JSAE Automotive Engineering Exposition 2014: Parts Suppliers (1)

New EV and HV technologies such as 48V hybrid systems exhibited

2014/06/16

Summary

 The Automotive Engineering Exposition 2014, organized by the Society of Automotive Engineers of Japan (JSAE), was held on May 21 to 23, 2014. This report contains parts and technologies for electric vehicles (EV) and hybrid vehicles (HV) that were exhibited by parts suppliers at the trade show. Exhibits of parts and technologies addressing fuel efficiencies and weight reduction will be introduced in a separate report.

 Bosch presented a 48V mild-hybrid powertrain system which is expected to be launched in Europe. Toyota Industries exhibited inverters and motors for Ultra Compact EVs, whose market is likely to expand. Nichicon Corporation exhibited a charger-integrated converter for the same market. Denso and Toyota announced the development of a high-efficiency silicon carbide power semiconductor. Mitsubishi Electric exhibited an EV motor drive system with a built-in silicon carbide inverter. TDK displayed a wireless charging technology which is under development. Advics exhibited a regenerative braking system for hybrid vehicles with conventional ESC. The system shares parts with the braking system on gasoline-fueled vehicles to keep costs to a minimum.


Related Reports:
Tokyo Motor Show 2013: Suppliers display EV/HV components (posted in December 2013)
JSAE Automotive Engineering Exposition 2014: new OEM powertrain technologies (posted in June 2014)



Electric vehicle concepts

 

EMIRAI 2 Q'mo II
Mitsubishi Electric's EV Concept EMIRAI 2 NTN's EV Commuter Q'mo II with in-wheel motors slated for road tests

 

Mitsubishi Electric EMIRAI 2  An EV concept car that brings together Mitsubishi Electrics’ electrification technologies. The front wheels are driven by a motor (maximum output:65kW), the rear wheels by two motors (maximum output: 30kW). The “e-torque vectoring system” is used in the rear wheels to assist steering by controlling two wheels independently when negotiating a curve. The system is being tested on the company’s proving course.
 Another feature of the EMIRAI 2 is a new human-machine interface (HMI) developed by the company. The new-generation display system seamlessly changes the content of three variable displays and a head-up display (HUD) in the windshield according to the driver's preference and driving conditions. The driver can get necessary information with the least eye movement.
NTN Q'mo II  NTN's first-generation Q'mo Concept Car was exhibited earlier at the 2011 Tokyo Motor Show. The motor and the gearbox are integrated as a unit so that an in-wheel motor can be built into all four wheels. This allows pivoting and lateral motion.
 This year, NTN exhibited the Q'mo II at the Automotive Engineering Exposition. The top speed has been increased to 70km/h and the second-generation concept car is slated for tests on public roads shortly. For the sake of weight reduction, an in-wheel motor is built into only two rear wheels with maximum output of 16kW (8kW x 2). The car has an electric range of 50km after six-hour charge.

 

 



Hybrid systems

 Bosch introduced a 48V mild hybrid system. According to the company, the system provides a diverse solution at an affordable price in meeting CO2 emission standards that keep growing stricter. The hybrid vehicle market in Japan is peculiar in that the automakers are independently developing full hybrid systems to compete for motor drive power assistance and higher fuel efficiency. In contrast, European automakers are sharing parts to reduce overall cost in meeting the strict CO2 emission standards through joint efforts as an industry. Bosch reportedly is developing a system that consists of a motor, battery and converter that will be offered to automakers for 500 to 800 Euros (according to Nikkan Kogyo Shimbun dated May 28, 2014).

