The Power Surge: Exploring the Advantages of 800V Architecture in Battery Electric Vehicles
What is 800V architecture?
Electric vehicles encompass a myriad of electrical components, including the battery, motor, electronic control, and various auxiliary equipment and wiring. Collectively known as the electrical architecture, these elements form the backbone of EV functionality.
During the vehicle design process, the operating voltage of high-voltage equipment plays a crucial role. If this voltage is controlled within the range of 300-500V, it is commonly referred to as the 400V architecture. However, when the voltage is regulated between 600-900V, it falls under the umbrella of the 800V architecture.
It's important to note that the term "800V" does not represent a fixed value but rather denotes the voltage range of 600-900V. This distinction emphasizes the higher operating voltage and enhanced capabilities of the electrical system.
By embracing the 800V architecture, electric vehicles can unlock improved performance, efficiency, and charging capabilities. This advancement in electrical infrastructure paves the way for a more seamless and powerful driving experience.
Advantages of 800V Architecture
Advantage 1: Increased Fast Charging Speed
In the realm of fast charging, voltage and current play crucial roles in determining the charging speed. While increasing current can boost charging speed, it also leads to elevated heat and energy loss. Therefore, it is more sensible to augment the voltage.
By doubling the voltage, the charging power also doubles, theoretically reducing the charging time by half. However, as the power diminishes during the latter half of the fast-charging process, the actual reduction in charging time may not be proportional. It is worth noting that the performance specifications of the charging station, such as maximum power, voltage, and current, also impact the charging time. Consequently, the 800V model exhibits significantly improved charging speeds, albeit with varying effects on different charging stations.
Furthermore, employing batteries capable of withstanding higher current levels can further expedite the charging process.
Advantage 2: Reduced Vehicle Energy Consumption
Increasing the working voltage of vehicle equipment while maintaining the same power output results in reduced current flow. As per the current heating formula, this reduction in current significantly diminishes heat losses.
The 800V architecture, with its higher voltage, necessitates the use of silicon carbide (SiC) in the vehicle's voltage-to-current conversion equipment. This combination of 800V and SiC technology can lower the vehicle's energy consumption by approximately 8 percent, presenting a remarkable achievement.
To summarize, the 800V architecture offers extended battery life and faster charging capabilities, thereby enhancing the competitiveness of electric vehicles. It has become a prominent trend in the development of electric vehicles.
Disadvantages of 800V Architecture
Increased Vehicle Costs
Implementing the 800V architecture entails the redesign and testing of various vehicle components. Additionally, the utilization of silicon carbide (SiC) comes at a higher cost. Consequently, in the short term, the equipment costs for vehicles adopting the 800V architecture tend to be higher.
Charging Speed Dependency on Charging Stations
800V models typically possess a maximum charging power exceeding 200KW. However, the majority of charging stations offer power outputs around 120KW. As a result, maximizing the potential charging time improvement for 800V vehicles becomes challenging due to the limitations of existing charging infrastructure.
While the 800V architecture presents undeniable advantages, it is important to acknowledge these drawbacks. The increased vehicle costs and reliance on compatible charging infrastructure are factors that should be considered in the overall evaluation of adopting the 800V architecture.
Several Different Forms of 800V Architecture
Considering the aforementioned advantages and disadvantages, various forms of 800V architecture have emerged, each striving to capitalize on the benefits while mitigating the drawbacks. Let's explore these different forms:
Whole Car High Voltage Equipment at 800V
In this configuration, the entire vehicle's high-voltage equipment operates within the 800V range, eliminating the need for voltage conversion between devices.
Advantages: Fast charging speed and minimal energy consumption.
Disadvantages: Relatively higher cost compared to other forms.
Some High Voltage Equipment at 800V
In this form, only specific components such as the high-voltage battery pack and drive motor operate at 800V, while other equipment remains at 400V, requiring voltage conversion between devices.
Advantages: Fast charging speed, energy savings during driving, and lower cost for 400V equipment.
Disadvantages: Additional voltage conversion equipment introduces some conversion losses.
800V Charging Support in a 400V Architecture
This configuration involves a battery pack capable of switching between 800V during charging and 400V during discharge, while other high-voltage equipment remains at 400V.
Advantages: Increased charging speed and lower equipment costs.
Disadvantages: The battery pack becomes more complex, and energy consumption reduction may not be achieved.
These forms can be seen as evolutionary stages from 400V to 800V, and as the cost of 800V components decreases over time, the full adoption of the 800V architecture or even higher voltages may become the norm.
By considering these different forms, manufacturers can choose the most suitable configuration based on factors such as cost, performance requirements, and infrastructure compatibility.
The 800V Model and the Charging Pile
Full Compatibility between 400V and 800V Models
The 800V model can be seamlessly used with a 400V charging pile, as the vehicle's onboard voltage converter allows for an increase in voltage as needed.
Similarly, 400V models find it easier to utilize 800V charging piles, which are capable of outputting the required voltage and current based on the specific requirements of the vehicle.
Superior Charging Speed for 800V Models on All Charging Piles
As per the current 2015 version of the national standard, charging piles are limited to a maximum voltage and current of 1000V/250A, resulting in most charging piles operating at a maximum of 750V/250A. This means that the 800V model can operate at its full power capacity on a larger number of available 120KW-180KW charging piles, and even extend into higher power ranges. Conversely, the 400V model possesses less power and is unable to sustain the same level of performance.
Although a new charging standard is set to be released, which will further increase the maximum voltage and current limits, the upgrade of charging infrastructure is expected to progress at a slower pace.
Abundance of 800V Charging Piles
Under the provisions of the 2015 version of the national standard, a significant number of charging piles constructed in recent years are actually suitable for 800V models. In fact, statistics indicate that approximately 70 percent of fast charging piles possess a voltage exceeding 750V.
These insights highlight the favourable compatibility of the 800V model with existing charging infrastructure, supporting its superior charging speed and convenience for electric vehicle owners.
The Prospect of 800V Architecture
Rise of 800V Models as the New Mainstream
Leading automotive companies have unveiled their plans for 800V models, signaling their imminent launch in significant numbers in the coming years. This trend indicates the growing acceptance and adoption of 800V architecture in the industry.
High-Power Supercharging Pile Construction Plans
Several car manufacturers and charging operators are diligently working on the construction of high-power supercharging piles.
Challenges in Building High-Power Supercharging Piles
The construction of charging piles with currents exceeding 300A poses certain difficulties. Due to the substantial heat generated by the wires, liquid-cooled charging guns are necessary, which can increase the cost. Typically, high-power supercharging piles adopt a one-pile, multi-gun configuration, allowing for simultaneous charging of multiple vehicles while dynamically allocating power. While this approach optimizes efficiency, it may reduce the opportunities for individual vehicles to access high-power charging.
Additionally, the construction and operation of supercharging piles have a significant impact on the power grid. Many installations require the integration of supporting energy storage systems, which adds to the overall construction cost.
Despite the considerable construction costs associated with high-power charging infrastructure, it is a challenge that is being embraced by infrastructure developers. This commitment to building robust charging networks underscores our country's dedication to the development of new energy resources and the proliferation of electric vehicles.