Filter circuit arrangement, an electric vehicle and a method of operating an electric vehicle

Abstract

The invention relates to a filter circuit arrangement, an electric vehicle and a method of operating an electric vehicle, comprising a rectifier-sided high voltage terminal and a rectifier-sided low voltage terminal, a network-sided high voltage terminal and a network-sided low voltage terminal, a vehicle ground connecting terminal, a first virtual ground circuit section, wherein the electrical connection of the network-sided high voltage terminal to the rectifier-sided high voltage terminal comprises at least one filter element of at least one filter circuit and the electrical connection of the network-sided high voltage terminal to the first virtual ground section comprises at least a first resistive element, wherein the electrical connection of the network-sided low voltage terminal to the rectifier-sided low voltage terminal comprises at least one filter element of at least one filter circuit and the electrical connection of the network-sided low voltage terminal to the first virtual ground section comprises at least a second resistive element, wherein the electrical connection of the first virtual ground section to the vehicle ground connecting terminal comprises at least a first capacitive element.

Claims

1. A filter circuit arrangement for connecting a vehicle-sided rectifier of a system of inductive power transfer to a traction network of a vehicle comprising: a rectifier-sided first voltage terminal and a rectifier-sided second voltage terminal, wherein, during operation, the rectifier-sided second voltage terminal is at a voltage lower than the rectifier-sided first voltage terminal; a network-sided first voltage terminal and a network-sided second voltage terminal, wherein, during the operation, the network-sided second voltage terminal is at a voltage lower than the network-sided first voltage terminal; a vehicle ground connecting terminal; and a first virtual ground circuit section; wherein an electrical connection of the network-sided first voltage terminal to the rectifier-sided first voltage terminal comprises at least one filter element of at least one filter circuit and an electrical connection of the network-sided first voltage terminal to the first virtual ground section comprises at least a first resistive element, wherein an electrical connection of the network-sided second voltage terminal to the rectifier-sided second voltage terminal comprises at least one further filter element of at least one second filter circuit and an electrical connection of the network-sided second voltage terminal to the first virtual ground section comprises at least a second resistive element, wherein an electrical connection of the first virtual ground section to the vehicle ground connecting terminal comprises at least a first capacitive element; characterized in that an electrical connection of the network-sided first voltage terminal to the first virtual ground section comprises at least one resonant filter circuit and/or in that an electrical connection of the network-sided second voltage terminal to the first virtual ground section comprises at least one another resonant filter circuit.

2. The filter circuit arrangement of claim 1, characterized in that the arrangement comprises a further virtual ground section, wherein an electrical connection of the further virtual ground section and the first virtual ground section comprises at least one resistive element.

3. The filter circuit arrangement of claim 2, characterized in that an electrical connection of the further virtual ground section to the vehicle ground terminal comprises at least a second capacitive element.

4. The filter circuit arrangement of claim 2, characterized in that an electrical connection of the network-sided first voltage terminal to the further virtual ground section comprises at least one second resonant filter circuit and/or in that an electrical connection of the network-sided second voltage terminal to the further virtual ground section comprises at least one second another resonant filter circuit.

5. The filter circuit arrangement of claim 1, characterized in that the resonant filter circuit comprises a series connection of an inductive element and a capacitive element.

6. The filter circuit arrangement of claim 1, characterized in that an electrical connection of the rectifier-sided first voltage terminal to the first or a further virtual ground section comprises at least one second resonant filter circuit and/or in that an electrical connection of the rectifier-sided second voltage terminal to the first or the further virtual ground section comprises at least one second another resonant filter circuit.

7. The filter circuit arrangement of claim 6, characterized in that the resonant filter circuit comprises a parallel connection of an inductive element and a capacitive element.

8. The filter circuit arrangement of claim 1, characterized in that an electrical connection of the rectifier-sided first voltage terminal to the first or a further virtual ground section comprises at least one second capacitive element and/or in that an electrical connection of the rectifier-sided second voltage terminal to the first or the further virtual ground section comprises at least one third capacitive element.

