Thermal management system and motor vehicle with a thermal management system

Abstract

The invention relates to a thermal management system (100) of a motor vehicle (200) comprising an electric machine (10), a traction battery (11), an inverter (12) and a coolant circuit (13), wherein the electric machine (10) has a stator (14) with a multiphase stator winding (15), the traction battery (11) is electrically connected to the inverter (12), the inverter (12) has several output phases (171, 172, 173) which are connected to the phases (161, 162, 163) of the multiphase stator winding (15) of the electric machine (10) to generate a rotating magnetic field, and the coolant circuit (13) is designed to carry a cooling medium (22). The coolant circuit (13) incorporates at least one heating resistor (211, 212, 213) which is electrically connected to the inverter (12) and is arranged to transfer heat to the cooling medium (22).Furthermore, the invention relates to a motor vehicle (200) comprising such a thermal management system (100).

Description

[0001] The invention relates to a thermal management system of a motor vehicle, in particular a thermal management system for preconditioning the motor vehicle, comprising an electric machine, a traction battery, an inverter and a coolant circuit, wherein the electric machine has a stator with a multiphase stator winding, the traction battery is electrically connected to the inverter, the inverter has several output phases which are connected to the phases of the multiphase stator winding of the electric machine to generate a rotating magnetic field, and the coolant circuit is designed to guide a cooling medium.

[0002] The invention also relates to a motor vehicle comprising a thermal management system, in particular a thermal management system for preconditioning the motor vehicle, with an electric machine, a traction battery, an inverter and a coolant circuit.

[0003] The traction battery is typically a high-voltage battery and supplies the inverter with direct current. In electric vehicles, the inverter is usually a pulse-width modulated (PWM) inverter and has three output phases that are electrically connected to three phases of the stator winding in such a way that a rotating magnetic field is generated when the electric motor is operating. A rotor is rotatably mounted inside the stator, which rotates in response to the rotating magnetic field and transmits the rotational motion to a transmission in the vehicle, which is connected to the vehicle's drive wheels. This process converts the electrical energy stored in the traction battery into kinetic energy.

[0004] In the context of electromobility, preconditioning refers specifically to preheating the traction battery and / or pre-conditioning the vehicle interior before departure. If the traction battery of an electric car reaches a temperature that is too low, particularly below 0°C, especially during the cold winter months, it can be permanently damaged if regularly charged at an excessively high rate. Therefore, common battery management systems reduce the charging power until the traction battery has reached a sufficiently high temperature. Depending on the battery type and cell chemistry, the optimal temperature for the traction battery should be between 25°C and 45°C.To avoid this delay and to be able to charge the traction battery directly with a high charging power, a prior heating of the traction battery is planned as part of the preconditioning process.

[0005] To generate the necessary heat, devices and control systems are provided that, in combination, generate the heat and regulate its distribution within the vehicle. Maintaining the numerous heat-generating devices and suitable control systems is costly, which is why setting and maintaining the ideal temperature distribution during preconditioning represents a significant cost factor.

[0006] The following is known from the state of the art: In particular, DE 10 2013 012 164 A1 describes a traction battery system for an electrically powered vehicle comprising a high-voltage battery, a temperature control device for temperature control of the high-voltage battery, a temperature measuring device for detecting the temperature of the high-voltage battery or the ambient temperature of the high-voltage battery, a battery control device, and an electric heating device for directly or indirectly heating the high-voltage battery, wherein the battery control device is configured to direct electric current generated by recuperative braking below a predefinable threshold temperature of the high-voltage battery or the environment of the high-voltage battery to the heating device.

