The CRMT range extender
The CRMT (Research Center for Thermal Machines) has developed a range extender which primary purpose is to extend the range of electric vehicles and extend their use. Electric traction can thus draw the energy needed to move the vehicle from the battery and / or motor generator. The CRMT offers a complete solution including:
- The range extender: Generator + thermal engine
- The controller: range extender controller + complete vehicle management
The CRMT controller manages power based on requests from the driver, the remaining battery power and the road profile. Energy management strategy implemented by CRMT is divided into three modes depending on the SOC (State of Charge: Remaining battery power) following two road profiles: a profile of urban road and a binding road profile (mountain …). In case the battery is charged above 75%, the motor generator will provide power only extra energy to the battery, for example on a steep road. In contrast, in the nominal mode, the motor generator provides the average energy consumption and the battery provides energy in transitional phases. When the battery passes the threshold of 25% state of charge, the motor generator produces its maximum power and the surplus is used to recharge the battery on the less demanding parts of the road.
CRMT management strategy has several benefits beyond increasing the range of the vehicle:
- The battery capacity can be reduced as the maximum power can be obtained by adding the energy provided by the range extender. The cost of the battery can thus be reduced,
- The battery is operating at maximum in its ”comfort” zone between 20% and 80% in order have a longer life,
- The engine works on points of maximum efficiency
- The flexibility of power management can be adapted to each road profile without degrading the performance of the vehicle
The driver with the push of a button can switch from hybrid mode to electric mode and vice versa, to adapt the fuel and electricity consumption to its needs. The electric mode is the best compromise for a short ride.
The CRMT Range extender has passed the NEDC homologation tests for Euro6 at UTAC homologation center:
|Range Extender compared to Euro 6 norm|
52% of max allowed
33% of max allowed
40% of max allowed
CRMT Range Extender technical data
- Displacement: 688 cc
- Bi-cylinder in V: 90°
- Max power: 11.5 kW electric @ 3000 rpm continuously
- Fuel: gasoline (CNG variant to come)
- Injection system: indirect multi-point phased injection
- After-treatment: Closed loop lambda control, 1 sensor per cylinder, 3 way catalyst.
- Mass: 45 kg
The Range Extender for urban vehicles is a particularly advantageous solution to provide sufficient autonomy to the vehicle while containing battery cost. Do you think this type of technology will emerge on mass production vehicle (Smart, Twingo, Up …)?