 

Boost recuperation machine belt-drive CVT8 Hybrid
The Boost Recuperation Machine at the core of Bosch's 48V hybrid powertrain Jatco's belt-drive CVT8 Hybrid under development

 

Bosch 48Volt hybrid powertrain solutions  Bosch proposed a 48V mild hybrid system that uses both the conventional 12V lead-acid storage battery and 48V lithium-ion battery. The key component is the BRM (Boost Recuperation Machine) that has a built-in inverter. As an alternator, it regenerates braking energy and assists the engine power during acceleration. The system also incorporates a start-stop system. The lithium-ion battery enables the use of air conditioner while the engine is inactive.
 The BRM is connected to the crankshaft via belt to regenerate energy or assist electric power. However, a large torque is required to 'crank' a cold engine at start of the day. Hence, a starter is needed for starting a cold engine (to drive the ring gear of the flywheel in a manual transmission model or that of the drive plate in an automatic transmission model).
 The system is compatible with varying structures of the automatic, manual, automated manual and dual clutch transmission in the current vehicles. This means the system can be flexible to suit the specific configuration. According to Bosch, a market has been prepared with standardized parts for 48V hybrid systems to offer various, affordable solutions for reducing CO2 emissions.
Jatco Belt-drive CVT8 hybrid  Jatco exhibited a belt-drive CVT8 Hybrid which is under development to be mated with a 2500cc-class engine. The company’s chain-drive CVT8 Hybrid is mated with a 3500cc-class engine, and already in the market. The chain-drive type is used in the Nissan Pathfinder that was released in the U.S. in 2013.
 Jatco is a manufacturer of belt-drive CVT known for silent operation and a wide gear ratio. The chain-drive CVT is more durable to a large torque.
Exedy Flywheel damper and clutch for hybrid vehicle  Exedy exhibited the flywheel damper and clutch that are used in Jatco's CVT8 Hybrid (fitted in Nissan's Pathfinder released in North America in 2013). The flywheel and damper functions are integrated as a unit to reduce the overall thickness. The dry type multi-plate clutch is compact enough to fit inside the motor.

 

 



Motors, inverters, and converters

 

motor/generator and inverter ultra-compact EV motor
Toshiba's motor/generator and inverter used on Ford vehicles Toyota Industries' ultra-compact EV motor
low-cost transaxle DC-DC converter
Aisin AI's low-cost transaxle for electric and hybrid vehicles based on MT technology Charger-integrated DC-DC converter for ultra-compact vehicles (exhibited by Nichicon)

 

Toshiba Hybrid drive system for passenger cars in the US  Toshiba exhibited the motor (generator) and the inverter that are supplied to Ford's Fusion, C-Max and Lincoln MKZ. The three models are fitted with the same hybrid system. The motor has maximum output of 88kW. The battery capacity is 1.4kWh (HV) and 7.6kWh (Plug-in Hybrid Vehicle: PHV).
Toyota Industries Inverter & motor for ultra compact EVs  Based on its expertise in developing electric forklifts, Toyota Industries has developed an inverter and a motor for ultra-compact electric vehicles. The inverter has a built-in vehicle control function and is supplied in combination with a 12kW motor.
 The inverter and motor combination (assembled and sold by Prozza) is used, for instance, in the electric version of the tricycle taxis in Asian countries. Demand expansion is expected in the future.
Exedy Motor with dysprosium free magnet  Dysprosium (Dy) is a rare earth that, when used in a magnet, increases the magnet's durability against high temperature. Exedy is developing a vehicle drive motor that does not depend on the rare earth. The company's goal is a motor with a Dy-free magnet with maximum output of 60kW, maximum torque of 144Nm and maximum speed of 20,000rpm. Exedy will use a water-cooled stator to prevent heat generation and a device to cool any heat immediately.
Aisin AI Low cost transaxle for electric vehicle  Aisin AI has achieved high reliability at low costs by leveraging its MT technology, parts and equipment standardization (up to 79% share ratio). When used in EVs, the transaxle allows availability of 2 additional speeds. When used in a hybrid system in which the rear wheels of a front-engine front-wheel drive car are driven by a motor, the motor may be disengaged in high-speed cruising and the car can be driven by the engine alone. This leads to higher fuel efficiency.
Nichicon Charger-integrated DC-DC converter  The charger-integrated DC-DC converter for EVs is used in Mitsubishi Motors' i-MiEV, Minicab-MiEV and trucks since June 2009. It is also used on Mazda Demio EV since August 2012.
 Nichicon's onboard charger is used on Nissan Leaf since September 2010.
 Many OEMs have developed and are road-testing ultra-micro electric vehicles under the "ultra-micro electric vehicle project" initiated by the Ministry of Land, Infrastructure, Transport and Tourism. Nichicon has developed a charger-integrated DC-DC converter to meet the project's goal. The air-cooled converter can be mated with lithium-ion battery and lead-acid storage battery as well.

