New energy vehicles have faced feedback from users regarding issues of short driving range, difficulty in charging, and slow charging. These issues require improvements in charging efficiency through increased current and elevated system voltage. However, high currents can lead to elevated component heat losses. Therefore, raising the system voltage to enhance charging efficiency has become the mainstream choice.
The electric drive system, as a core component of new energy vehicles, is crucial for reflecting the performance and core competitiveness of automotive products. Currently, both domestic and international brands such as Volkswagen, BMW, Mercedes-Benz, BYD, Geely, Great Wall, and others have been developing high-voltage platforms. The 800V electric drive system based on the high-voltage platform has become a key technology under active research in the industry.
Development Trends of 800V High-Voltage Electric Drive Technology
On September 4, 2019, Porsche unveiled its first all-electric sports car, the brand-new Taycan. The initial release featured the Taycan Turbo S and Taycan Turbo models, both representing Porsche’s commitment to high-performance electric power, known as “Porsche E-Performance.” These models marked the pinnacle of Porsche’s Taycan series of fully electric production vehicles.
Notably, the common electric vehicle system voltage at the time was 400 V. However, the new Porsche Taycan became the first production vehicle with a system voltage of 800 V. This innovative vehicle featured a dual-motor all-wheel-drive setup, incorporating technology derived from Porsche’s Le Mans championship-winning car, the 919 Hybrid. This 800 V system was coupled with dual permanent magnet synchronous motors and a two-speed transmission on the rear axle, effectively balancing performance and extended driving range.
The 800 V three-electric system exhibited low power consumption, integrated a voltage booster to enhance sustained power output, increased charging power, reduced charging times, and lowered system weight. Both the front and rear dual motors utilized AC permanent magnet synchronous motors, featuring a Hairpin winding technique with a slot fill rate of up to 70%. Additionally, localized laser welding was employed in the construction process. Porsche proudly announced that the Taycan could support over ten consecutive launches with consistent torque output, showcasing excellent motor thermal performance design capabilities.
Taycan Turbo S
|Front Motor Type:||Permanent Magnet Synchronous Motor (Water-cooled)||Permanent Magnet Synchronous Motor (Water-cooled)|
|Front Axle Transmission||Single-Speed Transmission (Gear Ratio: 8.05)||Single-Speed Transmission (Gear Ratio: 8.05)|
|Front Motor Peak Power/kW||175||190|
|Front Motor Peak Torque/N·m||300||400(440)|
|Front Motor Maximum Speed/r·min-1||16 000||16 000|
|Front Inverter Peak Current/A||300||600|
|Front Inverter Continuous Current/A||190||380|
|Front Motor Weight/kg||71||76|
|Rear Motor Type||Permanent Magnet Synchronous Motor (Water-cooled)||Permanent Magnet Synchronous Motor (Water-cooled)|
|Rear Axle Transmission||2-Speed Transmission (Gear Ratios: 16, 8.05)||2-Speed Transmission (Gear Ratios: 16, 8.05)|
|Rear Motor Peak Power/kW||335||335|
|Rear Motor Peak Torqu/N·m||500||500(610)|
|Rear Motor Maximum Speed/r·min-1||16 000||16 000|
|Rear Motor Weight/kg||170||170|
|System Comprehensive Output Power/kW||460(500)||460(500)|
|System Comprehensive Output Torque/N·m||850||1 050|
|Number of Battery Cells/个||396||396|
|Battery Operating Voltage/V||723(610~835)||723(610~835)|
|Fastest Charging for 100 km of Driving Range||5(WLTP) 4 (NEDC)||5(WLTP) 4 (NEDC)|
Table 1: Technical Specifications of the Porsche Taycan Electric Drive System
On December 2, 2020, Hyundai Motor Group globally unveiled its all-new electric vehicle-dedicated modular platform called E-GMP (Electric-Global Modular Platform). This platform features an 800 V electrical architecture, bidirectional charging, and the capability to achieve a charging power of up to 350 kW. It allows an 80% charge in just 18 minutes and the ability to drive 100 kilometers on a 5-minute charge.
Hyundai stated that its Integrated Charge Control Unit (ICCU) is the world’s first patented technology that elevates the voltage from 400 V to 800 V through the motor and inverter, enabling stable charging of an 800 V battery using a 400 V fast-charging station.
