ELECTRIC OR HYBRID VEHICLE TRACTION SYSTEM COMPRISING TWO THERMAL REGULATING FLUID LOOPS

Abstract

Electric or hybrid vehicle traction system comprising a thermal regulation circuit comprising a first circulation loop (8) having a first fluid circulation pump (20), at least one cooler (22) or heater (24), a traction battery (26) and a first fluid distribution valve (6), comprising a second circulation loop (12) having a second fluid circulation pump (32), electrical components (34) including a traction machine, an external heat exchanger (38) and a second fluid distribution valve (10), the first loop (8) and the second loop (12) having fluids which are different, and a common motorization (16) actuating the two distribution valves (6, 10) at the same time. Figure 1

Description

Title of the invention: ELECTRIC OR HYBRID VEHICLE TRACTION SYSTEM COMPRISING TWO THERMAL REGULATION FLUID LOOPS

[0001] The present invention relates to an electric or hybrid vehicle traction system equipped with an electric traction machine, a power supply battery for this machine, and a thermal regulation circuit comprising at least two fluid loops, as well as a method for managing this traction system and a vehicle comprising such a system.

[0002] A type of thermal regulation system for a known electric or hybrid vehicle, presented in particular by document FR-A1-3078386, comprises a fluid circuit comprising three loops, each having a temperature range adapted for its components. Two multi-way distribution valves each allow circulation between the loops of the same heat transfer fluid, comprising water with additives, in particular glycol forming an antifreeze, in order to regulate the thermal exchanges to optimize the operation of each of the components while reducing the overall energy consumption.

[0003] A first very low temperature loop comprises the vehicle's traction battery, a cooler for the vehicle's air conditioning system and a circulation pump to maintain this battery at a low temperature, cooling it if necessary.

[0004] A second high temperature loop comprises a cabin heat exchanger, an electric heater and a circulation pump in order to heat the cabin from an electric current consumption.

[0005] A third low-temperature loop comprises the traction machine, its control inverter, a heat exchanger with the exterior and a circulation pump in order to cool the machine and its inverter by dissipating the calories to the ambient air.

[0006] The two distribution valves arranged at the junction of the loops allow exchanges of the same fluid between these loops, for example, depending on the operating conditions of the vehicle and its environment, to heat the passenger compartment from the calories released by the electric machine and its inverter or by the battery, or to cool the passenger compartment from the cooler of the air conditioning system,

[0007] However, this type of thermal regulation system using the same fluid to carry out exchanges between the loops does not allow the type of fluid used for each application to be optimized. In particular, the traction battery includes electrochemical elements for storing electrical energy, which in the event of an incident in the battery box can cause a risk of fire that is difficult to extinguish.

[0008] Furthermore, the different valves for each loop with their independent motors pose problems of increasing the number of components, of complicating the automatic controls of the assembly, and add bulk, weight and costs to the vehicle.

[0009] The present invention aims in particular to avoid these problems of the prior art.

[0010] To this end, it proposes an electric or hybrid vehicle traction system comprising a thermal regulation circuit comprising a first circulation loop having a first fluid circulation pump, at least one cooler or heater, a traction battery and a first fluid distribution valve, comprising a second circulation loop having a second fluid circulation pump, electrical components including a traction machine, a heat exchanger to the outside and a second fluid distribution valve, this system being remarkable in that the first loop and the second loop comprise fluids which are different, and in that a common motorization actuates the two distribution valves at the same time.

[0011] An advantage of this traction system is that it allows a fluid to be provided that is suitable for each loop, in particular for the first loop a fluid with specific characteristics limiting the risks of accidents in the battery, which is different from the fluid of the second loop designed to circulate more easily in the traction machine and its control electronics.

[0012] Furthermore, despite the two separate loops, each having its own valve distributing its own fluid, greater complexity of the traction system is avoided thanks to the single motor operating both valves at the same time.

[0013] The vehicle traction system according to the invention may further comprise one or more of the following features, which may be combined with each other.

[0014] Advantageously, the two distribution valves comprise the same drive shaft receiving a seal between these two valves.

[0015] Advantageously, the first circulation loop comprises a dielectric fluid and the second circulation loop water with added glycol.

[0016] Advantageously, the second circulation loop comprises in series a heat exchanger between the fluids of the two loops, which depending on the position of the first valve also receives the fluid from the first loop.