9. An electric vehicle comprising the filter circuit arrangement according to claim 1, wherein an electric connection of the vehicle-side rectifier of a secondary unit of the system for inductive power transfer to the traction network of the electric vehicle comprises the filter circuit arrangement.

10. A method of operating the electric vehicle according to claim 9, wherein energy is inductively transferred to the electric vehicle.

Description

(1) The invention will be described with reference to the attached figures. The figures show:

(2) FIG. 1 a schematic block diagram of a system for inductive power transfer with a filter circuit arrangement according to the invention,

(3) FIG. 2 a schematic view on an electric vehicle according to the invention and

(4) FIG. 3 a schematic circuit diagram of a filter circuit arrangement according to the invention.

(5) In the following, the same reference numerals denote same or similar technical features.

(6) FIG. 1 shows a schematic block diagram of a system for inductive power transfer 1 with a filter circuit arrangement 2 according to the invention. The system 1 for inductive power transfer comprises a primary unit 3 with a primary winding structure 4 for generating an electromagnetic power transfer field. The primary unit 3 can e.g. be installed on a surface of a route or on a wall, e.g. of a garage. Further, the system 1 comprises a secondary unit 5 which can be also referred to as onboard receiving unit (ORU). The secondary unit 5 comprises a secondary winding structure 6 for receiving the power transfer field generated by the primary winding structure 4. Further, the secondary unit 5 comprises a rectifier 7 for rectifying the alternating voltage provided by the secondary winding structure during the reception of said power transfer field. Further shown is a filter circuit arrangement 2 for connecting the vehicle-sided rectifier 7 of the system 1 to a traction network 8 of a vehicle 9 (see FIG. 2). The filter circuit arrangement 2 can be part of the secondary unit 5. It is e.g. possible that the filter circuit arrangement 2 is arranged within a housing 10 of the secondary unit 5, e.g. the housing in which the secondary winding structure 6 and/or the rectifier 7 is arranged. It is, however, also possible that the filter circuit arrangement 2 is arranged outside said housing 10.

(7) The filter circuit arrangement 2 is used to filter the aforementioned noise signals, in particular the so-called common mode noise, the so-called differential mode noise and the so-called mixed mode noise. Further, the filter circuit arrangement 2 is used to filter ripples generated by the switching elements (not shown) of the rectifier 7 during the switching operations required for the rectification of the alternating voltage provided by the secondary winding structure 6.

(8) FIG. 2 shows a schematic electric vehicle 9 with a secondary unit 5 which is also shown in FIG. 1. It is shown that the secondary unit 5 is arranged at a bottom side of the vehicle 9. Further shown is a primary unit 3 (see FIG. 1). Further shown is the traction network 8 of the electric vehicle 9. In said electric vehicle 9, the secondary winding structure 6 is connected to the traction network 8 by means of the rectifier 7 and the filter circuit arrangement 2 (see FIG. 1). Vice versa, traction network 8 is connected to the secondary winding structure 6 by means of the filter circuit arrangement 2 and the rectifier 7. This means that a transmission of noise signals to the traction network 8, e.g. ripples or other undesired signal portions generated by the secondary winding structure 6 and/or by the rectifier 7, is suppressed and does not affect an operation of the traction network 8 or electric components connected to the traction network 8 in an undesired way. Further, the transmission of noise signals generated within the traction network 8, e.g. by components connected to the traction network 8, to the secondary winding structure 6 is suppressed and will not cause an undesired signal emission from the secondary winding structure 6.

(9) FIG. 3 shows a schematic circuit diagram of a filter circuit arrangement 2 according to the invention. The filter circuit arrangement 2 comprises a rectifier-sided high voltage terminal RTH and a rectifier-sided low voltage terminal RTL. Further, the filter circuit arrangement 2 comprises a network-sided high voltage terminal NTH and a network-sided low voltage terminal NTL.

(10) Further, the filter circuit arrangement 2 comprises a vehicle ground connecting terminal VG.

(11) Further, the filter circuit arrangement 2 comprises or provides a so-called first virtual ground section VGS1.

