Guide: DC conversion DC 400V to 800V for electric cars
In line with developments in the automotive market, Tame-Power has developed DC DC 400V-800V converters
Focus on the electric car market
The market for electric vehicles is growing rapidly, with electric engines accounting for an increasing share of the market as a result of the global electrification of transport and the development of networks of recharging points. The architecture of electric vehicles is therefore developing rapidly, and we are seeing a change in the voltage levels used in electric cars.
Increasing voltage levels in electric cars
Initially, conventional vehicle voltage levels were 12V or 24V, for all motors combined (internal combustion engines also have on-board electrical circuits). The main purpose of these low voltages is to supply low-voltage accessories and modules within vehicles.
With the advent of electric vehicles, these 12V or 24V low-voltage levels are no longer sufficient to power on-board electrical architectures: most vehicles are now equipped with batteries that operate on 400V circuits. Increasing the voltage level in electric vehicles means that system power can be increased considerably.
How does increasing the voltage level in electric vehicles improve performance?
In this case, we consider :
P (power in watts) = U (voltage in volts) × I (current in amperes)
Technically, the cross-section (diameter) of the conductor cables determines the intensity level of the architecture: the higher the intensity (A), the thicker the conductor must be. For the same current, a high voltage supply reduces the amperage of the circuit while providing greater power.
For example:
- An electric car with a 400V battery will be limited to a power of 200kW
- (400V x 500A = 200kW)
- An electric car fitted with an 800V battery will be able to achieve a higher power of 400kW:
- (800V x 500A = 400kW)
At the same current level and without increasing the cross-section of the cables, an electric vehicle can therefore benefit from higher power thanks to a proportionally higher voltage level.
So, for stationary or on-board applications, increasing the voltage level makes it possible to:
- The use of narrower conductors
- The use of smaller cooling systems
- Limiting current losses
- Increase power density
- Reduce charging time
- Designing systems that are more economical in terms of materials and energy
For stationary or on-board applications, increasing the voltage level makes it possible to:
- The use of narrower conductors
- The use of smaller cooling systems
- Limiting current losses
- Increased power density
- Reduce charging time
- Designing systems that are more economical in terms of materials and energy
Managing changes in voltage levels in electric cars
The majority of electric cars are equipped with 400V batteries. However, the most recent models are tending towards 800V circuits; increasing the voltage level makes it possible to considerably improve vehicle performance and recharge batteries at lower cost.
However, vehicles operating on an 800V network need to be capable of operating at 400V. To achieve this, they incorporate specific dedicated components such as on-board DC-DC converters.
Tame-Power is aware of this growing need, in view of the global electrification of vehicles and the increase in their performance, and has specially designed a DC DC 400V 800V converter:
