Definition

The combination of DC and DC converters consists of integrating several power conversion modules of the same reference within an electrical architecture in order to :

• Increase the total power distributed by the power conversion function,
• Transfer power to successive different voltage domains.

Context

The global electrification of land, air and sea transport involves the use of increasingly complex electrical architectures in greater numbers within electrical systems. As a result, there is a growing need to combine converters within the same electrical architecture in two ways:

• Combining DC-DC converters in parallel: to increase the total distributed power,
• Association of DC-DC converters in series: to convert power to different voltage levels.

Tame-Power’s contribution

Aware of the growing need for energy, Tame-Power offers to combine up to ten converter modules per system, giving a maximum output power of the order of a megawatt.

Equally aware that each electrical architecture is different and has its own constraints, Tame-Power allows its DC DC converter references to be combined in two ways:

• Association of DC DC converters in parallel
• Combination of DC DC converters in series

Association of DC DC converters in parallel

What is the purpose of combining DC-DC converters in parallel?

Combining several converters in parallel within the same electrical architecture makes it possible to achieve higher total distributed power.

To increase total output power, up to ten DC DC power conversion modules from the same reference can be combined. However, Tame-Power DC-DC converters connected in parallel do not always have to distribute the same power.

Any precharging systems required are not shown.

In the example shown, the DC-DC converters are in buck mode. The voltage-controlled DC-DC converter maintains a voltage level of 400V, while the other two current-controlled DC-DC converters supply most of the voltage.

In this case, the three power conversion modules are identified as each distributing 50kW so as to achieve a total distributed power of 150kW. However, the respective power of each converter does not have to be identical to that of the other DC DC conversion modules associated in parallel.

In addition, it is preferable for the majority of the current to come from the current-controlled converters, even if this means slightly oversizing them. In the above case, the current to be delivered to the load is 315A. The two current-controlled converters will therefore each supply 125A (50kW/400V) and the voltage-controlled converter will supply the remaining 65A.

Combining DC and DC converters in series

What is the purpose of combining DC-DC converters in series?

Combining DC-DC converters in series enables power to be transferred to successive different voltage ranges within the same electrical architecture.

They also perform the power conversion function using different transfer directions (buck or boost) within the same electrical architecture.

Any precharging systems required are not shown.

In the present configuration, the aim is to ensure the transition from a voltage level of 200V to a voltage level of 300V via an intermediate voltage range of 600V. The first DC-DC converter therefore operates in boost mode (200V to 600V), while the second DC-DC converter operates in buck mode (600V to 300V).