Electrical assembly of an electrical busbar and a cooling module

<u>TECHNICAL FIELD OF THE INVENTION</u>

0001The present invention relates to the field of electrical equipment, in particular for vehicles, such as inverters.

0002More specifically, the present invention relates to a subset of such equipment, namely an electrical assembly formed on a cooling module and comprising an electrical connection bar.

<u>STATE OF THE ART</u>

0003In many electrical equipment, in particular electrical power equipment such as inverters intended to supply energy to an electric vehicle engine, cooling modules are provided.

0004A cooling module, as is known, is used to dissipate heat produced by electrical components, such as electronic cards or capacitive elements in particular.

0005An active cooling module involves an external body, in particular a cooling liquid such as water for example, the circulation of which between an inlet and an outlet of the cooling module, said cooling module being arranged near or in contact with at least one element to be cooled, makes it possible to lower the temperature of said element to be cooled.

0006A passive cooling module, also known as a heat sink, does not involve an external body. A heat sink is usually made of a material with good thermal conductivity. It may include radiator elements, fins, intended to promote heat dissipation.

0007In electrical equipment such as a power inverter, an active cooling module is used. In the following, the expression “cooling module” designates an active cooling module.

0008On the other hand, in methods of assembling electrical equipment, improved modularity is now sought, in particular in order to facilitate assembly by using independent sub-assemblies in one piece.

0009In this context, the present invention relates to an electrical assembly formed on a cooling module, a portion of which receives, directly fixed to said module, an electrical connection bar in particular intended to receive at least one electrical connector from third-party electrical equipment. For example, in the context of a vehicle inverter, said electrical connection bar can be an alternative electrical connection bar, also designated “AC busbar”, intended to receive phase connectors of an electric motor of the vehicle .

<u>PRESENTATION OF THE INVENTION</u>

0010To this end, the present invention relates to an electrical assembly comprising a cooling module, in particular an active cooling module comprising a cooling liquid circulation network, and an electrical connection bar, said electrical connection bar being directly fixed to a receiving portion of the cooling module, said electrical assembly being intended to be attached to a chassis of first electrical equipment.

0011According to one embodiment, the electrical connection bar is screwed onto the receiving portion of the cooling module.

0012According to one embodiment, an electronic power module fixed on a first surface of the cooling module and a capacitive connecting element fixed on a second surface, opposite to the first surface, of the cooling module.

0013According to one embodiment, said receiving portion comprises opposite faces which are respectively in the same plane as the first surface of the cooling module and that the second surface of the cooling module.

0014According to one embodiment, the cooling module comprises a first portion comprising the first and the second surface, and in which said receiving portion forms a fork extending from the first portion of the cooling module.

0015According to one embodiment, the electrical connection bar comprises:<ul id="ul0001" list-style="dash" compact="compact"><li>a first part held between two arms of the fork, and</li><li>a transverse arm extending from one side of the first part, said transverse arm being located at the junction of the fork with the first portion of the cooling module, said transverse arm extending along the first surface of the cooling module and comprising connection terminals which come opposite terminals of said power module to be connected thereto.</li></ul>

0016According to one embodiment, the cooling module comprises a coolant inlet and a coolant outlet, the coolant module being configured so that the coolant circulates between the electronic power module and the capacitive element link.

0017According to one embodiment, the electrical connection bar comprises a body of electrical insulating material holding together the conductors of the electrical connection bar, said body coming against the cooling module so as to allow heat dissipation of the heat from the conductors to the cooling module.

0018The present invention also relates to electrical equipment comprising a housing in which is housed an electrical assembly as briefly described above.

0019According to one embodiment, said electrical equipment forms an inverter.

<u>PRESENTATION OF THE FIGURES</u>

0020The invention will be better understood on reading the description which follows, given only by way of example, and referring to the appended drawings given by way of nonlimiting examples, in which identical references are given to similar objects. and on which:<ul id="ul0002" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> : the <figref idref="f0001">figure 1</figref> shows an example of an electrical assembly according to the invention;</li><li><figref idref="f0001">Fig. 2</figref> : the <figref idref="f0001">figure 2</figref> shows the example of an electrical assembly according to the preceding invention, to which is attached an electronic power module and a capacitive connecting element;</li><li><figref idref="f0002">Fig. 3</figref> : the <figref idref="f0002">figure 3</figref> shows an example of electrical equipment, in this case an inverter, comprising an electrical assembly according to an example of the invention;</li><li><figref idref="f0002">Fig. 4</figref> : the <figref idref="f0002">figure 4</figref> shows a cooling module intended for an electrical assembly according to an example of the invention;</li><li><figref idref="f0003">Fig. 5</figref> : the <figref idref="f0003">figure 5</figref> shows an electrical connection bar intended for an electrical assembly according to an example of the invention.</li></ul>

0021It should be noted that the figures show the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary.

