Author Nut's New Year Message:
In 2021, I had the honor of meeting the principal, starting a public account tour in the field of new energy, and setting up at least two outputs per week. "Without thinking about the growth that accompanies it, the carving of time will only float on the surface." This kind of non-stop thinking has also gained a lot of me, and the pattern and perspective of looking at the problem will not be limited by my own work. This year I have met a lot of friends in the same industry, thank you for your support, the new year I will continue to dedicate more wonderful content for everyone. The Year of the Tiger is approaching in 2022, and I wish the readers of automotive electronics design a happy new year, a new year of tigers and tigers, and all the best!
Energy supply is an important link in the industrial chain of electric vehicles, and the energy supply model is closely related to the development of electric vehicles. At present, there are two modes of energy supply for electric vehicles, charging and replacing. Charging is divided into slow charge and fast charge, slow charge charging time is longer, fast charge will affect the battery life. The power exchange mode, which realizes rapid energy replenishment by directly and quickly and efficiently replacing the battery with lower power, has attracted more and more attention. New energy manufacturers, such as Weilai, will promote power replacement as a highlight technology in the way of electric vehicle energy replenishment.
Based on its own technical characteristics and applicable scenarios, the power exchange mode also faces many problems, if you want to further expand the power exchange mode, you need to further carry out in-depth research on technology from the following four dimensions:
▲Figure 1 Research direction of power exchange mode
First, the standardization of batteries and electric vehicles
(1) Standardization of battery system
As mentioned in the cell chapter of the new energy power battery technology trilogy before, in order to meet the capacity needs of the new energy market, the standardization of the entire battery cell system is crucial. For the power exchange mode, the standardization of the battery system can flexibly meet the needs of different mileage batteries. On January 18, Times Electric Service held a press conference online to release the overall solution of EVOGO, a power exchange service brand, and a combined power exchange. It mentions the "Chocolate Swap Block", which was specially developed for the realization of shared power exchange, small and high energy, free combination, and minimalist design. It is worth mentioning that the standardized battery block with wireless BMS technology (wireless BMS technology refers to the discussion on the future development trend of pure electric vehicle BMS system I wrote earlier) will greatly improve the flexibility and matching of the power battery system. The substation is adapted to the use of "chocolate power exchange block" brand models to achieve the freedom of choice of power exchange models. According to their own usage scenarios and habits, they can freely choose the number of rented replacement blocks.
▲Figure 2 Ningde era chocolate electric block
(2) Standardization of power exchange technology
At present, there are three main ways to change electricity, of which the chassis power exchange type is the most commonly used one.
▲Table 1 Power exchange method
▲Table 2 Technical requirements and characteristics of power exchange
Batteries and electric vehicles produced by different manufacturers are different, including size, interface and layout, which brings great difficulties to the unified standardized operation of the power exchange mode, so the formulation of a standard system supporting the power exchange mode requires enterprises and the government to work together to improve the formulation.
Second, the planning and construction of battery centralized charging stations and distribution stations
At present, many new energy manufacturers invest a lot of manpower and material resources in the power exchange mode, but everyone needs to further improve the complexity of the power exchange network, especially in the study of charging station and substation planning. Figure 3 illustrates the basic units to be considered at the planning and operational levels of the power exchange network and their interrelationships.
As can be seen from Figure 2, the planning of the power exchange network includes the planning of centralized charging stations, distribution station planning, and the number planning of batteries. In the future, with the continuous improvement of new energy vehicle sales, the establishment of centralized charging stations will be an effective way to achieve unified battery scheduling and monitoring. Through centralized management, it can effectively participate in grid load management and system peak shaving, improve the compliance efficiency of the power grid, and thus improve the efficiency of the overall operation of the system.
Figure 3 Layout diagram of the power exchange network
As a centralized charging station and electric vehicle connection intermediary, the distribution station needs to complete the power exchange task quickly and efficiently, and some of the replacement stations also shoulder the work of replenishing the battery, and at the same time manage the status of the replaced battery. In terms of planning and design, it is necessary to meet the requirements of floor space, circulation speed, capacity and climatic environment.
▲Figure 4 General power exchange system (distribution station) composition
▲Figure 5 EVOGO substation in The Ningde era
As shown in Figure 5, The Ningde Times Substation only needs three parking spaces for each standard station, and the single block can be replaced for about 1 minute, and 48 replacement blocks can be stored in the station. The substation can also be supplied in versions adapted to the climatic and environmental conditions of different regions.
Third, the circulation management of the battery
Figure 6 NIO Bass model
The circulation method of the battery should be studied according to the performance and life characteristics of the battery itself and the needs of the use of electric vehicles. Through its thoughtful and convenient power-up service model, NIO has completed the extensive laying of charging and power exchange facilities and battery circulation services. Launch battery rental service (BaaS, Battery as a Service), to achieve the separation of vehicle and electricity, users only need to pay the cost of buying a car, do not have to buy a power battery, take the way of paying rent every month to rent a battery, so that the amount of car purchase is directly reduced by about 70,000 yuan. This solves the customer's concern about the depreciation of the vehicle due to battery decay, and the savings in car purchase costs when buying a car also reduce the user's car purchase pressure. This service model helps to increase the sales of NIO and can also promote the circulation of batteries to a certain extent. But this will transfer the battery depreciation cost to the manufacturer.
summary:
In the face of the rapid growth of the new energy electric vehicle market, the power exchange model can meet the needs of the new energy market as an effective energy replenishment technology. The next step around the battery system and power exchange technology standardization will greatly promote the development of power exchange mode, especially with the mainstream battery manufacturers CATL into the game, will continue to compete around the standardization of batteries. The planning of battery replacement charging stations requires more systematic thinking and construction to cope with a large number of energy replenishment needs in the future. At the same time, in the field of battery circulation, innovative marketing models and programs are needed to truly realize the management of the whole life cycle of batteries.
About the Author: Nuts
Senior engineers in luxury car companies switched from engine testing to battery testing.
At present, he focuses on the research of battery testing technology.
I hope to work with you to "electrify, to the future"!