Batteries to store electrical energy, electricity is adopted for the dc output from the battery through the converter to motor. Dc motor by a brush dc motor and brushless dc motor, brushless dc motor for maintenance is not convenient to be replaced by brushless dc motor, brushless dc motor has become the most common entry-level electric vehicles use a type. On the technical characteristics, brushless dc motor can be divided into direct current motor characteristics of brushless dc motor and brushless dc motor with ac motor characteristics. We discussed the category of the more mainstream only dc motor features of brushless dc motor. According to the technical requirements of electric vehicles to the motor, dc motor can meet the basic requirements of electric vehicles, in addition, the brushless dc motor is also don't need to think about it during the period of user in-use vehicle maintenance problems, based on the characteristics of brushless dc motor as entry-level electric vehicle of choice. Say it is the first choice for entry-level motor because the motor itself also has some disadvantages, these disadvantages will become hinder the development of it in the electric car industry. Dc motor speed range is not wide, and maximum speed is 6000 RPM only, such speed attributes, it is difficult to meet the demand of working condition of electric vehicles, so, some vendors by matching for its secondary reducer or have a certain scope of transmission gear ratio of CVT transmission to compensate for the direct current motor's shortcomings in terms of speed. Apparently, the technical structure in space and weight control has adverse effect on the design of the vehicle. Of course, also can only for a single stage reducer motor matching, but the vehicle dynamic performance and the highest speed will be affected. Fans of asynchronous motor in addition to most domestic manufacturers of electric vehicle products, also includes is unique among electric vehicles camp of tesla MODEL S. In terms of technology, asynchronous motor why can gained popularity? Asynchronous motor can be summarized to the ac motor category. Frequency control of motor speed is a function of motor to be first, because of the wheel of pure electric vehicles is composed of motor and differential transmission mechanism to drive, motor speed range can meet the requirements of the motion of the vehicle itself, therefore, from the point of technical structure, the gearbox is no longer necessary for the whole power system device, but in terms of the performance of frequency control of motor speed, and puts forward higher requirements on motor, in addition, the reverse is also frequently met everyday when driving, so, also need motor can easily switch between positive &negative state. The ability of asynchronous motor with frequency control of motor speed, the effect is equivalent to what we understand level assembly for transmission of the vehicle during acceleration engine speed and the speed is more linear corresponding relation. And the reverse problem of the mentioned above, the asynchronous motor can also be easily through their own positive &negative switching to meet. It was easier for asynchronous motor to realize the kinetic energy recovery. Vehicle sliding or braking, wheel motor rotation, in this condition, motor power and electric energy can be recycled to the battery, in order to extend the range of the vehicle. Can meet the demand of electric vehicle technology on the function, but its structure is not complicated, the resulting is strong and durable, stable working status, easy to control cost and other advantages.
