Hybrid Technology
Background
The first hybrid electric vehicles (HEV) were built as early as the end of the 19th century, with the first patents filed in 1905. The emergence of increasingly powerful gasoline engines and the limited performance of electric motors meant that HEV development fell into oblivion. During the 1970’s, interest in HEV’s rose again due to the oil crisis, but vanished again quickly as soon as new oil wells were discovered.
The increasing cost of gasoline prompted the vehicle manufacturers to offer its customers an alternative. In 1997 Toyota launched the Prius, generally considered to be the first mass-produced hybrid vehicle on the market. From then on, new modules were required in vehicle production. Aside from an electric motor combined with a generator, other core modules of the HEV system were required, such as an AC/DC converter and a special HV battery, supplying up to 300V. Today, the electric motors are fed with over 600V at a continuous current of 80-100A by boosting the voltage.
Development
As the main wiring harness partner of Toyota for this development, YAZAKI supplied 100% of the high voltage EDS for the Prius I. YAZAKI has since gathered vast experience in this area, but as a new endeavour in the 1990’s, careful attention had to be paid to particular aspects.
At high voltage levels over 60V, all components have to be shielded in order not to interfere with sensitive equipment, such as Electronic Control Units (ECU) and receivers; examples of which are GPS and the car radio. The high current requires even thicker wire (up to 35 mm²), weighing half a kilogram per meter with an orange colour cable sheathing and special marking to indicate the highly dangerous power.
Other considerations are materials, air spacing, the creepage distance for the power circuits, vibration, and many more. If the components and connectors are not designed for the environment in which they will be used, short circuits and wire melting could occur, possibly resulting in the vehicle catching fire.
As hybrid vehicle technology continued to develop, a supplemental step was taken in the automotive industry’s 42V investigation. Due to increasing comfort and merging mechanical and electrical system technologies (Mechatronics), the requirement for more electrical energy in the vehicle was clear. YAZAKI, as a much valued company with extensive High Voltage EDS experience from the Prius I, entered the global MIT consortium ‘Advanced Automotive Electrical/Electronic Components and System’ as an active member. In Europe, YAZAKI joined the ‘Forum Bordnetze’ to assist with and to further the development of guidelines and technology supporting this industrial trend.
Over time, YAZAKI’s competencies in high voltage technology increased even further. New requirements had to be considered when designing the high voltage EDS of about 300 – 600V, as standard components for passenger vehicles are designed for a 12 V system. Additionally, big steps were taken, firstly in introducing large battery packs of 60kg or more, which are loaded in the trunk of the vehicle, and secondly by introducing the related system integration into the EDS.
Market Leader
At the start of this century, YAZAKI became the selected OEM partner to pioneer the EDS development of a 42/12V car, which ended up in the mass-production of the ‘Toyota Crown Mild Hybrid’ in the Japanese market.
YAZAKI has now over 10 years of experience in designing components for high voltage cars, which meet the arduous demands of the vehicles. In addition, with years of experience as a high voltage systems integrator, YAZAKI brings value to OEMs and automotive suppliers, as our knowledge of EV, FCV, and HEV architecture can help to achieve optimisation in the following areas:
- Vehicle and component packaging
- Power distribution topologies and load strategies
- High voltage cable assembly layout
- Power centre packaging
Global supplier
Parallel to the development of the Toyota Prius, YAZAKI engineers worked closely on both concept vehicles and mass-production with Nissan and Honda (Insight, Accord and Civic) in Japan and also with Chrysler (EV concepts) in the United States.
Drawing on its experience in Japan, YAZAKI North America started development with Ford US in 2001, resulting in the world's first hybrid sports-utility vehicle – the Escape Hybrid. YAZAKI is proud to have supplied the high voltage EDS for this vehicle, as the first mass produced HEV launched in the US market.
Aside from the fuel saving factor, European OEMs often look at the possibility of the strong torque of the electric engines because they beat the gasoline engines on their low rev count. Close collaboration is also taking place with European OEM’s on the development of hybrids and fuel cell vehicles.
With the European OEMs, YAZAKI is continuously working on improving their systems to meet the increasing requirement of reducing size and weight when the HEV systems are being optimised further. These development activities are not only with OEMs, but also with module manufacturers.
The perfect hybrid partner
YAZAKI’s history of innovation and technological advancement has resulted in valuable partnerships with many of the world’s auto manufacturers. We have developed centres of excellence in product development for specialised high voltage cable assemblies, connectors and other products for high voltage vehicles in Asia, North America and also in Europe.
Today, some hybrid electric vehicle on the road contains YAZAKI high voltage products. By applying our automotive acumen and technical expertise, we’re continuously developing next-generation technology and working with industry leaders to produce greener, cleaner vehicles for tomorrow. YAZAKI has gathered considerable experience and will continue to make key contributions to High Voltage applications for the future. As the next milestone, we are very much looking forward to supplying some of the first hybrids to be introduced in Europe.