<u>DETAILED DESCRIPTION OF THE INVENTION</u>

0022In the description which will be given below, the invention will be described mainly for the production of an inverter, in particular intended for supplying an electric machine such as a rotary electric machine of a motorization system of a vehicle . However, the invention also relates to any electrical equipment capable of comprising an electrical assembly as described below.

0023With reference to the <figref idref="f0001">figure 1</figref>an electrical assembly 10 is proposed comprising a cooling module 11, a receiving portion 110 of which receives, directly fixed to said cooling module 11, an electrical connection bar 12.

0024For example, the electrical connection bar 12 is screwed to the cooling module 11. Alternatively, the electrical connection bar 12 can be fixed to the cooling module by bolting or by embedding via gadroons, or by any other means.

0025A first advantage lies in the fact that the direct contact between the electrical connection bar 12 and the cooling module 11 makes it possible to cool the electrical connection bar 12. In fact, when using the electrical equipment to which the electrical assembly 10 relates, when the electrical connection bar 12 receives electrical connectors, for example phase connectors of an electric vehicle engine when the electrical equipment is a power inverter of a vehicle, a heating of said electrical connection bar 12 occurs.

0026In the same context, the electrical connection bar 12 also comprises electrical conductors 120 with terminals 122 intended to be connected to corresponding terminals of third-party electrical equipment, for example a motor, which contributes to producing a heating of the bar electrical connection 12.

0027The receiving portion 110 extends from a first portion 118 of the cooling module 11, said first portion 118 having a first surface 114 and a second surface 115, said first and second surfaces 114, 115 being intended to receive respectively, always according to the example mentioned above, an electronic power module and a capacitive connection element.

0028More specifically, as shown in the <figref idref="f0001">figure 2</figref>, according to one embodiment, the electrical connection bar 12 comprises electrical conductors 120, in particular flat conductors of the "leadframes" type according to the term in English commonly used. Electrical terminals 123 of electrical conductors 120 are intended, at one end of the electrical connection bar 12, to be received by electrical terminals of an electrical device such as an electronic power module 20 of an inverter, said electronic module of power 20 being fixed to the cooling module 11 and cooled by the latter. According to this embodiment, on the other hand, the electrical connection bar 12, at the end opposite to the first end, comprises electrical terminals 122 intended to receive phase connectors of an electric motor powered by the inverter via the electronic power module 20.

0029As shown in the <figref idref="f0001">figure 1</figref>, the cooling module 11 comprises for example an inlet 111 of coolant and an outlet 112 of coolant.

0030Thus, in particular, the coolant circulates in channels located between the first and second surfaces 114, 115 of the cooling module 11. The inlet 111 and the outlet 112 of coolant are for example arranged in the second surface 115 of the cooling module 11, i.e. on the surface to which the capacitive connecting element 30 is fixed, on the side opposite to the first surface 114 to which the electronic power module 20 is fixed on the<figref idref="f0001">figure 2</figref>.

0031The electrical connection bar 12 may include a transmission module 13. The transmission module 13, integrated in the electrical connection bar 1, is notably configured to connect to an electrical connector of an electrical equipment to take a representative electrical signal a physical property of said electrical device. Such electrical equipment is for example an electric motor controlled by the electronic power module 20, the transmission module 13 transmitting a signal representative of the position of the motor to for example a control card of the inverter.

0032According to one embodiment, a body 121 of electrical insulating material is provided in the electrical connection bar 12 to hold the electrical conductors 120 together, and electrically insulate them between their electrical terminals 122, 123. However, the body can be in one material promoting heat exchange with the cooling module 11. In particular, the body 121 can be overmolded, glued, or force-fitted to the electrical conductors 120, before the electrical connection bar 12 is attached and fixed to said cooling module 11, at the receiving portion.

0033In addition, it is specified that a thermal interface can also be added between the electrical connection bar 12 and the cooling module 11, in particular along the body 21 of the electrical connection bar 12. Such a thermal interface can be made of a TIM type material (for "Thermal Interface Material" meaning thermal interface material).

0034As shown in the <figref idref="f0001">figure 1</figref>, the electrical assembly 10, comprising the cooling module 12 and the electrical connection bar 12 fixed to a receiving portion 110 of said cooling module 11, makes it possible to improve the rigidity of said electrical connection bar 12.

0035A seal 14 can be held in position on the body 21, around the connection bar 12 to come, in particular against a chassis of the electrical equipment when the electrical conductors 120 pass through an opening of the chassis to connect to a third-party electrical equipment, including an electric motor.

0036The <figref idref="f0002">figure 3</figref> represents, in isolation, a cooling module 11, such as intended to form part of an electrical assembly according to an example of the invention. The<figref idref="f0002">figure 4</figref> represents, in isolation, a complementary connection bar 12, such as intended to form part of an electrical assembly according to the same example of the invention.

