The charging of electric cars can be completed by ground chargers (stations) or on-board chargers. The main function of ground charging stations and on-board chargers is to effectively complete the electric energy replenishment of electric car batteries. The types and operating characteristics of electric cars determine their energy supply methods. According to whether the battery is separated from the car body, it can be divided into two ways: the whole car charging method and the battery replacement method.
(1) car charging method. When the car is charging supplementally, the charger and the charging car are connected through the charging plug, and the battery can be charged directly without being removed from the car. The advantage is that the charging operation process is simple and does not involve processes such as battery storage and battery replacement. However, the charging time of the car has used the operating time of the car in ancient times, and the car utilization rate is low, which is not conducive to maintaining the balance of the battery pack and prolonging the service life of the battery pack.
(2) Battery replacement method. When the car is supplemented for charging, the battery that needs to be charged is removed from the car, and then a fully charged battery is installed on the car. The car immediately leaves and continues to be transported, and the unloaded battery is recharged by the ground charging system. Taking the battery ground charging method is beneficial to improve the efficiency of the car and increase the service life of the battery, but it places high requirements on the car and battery replacement equipment.
It can be seen that different power supply methods have their own characteristics and scope of application. Therefore, in practical applications, it is necessary to choose according to various factors such as the type, number and operating efficiency of the car, the number and performance of the battery, the system configuration cost and management, etc,and can organically combine a variety of programs to achieve the best operation of electric cars
According to the above analysis, the electric cars are classified according to the way of electric energy supply:
(1) It is suitable for cars that adopt the whole-car charging method. Urban sanitation, urban express delivery cars, engineering cars, government official cars, corporate commercial cars, and private cars. They can make full use of the night outage period for charging to meet the next-time driving range needs.
(2) Suitable for cars with battery replacement charging methods. Taxi, social operation cars. They need to replenish power in a timely and fast manner, try to increase the operating time, and obtain greater economic benefits.
(3) It is suitable for cars that adopt the combination of the whole car charging method and the battery replacement method. Buses, cars for special parks, and social operating cars. It not only considers the performance and life of these car batteries, but also ensures the operating time of the car and improves the utilization rate. They can use the whole car charging method during the outage period, and use the battery replacement method during the operation period. In addition, the car power battery can be equipped with different schemes according to the car situation. For a large number of cars belonging to the same company, the company to which the car belongs can establish a storage room for the battery, while for cars with a small number and relatively scattered ownership rights can be distributed by the battery. The center distributes batteries, reducing one-time investment and replacement costs.
(4) It is suitable for cars that use on-board chargers for AC charging. Private cars are generally parked in parking lots or underground garages when they are out of service due to their short use time. At this time, the AC power provided by the parking lot can be used to charge the cars. As the battery capacity of general private cars is small, the charging power is also small. The charger can be installed in the car. It can make full use of the low electricity price stage for charging to minimize operating costs.