Transportation has gained a great deal of importance in the growth of modern society by fulfilling the needs of mobility in everyday life. But vehicles using fossil fuels persistently bring serious problems to environment and life. Research and development activities constantly emphasize the acute need to develop high-efficiency, clean and safe transportation systems. Hence, the ideal transportation system should envisage zero-emission without any pollution. In this perspective, Solar and Electrical energy based hybrid vehicles provide the most effective and viable long-term solution by using renewable energy sources for mobility. Such a transportation system rely upon the major components, namely, energy system (Battery, Super-capacitor, Solar panel), control electronics for battery charging, drive electronics between energy source & electric motor and power transmission from motor to wheel through gear set.
Recently,
Vikram Sarabhai Space Centre (VSSC), ISRO, Thiruvananthapuram, demonstrated the running of a Solar Hybrid Electric Car using in-house expertise and resources within ISRO to pave the way for achieving an environmental friendly transportation system. The major challenges accomplished through multidisciplinary (Chemical, Mechanical, Electronics and Automobile) efforts include design and realisation towards:
- Solar panel to suit the roof top of car
- Super-capacitor to meet the high peak current of beyond 100 A level
- Integral gear box to augment the performance of Brushless DC (BLDC) motor
- Control electronics for the battery and solar panel interface and drive electronics for running the motor in a smooth way
- Conversion of Internal Combustion Engine (ICE) based vehicle to fit in with the electric motor.
To drive the car, energy was supplied to the vehicle by state of the art high energy density Lithium ion batteries connected across high power density Super-capacitors. Battery delivered the sustained energy requirement while Super-capacitor supported the peak power demand during high torque conditions. This arrangement of power sharing helps in enhancing the life of power-restricted batteries. At the same time, a high efficiency solar panel fitted on rooftop of the car could continue to refill the charge to battery during sunlit period. In order to convert the electrical energy into mechanical means for driving the wheel, it was necessary to integrate an efficient power conversion module between energy system and electric motor. A Brushless type motor was selected, which offered improved torque with reduced energy input while being light in weight. Concerted efforts were made to ensure that the associated safety aspects are not compromised while combining various active subsystems of different behaviour for a focused objective.
The significant indigenous efforts forming part of ISRO applications are successfully exploited from developed components, namely, Super-capacitor, BLDC motor, Solar array and panel, Control & drive electronics and integration methodology inside the vehicle.
The Solar Hybrid Electric car was successfully demonstrated including the uphill drive during the last week of March 2017.
Having gained the experience in the development of electricity driven car, further actions are in progress to reduce the cost through indigenous Li-ion pouch cells/Fuel cell along with Super-capacitor as well as electric motor.
Major Components
Modified BLDC Motor
Super-Capacitor
Solar Hybrid Electric Car demonstration by VSSC
