Electrical vehicle charging system for charging an electrical vehicle
A system and method for a liquid cooled cable arrangement for high-power fast charging of electric vehicles includes a charging connector and a liquid cooled charging cable. The cable comprises several insulated positive and negative conductors for supplying charging current, an inner fluid channel and an outer fluid channel surrounding the inner fluid channel. The positive and negative conductors are arranged within the inner fluid channel. The charging connector includes at least a positive contact electrically connected to the positive conductors by a first connecting element, and a negative contact electrically connected to the negative conductors by a second connecting element. The first and second connecting elements include a thermally conductive and electrically conductive material and are electrically isolated from each other. The first and second connecting elements are thermally connected to the inner and outer fluid channels.
1. A liquid cooled cable arrangement for high-power fast charging of electric vehicles, comprising:
a charging connector and a liquid cooled charging cable, wherein the liquid cooled charging cable comprises several insulated positive conductors and several insulated negative conductors for supplying charging current, an inner fluid channel, and an outer fluid channel surrounding the inner fluid channel, the inner fluid channel and the outer fluid channel together providing a supply path and a return path for liquid coolant;
wherein the positive conductors and the negative conductors are arranged within the inner fluid channel;
wherein the charging connector comprises at least a positive contact electrically connected to the positive conductors by a first connecting element and a negative contact electrically connected to the negative conductor by a second connecting element;
wherein the first connecting element and the second connecting element each includes a thermally conductive and electrically conductive material, the first and second connecting elements being electrically isolated from each other;
wherein the first connecting element and the second connecting element each is thermally connected to the inner channel and to the outer channel of the charging cable such that heat generated in the contacts during charging can be removed by the liquid coolant; and
wherein the fluid channels in at least one of the first connecting element and the second connecting element include an axial channel part and a radial channel part, wherein the axial channel part is open towards an axial surface of the connecting element, the radial channel part is open towards a radial surface of the connecting element and the axial channel part and the radial channel part are fluidly connected to each other.
2. The liquid cooled cable arrangement of claim 1 , wherein the first connecting element and the second connecting element each comprises the fluid channels fluidly connecting the inner fluid channel and the outer fluid channel of the charging cable such that heat generated in the contacts during charging can be removed by the liquid coolant.
3. The liquid cooled cable arrangement of claim 1 , wherein the first connecting element and the second connecting element each includes a charging cable mating part for connection with the charging cable, and a contact mating part for connection with the respective contact, wherein the contact mating part has a wider radial extension than the charging cable mating part.
4. The liquid cooled cable arrangement of claim 1 , further comprising an insulating casing that houses the first connecting element and the second connecting element, the insulating casing disposed to electrically insulate said connecting elements from each other.
5. The liquid cooled cable arrangement of claim 4 , wherein the insulating casing is disposed to house the positive contact and the negative contact and electrically insulates said contacts from each other.
6. The liquid cooled cable arrangement of claim 4 , wherein the insulating casing is disposed to provide a connector housing insulating the connector from a surrounding environment.
7. The liquid cooled cable arrangement of claim 4 , wherein a gap is formed between the insulating casing and each connecting element, which gap forms the fluid channels fluidly connecting the radial channel parts with the outer fluid channel of the charging cable.
8. The liquid cooled cable arrangement of claim 4 , wherein the insulating casing is injection molded.
9. The liquid cooled cable arrangement of claim 1 , wherein the liquid coolant is a dielectric fluid.
10. The liquid cooled cable arrangement of claim 1 , wherein the first plurality of positive conductors and the second plurality of negative conductors are crimped and/or welded or soldered to a respective connecting element.
11. The liquid cooled cable arrangement of claim 1 , wherein the contacts are connected to a respective connecting element by a push-in mechanism, by screwing and/or by welding or soldering or brazing and/or by gluing.
12. The liquid cooled cable arrangement of claim 1 , wherein the contacts comprise at least one of pockets for thermocouples, pockets for contact springs close to tips of the contacts, stress relief openings at joints between different contacts, and cooling channels connected to the fluid channels.
13. A method for liquid cooling a charging connector connected to a liquid cooled charging cable for high-power fast charging of electric vehicles, comprising:
providing the liquid cooled charging cable, the liquid cooled charging cable comprising:
several insulated positive conductors and several insulated negative conductors for supplying charging current and an inner fluid channel and an outer fluid channel surrounding the inner fluid channel, the inner fluid channel and the outer fluid channel together providing a supply path and a return path for liquid coolant;
wherein the positive conductors and the negative conductors are arranged within the inner fluid channel;
wherein the charging connector comprises at least a positive contact electrically connected to the positive conductors by a first connecting element and a negative contact electrically connected to the negative conductors by a second connecting element;
wherein the first connecting element and the second connecting element each includes a thermally conductive and electrically conductive material and are electrically isolated from each other;
wherein the first connecting element and the second connecting element each is thermally connected to the inner channel and to the outer channel of the charging cable;
wherein the fluid channels in at least one of the first connecting element and the second connecting element include an axial channel part and a radial channel part, wherein the axial channel part is open towards an axial surface of the connecting element, the radial channel part is open towards a radial surface of the connecting element and the axial channel part and the radial channel part are fluidly connected to each other; and
conveying liquid coolant through the inner fluid channel, the connecting elements and the outer fluid channel for removing heat generated during charging in the contacts.
14. The method of claim 13 , wherein the first connecting element and the second connecting element each comprises the fluid channels fluidly connecting the inner fluid channel and the outer fluid channel of the charging cable; and wherein the method further includes conveying liquid coolant through the fluid channels of the first connecting element and the second connecting element for removing heat generated during charging in the contacts.
15. The method of claim 13 , wherein the liquid cooled charging cable includes an insulating casing, wherein a gap is formed between the insulating casing and each connecting element, and wherein the method further includes conveying liquid coolant through the gap for removing heat generated during charging in the contacts.