However, according to data provided by Zhiyan Consulting, although the shipment of charging piles has increased significantly in the past year (from 120,000 to nearly 300,000), the expected surge has not occurred.
The market development has not been entirely satisfactory. While there are issues related to coordinating the interests of various parties, there are also various obstacles from a technical perspective. Among these, the most urgent issue to be resolved is the charging time, which is of utmost importance to the user's charging experience. In addition, there is the problem of real-time interaction of charging pile information, and these issues all focus on high-power DC charging piles.
Anxiety-driven recharging in progress
To address charging anxiety for electric vehicles, faster charging speeds have become a key requirement for fast charging stations, with the goal of providing 200 kilometers of range with just 5 minutes of charging becoming a common industry standard. The DC-DC modules of charging piles can be upgraded in two ways: increasing power density and increasing charging voltage. The former requires high-performance real-time microcontrollers and power devices supporting higher switching frequencies, while the latter demands higher voltage withstand capabilities and higher conversion efficiency from the power devices. Third-generation wide-bandgap semiconductor power devices would be an excellent choice. Furthermore, with the increased switching frequency of third-generation semiconductors, more complex power supply topologies and control algorithms are required, further increasing the demand for real-time controllers.
When discussing the main control unit of DC charging piles, the Texas Instruments (TI) C2000™ microcontroller, which holds a significant market share, must be mentioned. In fact, the C2000 microcontroller has a long-standing reputation in the Chinese market, widely used in power electronics control and providing advanced digital signal processing in industrial and automotive applications. For over 20 years, the C2000 microcontroller has been at the forefront of the analog-to-digital control revolution. Through continuous development, the current third generation boasts even better performance: stronger computing power and richer peripheral resources.
The C2000 microcontroller, with its built-in C28x math-optimized core, combines the advantages of both a microcontroller and a digital signal processor. Through various high-efficiency computing cores, the C2000 microcontroller can achieve μs-level loop computation times. For example, in a bidirectional high-density GaN CCM totem-pole PFC, utilizing the TMU, the C2000 microcontroller can reduce PWM computation from 10μs to below 0.5μs, ensuring cycle-by-cycle adaptive dead-time calculation, thereby achieving the most precise and efficient control of the GaN FET.
The integration of more advanced peripherals is another major advantage of the C2000 microcontroller in meeting complex topologies. By integrating a 3.6M SPS sampling rate and a 12-bit to 16-bit resolution ADC, it achieves faster current and voltage sampling; it also has a 150ps resolution PWM, which can meet the higher switching frequencies of third-generation semiconductors, enabling charging modules with high dynamic characteristics and significantly improving efficiency and reducing size.
As bus voltage is increased in pursuit of higher efficiency, complex multilevel topologies become increasingly common. NPC and ANPC topologies are two of the most popular topologies for bidirectional PFC/inverters, as they can limit voltage stress on the switching devices to half the bus voltage. However, these topologies require more PWM channels from the MCU and a special protection scheme to maintain voltage balance across the power switch during any shutdown. The C2000 microcontroller third-generation devices offer unique configurable logic blocks (CLBs) that enable onboard fault protection, ensuring real-time protection under all operating conditions without any external logic circuitry, similar to the flexibility of FPGAs/CPLDs. This is illustrated, for example, in the TIDA-010210 6.6kW three-phase three-level ANPC inverter/PFC bidirectional power stage reference design.
On the other hand, for the high-efficiency, high-power-density power electronics and very high power density design goals of fast charging piles, third-generation semiconductors (including SiC, GaN, etc.) have become rising stars in the market and are the most important semiconductor technologies for achieving carbon peaking and carbon neutrality. Compared with the previous two generations, they have unique properties such as a large bandgap, high breakdown electric field, high thermal conductivity, high electron saturation drift velocity, and low dielectric constant. Therefore, they can reduce system heat dissipation costs and passive device size, provide higher energy efficiency or higher power density, and reduce the total system cost.
