Operating characteristics and operating modes of electric vehicles

1. Operating characteristics of electric vehicles
(1) There is a lot of stored electric energy, and the charging power is large. The stored electrical energy of an ordinary electric vehicle is about 40kWh (kWh), which is equivalent to half a month’s electricity consumption of an ordinary family. In order to fully charge the battery of an electric vehicle in a short time, the charging power of the charger is required to be large. Generally, the charging power of the on-board charger (slow charging) is 2-3 kW, and the charging power of the dedicated DC charging pile is 10-100 kW. It takes 1-2 hours to fully charge the on-board battery of an ordinary electric vehicle with a 20kW DC charging pile.
Electric buses can store 250 to 300 kWh of electrical energy. The charging power of the on-board charger is 5 to 20kW. The charging power of the dedicated DC charging pile is 20-200kW. It takes 4-6 hours to fully charge the on-board battery of an electric bus with a 40kW DC charging pile. The shorter the charging time of the electric vehicle, the greater the output power requirement of the charging pile.
(2) The running distance is short. Generally, the maximum mileage of electric vehicles is about 300km. Considering factors such as road conditions, air conditioning, safety factor, and battery attenuation, the actual one-way operation is 150-200km. Without the support of charging stations (piles), the activity radius should not exceed 75-100km.
2. Electric vehicle operation mode
The service object of the electric vehicle charging station is a variety of electric vehicles, and the charging station must meet the charging needs of different electric vehicles. Electric vehicles have different requirements for driving range and charging time under different operating modes, which directly affect the construction method and power requirements of charging stations. According to the current city’s target market positioning of electric vehicles and the development trend of electric vehicles, there are the following operating modes according to the purpose of electric vehicles:
(1) Bus operation mode. Bus operation modes have certain commonalities, usually the driving route, driving mileage and driving time are fixed. The bus operation mode should adopt the vehicle charging method. This is because their mileage and route can be estimated, and they can make full use of the night outage period for charging to meet the next mileage requirement. Since electric buses usually have a dedicated parking lot, a charging station can be built in the parking lot of the first and last bus stops, and the regular charging can be carried out during the nighttime trough. It should be able to achieve rapid replenishment of electrical energy.
(2) Taxi operation mode. According to the continuous driving range of a taxi after one charge, the necessary charging facilities should be provided within its corresponding travel range. Taxi needs to replenish electric energy in a timely and fast manner to maximize operating time and obtain greater economic benefits. Special charging stations or battery replacement points should be established in urban areas to improve operational efficiency. During the operation period of the taxi, it should be able to complete the electric energy supplementation through fast charging or quick replacement of the battery pack.
(3) Operation mode of official vehicles or social vehicles. Vehicles in the operation mode of official vehicles or social vehicles are driven by drivers of units, departments or the general public, and corresponding charging facilities should be built in areas where official vehicles are concentrated or in residential areas. The driving routes and mileage of official vehicles, commercial vehicles, and social vehicles can generally be estimated; the driving routes and mileage of construction vehicles are not fixed and vary greatly, and they should be able to complete electric energy supplementation through fast charging or quick replacement of battery packs.
(4) Demonstration area operation mode. If the number of vehicles equipped for the demonstration operation is limited, in order to improve the efficiency of vehicle operation, the battery pack should be replaced, but this requires an increase in the investment of the battery pack. If the equipped vehicle can meet the operational requirements, the vehicle charging method should be adopted, which can reduce the investment of the battery pack and reduce the workload caused by the battery replacement operation. In view of the small number of vehicles used in the demonstration area and the relatively concentrated operating range, centralized large-scale charging stations (battery replacement points) can be established in the demonstration area.
(5) Private car operation mode. Private cars used for commuting have relatively fixed parking times and positions, and can make full use of the parking time for charging. Therefore, it is possible to rely on the parking lot to build simple charging facilities and provide charging services without building large-scale centralized charging stations. cut costs. You can also decide to use the vehicle charging method or the battery pack replacement method according to the actual situation of the individual. The capacity of the on-board battery of a private electric vehicle is small, the charging time is not too long, the cost of the battery is low, and the way to supplement the electric energy is only convenient for the user.
In addition, for the charging station, the operation mechanism of the vehicle entering the charging station also affects the power demand of the charging station. The more concentrated the time when the vehicle enters the charging station, the greater the power load of the charging station will be, and the greater the power demand of the charging station will be. Electric vehicles should take full advantage of the grid valley stage for charging, which can minimize operating costs for vehicle owners, and grid companies can use this to adjust the peak-to-valley difference in the grid.