[0017] Advantageously, the first loop comprises a direct path which makes it possible to short-circuit the passage of the fluid in the battery.

[0018] Advantageously, the second loop comprises a direct path which makes it possible to short-circuit the fluid passage in the external heat exchanger.

[0019] The invention also relates to a method of operating a traction system comprising any one of the preceding characteristics, remarkable in that in a first position of the common motorization the two loops operate independently without heat exchange between them.

[0020] The invention further relates to a method of operating a traction system comprising any one of the preceding characteristics, remarkable in that in a second position of the common motorization the first loop operates by short-circuiting the battery with the direct path of the first loop, and the second loop operates independently without heat exchange with this first loop.

[0021] The invention further relates to a method of operating a traction system comprising any one of the preceding characteristics, the second circulation loop comprising in series a heat exchanger between the fluids of the two loops, remarkable in that in a third position of the common motorization the two loops exchange calories through this heat exchanger.

[0022] The invention further relates to an electric or hybrid motor vehicle, equipped with a traction system comprising any one of the preceding characteristics, which also provides heating or cooling of the passenger compartment.

[0023] The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description below given by way of example, with reference to the appended drawings in which:

[0024] [Fig. 1] is a diagram of the thermal regulation circuit of a traction system according to the invention showing the two loops;

[0025] [Fig.2] presents this diagram in a first independent operating mode of the two loops with thermal regulation of the battery;

[0026] [Fig.3] presents this diagram in a second independent operating mode of the two loops without thermal regulation of the battery; and

[0027] [Fig.4] presents this diagram in a third combined operating mode of the two loops with heat exchanges between them.

[0028] [Fig.l] shows the thermal regulation circuit of a traction system of an electric or hybrid motor vehicle, with two separate fluid loops receiving different heat transfer fluids, comprising a first loop 8 at very low temperature controlled by a first distribution valve 6, and a second loop 12 at low temperature controlled by a second distribution valve 10.

[0029] The two valves 6, 10 comprise a common shaft 4 actuated in rotation by a single motorization 16 of these valves, supporting the two valves which rotate at the same time, with a dynamic sealing joint 14 tightening the shaft, interposed axially between the two valves to avoid exchanges of fluid between them.

[0030] The first fluid loop 8 successively comprises, starting from the first valve 6, a first circulation pump 20, a cooler 22 and an electric heater 24 also forming part of the air conditioning system of the passenger compartment of the vehicle, then a battery 26 supplying an electric traction machine of the vehicle.

[0031] After the heater 24 of the first loop 8, a direct return path 28 arranged in parallel with the battery 26 allows a return of the fluid directly to the first valve 6 by short-circuiting this battery.

[0032] The first fluid loop 8 also comprises, starting from the first valve 6, an outlet 40 to a heat exchanger between the fluids of the two loops 30, then a return 42 from this exchanger to the first valve.

[0033] The second fluid loop 12 successively comprises, starting from the second valve 10, the heat exchanger between the two different fluids of the loops 30, a fluid circulation pump 32, then a set of electrical components 34 comprising the electric traction machine, its power inverter and a battery charger from an external electricity distribution network.

[0034] After the set of electrical components 34, the second loop 12 comprises a direct return path 36 towards the second valve 10, and in parallel a heat exchanger with the exterior 38 then returning towards this second valve.

[0035] The heat transfer fluid of the second loop 12 comprising the electric traction machine is water with added glycol and other additives, commonly used in vehicle cooling circuits, which provides both high fluidity facilitating the work of the second circulation pump 32 which may have low power, and a high thermal capacity.

[0036] The heat transfer fluid of the first loop 8 is a dielectric fluid, ensuring good thermal conduction as well as electrical insulation, which passes into heat exchange plates of the traction battery 26 in contact with the electrochemical energy storage cells to cool them. In the event of leakage of the dielectric fluid into the battery box 26, the electrical insulation property of this fluid provides additional safety by avoiding short circuits with the electrochemical cells or with the high voltage connections in the box, which reduces the risk of fire.

[0037] On the other hand, the dielectric fluid of the first loop 8 is more viscous than water with added glycol, which requires greater power for the circulation pump 20, and is more corrosive, which requires adaptation of the components. receiving.

[0038] The two fluid loops 8, 12 operate with their own separate heat transfer fluids, with the possibility of heat exchange between them thanks to the fluid exchanger 30. The common motorization 16 of the valves 6, 10 makes it possible, with the rotation of the common shaft 4, to obtain different angular positions of the valves of the two valves, comprising at least three operating positions.

