A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.
The basic principle with hybrid vehicles is that the different motors work better at different speeds; the electric motor is more efficient at producing torque, or turning power, and the combustion engine is better for maintaining high speed better than a typical electric motor.
A short, but fun, demonstration of the magnetic field strength of a rotor from a hybrid-electric motor. The permanent magnets inside a hybrid-electric vehicle’s AC Synchronous motor are made of neodymium iron boron and are very strong.
This strength contributes to the instant torque and high power of electric motors used in most of today’s hybrid and electric vehicles.