MIEV

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MIEV (Mitsubishi In-wheel motor Electric Vehicle) or MiEV (Mitsubishi innovative Electric Vehicle) (IPA /ˈmiːv/)^[1] is the name given by Japanese automaker Mitsubishi Motors to its alternative propulsion technologies.^[2] It was first introduced in the Mitsubishi Colt EV, a concept car introduced at 2005 Tokyo Motor Show which used a series of lithium-ion batteries to power electric motors located in the wheels.^[3] Subsequent developments have included an electrically powered Mitsubishi i kei car which is aimed for introduction to the Japanese market in 2010.^[1][4]

[edit] History

An in-wheel motor onboard the Colt EV concept vehicle, with the wheel and tyre cut away for better viewing

Before developing the first MIEV concept, Mitsubishi built several electric vehicles in the 1990s as they attempted to develop alternative propulsion systems. Development began in the 1970s, and 36 Libero EVs were sold between 1993 and 1996.^[5] Their FTO EV broke the record for the furthest distance achieved by an electric vehicle in 24 hours when it covered 2,142.3 km on December 19–20, 1999,^[6][7] and following this success they entered an Eclipse EV in the annual Shikoku EV Rally in 2001, completing over 400 km on a single charge.^[5]

[edit] MIEV technology

MIEV motors are constructed using an in-wheel motor rotor, an in-wheel motor starter, a rotor bracket, starter bracket and inverter directly behind the brakes. Engine power output is 47 kW and torque output 180 N·m. The batteries can be charged from a standard 15 A/200 V car charger in seven hours and with a three-phase electric power charged in 25 minutes (for up to 80 percent of full capacity).^[2] The batteries are located under the floorpan and in the Colt uses 22 Li-ion modules to produce a cumulative 325 V. The design allows for an entirely electric vehicle, or a hybrid using the batteries to supplement a traditional internal combustion engine or a hydrogen fuel cell.^[8]

[edit] Benefits

According to Mitsubishi, locating the motor behind the wheel offers the company three distinct advantages:^[8]

1. It allows for a four wheel drive system without need of transmission, driveshafts, differential gears or other complex mechanical components. Mitsubishi Motors has been one of the few companies to persist in offering 4WD on vehicles other than SUVs since the technology's heyday in the 1980s.
2. Placing the drive system entirely in the wheels allows for greater freedom of design for interior stylists.
3. The space created facilitates the storage of the batteries, allowing for extra modules to be fitted which would offer increased power and range compared to previous electric vehicles.

[edit] MIEV vehicles

• Mitsubishi Colt EV (2005) — based on the platform of a Mitsubishi Colt, and first exhibited in 2005. It was the first Mitsubishi EV where mass production and public sale in 2010 was mooted.^[9]
• Mitsubishi Lancer Evolution MIEV (2005) — a Mitsubishi Lancer Evolution IX sedan with four 50 kW motors, which took part in the 2005 Shikoku EV Rally.^[4]
• Mitsubishi Concept-CT MIEV (2006) — a sport compact prototype exhibited at the 2006 North American International Auto Show.^[10]
• Mitsubishi Concept-EZ MIEV (2006) — a compact mono-box prototype exhibited at the 2006 Geneva Motor Show.^[11]

[edit] MiEV vehicles

• Mitsubishi i MiEV (2006) — a research vehicle based on the Mitsubishi i kei car, first exhibited at the 22nd International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium & Exposition in Yokohama. This vehicle was the first where the "i" in MIEV stood for "innovative", as it eschews the in-wheel motors in favour of a more conventional array of batteries, motor and inverter to replace the "rear midship" engine and fuel tank of the conventional car. MMC plans to provide three power companies with vehicles in 2006 and 2007 in order to conduct joint research to evaluate how fast-charge infrastructure may be developed for EVs. Fleet testing by five power companies will be conducted later in 2007. The car has a range of 130 kilometres for the 16 kW·h pack and 160 kilometres for the 20 kW·h pack. Top speed is 130 km/h.^[2]

[edit] Footnotes