(12) The electric connection of the network-sided high voltage terminal NTH to the rectifier-sided high voltage terminal RTH comprises at least one filter element of at least one filter circuit. In the embodiment shown, said electrical connection comprises a first high voltage inductive element L1H, a second high voltage inductive element L2H and a third high voltage inductive element L3H, wherein said inductive elements L1H, L2H, L3H can e.g. be provided by coils respectively. The term high voltage is only chosen for terminology purposes and does not denote a specific electrical characteristic of the respective element. Correspondingly, the term low voltage is only chosen for terminology purposes and does not denote a specific electrical characteristic of the respective element.

(13) These inductive elements L1H, L2H, L3H of said electrical connection provide elements of a first high voltage filter circuit, a second high voltage filter circuit and a third high voltage filter circuit which will be explained in the following.

(14) Correspondingly, the electrical connection of the network-sided low voltage terminal NTL to the rectifier-sided low voltage terminal RTL comprises at least one filter element of at least one filter circuit, namely a first low voltage inductive element L1L, a second low voltage inductive element L2L and a third low voltage inductive filter element L3L. These inductive elements L1HL, L2L, L3L of said electrical connection provide elements of a first low voltage filter circuit, a second low voltage filter circuit and a third low voltage filter circuit which will be explained in the following.

(15) Further, the electrical connection of the network-sided high voltage terminal NTH to the first virtual ground section VGS1 comprises at least a first resistive element R1. Correspondingly, the electrical connection of the network-sided low voltage terminal NTL to the first virtual ground section VGS1 comprises a second resistive element R2. Resistive elements R1, R2 and the context of this invention can e.g. be provided by resistors. A resistance of the first and the second resistive element R1, R2 can e.g. be equal.

(16) It is further shown that electrical connection of the network-sided high voltage terminal NTH to the first virtual ground section VGS1 comprises a first high voltage capacitive element C1H and the electrical connection of the network-sided low voltage terminal NTL to the first virtual ground section VGS1 comprises a first low voltage capacitive element C1L.

(17) The first high voltage capacitive element C1h is electrically arranged in parallel to the first resistive element R1. Correspondingly, the first low voltage capacitive element C1L is arranged electrically in parallel to the second resistive element R2. A capacitance of said first high and low voltage capacitive elements C1h. C1I can be equal.

(18) Within the electrical connection of the network-sided high voltage terminal NTH to the first virtual ground section VGS1, the parallel connection of the first resistive element R1 and the first high voltage capacitive element C1H is electrically connected in series with the first high voltage inductive element L1H. Thus, the circuit arrangement 2 comprises also a series connection of the first high voltage inductive element L1H and the first capacitive element C1H within electrical connection of the network-sided high voltage terminal NTH to the first virtual ground section VGS1. This series connection provides a first high voltage filter circuit.

(19) Correspondingly, the parallel arrangement of the second resistive element R2 and the first low voltage capacitive element C1L is electrically connected in series to the first low voltage inductive element L1L within the electrical connection of the network-sided low voltage terminal NTL to the first virtual ground section VGS1. Thus, the circuit arrangement 2 also comprises a series connection of the first low voltage inductive element L1L and the first low voltage capacitive element C1L which provides a first low voltage filter circuit.

(20) The first high voltage filter circuit and the first low voltage filter circuit are provided by resonant filter circuits, e.g. series resonant filter circuits.

(21) Further, the electrical connection of the first virtual ground section VGS1 to the vehicle ground connecting terminal VG comprises at least a first capacitive element C1. The vehicle ground connecting terminal VG denotes a terminal providing a reference potential of the vehicle, e.g. a potential of the vehicle chassis.

(22) Further shown is that the filter circuit arrangement 2 comprises a further virtual ground section VGS2. An electrical connection between the first and the further virtual ground section VGS1, VGS2 comprises at least one resistive element BR which can also be referred to as balancing resistor. Further shown is that the electrical connection between the further virtual ground section VGS2 and the vehicle ground connecting terminal VG comprises a second capacitive element C2. A capacitance of the first and the second capacitive element C1, C2 can be different from one another.

