http://www.greencarcongress.com/2009...

TM4 Partners with Tata Motors and Miljø in EV Project

22 January 2009

Miljø Innovasjon, a subsidiary of Tata Motors, has selected TM4, a subsidiary of Hydro-Quebec, to provide electric motors, power electronics and vehicle controllers for an electric car demonstration program to be launched in Norway in 2009-2010. Electrovaya is providing the Li-ion batteries. (Earlier post.)

Under this program, Miljø will produce more than one hundred units of an all-electric version of Tata Motors’ new Indica Vista.

For this project, Tata Motors and Miljø will benefit from TM4’s latest generation of motors for the automobile industry, the TM4 MΦTIVE series. The TM4 motors use an inverted rotor topology for maximum torque density.

Compared to rotor centric permanent magnet motors, the inverted rotor topology (where the rotor rotates on the outside of the stator) has a larger magnetic field. The additional radius provides higher torque and power density and leads to better efficiency.

Miljø will use the MΦ120 permanent magnet brushless motor, part of the TMΦtive series, optimized to have high over-torque capacity. Its design allows a greater power density output, for high and continuous efficiency over a wide range of operating speeds. The motor is driven by an inverter/controller specifically designed for automotive applications.

The MΦ120 offers maximum power of 120 kW, with 37 kW continuous, and 170 Nm peak torque, with 60 Nm continuous. It weighs 26 kg, and has a maximum 4.6 kW/kg power-to-weight ratio. The motor offers 96% efficiency at normal speed.

Miljø will use a 60 kW peak controller, according to TM4; the peak power output of the system (motor and drive) will be 60kW.

In 2003, TM4 custom-designed the first generation of Electric Traction Systems for SVE’s Cleanova. (Earlier post.) This system is an integrated traction system combining an electric motor and a generator coupled to an internal combustion engine (ICE). This unique traction system uses a clutch system that enables reconfiguration of the drive line from a high torque electric vehicle to a series hybrid. The latest version of the system is a dual system, series parallel hybrid or electric, on command.

TM4 is also working with Magna to design, develop and demonstrate a new automotive electric powertrain based on TM4’s high density permanent magnet motor, although the company is not involved in Magna’s BEV project with Ford (earlier post).

Tata Motors Limited is India’s largest automaker, with revenues of US$9 billion in 2008. Miljø Innovasjon, in which Tata Motors holds a controlling interest through its subsidiary Tata Motors European Technical Centre, produces electric versions of vehicles manufactured and sold by Tata Motors.