Filter assembly, voltage converter having a filter assembly

#This application is a U.S. National Stage Application of International Application No. PCT/EP2015/078442 filed Dec. 3, 2015, which designates the United States of America, and claims priority to DE Application No. 10 2014 225 416.7 filed Dec. 10, 2014, the contents of which are hereby incorporated by reference in their entirety.

#The present disclosure relates to filters. Teachings thereof may be embodied in a filter assembly, e.g., a filter assembly for filtering output currents from a voltage converter.

#Voltage converters are often used in power-electronics fields, e.g., in on-board electrical systems of motor vehicles having two or more on-board electrical system branches, in which different voltage levels prevail and in which a voltage at one voltage level is converted in a unidirectional or bidirectional manner into a voltage at another voltage level. For design reasons, output currents from these voltage converters contain AC voltage components which can lead to functional faults in the electrical or electronic components which are connected downstream. Therefore, radio interference-suppression limit values are provided, e.g., in the automotive sector, for the output currents from voltage converters.

#An exemplary embodiment of the invention is described in more detail below with reference to the appended drawing, in which:

#FIG. 1 is a schematic exploded illustration of a section of a filter assembly according to one embodiment of the invention; and

#FIG. 2 is a schematic illustration of a side view of a section of the filter assembly illustrated in FIG. 1.

#The teachings of the present disclosure may be embodied in a filter assembly. For example, a filter assembly may comprise a current conductor which has a curved (bent or kinked) profile and is designed for conducting a current (for example an output current from a voltage converter). In some embodiments, the filter assembly also comprises a first ferrite body and a second ferrite body which each have a curved profile and jointly (substantially) surround the current conductor. In this case, the first ferrite body and/or the second ferrite body have at least one recess which likewise has a curved profile and extends along the current conductor. The profile of the ferrite bodies, in particular the profile of the recess in said ferrite bodies, may correspond to the profile of the current conductor. A curved design of the current conductor allows a flexible design, which is matched to the available installation space, of the current conductor and also of the two ferrite bodies and therefore a construction of the filter assembly such that installation space is saved while having the same total inductance of the filter assembly and therefore the same filter action, or a higher total inductance and therefore a better filter action with the same installation space of the filter assembly.

#The first ferrite body and/or the second ferrite body each form one of two ferrite core halves which, owing to their curved profiles, can jointly surround the current conductor in spite of its curved profile. This allows, in particular, the current conductor to be continuously surrounded in a manner extending over the curved extent of the current conductor by a single ferrite core (which consists of two ferrite core halves), said surrounding allowing a higher total inductance overall for the filter assembly and therefore a better filter action in comparison to a current conductor being surrounded in sections by a plurality of ferrite cores which are physically separate from one another. In this case, the term “jointly surround” means that the two ferrite bodies jointly form the same ferrite core (which surrounds the current conductor) and jointly surround substantially the same section of the current conductor. The surrounding runs around the current conductor in the circumferential direction.

#The curved profiles of the two ferrite bodies additionally allow the entire, exposed installation space in the filter assembly around the current conductor to be filled with the ferrite material, as a result of which the cross-sectional area of the ferrite core through which the magnetic field flows is considerably increased. A relatively high total inductance for the filter assembly is achieved in the filter assembly with the same installation space as a result. In addition, the saturation behavior of the filter assembly can be managed substantially better. This allows the filter assembly to be shaped such that more installation space is saved while having the same or even a better filter action.