(23) Further shown is that the electrical connection of the network-sided high voltage terminal NTH to the further virtual ground section VGS2 comprises a second high voltage capacitive element C2H. In particular, said electrical connection comprises a series connection of the second high voltage inductive element L2H and the second high voltage capacitive element C2H. This series connection provides a second high voltage filter circuit which is designed as a second resonant filter circuit. More particular, the electrical connection of the network-sided high voltage terminal NTH to the further virtual ground section VGS2 comprises a series connection of the first high voltage inductive element L1H, the second low voltage inductive element L2H and the second high voltage capacitive element C2H.

(24) Correspondingly, the electrical connection of the network-sided low voltage terminal NTL to the further virtual ground section VGS2 comprises a second low voltage capacitive element C2L. In particular, said electrical connection comprises a series connection of the second low voltage inductive element L2L and the second low voltage capacitive element C2L. This series connection provides a second low voltage filter circuit which is designed as a second resonant filter circuit. More particular, the electrical connection of the network-sided low voltage terminal NTL to the further virtual ground section VGS2 comprises a series connection of the first low voltage inductive element L1L, the second low voltage inductive element L2L and the second low voltage capacitive element C2L.

(25) It is further shown that the electrical connection of the rectifier-sided high voltage terminal RTH to the further virtual ground section VGS2 comprises a third capacitive element C3. Further, said electrical connection comprises the aforementioned second high voltage capacitive element C2H and a parallel connection of the third high voltage inductive element L3H and a third high voltage capacitive element C3H. In particular, a series connection of the second high voltage capacitive element C2H and the aforementioned parallel connection of the third high voltage inductive element L3H and the third high voltage capacitive element C3H is electrically arranged in parallel to the third capacitive element C3 and provides the electrical connection of the rectifier-sided high voltage terminal RTH to the further virtual ground section VGS2. The parallel connection of the third high voltage inductive element L3H and the third high voltage capacitive element C3H provides a third high voltage filter circuit, i.e. a resonant filter circuit which is designed as a parallel resonant filter circuit.

(26) Correspondingly, the electrical connection of the rectifier-sided low voltage terminal RTL to the further virtual ground section VGS2 comprises a fourth capacitive element C4. Further, said electrical connection comprises the aforementioned second low voltage capacitive element C2L and a parallel connection of the third low voltage inductive element L3L and a third low voltage capacitive element C3L. In particular, a series connection of the second low voltage capacitive element C2L and the aforementioned parallel connection of the third low voltage inductive element L3L and the third low voltage capacitive element C3L is electrically arranged in parallel to the fourth capacitive element C4 and provides the electrical connection of the rectifier-sided low voltage terminal RTL to the further virtual ground section VGS2. The parallel connection of the third low voltage inductive element L3L and the third low voltage capacitive element C3L provides a third low voltage filter circuit, i.e. a resonant filter circuit which is designed as a parallel resonant filter circuit.

(27) In other words, the electrical connection of the network-sided high voltage terminal NTH to the rectifier-sided high voltage terminal RTH comprises a series connection of the first, the second and the third high voltage inductive elements L1H, L2H, L3H. Further, the electrical connection of the network-sided low voltage terminal NTL to the rectifier-sided low voltage terminal RTL comprises a series connection of the first, the second and the third low voltage inductive elements L1L, L2L, L3L.

(28) It is further indicated that coils providing the first high voltage inductive element L1H and the first low voltage inductive element L1L are wound in the same direction with respect to a current flowing from the respective network-sided voltage terminal NTH, NTL to the first virtual ground section VGS1. It is further indicated that coils providing the second high voltage inductive element L2H and the second low voltage inductive element L2L are wound in the same direction with respect to a current flowing from the respective network-sided voltage terminal NTH, NTL to the further virtual ground section VGS2. It is further indicated that coils providing the third high voltage inductive element L3H and the third low voltage inductive element L3L are wound in the opposite directions with respect to a current flowing from the respective rectifier-sided voltage terminal RTH, RTL to the further virtual ground section VGS2.

(29) By means of the first and the second high and low voltage filter circuits, common mode noise and differential mode noise generated within the traction network 8 (see FIG. 1) can be suppressed. By means of the third filter circuits, ripples generated by the operation of the rectifier can be suppressed.