文档介绍：1 Technical Overview of Electric Vehicle
The advantage of the EVs is the mechanical simplicity of the drivetrain. For example, an EV drive train can convert energy stores into vehicle motion, just like a conventional vehicle, and it can also reverse direction and convert vehicle motion back into energy stores through regeneration barking, which means that theirs energy/work loop is inherent bi-directional. Besides, moving parts of the electric motor in the EVs consist primarily of the armature (DC motors) or rotor (AC motors) and bearings, a relatively simple and far more efficient machine. other advantages include electric motor torque much more suited to the torque demand curve of a vehicle. EV drive train often needs only one gear ratio other than two or more. More-over, a reverse gear is unnecessary because the rotational direction of the motor itself can be reversed simply by reversing the electrical in-put polarity.
However, the function capabilities and the cost/benefits profile of electronic system are plicated. Electrical power is delivered to the wall outlet in the form of alternating current, and must be converted into direct current in order to charge EV batteries. In the case of EVs powered by DC motor, electricity from the battery must then be “chopped” into small bursts of variable duty cycle in order to control the speed and torque of the motor. With EVs using AC motors, the direct current from the battery must plex power condition in order to deliver alternating current and provide control over motoring output. The main disadvantage of BEVs is limited energy stores due to the limitations of the secondary battery, and HEVs tend to be plagued by increased mass and costs due to the plexity of the power system.
2 Battery-power Electric Vehicle (BEV)
For the battery-power electric vehicles, there is either a purpose-built EV or a conversion of an existing gasoline powered vehicle. Some of the EVs, such as GM EV1, Ford Ranger and Toyota Prius will be