Electric vehicles
2.3 Range Anxiety – early 21st century
When Elon Musk joined Tesla as the new CEO, the launch of their model S, model 3, and model Y took the market by storm. Their acceleration was fast, and the drive was noise-free, while also being pollution-free and high-performance. 6 However, questions began to be raised, with most concerned about the range of EVs and others arguing that the cost of such models was more expensive than the average petrol car. A survey conducted in 2019 by Kia Motors ‘ found that 80
percent of fleet managers were held back from actually making the switch due to range anxiety ’ (GEOTAB 2024). Range anxiety is the fear that an EV cannot complete a journey due to insufficient charge, and this intimidates people into buying ICE cars which have greater ranges. Although such issues with EVs exist, engineers are currently tackling such problems with innovative solutions. 7
Technicalities 3.1 Induction Motor
The induction motor, invented by Nikola Tesla, consists of two main components: the stator and the rotor. Stators are stationary, with a series of copper windings placed in slots around the interior of the stator core. These windings are linked to a power supply that transfers an alternating current which induces a rotating magnetic field . The rotor is found inside the stator, and it includes a core with aluminium or copper bars embedded in it. The bars are short-circuited by end rings forming a cage-like structure. The frequency of the AC supplied to the stator windings can be controlled using a variable frequency drive to vary the rotating speed of the RMF which is known as the synchronous speed (N s ), and this is also influenced by the number of poles in the stator (P): 𝑁 𝑠 = 120∗𝑓 𝑃 . As the RMF rotates, it induces
an EMF in the conductive bars of the rotor (this effect is known as Faraday’s Law of Electromagnetic Induction) which causes a current to pass through the short-circuited rotor bars. The RMF coming from the stator and the current in the rotor bars interact to exert a Lorentz force on the rotor bars producing torque that causes the rotor to revolve in the same direction as the RMF. The circular motion
Shanmugam, Three Phase Induction Motor 2023
of the rotor will accelerate until a speed slightly below synchronous speed is reached to ensure that relative motion never ceases, and an EMF is always generated. This speed is known as the motor speed,
6 Lesics 2017. 7 GEOTAB 2024.
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