This is the first post in a series that will explore the basics behind electric motors. Note that this series is intended for a general audience and so makes some simplifying assumptions. For a more in-depth treatment of the topic please refer to the recommended reading page.
Electric motors are power converters, taking electrical power and converting it to mechanical power with some losses along the way. The faster the motor spins, or the more torque you require, the greater the electrical power that must be supplied. The contour plot below shows the mechanical power output of a typical electric motor.
https://plotly.com/~richardparsons/3/?share_key=uRik3apuvCzixb8PI24zni
An electric motor is typically defined as a device that converts electrical power into mechanical power.
Electric Power ($P_{elec}$) entering the motor is defined as:
$$ P_{elec}= VI $$
where
Typically, the electrical power entering an electric motor is either:
As the name may suggest, DC motors use a DC power source while AC motors use an AC power source. At Kite, we exclusively deal with AC motors and so will focus on these. If a single AC power source is used then the power delivery is not constant with time. This is visualised if we display the power entering (VI) a single-phase motor as it rotates through 360 electrical degrees.