According to statistics from the National Energy Administration, as of the end of October 2016, there were 107000 electric vehicle charging stations in China, an increase of 118% from the previous year. Including private charging stations, the total number of charging stations has exceeded 170000. Previously, Tong Guangyi, Deputy Director of the Electric Power Department of the National Energy Administration, stated that according to the Guiding Opinions on Accelerating the Construction of Electric Vehicle Charging Infrastructure, the vehicle to pile ratio will approach 1:1 by 2020.
On the one hand, the number of charging stations affects the promotion of electric vehicles, and on the other hand, the increasing speed of charging time affects the choices of electric vehicle users. Electric vehicle charging modes typically include regular charging and fast (super) charging. Conventional charging refers to the use of portable charging devices equipped with the vehicle for charging, which can be powered by household power sources or dedicated charging stations. The charging current is generally around 16-32A, and the current can be DC, two-phase AC, or three-phase AC. Therefore, depending on the capacity of the battery pack, the charging time is 5 to 8 hours. The fast (super) charging mode usually uses a large current to directly charge the battery through an off board charger, allowing the battery to be charged to about 80% of its capacity in a short period of time, hence also known as emergency charging. The current and voltage of the fast charging mode are generally between 150-400A and 200-750V, with a charging power greater than 50kW. This method is mostly DC power supply, and the ground charging machine has a large power output and a wide range of output current and voltage changes.
On the basis of existing battery energy density, increasing battery capacity has become the most direct and effective way to improve range. However, the larger the battery capacity, the longer the charging time, and how to improve charging efficiency is the focus of technological research. According to statistics, the tendency of consumers to expect fast charging time outside is that almost everyone cannot accept charging time exceeding 30 minutes, 78.4% of people can accept charging time within 20 minutes, 53.8% of people cannot accept charging time longer than 15 minutes, 26.9% of consumers hope charging time is within 10 minutes, and 6.9% of consumers hope charging time is within 5 minutes.
Source: “Zhongshan Electric Vehicle Patent Navigation Research Report”, “China New Energy Vehicle Industry Development Report”
Figure 1 Trend Analysis of Fast Charging Time
Data source: “Zhongshan Electric Vehicle Patent Navigation Research Report”, analyzed and organized by Zhongshan Yunchuang
Figure 2 Analysis of Patent Regions Related to Fast Charging
Among the patents related to fast charging technology, the application regions mainly include China (CN), Japan (JP), the United States (US), international patent applications (WO), Europe (EP), South Korea (KR), and Germany (DE). Among them, China has the highest number of applications, followed by Japan. From the perspective of consumers’ requirements for charging time, fast charging technology for electric vehicles is also a future research direction, and existing patent information can be fully utilized in research and development.
Data source: “Zhongshan Electric Vehicle Patent Navigation Research Report”, analyzed and organized by Zhongshan Yunchuang
Figure 3 Analysis of Patent Applications Related to Fast Charging
From the perspective of patent applicants, TOYOTA, MITSUBISHI, HONDA, and NISSAN rank among the top four in terms of the number of applications. As early as 2011, nine Japanese companies, including Toyota, MITSUBISHI, and HONDA, reached an agreement to jointly establish an integrated organization in Japan to build a fast charging network system for electric vehicles and promote the popularization of electric vehicles. Currently, Tesla has established supercharging stations in many places, becoming a representative of fast charging in supercharging stations.
When optimizing research and development through technology reference, it is possible to understand existing patented technologies, analyze optimization directions, and form a layout of technology optimized patents. Taking a US electrochemical patent as an example, the fast charging technology (201580052062. X) discloses a charging control system for rechargeable batteries with variable internal resistance. Different charging programs are set, and at the beginning of charging, a temperature sensor senses the battery temperature and feeds it back to the controller. When the temperature of the battery is below the predetermined charging value and the battery is in the high range, charge the battery under the regenerative charging program; When the temperature of the battery is higher than the predetermined charging value, the battery is in a low internal resistance state and is charged under another program (such as a constant current constant voltage program).
After learning about the patented technology, R&D personnel can use this existing technology to understand which aspects of the patented technology can be further optimized, such as how to further accelerate the charging speed during low-temperature charging, and how to ensure charging safety during high-temperature charging. On the basis of these optimization plans, form its own intellectual property layout.
This patent is protected from the aspects of charging control system and charging method, and is described in a hierarchical manner. The scope of protection requested is relatively large. When referencing the patent, it is important to understand the validity of the patent, pay attention to risk investigation and response, and consider how to deal with it from other aspects. For patents under examination, their status and scope of authorization should be monitored, and patent risks should not be ignored. When optimizing the layout, patent application documents should also focus on protecting technological innovation within the most reasonable scope, avoiding others from easily avoiding it, improving patent quality, and maximizing the value of patents.