SiC has a wider user base due to its earlier launch. However, "it's too early to conclude whether SiC or GaN is superior. In the long run, silicon-based GaN has greater potential for cost reduction," said Fu Yang, Technical Support Manager for North China at Texas Instruments. In any case, as the manufacturing processes of third-generation semiconductors mature, their overall cost advantage will become more pronounced.
TI has a presence in both areas. On the SiC side, it improves system robustness and reliability, reduces form factor, and easily complies with EMI standards by providing drivers with integrated capacitive isolation. TI's involvement in GaN dates back to 2010, culminating in the launch of the first 10kW converter connected to the cloud grid in 2017 with Siemens. Furthermore, through continuous experimentation with new architectures, GaN has been adapted to a wider voltage range, such as 800V and 1000V (see reference), which increases the likelihood of seeing GaN in charging piles in the future. To ensure high reliability, TI has conducted over 40 million hours of device reliability testing and over 5 GWh of power conversion application testing on GaN FETs. Simultaneously, to further improve reliability and integration, TI has launched GaN devices integrating drivers. Even more impressively, TI owns its own GaN process and manufacturing facilities, ensuring product quality and stable supply.
Beyond charging time, one of the biggest frustrations for users is the uncertainty about the availability of charging stations when they need to charge. This necessitates the use of secure wireless connectivity for remote access and control. TI offers a range of secure wireless connectivity products, from short-range near-field communication (identification, information protection) to long-range proprietary protocol communication, and is also compatible with common BLE and WiFi communication technologies. These allow charging stations to update their status in real time, letting users know their availability.
Data security is increasingly valued by both users and operators, thus solutions require secure authentication, data communication, and other functionalities. TI incorporated information security protection mechanisms into its WiFi products long ago, such as verifying the integrity of data in external Flash memory to prevent unauthorized access and protect sensitive data, as well as robust security mechanisms for encrypted channels and key management.
More needed
In fact, a safer, smarter, and faster charging station involves far more technologies than those mentioned above. For example, supercharging stations operate in high-power, high-voltage outdoor environments with special safety and reliability requirements. Therefore, the stability and intelligence of the isolation and gate devices used in such environments, as well as the protection provided to the power devices, are prerequisites for the DC module to operate in a safer state.
According to Fu Yang, Technical Support Manager for North China at Texas Instruments, TI is conducting innovative research in various aspects to address the challenges of the charging pile market. One of these challenges is how to improve the user experience with smarter charging piles, which will require the use of edge computing and AI technologies.
On the traditional product front, progress is also proceeding steadily. For example, TI's next-generation power products with high integration integrate current sampling and isolation, as well as isolated power management chips, into a smaller chip, helping customers save PCB area and costs; and based on existing silicon devices, higher power density is achieved through more complex topologies without using more advanced power devices…
Beyond its advanced technology, TI offers a wide range of products and different collaboration methods to cater to diverse users and needs. Most importantly, as a corporate social responsibility company that has been deeply rooted in China for 35 years, TI is willing to provide comprehensive local support to help Chinese companies succeed and integrate into the development of China's information industry.
At the 2021 Two Sessions, carbon peaking and carbon neutrality were included in the Government Work Report for the first time, along with the requirement to "increase parking lots, charging piles, battery swapping stations, and accelerate the construction of a power battery recycling system." According to the draft "New Energy Vehicle Industry Development Plan (2021-2035)" released by the Ministry of Industry and Information Technology at the end of 2019, my country's new energy vehicle ownership is projected to reach 64.2 million vehicles by 2030. Even if the vehicle-to-charging-pile ratio cannot reach 1:1, it still signifies a leapfrog development in the future charging pile market. The secret to riding the wave and staying ahead is finding partners who can take a step-by-step, down-to-earth approach, and patiently solve problems one by one. TI has always adhered to this principle and is committed to creating a better future. TI will continue to work hand in hand with you to meet future challenges!