 

 



High-efficiency power semiconductors made of silicon carbide

 Denso, Toyota Motor Corporation, and Toyota Central R&D Labs have jointly developed a new high-efficiency silicon carbide (SiC) power semiconductor. Toyota plans to use the power semiconductor in automotive power control units (PCU). Toyota will begin proving tests of the vehicles fitted with the new PCUs on public roads in Japan within a year. Toyota reportedly plans to start using the PCUs on hybrid vehicles to be launched in 2020.

 Mitsubishi Electric exhibited an EV motor drive system with a built-in silicon-carbide inverter.

 

SiC inverter EV motor drive system
SiC inverter developed by Denso Mitsubishi Electric's EV motor drive system with a built-in silicon-carbide inverter,(on the right), and inverter-integrated motor, (on the left)

 

Denso/
Toyota Motor
 Denso developed a high-quality 6-inch SiC wafer with significantly fewer crystal defects (one tenth of those found in competitors' products). Using the new SiC wafer, Denso developed a smaller, air-cooled high-power density inverter module (volume: 0.75 liters, output: 75kW, power density:100kW/liter).
 Toyota plans to use the SiC power semiconductors (transistors and diodes) in the PCUs (mainly a boost converter and an inverter) that control the drive motors on hybrid vehicles. The company aims to eventually increase the hybrid vehicle fuel efficiency by 10% and reduce the PCU size by 80% compared to current silicon-only power semiconductors.
 SiC power semiconductors have low power loss when switching on and off, allowing for more efficient, less resistant flow of electric current even at high frequencies. This enables downsizing ot the coil and capacitor, which account for 40% of the size of the PCU.
 Toyota has built a clean room dedicated to the development of SiC semiconductors. The company will start road tests of the power semiconductors within a year. In an in-house test on the company's test course, Toyota has confirmed a fuel efficiency increase exceeding 5% compared to the conventional silicon-only semiconductors.
Mitsubishi Electric  Mitsubishi Electric exhibited an EV motor drive system with a built-in SiC inverter. The inverter, entirely made of SiC power semiconductors, is built into the motor. This led to the smallest motor drive system in industry (14.1 liters, 60kW). The cooling performance has been improved as well by integrating the coolers for the motor and the inverter.

 

 



Batteries, capacitors, and wireless chargers

 Nippon Chemi-Con has developed a nano-hybrid capacitor which have three times as high energy density as the current electric double-layer capacitor (EDLC) made from activated carbon. Its sample shipment will start soon. TDK announced a wireless charging system which is under development.

 

Nippon Chemi-Con Nano-hybrid capacitor  Nippon Chemi-Con has developed a nano-hybrid capacitor having a negative electrode made of nc-Li4Ti5O12 and carbon nano-fiber (CNF) compound. The company is working on its commercialization. The positive electrode is made of activated carbon as in EDLC. Sample shipment will start shortly toward start of production in 2015.
 The nano-hybrid capacitor has three times as high energy density and similar power output performance as the conventional activated carbon EDLC. It is safer than lithium-ion capacitors. These facts led to the development.
OKAYA/TPR EDLC  TPR and Okaya Electric Industries jointly developed an electric double-layer capacitor (EDLC). The companies are aiming for producing the EDLC for automotive use. On account of severe price competitions, their initial step will be to explore various other applications for the EDLC such as emergency power supply and power smoothing of natural energies.
TDK Wireless charging technology  TDK exhibited wireless charging technology based on resonant inductive coupling which is being developed for electric vehicles.. This technology transmits electric energy efficiently and wirelessly between two circuits (transmitter and receiver) that are placed apart from each other and tuned to resonate at the same frequency.
 The wireless charging can be done regardless of the weather. The receiver coil is made smaller (A4 size) than the transmitter coil to ensure high transmission efficiency even when the two coils are slightly offset from each other. The company aims to develop new technology for wireless charging while the vehicle is driving.
In 2009, TDK developed coil units for wireless charging for smartphones and other small electronic devices. The units are already produced and sold in the market.
Saikawa/Toshiba Rescue EV
(Portable charging device)
 As many as 500 electric vehicles stall on expressways each year after running out of electric energy. Saikawa and Toshiba jointly developed a portable charging device that provides an extra range. The device uses Toshiba's SCiB lithium-ion battery to supply electric energy enough to keep the vehicle running to the nearest charging station. The device weighs 300kg and can be installed on a mini truck. It is slated for shipment starting this summer.
 Until this summer, the stalling electric vehicle is hauled by a Japan Automobile Federation (JAF) service truck to the nearest charging station.
Wireless charging system The rescue EV
Wireless charging system for EVs being developed by TDK. The resonator, left, is designed for efficient transfer of electric energy between coils. The rescue EV, jointly developed by Saikawa and Toshiba, supplies enough energy to keep the stalling vehicle running to the nearest charging station.

