Frequently used terms and key electric mobility topics simply explained.
Compared with a combustion engine, which runs on petrol or diesel, an electric motor works quite simply. Basically, in an electric motor, electrical energy is converted into mechanical energy through the generation of magnetic fields. As these magnetic fields attract or repel each other, they generate force – which is ultimately used to drive the car. The electricity needed to keep the electric motor running is drawn from a battery.
An electric motor allows a car to accelerate very quickly and smoothly even at low speeds. To protect the battery, the torque is limited in certain cars to prevent overheating. Electric motors produce very little noise and vibration, are highly efficient and produce no emissions.
When people talk about an electric car, they often focus on the battery. While this is indeed the heart of electric mobility, the motor also plays an important role. Three different engines are basically used for electric cars, the most common of which is the permanent-magnet synchronous motor (PMSM). Some brands of car use the induction motor or the separately excited synchronous motor (SSM). Basically, the differences between the engines are small. In many cases, manufacturers even choose a combination and install different engines at the front and rear axles. As a rule, the PMSM is combined with the induction motor.
The PMSM is a special form of the AC motor. Permanent magnets are used in this electric machine. This involves two electromagnets, the stator and the rotor. The stator is immobile and creates a constant magnetic field due to the direct current. The rotor, on the other hand, turns and sets the vehicle in motion, running at the same speed as the magnetic field. The advantage of this motor is its high power density and efficiency. It is also compactly built, relatively low-maintenance and low-wear, does not overheat and performs best in terms of recuperation.
With the asynchronous machine, the rotor field is generated by induction, which is why it has no sliding contacts and thus has slight advantages in terms of wear and maintenance. The separately excited synchronous machine transfers energy to the rotor via a sliding ring system. This type is also only subject to slight wear and tear. No rare-earth magnets such as iron, cobalt or neodymium are required for the production of separately excited synchronous machines and induction motors.
Various companies are working on building a magnet-free electric motor that does not require any rare earth elements at all. This approach involves combining the strengths of the different electric motor concepts.
A car with a combustion engine has a total of around 90 times more moving parts than an electric car. The drive train alone consists of around 1400 parts in a car with a combustion engine, whereas in an electric drive it is made up of only 210 parts. An electric car requires no starter, injection system, spark plugs, crankcase, tank or exhaust. An electric car also has no complex manual transmission, no automatic start-stop system, no clutch, no catalytic converter and no particulate filter.
What is more, electric cars do not need oil that has to be periodically checked and changed. Only the brake fluid and coolant for the batteries need to be changed from time to time. Recuperation during braking means that brakes and tyres wear less quickly and last longer. It is therefore clear overall that there is less work and therefore less cost involved in maintenance and servicing.
Switzerland applies the same CO2 emission regulations for new vehicles as the EU. From 2021, emissions from passenger cars registered for the first time in Switzerland must not exceed 118 grams of CO2 per kilometre on average, in accordance with the WLTP. Emissions from light commercial and light articulated vehicles registered for the first time must not exceed 186 g CO2/km. These target values correspond to the targets of 95 grams per kilometre for new passenger cars and 147 grams per kilometre for new light commercial and light articulated vehicles previously applied on the basis of the NEDC measurement procedure. Based on these target values, each importer’s fleet must comply with an individual target. If this target is exceeded, a sanction is imposed. (Source: Swiss Federal Office of Energy)
The Swiss like to be on the move. According to data from the Federal Statistical Office (FSO) in Neuchâtel, each inhabitant of Switzerland covers a total of 36.8 kilometres a day within Switzerland on average – on the way to work, to the shops or during their leisure time. These figures apply to 2015, as more recent figures on the microcensus Mobility are not yet available. The level of mobility, i.e. the proportion of the population who travel outside their home every day, has remained unchanged for many years at around 89 per cent, or nearly 9 out of 10 people. Around two thirds (65%) of the average daily distance, i.e. approximately 24 kilometres per day, were travelled by car in 2015, and about a quarter (24%) by public transport. The remainder was accounted for by walking and cycling. Until the outbreak of the coronavirus crisis in March 2020, the distribution shifted slightly in favour of public transport and walking and cycling. Since then, however, a shift back towards the private car has been observed, while the bicycle has also gained popularity as a means of transport during the pandemic.
One thing is certain: the range of the electric cars currently available is more than sufficient for the average daily distance covered by the Swiss in their cars.
Electric engines are much quieter than combustion engines. The engine is almost completely inaudible, save for a soft whirring at most. Up to a speed of 30 km/h, electric cars appear to be silent, a great advantage for residents in residential areas and other locations with a 30 km/h speed limit. At higher speeds, however, the difference in noise compared to a vehicle with a combustion engine becomes smaller and smaller. The noise created by the rolling of the tyres and the displacement of air becomes more and more significant at these speeds.