaluation of the specific drive train components and their cost estimates. Section 3 also provides a summary of the total electrical drive train cost for the Camry hybrid vehicle and contrasts these estimates to the costs for the second generation Prius that we estimated in 2005. Most of the information on cost and performance were derived from meetings with the technical staff of Toyota, Nissan, and some key Tier I suppliers like Hitachi and Panasonic Electric Vehicle Energy (PEVE) and we thank these companies for their kind co- operation. Energy and Environmental Analysis, Inc. 2-1 2 CAMRY HEV DESIGN 2.1 VEHICLE DESCRIPTION The model year (MY) 2007 Toyota Camry hybrid electric vehicle (HEV), see Figure 2-1, is derived from a conventional 2.4L Camry with the Toyota’s Hybrid Synergy (THS) second generation system incorporated within existing body packaging. Figure 2-1. MY2007 Toyota Camry HEV. Highlights of the Camry HEV technology are as follows: • 2.4L 147hp Atkinson cycle L-4 aluminum block and head engine; • THS drive with 105kW electric motor; • 245V nickel metal hydride (Ni-MH) battery pack; • Electrically variable continuously variable transmission (CVT) free wheeling diodes (FWDs) transaxle; • 143kW (192hp), 275N-m total system rating; • 0–60 mph in 8.9 seconds; Energy and Environmental Analysis 2-2 • Advanced Technology – Partial Zero Emission Vehicle (AT–PZEV) emissions certification; • EPA label fuel economy 40/38/39 (city/highway/combined); • Steel unit body design with steel closure panels; • Vehicle aerodynamic drag coefficient Cd of 0.27; and • Produced in Toyota’s Georgetown, Kentucky plant. The Camry HEV is certified to Super Ultra Low Emission Standards (SULEVs), California’s classification for exhaust emissions, which is the most stringent current standard for conventional internal combustion-powered vehicles. The add-on hybrid components were designed to qualify the vehicle as an AT–PZEV (a classification used in California emissions control programs), but the AT–PZEV requires a longer warranty period, so Toyota decided to classify the Camry as a SULEV. Compared to the regular 2.4L Camry with 5-speed automatic transmission (EPA FE rating 24/33mpg), the hybrid improves city fuel economy by 67%, but highway improvement is only 15%. Some of the fuel economy improvements are attributable to the body add-on features such as underbody fairings which reduce aerodynamic drag from 0.28 to 0.27. 2.2 THE HEV SYSTEM LAYOUT The Camry’s high voltage hybrid system operates the electrical motor, generator, A/C compressor, and inverter/converter. All other devices, including the electric power steering, are supported by a conventional 12V battery. As a result, the vehicle utilizes four electrical systems: • Nominal 12V DC; • Maximum 34V AC; • Nominal 245V DC; and • Maximum 650V AC. Figure 2-2 illustrates how these circuits interact. The main system battery stores power at 245V DC. This voltage is used directly to drive the A/C compressor. An inverter/converter contains a circuit that boosts the battery voltage to 650V DC. The inverter packaged in the same housing creates three-phase AC current (variable to max 650V AC) to power the traction motor and generator in the transaxle. The 34V AC circuit is used for electric power steering. Energy and Environmental Analysis, Inc. 2-3 Figure 2-2. Camry HEV System Schematic. Figure 2-3 identifies the key hybrid components on the vehicle layout. Table 2-1 summarizes each component function and location. Energy and Environmental Analysis 2-4 Figure 2-3. Camry HEV Component Layout. Energy and Environmental Analysis, Inc. 2-5 Table 2-1. Camry HEV Component Description and Function Numbers are labeled on Figure 2-3. Number Description Location Function 1 Lead acid 12V battery Trunk area. Powers low voltage devices, including electric power steering (EPS). 2 Ni-MH battery pack Behind rear seat. Powers high voltage devices. 3 Power cables Under passenger floor and engine compartment. Carry high voltage DC and AC current between battery pack, inverter/converter, motor, generator, and A/C compressor. 