 

 



Regenerative braking system that shares parts with braking system of gasoline-fueled vehicles

 Advics exhibited a regenerative cooperation braking system with a conventional ESC. It shares parts with the brakes on gasoline-fueled vehicles to reduce the cost to one half that of the brake-by-wire regenerative cooperation braking system. The new system is used in Nissan Pathfinder HV being sold in North America. According to Advics, the new system has virtually the same energy recovery efficiency (approximately 2% lower) as that of the brake-by-wire regenerative cooperation braking system.

 NTN exhibited a module for converting the rotary motion of the hydraulic control motor to a linear motion using a ball screw. The module is used in regenerative cooperation braking systems.

 

ESC unit and booster ball-screw drive module
ESC unit,(on the left), and booster,(on the right), make Advics' low-cost regenerative braking system. NTN's ball-screw drive module for electric hydraulic brake. The ball screw for converting rotary motion of a hydraulic control motor to linear motion is shown to the right.

 

Advics Regenerative braking system with conventional ESC  Electric vehicles and hybrid vehicles are fitted with a brake-by-wire regenerative braking system to maximize the efficiency of energy regeneration. Advics has developed a system with the ESC and the associated pump that constantly control regenerative coordination while keeping the braking system of the non-electric vehicles. The new system shares many parts with the non-electric vehicles and the cost is said to be halved to that of the conventional brake-by-wire system.
 The new system consists of (1) hybrid motor for regenerative braking, (2) ESC unit for hydraulic control braking, and (3) basic hydraulic braking by the driver's pedal effort (including booster amplification). The company extended the idle stroke time of the master cylinder to suppress the basic hydraulic braking. During the extended idle stroke, the system keeps the regenerative brake and ESC hydraulic control brake operative to maximize the efficiency of regeneration.
 In conventional braking systems, the ESC pump is used only when the ABS is activated. In the new regenerative braking system, the ESC pump is used continuously and hence its durability had to be increased. Advics' gear pump type ESC is known for smooth operation with little return of force to the brake pedal. This was a critical factor in developing the new system. According to the company, Advics is the only supplier of gear pump-type ESC (others use piston type ESCs).
 The regenerative braking system with a conventional ESC is used in Nissan's Pathfinder that was released in North America in 2013. It is as efficient (98%) in energy regeneration as the brake-by-wire system.
NTN Ball screw drive module for electric hydraulic brake  The ball-screw drive module for electric hydraulic brake is used in the regenerative  brakes of Honda's Fit Hybrid and Accord Hybrid (the brake system itself is supplied by Nissin Kogyo). The module converts rotary motion of the motor to a linear motion to drive the hydraulic cylinder.
 In a regenerative brake, the necessary braking force is calculated based on the driver's pedal efforts and the speed of travel. Proper distribution of the force from the drive motor to the regenerative brake and the hydraulic brake is determined accordingly.
 The module uses a ball screw and a reduction gear to convert rotary motion of the hydraulic control motor to a linear motion. The hydraulic brake is controlled accordingly. This enables more precise control of the hydraulic braking force and more efficient energy regeneration.

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