Electric propulsion systems are one of the most important parts of any electric or hybrid vehicle. In fact these systems represent heart of electric and hybrid vehicles and they are consisting of electric motors, electric controllers and power converters. Electric motor is converting electric energy into mechanical energy. Mechanical energy is needed to propel the vehicle. Another part of electric motor is to enable regenerative breaking which considerably charge vehicle battery.

Electric controllers are giving control signals controlling the electric motor operation, producing required power and torque. Electronic controller is divided into these units

Sensor

Processor

Interface circuitry

Sensor is translating measured quantities like temperature, torque, voltage, speed, and flux into electric signals trough interface circuitry. All signals are imposed to some sort of conditioning before being submit to processor. Output signals from processor usually are amplified to the certain level enabling easier further use.
Power converter is unit supplying electric motor with proper voltage.
In order to define appropriate electric propulsion system for any electric and hybrid vehicle, there are a lot of factors needed to be specified. Maximum speed, acceleration, braking, climbing capability, range, vehicle weight and volume.