An electric heating system and a vehicle

Abstract

The present disclosure relates to an electric heating system for a vehicle. The electric heating system comprises: a power supply including a positive electrode and a negative electrode; an inverter including three phase bridge arms, each phase bridge arm including an upper bridge arm connected between the positive electrode of the power supply and the midpoint of the phase bridge arm and a lower bridge arm connected between the negative electrode of the power supply and the midpoint of the phase bridge arm, wherein the upper bridge arm and the lower bridge arm of the same phase bridge arm are alternately turned on and off. The electric heating system also comprises a motor driven by the inverter and including three phase windings, each phase winding having one end connected to the midpoint of a corresponding phase bridge arm and the other end connected to a common neutral point. The electric heating system further comprises an electric heating element having one end connected to the neutral point and the other end connected to the positive electrode or the negative electrode of the power supply. The present disclosure also relates to a vehicle including such an electric heating system.

Description

[0001] An electric heating system and a vehicle

[0002] Technical field

[0003] Embodiments of the present disclosure relates to generally an electric heating system and a vehicle comprising such electric heating system.

[0004] Background

[0005] In new energy vehicles, it is known to use the phase windings of the motor as active heating components, and the thermal management system of the vehicle transfers the heat generated by the motor to components that need to be heated. The current flowing through the phase windings of the motor to generate heat may include a driving current that drives the motor to operation and an additional heating current. Both the driving current and the heating current can be controlled by the inverter of the motor control unit, so there is no need to provide a an electronic control component dedicated for the heating.

[0006] In some cases, it is necessary to generate heat when the motor is not in operation. For example, before starting the vehicle or when charging the vehicle in a low temperature environment, the battery needs to be heated by the heat generated by the phase windings of the motor to improve the charging and discharging capacity. When the motor is not in operation, the rotor of the motor no longer rotates, and the relative angle between the stator and the rotor is fixed. For a three-phase motor that the relative angle of the stator and the rotor is fixed at certain value, the current flows into the motor from one phase winding and flows out from the other two phase windings, or flows in from two phase windings and flows out from another phase winding. The current on different phase windings of the motor is uneven, and the heat generated is also different. Over time, this difference in heat generation can produce a temperature difference of up to 100°C on different parts of the motor. This large temperature difference will accelerate the aging of the motor and reduce the life of the motor. The temperature difference between the various parts of the motor can be alleviated by reducing the current flowing in the phase winding. However, the heat generated by the motor then cannot meet the needs of vehicle thermal management.

[0007] Summary

[0008] Accordingly, the present disclosure aims to solve the above-mentioned problems, and an object of the present disclosure is to provide an electric heating system and a vehicle including said electric heating system. The electric heating system according to the present disclosure is capable of controlling the heating current through an inverter of a motor control unit to generate heat sufficient to meet the thermal management needs of the vehicle without causing uneven current in the phase windings of the motor and avoiding degradation in the life of a motor.

[0009] The object is achieved by an electric heating system according to one embodiment of the present disclosure, which comprises: a power supply comprising a positive electrode and a negative electrode; an inverter, comprising three phase bridge arms, each phase bridge arm comprising an upper bridge arm connected between the positive electrode of the power supply and a midpoint of the phase bridge arm and a lower bridge arm connected between the negative electrode of the power supply and the midpoint of the phase bridge arm, wherein the upper bridge arm and the lower bridge arm of the same phase bridge arm are alternately turned on and off; a motor being driven by the inverter and comprising three phase windings, each phase winding being connected at one end to the midpoint of a corresponding one of the phase bridge arms, and at the other end to a common neutral point, and an electric heating element, the electric heating element connected at one end to the neutral point and at the other end to the positive electrode or the negative electrode of the power supply.

[0010] One of the objects of the present disclosure is to provide an electrical heating system that utilizes an inverter as an electrical control component to generate heat sufficient to meet the needs of thermal management of a vehicle without causing a degradation in the life of a motor. The electric heating system according to the present disclosure includes an electric heating element through which an electric current flow to generate heat for vehicle thermal management. The electric heating element is connected between a power supply and a neutral point shared by the three phase windings of the motor, allowing the current to be evenly distributed among the three phase windings of the motor, thus there is no temperature differences on the motor. When the thermal power of the electric heating system needs to be increased to meet vehicle thermal management requirements, the current flowing through the electric heating element can be increased without damaging the motor. In addition, the electrical connection between the power supply and the heating elements is controlled by an inverter, eliminating the need for additional electronic control components.

