Safety precautions for electric vehicles

Electric cars have been favored by public friends because of their high cost performance. However, in recent years, traffic accidents caused by driving electric vehicles have occurred from time to time. This is because the electric vehicle has a high speed and inertia, and the sound is very small when driving on a Motor vehicle lane, and it rarely causes the driver's attention. Therefore, it is easy to cause a traffic accident.

Today Xiao Bian gave everyone some attention when driving electric vehicles safely.

1, the maximum speed does not exceed 20 km / h. According to the standard, the maximum speed of an electric bicycle is ≤ 20 km/h. If the speed is too fast, excessive inertia may cause the brake to fail, and the load on the main structure such as the frame and the front fork increases, and the risk of breaking easily occurs. In addition, the electric bicycle running at low speed is conducive to the increase of continued mileage, physical experiments show that an excessively high speed will increase the "acceleration" loss of the vehicle and will also increase the energy consumption per unit of mileage.

2, braking should not be too eager to prevent "speed." The control system of an electric vehicle generally adopts a PWM (Pulse Width Modulation) method to regulate the traveling speed and perform various protection functions. In the PWM system, the main execution components in the main loop are a power type MOS tube, a freewheeling diode, and a high-quality large capacity. capacitance. The most serious fault in the electric vehicle control system is that the power type MOS tube is broken through and the motor will lose control, and the motor's blocking and inrush current can often reach several tens of amps. The vehicle cannot be stopped. The forced braking may also be in a short time. The fuse (fuse) cannot be disconnected inside. Users are panicked in the face of such unexpected situations, and improper handling is prone to security incidents. This situation is commonly called "speed car." To prevent "flying cars", we must first greatly enhance the safety margin in design, and must select high-quality critical components. Secondly, a "runaway" device can be set up. Once an abnormality occurs, the user can quickly cut off the total power supply by jogging his thumb to ensure personal safety.

3, pay attention to maintenance, vigilant "fork and fork assembly damage." The fork and front fork assembly is subjected to great impact and fatigue, especially when it comes to emergency brakes, sudden turnings, and dark holes on the floor, which poses a great challenge to the manufacture quality of electric bicycles. Loosening of the locking screw, insufficient handlebar strength, and weakness of the fork bearing area may cause serious accidents. The correct way to prevent "fork and fork assembly damage" is still to improve the quality and cost of safety-related parts, and to strengthen the detection means.

4, Beware of "electricity out of control accident." Electrothermal accidents fall into two categories. One is the "heat accumulation" out of control accident during driving. Since the operating current of the electric vehicle is a function of the load, when the continuous operation is under a high current condition, if the resistance of some contact parts is too large, Will be hot, if the design is not good, will increase the thermal effect, and some electric vehicles will even appear to operate "spontaneous." The other type is “thermal runaway” during charging. Some low-cost and low-quality chargers have serious heat and may even “spontaneously burn” because charging is generally performed at night unattended. Once spontaneous combustion cannot be handled in time, The consequences could be disastrous. The most effective way to eliminate the "electricity out of control accident" is to strictly control the contact resistance and ensure good contact. Second, possible heat accumulation points should use fire-retardant materials to eliminate combustion. Third, the charger must ensure quality and strictly control the temperature. l, and to use flame-retardant shell. In addition, braking is an important technical indicator of electric bicycles. The grades of the braking systems vary greatly. Choosing a good braking system is an important measure to reduce the maintenance rate and improve safety. When starting or climbing, it is necessary to help the user with an ankle to prevent excessive start-up currents, long-term overloading of components, and cause overheating damage to motor coils, circuits, batteries and governors, and even cause disasters.

Xiaobian has so many suggestions. In ordinary life, the people's friends still need to pay attention to more places to sum up, to avoid the tragedy.