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Electric systems
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DC motors
Electric motors that nowadays are used to propel electric and hybrid vehicles got some characteristics differing from industrial electric motors. Motors used in vehicles need to satisfy many conditions. Frequent starts and stops, high ratio of acceleration and deceleration, low torque on high speed movement, high torque on low speed climbing. The electric motor propelling electric and hybrid vehicles can be sort into 2 groups:
commutatorless motors
The performance of DC motors, practically can be expressed by the armature voltage, field flux and electromotive force.
Typically, there are four types of wound-field DC motors, depending on the mutual interconnection between the field and armature windings. They are separately excited, shunt excited, series excited, and compound excited.
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Electric propulsion systems
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
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.










