At present, chademo3.0 is also in the stage of pre release, and the official release will come with China power grid this year. So the information we can find now is some ideas in the design and improvement of this standard. There are a lot of things worth our attention.

The first part is the design of the pilot circuit

As shown in the figure below, due to historical reasons, the control pilot circuit is different at the DC level. Ccs1 and CCS2 are built on the AC pilot circuit, and the communication is completed based on PLC communication; the DC pilot circuit of chademo and GBT is separated from AC, so it can be considered independently. After the basic connection is established, can communication is enabled for subsequent content. So the question here is how to realize many functions in the future

1) China, Europe and the United States are the three major markets of electric vehicles in the world. The potential market of Southeast Asia, which is gradually increasing in the future, needs to be compatible with a solution. If the interface and pilot circuit are considered, the vehicle end should configure this function well

2) The original AC charging involves orderly charging and v2x. Due to the simple interaction, it is difficult to realize the next intelligent work. This charging interface of Chaoji also provides certain support for subsequent small DC charging

How to design Chaoji charging standard compatible with various standards

Figure 1 guide circuit of electric vehicle

What the designer wants to do is to make the guiding circuit at the end of the vehicle as consistent as possible with that of most vehicles, especially the design of CC1 and CP circuits; CC2 enables the vehicle to be more distinguishable.

How to design Chaoji charging standard compatible with various standards

Fig. 2 control pilot circuit of Chaoji

The most important thing for forward compatibility is to provide a resistance distribution scheme for the simple enough Chaoji plug resistance through the impedance adjustment provided by the adapter, so that Chaoji vehicles can be connected with the circuits of chademo2.0, GB / t2015 and CCS after being equipped with the adapter.

How to design Chaoji charging standard compatible with various standards

Figure 3 from the beginning, from the point of view of compatibility, the design considered by adapater is added

In the process of start-up and docking, considering the difference before compatibility with gbt27930 and chademo, a set of compatible initial charging start-up sequence scheme is made.

How to design Chaoji charging standard compatible with various standards

According to this design direction, if the following European car companies directly adjust CCS2 (developed to version 3.0) to Chaoji, make the following design, and add the following guidance. This is also possible in the case that the sales of European pure electric vehicles will increase in China in the future and need to be compatible with high-power charging facilities. If this kind of development, it must be treated separately according to DC and ac. even in the future, most automobile enterprises will cancel the AC on Bev directly, and use small tributaries to carry out synchronous operation directly below.

How to design Chaoji charging standard compatible with various standards

Figure 5 the possibility of CCS2 moving towards Chaoji is also possible in the future

Note: the 120V low-voltage DC scheme proposed by chademo below is still very large in the pure electric sense of A00. Remove the OBC of A00 grade pure electric car and replace it with a set of low-cost charging. It is hopeful that Japan will promote K-car electrification at A00 level, which is the hope of Japan to make pure electric. Otherwise, it depends on the current Japanese car companies in a I don’t have a lot of hope for the SUVs of the class A and the compact class

How to design Chaoji charging standard compatible with various standards

Figure 6 Japan proposal for small DC within 120V 100A

02 design considerations for 400A & 30 minutes

From the current point of view, we initially went up from the rated specification of 250A, so the next step is to consider the continuous 400A @ 30min trafficability to consider the feasibility of the entire electrical connection, regardless of the electrical connection design of the vehicle and the pile. Now let’s look at the 95mm2 cable in the car. At present, under the condition of using aluminum wire, Tesla can play 700a in a few minutes, so controlling the temperature rise of the whole circuit is a very important thing. It is expected that different charging current designs of 300A, 400A and 500A will be formed later.

Note: the metal connector will corrode faster if it is sprayed with snow remover in the north, so it is worth considering the layout and service life of DC quick charging connector

How to design Chaoji charging standard compatible with various standards

Fig. 7 control of temperature rise during fast charging at 400A

Summary: it is expected that this set of standards will be released in the middle of the year. Once the implementation phase is really started, the race for fast charging power and speed of pure electric vehicles will be further carried out after the two main lines of mileage and price reduction.

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