[0007] From DE 10 2022 004 894 B3, a temperature control device for a motor vehicle is known, comprising a refrigerant circuit through which a refrigerant flows, in which at least one refrigerant compressor for compressing the refrigerant, at least one evaporator for evaporating the refrigerant, and a cooling heat exchanger around which air flows for cooling the refrigerant are arranged, wherein: • the temperature control device has a temperature control circuit through which a temperature control medium flows, in which at least one electrical or electronic component is arranged which is to be temperature controlled by means of the temperature control medium; • the temperature control device has a third heat exchanger arranged in both the refrigerant circuit and the temperature control circuit, through which the refrigerant and the temperature control medium flow, and which is provided in addition to the evaporator and in addition to the cooling heat exchanger, through which heat can be exchanged between the refrigerant and the temperature control medium; • in the refrigerant circuit downstream of the third heat exchanger and upstream of the refrigerant compressor, a collector is arranged in which a gas phase of the refrigerant and a liquid phase of the refrigerant can be accommodated simultaneously; • the refrigerant circuit has a first line element that is fluidically connected to the collector and fluidically to the refrigerant compressor, by means of which the refrigerant can be conveyed from the collector to the refrigerant compressor; • the refrigerant circuit has a second line element fluidically connected to the evaporator, which is fluidically connected to the first line element at a bypass point located downstream of the collector and upstream of the refrigerant compressor, so that the refrigerant flowing through the evaporator and from the evaporator into the second line element, and subsequently flowing through the second line element, can be guided from the evaporator to the bypass point by means of the second line element, bypassing the collector, and can be introduced into the first line element at the bypass point; and • the third heat exchanger is arranged in a third piping element of the refrigerant circuit through which the refrigerant flowing through the third heat exchanger can flow; wherein • the third line element is fluidically connected to the second line element at a second bypass point, so that the refrigerant flowing through the third heat exchanger and the third line element can bypass the collector at the second bypass point into the second line element and then be introduced into the first line element by means of the second line element bypassing the collector at the first bypass point.

[0008] US patent 10,587,162 B2 discloses an electric motor comprising the following: • a case; • a stator comprising a stator lamination and end windings; and • a rotor connected to the housing via at least one rotor bearing, the rotor comprising the following: • a hollow cylindrical body with an inner wall, an outer wall, a first distal end and a second distal end; • a first wave section coupled to the first distal end of the hollow cylindrical body; • a second wave section coupled to the second distal end of the hollow cylindrical body; • a fluid supply tube with a fluid receiving end and a fluid supply end, wherein the fluid supply end extends into the hollow cylindrical body; and • a large number of fluid outlet openings; • at least one drive motor fluid pump to pump fluid into the fluid receiving end of the fluid supply pipe; and • a drive motor electronics, wherein in a waste heat mode the drive motor electronics drives the stator with or without causing rotation of the rotor; • the drive motor fluid pump fills the hollow cylindrical body at least partially with the fluid in order to force the fluid out of the hollow cylindrical body to collect heat from the stator windings; and • the drive motor fluid pump circulates the fluid to a heat exchanger to heat a battery.

[0009] Finally, DE 10 2009 034 609 A1 discloses a machine which has an electric machine which is combined with an energy recovery device, a thermovoltaic generator, wherein the energy recovery device can convert thermal energy into another form of energy, wherein the other form of energy is in particular electrical energy and / or mechanical energy, wherein the energy recovery device is coupled to an element of the electric machine which heats up during operation of the electric machine.

[0010] Starting from this, the object of the present invention is to create a thermal management system and a motor vehicle with such a thermal management system that overcomes the disadvantages of the prior art.

[0011] In particular, the generation and distribution of heat should be made possible with comparatively little effort and therefore in a comparatively cost-effective manner.

[0012] This problem is solved by the thermal management system according to claim 1 and the motor vehicle with such a thermal management system.

[0013] The thermal management system is designed for a motor vehicle and comprises an electric machine, a traction battery, an inverter, and a coolant circuit. The electric machine has a stator with a multiphase stator winding, the traction battery is electrically connected to the inverter, the inverter has several output phases which are connected to the phases of the multiphase stator winding of the electric machine to generate a rotating magnetic field, and the coolant circuit is designed to carry a cooling medium. According to the invention, the coolant circuit includes at least one heating element which is electrically connected to the inverter and is arranged to transfer heat to the cooling medium.

[0014] This allows the at least one heating element to be directly powered by the inverter during heating operation, which is already required in an electric vehicle. The inverter thus performs a dual function, powering both the stator winding and the at least one heating element, thereby eliminating the need for a separate power source and / or related peripheral devices.

[0015] Advantageous embodiments of the invention are specified below and in the dependent claims.

[0016] According to an advantageous embodiment of the invention, the electric machine has a housing that partially accommodates the coolant circuit. This housing also accommodates the stator and the rotor, so that the heat generated at the stator during normal operation of the electric machine is effectively dissipated.

[0017] Preferably, the at least one heating element is arranged in a section of the coolant circuit that is housed within the casing of the electric machine. This protects the heating element from mechanical damage and eliminates the need for an additional casing element for its secure mounting.

