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Electric drive systems are being introduced as an alternative power train within cars in an effort to improve driveability and deliver lower-zero emissions vehicles.
For an electric vehicle, identify the advantages associated with electrical drive systems and the engineering challenges associated with electrical energy storage for delivering a product with the same user functionality as a conventional ICE based vehicle. You should also report why electrical based drive trains can both improve and compromise the environmental performance.
EVs are significantly more efficient than ICE owing to their simpler system excluding such engine accessories as water pump, oil pump, fan, etc.; the regenerative braking they employ; and more efficient conversion to shaft energy. Lower energy consumption reduces the indirect emissions of EVs at the grid while the tailpipe emissions are at zero.
However, EVs can be environmentally compromising at production. The mining activity associated with extraction of battery elements such as lithium, nickel and cobalt is a very polluting process. Upon production, the batteries emit toxic fumes.
Electric drive systems have a flatter torque curve at low rpms. So, unlike, ICE they provide instant torque. The power delivery is smooth and continuous due to absence of power strokes. Additionally, with simpler system, less maintenance is required and there is less load lost to appliances, meaning EVs can offer same performance while having lower graded power.
The main disadvantage is the underdeveloped batteries. Their specific energy is relatively small, so they are heavier and have smaller range. The problem is exacerbated by the scarcity of charging points and the charging duration of, typically, 8-12 hours. Increasing the specific energy limit of batteries and achieving quicker charging times remains to be the main engineering challenge.
(10 Marks)
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