0037In detail, according to the embodiment shown in the <figref idref="f0002">figure 3</figref>, the cooling module 11 has a first portion 118 and a receiving portion 110. The first portion 118 comprises the first surface 114 and the second surface 115. The receiving portion 110 comprises opposite faces which are respectively in the same plane as the first surface 114 of the cooling module 11 and that the second surface 115 of the cooling module 11. The cooling module 11 may include a cavity 119 intended to receive current sensors measuring the currents between the electronic power module 20 and the electrical connection bar 12. The current sensors comprise for example C-magnets 40 (visible on the <figref idref="f0001">figure 2</figref>).

0038In addition, still according to the embodiment of the <figref idref="f0002">figure 3</figref>, the receiving portion 110 forms a fork extending from the first portion 118 of the cooling module 11, said fork comprising two arms 116, 117.

0039With reference to the <figref idref="f0002">figure 4</figref>, the electrical connection bar 12, correspondingly, comprises a first part 124 intended to be held between the two arms 116, 117 of the fork which forms the receiving portion 110 (as shown elsewhere on the <figref idref="f0001">figure 2</figref>). The electrical connection bar 12 also comprises a transverse arm 125 extending from one side of the first part 124, said transverse arm 125 being intended to be located at the junction of the fork with the first portion 118 of the cooling module 11 . The transverse arm 125 extends along the first surface 114 of the cooling module 11 and includes the connection terminals 123 which are intended to be located opposite the terminals of a power module 20 fixed on said first surface 114 of the cooling module 11, to be connected to it (as shown elsewhere on the <figref idref="f0001">figure 2</figref>).

0040With reference to the <figref idref="f0003">figure 5</figref>, the electrical assembly 10 according to the invention is intended to be integrated into electrical equipment 1, in particular an inverter.

0041The electrical equipment comprises an electrical assembly 10 according to the invention, with a cooling module and an electrical connection bar, said cooling module being sandwiched between an electronic power module 20 and a capacitive connecting element 30.

0042On the <figref idref="f0003">figure 5</figref>, there is shown a chassis 2 inside which is housed an electrical assembly 10, in particular equipped with an electronic power module and with a capacitive connection element, said chassis 2 being closed by a cover 3.

0043In particular, an electronic power module 20 is an assembly comprising a plurality of semiconductor chips forming an electrical circuit encapsulated in the same envelope. More specifically, in this case, the electronic power module 20, as shown in the<figref idref="f0001">figure 2</figref>, may be an assembly comprising components through which energy passes supplying an electric machine, for example an electric motor, said components being in particular intended to transform a direct current into alternating currents or vice versa. Such an electronic power module 20 is configured to allow a controlled passage of electrical energy between a high-voltage supply battery and the electrical machine.

0044In addition, by “capacitive connecting element” 30 is meant a capacitive element, also designated “DC-link capacitor” in English, providing a filtering function in particular for stabilizing the voltage supplied to the electronic power module.

0045Thus, the cooling module 11 is first configured to cool, on the one hand, the electronic power module 20 and, on the other hand, the capacitive connection element 30.

0046According to the invention, the cooling module 11 also cools the electrical connection bar 12.

0047In the embodiment according to which the electrical equipment 1 is an inverter, the electrical connection bar 12 is in particular an alternative connection bar, intended to receive phase connectors of an electric motor supplied with energy by said inverter, in particular at the level of the electrical terminals 122 located at the second end of the connection bar 120.

0048According to the invention, the cooling module 11 thus provides a support function on which the electrical connection bar 12 is assembled and maintained.

0049In addition, the electrical assembly 10 according to the invention makes it possible to integrate the electrical connection bar 12 in the control of the cooling of the electrical equipment to which said electrical assembly relates.

0050The cooling module 11, within the electrical assembly 10 that it forms with the electrical connection bar 12, provides, with respect to said electrical connection bar 12, both a cooling function and a stiffening function.

0051Concerning the stiffening function, it is specified that the improvement is for example obtained due to the direct fixing of the electrical connection bar 12 to the cooling module 11.

0052It is also specified that an advantage of the invention lies in the fact that the electrical assembly 10, comprising the cooling module 11 and the electrical connection bar 12, fixed to said cooling module, in particular by screwing, is one piece. Said electrical assembly 10 therefore constitutes an independent assembly whose functions can be tested separately.

0053In particular, on the basis of the electrical assembly 10 according to the invention, an electronic power module 20 and a capacitive connecting element 30 can be assembled to form a sub-assembly of inverter 100.

0054Such an inverter sub-assembly 100 can be tested independently, which improves the modularity of an inverter assembly method.

0055Once independently tested, the basic electrical assembly 10 or the inverter sub-assembly 100 can be attached in a frame 2 closed by a cover 3 to form electrical equipment 1, such as an inverter.