Gupte, S., Sharma, S., Garg, S., and Kumar, V., "Multistage Combined Motors Serving Varying Torque and Current Requirements for Hybrid and Pure Electric Vehicles," SAE Technical Paper 2015-26-0119, 2015, doi:10.4271/2015-26-0119.
The torque and current requirement of a vehicle, be it a hybrid vehicle or purely electric vehicle, tends to vary as per the variations in the driving cycles, for example while going uphill the torque requirement of the vehicle entails for a sudden increase and similarly when the vehicle is traversing downhill the torque requirement of the vehicle deteriorates. In case of hybrid vehicles as well as purely electric vehicles, the electric motor forms the integral part which caters to the torque and current requirements. Since the performances of various electric motors are distinct from one another due to their unique characteristics, so for an optimized output one has to compromise upon one parameter or the other. In order to avoid this and enhance the performance in this research, instead of using a single electric motor to satisfy the vehicle's requirement like that of torque and current, two or more than two electric motors are used in order to avail their combined features. The motors being used in conjunction in the whole system can thus be operated in synchronization with the requirement of the various driving cycles. A proper control mechanism is being instilled in order to ensure that the electric motors work in proper synchronization as per the desired requirements. Hence using two or more than two electric motors in case of differential drive, chain drive or in case of electric motors fitted in the wheel hub, a better performance of the vehicle can be utilized giving all the parameters an adequate attention.