4 Inverter/converter Engine compartment. Boost and inverts the high voltage DC current from the battery pack to three-phase AC current and vice-versa. Powers the A/C compressor. 5 Engine Engine compartment Powers the vehicle and generator. 6 Generator Transaxle Recharges battery pack. 7 Motor Transaxle Powers front wheels. 8 A/C compressor Engine compartment. Powers A/C system. 9 12V DC-DC converter Battery pack. Steps-down 245V DC from battery pack to 12V to recharge the low voltage battery. 2.3 CAMRY HEV POWER TRAIN The Camry HEV is equipped with a modified 2.4L I4 double overhead camshaft (DOHC) electronic fuel injection (EFI) engine and electronically controlled CVT. The FWD transaxle has two built-in motor/generators (MGs). The vehicle is designed around the THS II “full” hybrid architecture which provides propulsion in five modes depending on the battery state of charge: 1. During light acceleration and low speeds the vehicle is powered by the electric motor. 2. During normal driving, the vehicle is mainly powered by the gasoline engine. Some power from the engine drives the generator to charge the battery. 3. During high loads, both the engine and motor power the vehicle. 4. During braking or deceleration, regenerative braking charges the battery. 5. While the vehicle is stopped, the motor and engine are off and the battery powers accessories. 2.3.1 Engine Details The Camry’s 2.4L I4 engine was modified for hybrid duty and operates as an Atkinson cycle engine. The cycle modification was possible because of the variable valve timing (VVT) and electric motor assist availability. The Atkinson cycle engine offers higher thermal efficiency and lower pumping losses due to independent control of the compression and expansion stroke duration. If conditions are favorable, the ECU delays the intake valve closing, effectively Energy and Environmental Analysis 2-6 delaying the start of compression. This feature maintains relatively high compression ratio availability and, therefore, higher overall thermal efficiency at the expense of peak power. Figure 2-4 compares the Atkinson and conventional cycle engines on a Pressure-Volume (P-V) scale. In addition to pumping loss reduction, the Atkinson engine allows peak efficiency improvement from 35–38%. However, this thermal efficiency comes at a peak power penalty. The HEV Camry 2.4L I4 delivers 147hp while the conventional Camry peaks at 160hp (about 7% higher). This tradeoff is possible on a hybrid because the engine peak power loss is compensated through electrical power assist capability. Figure 2-4. Atkinson Cycle Engine P-V Diagram Compared to Conventional Otto Cycle. Toyota targeted other engine changes to improve fuel economy and noise vibration and harshness (NVH) response on the Camry hybrid version. Intake and exhaust manifolds were reworked for easier flow, including large diameter passages and thinner walls. Pistons and intake camshaft were revised for lower weight and higher strength. Adapting the engine to hybrid operation has also enabled elimination of belts and other components related to power steering, A/C, and the alternator. Energy and Environmental Analysis, Inc. 2-7 Table 2-2 summarizes key characteristics of the 2.4L engine used in the Camry HEV. The modifications resulted in a very high expansion ratio engine (12.5:1). Due to the Atkinson cycle employed, peak power is down from 160 hp on the conventional Camry to 147 hp, but peak efficiency increases from about 34–37.5%. Table 2-2. Toyota Camry HEV 2.4L Engine Details Displacement and type 2.4L I4 Atkinson cycle Expansion ratio 12.5:1 Compression ratio 9.6:1 Construction Aluminum alloy head and block Valve train DOHC, four valves/cylinder with VVT-i Engine peak power 147 hp @ 6,000rpm Engine peak torque 138lb-ft @ 4,400 rpm 2.3.2 Electric CVT Transaxle The CVT functionality in the Camry FWD transaxle is achieved using two motor-generators. The transaxle is a compact three shaft design and uses two sets of planetary gears. No clut