[0018] In particular, the coolant circuit is connected to at least one heat sink for heat dissipation, preferably the traction battery. This allows the traction battery to be preconditioned (tempered) by means of the heating element, so that it can be charged ideally, i.e., quickly and / or without damage, even at low ambient temperatures. Alternatively and / or additionally, the coolant circuit can be connected to the vehicle cabin as a heat sink for heat dissipation, so that a comfortable interior temperature can be established before the journey begins.

[0019] The coolant circuit is preferably designed to use cooling water as the cooling medium. In the area of ​​the electric machine, the coolant circuit is partially designed as a water jacket cooling system.

[0020] The electrical connection between the inverter and the at least one heating resistor is preferably switchable by means of an actuator such that the phases of the stator winding are de-energized when the at least one heating resistor is powered. Such an actuator can be implemented, for example, by means of automatically switchable switches. This allows the at least one heating resistor to be supplied with electrical current even when the electric machine is stationary, i.e., not rotating, and thus also when the vehicle is at a standstill. This offers particular advantages during the preconditioning of the traction battery, because in this case no power is dissipated across the stator winding that would otherwise be lost and not converted into kinetic energy when the vehicle is stationary.

[0021] Alternatively, the current-conducting connection between the inverter and the heating resistor is provided without a switch, so that the at least one heating resistor is energized when the phases of the stator winding are powered. Preferably, the at least one heating resistor is connected in parallel to one of the phases of the stator winding. This eliminates the need for actuators, particularly actuators with switches, at the expense of energy efficiency.

[0022] Specific embodiments of the invention are explained below with reference to the figures. These show: Fig. 1 a schematic view of a motor vehicle's thermal management system; Fig. 2 a detailed view of a first embodiment of a thermal management system of a motor vehicle; Fig. 3 a detailed view of a second embodiment of a thermal management system of a motor vehicle; and Fig. 4 a motor vehicle with a thermal management system.

[0023] Fig. Figure 1 shows a thermal management system 100 for preconditioning a motor vehicle 200. The thermal management system 100 comprises an electric machine 10, a traction battery 11, an inverter 12, and a coolant circuit 13. The electric machine 10 has a stator 14 with a stator winding 15 having three phases 161, 162, 163. The traction battery 11 is designed as a high-voltage battery 111 and is conductively connected to the inverter 12. The inverter 12 is designed as a pulse inverter 121 and has three output phases 171, 172, 173, which are connected to the three phases 161, 162, 163 of the stator winding 15 of the electric machine 10 to generate a rotating magnetic field within the stator 14.A rotor 18 is rotatably mounted within the stator 14. This rotor rotates in response to the rotating magnetic field and transmits the rotational motion to a gearbox 19 of the vehicle 200, which is connected to the (not shown) drive wheels of the vehicle 200. This process converts the electrical energy contained in the traction battery 11 into kinetic energy. The coolant circuit 13 runs sectionally within a housing 20 of the electric machine 10, which contains the stator 14 and the rotor 18, and at least partially encloses the traction battery 11. The coolant circuit 13 incorporates three heating elements 211, 212, 213, which are electrically connected to the inverter 12 and are arranged to dissipate heat to a cooling medium 22, where, in the illustrated embodiment, the cooling medium 22 is water 221.This allows the traction battery 11, which in the illustrated embodiment is a heat sink 23, to be preconditioned before an upcoming journey or charging process by first transferring heat to the cooling medium 22 and then to the traction battery 11 via the heating resistors 211, 212, 213.

[0024] Fig. Figure 2 shows a detailed view of a first embodiment of the thermal management system 100 with the traction battery 11, the inverter 12, the phases 161, 162, 163 of the stator winding 15, and the heating resistors 211, 212, 213, each arranged in the (not shown here) coolant circuit. In the illustrated embodiment, the current-conducting connection between the inverter 12 and the heating resistors 211, 212, 213 can be switched by means of an actuator 24 such that the phases 161, 162, 163 of the stator winding 15 are de-energized when the heating resistors 211, 212, 213 are energized. The actuator 24 is implemented by automatically switchable switches 241, 242, 243. This allows the heating resistors 211, 212, 213 to be supplied with electric current even when the electric machine 10 is stationary, i.e., not rotating, and thus also when the motor vehicle 200 is stationary.This offers particular advantages in the preconditioning of the traction battery 11, because in this case no power drops across phases 161, 162, 163 of the stator winding 15, which is not converted into kinetic energy when the vehicle is stationary and would therefore be lost.

