CROSS-REFERENCE TO RELATED APPLICATIONS

The present Patent Application claims priority to EP patent application 20159089.0 filed Feb. 24, 2020, the entire contents of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a mounting base for attaching to direct-current to direct-current (DC/DC) converter units, such as used in electric vehicles.

The invention also relates to an assembly of a mounting base and DC/DC converter units and to an electric vehicle comprising such an assembly.

BACKGROUND ART

Electric vehicles have a fixed size high-voltage (HV) battery/fuel cell or supercapacitor, that is connected via a DC/DC converter to a direct-current (DC)-link that connects to a DC/AC converter that in turn drives the electric motor. The DC-link may also charge a low-voltage (LV) battery that powers secondary devices. These secondary devices such as lights, fans or dashboard are powered by (lead/acid) batteries of various sizes.

The varying power needs of different vehicles is handled by having a DC/DC converter of fixed size and to use varying sizes of energy storage for the secondary devices. The solution that is realized with lead-acid batteries results in increased weight, assigning of space and issues in relation to environmental sustainability.

This lay-out has the disadvantage that the known secondary power systems are heavy, require a lot of space and raises issues in view of sustainability.

There is a need for a flexible design that allows easy adaptation of the electric components to the vehicle lay-out with minimum impact on the mechanical and thermal design.

SUMMARY

According to the invention, a mounting base is provided for attaching three or more DC/DC converter units, the mounting base comprising:three or more mounting area's each with a mechanical connector member for attaching to a complementary mechanical connector member on the units, and an electrical connector for attaching to a complementary electrical connector on the units,an electrical conductor attached to the electrical connectors in each mounting area, and attached to a main connector on the mounting base, for connecting to a HV connector of a main HV supply,a cooling channel extending in heat conducting contact along the mounting areas,for at least two mounting areas a switching member on the mounting base for connecting with a first terminal to an output of the converter unit and having a second terminal for connecting to a secondary electric unit.

The mounting base according to the invention provides a modular DC/DC converter configuration and can be mechanically and electrically connected to a varying number of DC/DC converter units, that may be manufactured with a standardized mechanical and electrical connectors. The mounting base is of standardised dimensions and lay-out and can be fitted with the number and with the type of converter units, depending on the configuration of secondary devices that need to be powered by the HV power source that is utilized in a specific type of electric vehicle.

The DC/DC converters may have different output voltages to support multiple voltage levels of the secondary devices.

The mounting base can be populated with different numbers of DC/DC converters to support different power requirements in a cost-effective manner.

Groups of DC/DC converters may be clustered to enable redundancy of secondary devices for loads that are safety critical. The invention provides increased safety as failure of one DC/DC converter only reduces the total power output by 1/n when n DC/DC converters are connected to the base.

The HV power source of the vehicle is connected to the main connector on the mounting base for powering each of the LV converter units. These LV converter units, which may have different output voltages, are placed in heat-exchanging contact with the cooling channel in the mounting base.

Each DC/DC converter unit on the mounting base is with its output connected to the first terminal of a switch that with its second terminal is arranged for attaching to a secondary electrical unit. The switches effect the distribution of power to the secondary devices, and may have a fuse functionality. Each modular DC/DC converter can independently contribute to the power output of the assembly of mounting base and converter units. By operation of the switches, the secondary electrical units can be selectively powered by the DC/DC converter units.

The standardized mounting base according to the invention forms an electrical, thermal and mechanical interface that is easily scalable for varying the output power by variation of the number of converter units. By use of the mounting base, the 12-volt (V) board net, fuses and distribution boxes can be omitted.

In an embodiment of the mounting base according to the invention, a mounting area is provided with mechanical and electrical connectors for connecting to a logic unit on the base. The logic unit may comprise algorithms for functional control of the DC/DC converter units, operating the switches. The logic unit also diagnoses functionality of the DC/DC converter units, switch and fuse functionality and communicates with the vehicle control system. The logic unit may contain software functionality with high safety integrity.

In a further embodiment, a switching member is adapted for connecting the output of a first converter unit to a second converter unit, to provide a predetermined redundant output voltage at the output of the combined converter units.

In this way a redundant voltage output can be obtained using a number of converter units in parallel.

In one embodiment, the cooling device comprises a central cooling channel with on an upper and on a lower side thereof a support member that is in heat conducting contact with the cooling channel, each support member comprising at least two mounting areas for carrying converter units. This results in a compact construction that occupies a relatively small surface area.

In another embodiment, two or more parallel rows of at least two mounting areas are placed on the same side of the mounting base. This results in a construction of reduced height dimensions.

