How Do Electric Vehicles Work?

ever wondered how evs get from a to b is it essentially the same as an internal combustion car but wired up to a giant battery or is there some altogether more subtle trickery afoot join us today as we pop the frunk and ask how exactly do electric engines work surprisingly the operating principle behind most modern electric vehicles pre-dates the internal combustion engine by a number of decades in 1834 a dutch professor named sebranda stratting of groningen netherlands built his own small electric vehicle the catch being its battery was non-rechargeable internal combustion engines work on the principle that fuel and air when compressed and ignited cause a tiny explosion that’s the combustion part this explosive force pushes a piston that piston’s linear motion in concert with a team of fellow pistons transforms into rotary motion via a mechanical crankshaft this in turn spins your wheels along the highway conversely the fundamental principle that drives electric cars is magnetism everybody knows how opposing poles on a magnet attract and how a like poles repel each other so let’s imagine an experiment using two magnets one fixed the other mounted on a nearby rotating shaft if the two poles nearest to each other on both magnets share the same polarity say north to north the magnet on the shaft will be repelled because it’s attached to a shaft the shaft will turn that is until the south pole on the shaft magnet is aligned with the north pole on the fixed magnet whereupon the shaft will again be still in our imaginary experiment we’ve made the shaft turn a half rotation all very well but that won’t get us very far on the morning commute here’s where electromagnetism enters the chat in a fixed or permanent magnet like the kind you have on your fridge at home those magnetic poles are rigid and never change north is always north south is always south on an electromagnet however which is essentially a core of metal coiled in electrical wires this magnetic polarity can be reversed imagine one of our experimental magnets is now an electromagnet if the south pole quickly flips over to north the fixed magnet will yet again repel the moving magnet rotating our shaft another half spin that’s a whole spin now we’re slowly getting there for a basic illustration of how this polarity reversal works imagine a very simple circuit involving a battery and a light bulb electrons flow in one direction from the battery through the wires to the light bulb and back again to the battery if we remove our battery from the circuit flip it 180 degrees then replace it in the circuit those electrons will still flow around the circuit just in the opposite direction either way the bulb lights up electromagnets like light bulbs work whichever direction the electrons are flowing but rather brilliantly the polarity of the magnet gets reversed with the flow of electrons so to keep our magnets in permanent repel mode we just need to keep reversing the polarity of the magnet how do we do that one way would be to keep popping out the battery and flipping it around but that’s a lot of trips to the mechanics with your ev for the sake of a few feet of ground covered so the real trick to making a magnet spin which is essentially how electric motors work is through the so-called inverter the inverter module on the ev draws direct current from the car battery and through a clever combination of quick switches slick circuitry and capacitors flips the flow of electrons back and forth nearly 60 times a second domestic electric motors like the one you have in your hairdryer don’t require an inverter why because the current that comes from your wall outlet already flips back and forth that’s why it’s named alternating current or ac batteries of any type can only ever produce dc or direct current so spinning magnets driven by alternating current passing through coils of wire is essentially what drives electric cars electric powertrains have a number of advantages over the internal combustion engine for starters the motion produced by the motor is already rotary in nature dirty pistons on an ice require a complicated breakable crankshaft just in order to turn their linear motion into rotary movement so evs are less likely to fail or require expensive time-consuming maintenance here’s another clever thing about that inverter by adjusting the frequency and amplitude of its newly created ac current the vehicle’s speed and torque can be finally calibrated by its driver there’s no such fine control built into an explosively hot internal combustion engine which is why expensive and accident-prone additions like gearboxes are a tiresome necessity another nifty detail about any ev’s powertrain is when the shaft-mounted magnet or rotor in engineering parlance is itself spun it generates electricity this reversal very handily recharges the car battery how can the rotor be turned you ask with any hefty source of kinetic energy like say a breaking automobile which is handy this is to be clear a very simple overview there’s different types of electric motor and refinements to the design are happening all the time not least at one particular californian car company named for the 19th century genius who discovered the magic of alternating current by himself nikola tesla what do you think will your next vehicle be an ev let us know in the comments and don’t forget to subscribe for more flipping electrifying tech content