Electric Automobile Technologies
Share This Page
Why Does the Electric Motor Whine?
The whine of an electric motor is a combination of two physical sources: electromagnetic tones produced by the magnetic forces inside the motor and the high-frequency switching sound of the inverter; to these, the mechanical contributions of the redu…
Read More
How Do High-Voltage Contactors Cut the Circuit in Case of a Fault?
What disconnects the battery during a fault, short circuit, or collision in an electric vehicle is not a single switch, but a layered safety architecture: The main contactors open the circuit within milliseconds, arc suppression systems quench the el…
Read More
Can Gallium Nitride Replace Silicon Carbide?
Short answer: no, GaN will not replace SiC - but it is rapidly moving in alongside it. Thanks to its high switching frequency and low losses, gallium nitride offers more efficient and cheaper solutions than silicon carbide in the low-to-mid power ran…
Read More
What Is a Resolver? How Does an Electric Motor Know Its Own Position?
A resolver is an inductive position sensor, operating on the transformer principle, that measures the instantaneous angular position of an electric motor's rotor. The inverter can produce torque by keeping the stator magnetic field 90 degrees ahead o…
Read More
Why Are Axial Flux Motors a Topic of Interest in Electric Cars?
In axial flux motors, the magnetic flux flows in a direction parallel to the motor's rotational axis; unlike the radial (armature) direction flux in conventional radial flux motors, it travels in a straight line from pole to pole through a disc-shape…
Read More
Why Can't an Electric Car Sometimes Deliver Full Power?
An electric car sometimes cannot deliver full power because when the temperature sensors on the battery, inverter, and motor detect that conditions are outside the safe operating range, the power electronics deliberately throttle the current and outp…
Read More
Battery Preheating: The Prerequisite for Fast Charging in Cold Weather
Battery preheating (preconditioning) is a thermal management function that brings an electric vehicle's battery to its ideal operating temperature before fast charging. The vehicle heats the battery before reaching the fast charging station entered i…
Read More
How Do Regenerative and Mechanical Brakes Work Together?
In an electric vehicle, the braking demand is first met by regenerative braking, which turns the electric motor into a generator; when the motor's torque is insufficient or the speed is very low, the hydraulic brakes engage. Distributing the work bet…
Read More
What Is Hairpin Winding and What Does It Bring to the Electric Motor?
Hairpin winding is the use of U-shaped bent rectangular copper bars in place of the round copper wires in an electric motor's stator. This geometry fits more copper into the slot, raising the fill factor from the 45-50% level of classic winding to ab…
Read More
At What RPM Range Does an Electric Motor Operate Most Efficiently?
An electric motor reaches its peak efficiency not at a single point, but in a specific region of the torque-speed plane; in most current designs, this region corresponds to the low-to-mid speed and mid torque range. So the short answer to the questio…
Read More
Why Do Electric Cars Still Have a 12 Volt System?
In electric cars, the 12-volt system is fed by a DC-DC converter that steps down the high voltage of the main traction battery to the low voltage needed by auxiliary systems; without this layer, the airbag, ABS, electric power steering, and control e…
Read More
Why Is the Onboard Charger Deliberately Designed to Be Small?
What determines an electric vehicle's AC charging speed at home is not the wall-mounted charging unit but the onboard charger inside the vehicle; this device is deliberately kept in the 7-22 kW band, meaning a narrow power range, because the heavy li…
Read More