In 2021, other automotive companies such as Continental, BYD, Geely, BAIC, Changan, GAC, Dongfeng, and XPeng have followed suit by releasing their 800 V high-voltage platform architectures. These developments indicate that the 800 V high-voltage electric drive system is poised for explosive growth, with vehicles expected to commence production in 2022.
Compared to a 400V system, the 800V system offers several advantages:
1. Higher Charging Power Eliminating Charging Time Anxiety:
- The industry generally considers 500A as the limit for vehicle-level cable connectors. Higher currents would significantly increase the complexity of the electrical system design.
- In a 400V system, the charging power of around 200kW is seen as a limit for many vehicle designs.
- In contrast, the 800V high-voltage system can push this limit to 400kW.
- With 800V and a 400kW charging station, a long-range electric vehicle with a 100kWh battery, charged from 20% to 80%, can achieve a full charge in just 9 minutes.
- This is roughly equivalent to the time it takes to refuel a traditional gasoline vehicle, eliminating charging time anxiety for electric vehicle users.
This is particularly important for electric vehicle users, as it allows them to continue their journey more quickly, reducing waiting times at charging stations, especially during long-distance travel.
2. Lower Fast Charging System Costs:
- While fast-charging systems based on 400V technology exist, the 800V high-voltage system can achieve lower system costs, especially for high-power charging applications.
- The table below illustrates a qualitative comparison of the total assembly costs for vehicles with 400V and 800V high-voltage systems.
- In the short term, for charging powers above 250kW, and in the long term, for charging powers above 150kW, the 800V high-voltage system demonstrates a clear advantage in terms of system cost.
|Assumptions: Same Fast Charging Power||400V System Costs||800V High-Voltage System Costs||Remarks|
|Battery System||0||–||Insulation requirements increased|
|Electric Drive System||0||–||Numerous requirements improved|
|OBC+DCDC System||0||–||Numerous requirements improved|
|Distribution System||0||+||Reduced current, allowing for a decrease in specifications for main relays, fast-charging relays, and related fuses|
|High-Voltage Wiring System||0||+||Lower current, enabling a reduction in wiring system specifications|
|High-Voltage Thermal Management System||0||–||Numerous requirements improved|
|Low-Voltage Thermal Management System||0||0||Basic requirements remain the same|
Table 2: Vehicle Assembly Costs for Fast Charging Applications
3. low charging losses in fast charging applications:
- Compared to the 400V system, the 800V high-voltage technology also reduces thermal losses, improving overall efficiency. Higher voltage levels enable a reduction in current, which, in turn, decreases resistance in wires and connectors.
- This means more electrical energy is transferred to the electric vehicle’s battery without being lost during the transmission process. This enhances charging efficiency, reduces energy wastage, and contributes to lower operating costs for electric vehicles.
4. Vehicles exhibit low energy consumption during operation
- The higher voltage and lower current in the 800V system yield another critical advantage during vehicle operation.
- The 800V system aids in reducing internal resistance within electric vehicles, enhancing power transmission efficiency.
- This results in lower energy consumption, extending battery lifespan, and increasing the driving range. Consequently, it reduces driver anxiety and heightens the attractiveness of electric vehicles.
- Vehicles can more efficiently utilize electrical energy while driving, decreasing the frequency of battery charging and maintenance.
- This means electric vehicles become more cost-effective and sustainable, covering longer distances on a single charge.
In conclusion, the 800V high-voltage technology in new energy vehicles offers significant advantages in terms of charging efficiency, improved energy efficiency, power output, and future expandability. This technology plays a crucial role in driving the development of the new energy vehicle industry, providing users with a more efficient and convenient charging experience. It also establishes a solid foundation for enhancing the performance and market competitiveness of electric vehicles.
Currently, 800V systems are primarily found in high-performance electric vehicles, but they may become more prevalent in a broader range of electric vehicle types in the future. As technology costs decrease and more manufacturers adopt the 800 V high-voltage electric drive system, this technology is likely to become more widespread in the mass market. This means that consumers will be able to enjoy the advantages of electric vehicles equipped with 800V high-voltage systems to a greater extent.