[0025] Fig. Figure 3 shows a detailed view of a second embodiment of the thermal management system 100 with the traction battery 11, the inverter 12, the phases 161, 162, 163 of the stator winding 15, and the heating resistors 211, 212, 213, each arranged in the (not shown here) coolant circuit. In the illustrated embodiment, the current-conducting connection between the inverter 12 and the heating resistors 211, 212, 213 is switchless, so that the heating resistors 211, 212, 213 are energized when the phases 161, 162, 163 of the stator winding are energized. Each heating resistor 211, 212, 213 is connected in parallel to one of the phases 161, 162, 163 of the stator winding 15. This eliminates the need for actuators, albeit at the expense of energy efficiency.

[0026] Fig. Figure 4 shows a motor vehicle 200 with a thermal management system 100, as previously described. Reference symbol list 100 Thermal Management System 200 motor vehicles 10 electric machine 11 Traction battery 111 High-voltage battery 12 inverters 121 Pulse inverters 13 Coolant circuit 14 Stator 15 Stator winding 161 Phase (of the stator winding) 162 Phase (of the stator winding) 163 Phase (of the stator winding) 171 Initial phase (of the inverter) 172 Initial phase (of the inverter) 173 Initial phase (of the inverter) 18 Rotor 19 gearboxes 20 cases 211 Heating resistor 212 Heating resistor 213 Heating resistor 22 Cooling medium 221 Water 23 Heat sink 24 Actuators 241 switches 242 switches 243 switches QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2013 012 164 A1

[0006] DE 10 2022 004 894 B3

[0007] US 10,587,162 B2

[0008] DE 10 2009 034 609 A1

[0009]

Claims

Thermal management system (100) of a motor vehicle (200), in particular a thermal management system (100) for preconditioning the motor vehicle (200), comprising an electric machine (10), a traction battery (11), an inverter (12) and a coolant circuit (13), wherein the electric machine (10) has a stator (14) with a multiphase stator winding (15), the traction battery (11) is electrically connected to the inverter (12), the inverter (12) has several output phases (171, 172, 173) which are connected to the phases (161, 162, 163) of the multiphase stator winding (15) of the electric machine (10) to generate a rotating magnetic field, and the coolant circuit (13) is designed to carry a cooling medium (22), characterized in that the coolant circuit (13) has at least one heating resistor (211, 212, 213) includes,which is electrically connected to the inverter (12) and is arranged to transfer heat to the cooling medium (22). Thermal management system (100) according to claim 1, wherein the electric machine (10) has a housing (20) which sectionally accommodates the coolant circuit (13). Thermal management system (100) according to claim 2, wherein the at least one heating resistor (211, 212, 213) is arranged in a section of the coolant circuit (13) which is received by the housing (20) of the electric machine (10). Thermal management system (100) according to one of the preceding claims, wherein the coolant circuit (13) is connected to at least one heat sink (23) for heat dissipation. Thermal management system (100) according to claim 4, wherein the heat sink (23) is the traction battery (11). Thermal management system (100) according to one of the preceding claims, wherein the coolant circuit (13) is designed to guide cooling water (221) as the cooling medium (22). Thermal management system (100) according to one of the preceding claims, wherein the current-conducting connection between the inverter (12) and the at least one heating resistor (211, 212, 213) can be switched by means of an actuator (24) such that the phases (161, 162, 163) of the stator winding (15) are de-energized in the current-energized state of the at least one heating resistor (211, 212, 213). Thermal management system (100) according to one of claims 1 to 6, wherein the current-conducting connection between the inverter (12) and the heating resistor (211, 212, 213) is switch-free, so that the at least one heating resistor (211, 212, 213) is energized in the energized state of the phases (161, 162, 163) of the stator winding (15). Thermal management system (100) according to claim 8, wherein the at least one heating resistor (211, 212, 213) is connected in parallel to one of the phases (161, 162, 163) of the stator winding (15). Motor vehicle (200) comprising a thermal management system (100), in particular a thermal management system (100) for preconditioning the motor vehicle (200), with an electric machine (10), a traction battery (11), an inverter (12) and a coolant circuit (13), characterized in that the thermal management system (100) is configured according to one of claims 1 to 9.

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