ChadeMO Association releases Chaoji charging interface

Introduction: Last week, Japan's CHAdeMO Association (Japan Electric Vehicle Fast Charger Association) and the China Electricity Council jointly released a new version of the CHAdeMO fast charging standard, CHAdeMO 3.0. This charging interface is relatively smooth under the promotion of Japan. There are two opinions in China. From the perspective of charging facilities, they hope to move towards a better improved version and provide adapter converters for the original charging interface; while the vehicle side hopes to adjust and optimize the original interface. However, from the perspective of future development, it is more likely to move forward.

01 CHAdeMO3.0 Standards

The technical cooperation on Chaoji charging interface and fast charging is based on the cooperation on the new fast charging standard led by China and Japan. According to the current development trend, some Southeast Asian countries, India and South Korea may develop in this direction in the future. For a long time, the charging of electric vehicles in Japan was limited to the lower charging power of ChadeMO. This time, a big step was achieved at once. The charger of CHAdeMO 3.0 standard is smaller in size and the cable will be smaller, but due to the optimization of the design, the charging power of the vehicle can exceed 500kW (maximum current 600A).

Figure 1. Progress of ChadeMO3.0 

In 2020, the testing standards will be discussed and implemented at both the ChadeMO and GB/T levels. Judging from the timing, the actual progress in Japan may be slightly faster. It is expected that 2021 will be a key point for the implementation of the standards. 

Figure 2 Discussion and cooperation between China and Japan on Chaoji charging standard

From a physical point of view, in the future, charging pile modules will first support high-power and high-voltage charging, and then realize multi-head processing in the charging module and charging cable part. The adoption of Chaoji requires support from hardware interfaces, hardware guidance circuits, software protocols, interfaces, and cable liquid cooling technology. 

Figure 3 Expected deployment of Chaoji interface 

02 Disclosure of technical aspects

There are many contents involved in the technical part. The figure below divides the parts into interface/adapter design, system safety and communication & forward compatibility design. This standard needs to take into account the large number of previously deployed charging piles and the continued use of millions of pure electric vehicles, so the workload is relatively large. Both SWG1 and SWG3 are led by Brother Ni Feng. It is not easy to come this far. The successful stage is also a new stage for China to export technology, standards and products in the field of DC charging to the world in the future. The new infrastructure will continue to hit a wave of DC charging piles, and this field can really be expected in the next 10-20 years. 

Figure 4 Main technical topics

1) Design of connection size and strength Compared with the previous Chademo2.0 and CCS, this charging interface design leaves enough spacing, and further considering that the actual plug is swung around (the operator is self-service and will not handle it with care), a lot of considerations are made in the structural strength. This is mainly to balance the space occupied by CCS due to the integration of AC and DC. At present, as large-capacity pure electric vehicles begin to separate AC and DC for the convenience of wiring, this design mode has an advantage. 

Figure 5 Design of charging interface 

2) Charging Adapter At present, there are great objections from all levels in China to the conversion from the existing GBT standard to Chaoji. In fact, the current interface was hastily developed and is inherently flawed. Therefore, the future conversion is bound to affect many things, so the design of the adapter is very important. 

Figure 6 The charging adapter is also mainly based on Tesla's experience.

Summary: I will stop here for today. Tomorrow I will sort out the revisions to the charging compatibility-related guidance circuit and Chaoji’s CAN communication for readers’ reference.