[0039] [Fig.2] shows, with the first position of the motorization 16, the operation of the two loops 8, 12 independently, without heat exchange between them.

[0040] In the first loop 8 the circulation of the dielectric fluid generated by the first pump 20 allows heating of the battery 26 using the heater 24, for example when starting the vehicle with a cold outside temperature, or cooling of this battery using the cooler 22. In the second loop 12 the facilitated circulation of the glycolated water which is very fluid, by the second pump 32, allows cooling of the electrical components 34 which then dissipates the calories in the external heat exchanger 38.

[0041] [Fig. 3] shows, with the second position of the motorization 16, the operations of the two loops 8, 12 which are also independent. The second loop 12 has the same autonomous operation.

[0042] The first loop 8 uses the first direct return path 28 to avoid passing through the battery 26, the fluid passing only through the cooler 22 and the heater 24.

[0043] [Fig.4] shows, with the third position of the motorization 16, an exchange of thermal energy between the two loops 8, 12, thanks to a passage of the first loop in the heat exchanger between fluids 30 which allows a transfer of calories between the dielectric fluid and the glycolated water.

[0044] In this case, the second direct return path 36 is used at the outlet of the electrical components 34 which have heated the fluid of the first loop 8, to pass into the heat exchanger between fluids 30 which transmits its calories to the dielectric fluid in order to in turn heat the battery 26.

[0045] In this way, in particular for cold starts of the vehicle, the battery 26 is heated in order to improve its operating characteristics without consuming electric current in the heater 24.

[0046] The different positions of the valves 6, 10 are achieved by means of a motorization 16 comprising a single motor with its control, which makes it possible to simplify the control system of the thermal regulation circuit, to reduce the number of components, to reduce the mass of the vehicle and the manufacturing costs. In addition, the nature of the fluids of the two loops 8, 12 is optimized in order to improve safety in battery 26, while maintaining ease of circulation of the fluid in the second loop 12 which remains very fluid.

Claims

Claims

1. Electric or hybrid vehicle traction system comprising a thermal regulation circuit comprising a first circulation loop (8) having a first fluid circulation pump (20), at least one cooler (22) or heater (24), a traction battery (26) and a first fluid distribution valve (6), comprising a second circulation loop (12) having a second fluid circulation pump (32), electrical components (34) including a traction machine, an external heat exchanger (38) and a second fluid distribution valve (10), characterized in that the first loop (8) and the second loop (12) comprise fluids which are different, and in that a common motorization (16) actuates the two distribution valves (6, 10) at the same time.

2. Traction system according to claim 1, characterized in that the two distribution valves (6, 10) comprise the same drive shaft (4) receiving a seal (14) between these two valves (6, 10).

3. Traction system according to claim 1 or 2, characterized in that the first circulation loop (8) comprises a dielectric fluid and the second circulation loop (12) comprises water with added glycol.

4. Traction system according to any one of the preceding claims, characterized in that the second circulation loop (12) comprises in series a heat exchanger (30) between the fluids of the two loops (8, 12), which depending on the position of the first valve (6) also receives the fluid from the first loop (8).

5. Traction system according to any one of the preceding claims, characterized in that the first loop (8) comprises a direct return path (28) which makes it possible to short-circuit the passage of the fluid in the battery (26),

6. Traction system according to any one of the preceding claims, characterized in that the second loop (12) comprises a direct return path (36) which makes it possible to short-circuit the passage of the fluid in the external heat exchanger (38).

7. A method of operating a traction system according to any one of the preceding claims, characterized in that in a first position of the common motorization (16) the two loops (8, 12) operate independently without heat exchange between them.

8. Method of operating a traction system according to any one of claims 1 to 6, characterized in that in a second position of the common motorization (16) the first loop (8) operates by short-circuiting the battery (26) with the direct path of the first loop (28), and the second loop (12) operates independently without heat exchange with this first loop (16).

9. Method of operating a traction system according to any one of claims 1 to 6, the second circulation loop (12) comprising in series a heat exchanger (30) between the fluids of the two loops (8, 12), characterized in that in a third position of the common motorization (16) the two loops exchange calories through this heat exchanger (30).

10. Electric or hybrid motor vehicle, characterized in that it comprises a traction system according to any one of claims 1 to 6, also providing heating or cooling of the passenger compartment.

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