[0011] The electrical heating system according to the present disclosure may also have one or more of the following features separately or in combination.

[0012] According to an embodiment of the present disclosure, a switching device is connected between the electric heating element and the positive electrode or the negative electrode of the power supply, or a switching device is connected between the common neutral point and the electric heating element. The switching device cooperates with the phase bridge arm of the inverter to control the electrical connection between the electric heating element and the power supply.

[0013] According to an embodiment of the present disclosure, the switching device is a MOS device or an IGBT device, or the switching element is a relay.

[0014] According to an embodiment of the present disclosure, the electric heating system can control the heating power of the electric heating element both when the motor is in operation and when it is not in operation.

[0015] According to an embodiment of the present disclosure, the electric heating system is configured to control the voltage at the neutral point to control the heating power of the electric heating element when the motor is in operation.

[0016] According to an embodiment of the present disclosure, the electric heating system is configured to control the current flowing through the electric heating element to control the heating power of the electric heating element when the motor is in operation.

[0017] According to an embodiment of the present disclosure, the heating power of the electric heating system is the sum of the heating power generated by the phase windings of the motor and the heating power generated by the electric heating element when the motor is in operation.

[0018] According to an embodiment of the present disclosure, the electric heating system is configured to maximize the direct-axis current flowing through the phase winding of the motor and control the torque generated by the motor, and simultaneously control the current flowing through the electric heating element or control the voltage at the neutral point, so as to control the heating power generated by the electric heating element.

[0019] According to an embodiment of the present disclosure, the electric heating system is configured to control the turning on and off of the upper bridge arm and the lower bridge arm by means of PWM signals to control the heating power of the electric heating element when the motor is not in operation.

[0020] According to an embodiment of the present disclosure, the three phase bridge arms of the inverter are each provided with a first current sensors for measuring the current flowing through the midpoint of the corresponding phase bridge arm for determining the current flowing through the electric heating element.

[0021] According to an embodiment of the present disclosure, the electric heating system further comprises an additional current sensor for measuring the current flowing through the electric heating element.

[0022] According to an embodiment of the present disclosure, the additional current sensor is arranged between the electric heating element and the power supply, or the additional current sensor is arranged between the neutral point and the electric heating element, or the additional current sensor is arranged between the power supply and the inverter.

[0023] According to an embodiment of the present disclosure, the electric heating system further comprises a voltage sensor for measuring a voltage applied to the electric heating element.

[0024] According to an embodiment of the present disclosure, the electric heating element is used to heat a heat transfer medium circulating in a heat transfer cir- cuit.

[0025] According to an embodiment of the present disclosure, the electric heating element is directly connected to the neutral point, or the electric heating element is connected to the neutral point through the inverter, and the electric heating element is directly connected to the power source, or the electric heating element is connected to the power source through the inverter.

[0026] According to an embodiment of the present disclosure, the electrical connection between the phase winding and the midpoint of the phase bridge arm is integrated into a busbar assembly arranged between the inverter and the motor, and the electrical connection between the electric heating element and the inverter is also integrated into the busbar assembly.

[0027] The present disclosure also provides a vehicle comprising the electrical heating system as described above.

[0028] Description of the drawings

[0029] The above and other features and advantages of the present disclosure will become more apparent through the following detailed description of exemplary embodiments in conjunction with the accompanying drawings, and the description and drawings are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. The following drawings are not intentionally drawn to scale according to actual size, and the focus is on illustrating the main purpose of the present disclosure.

[0030] Figure 1 is a schematic block diagram of an electric heating system according to an embodiment of the present disclosure, wherein the electric heating element of the electric heating system is arranged between the neutral point of the motor and the negative electrode of the power supply;

[0031] Figure 2 is a schematic block diagram of an electric heating system according to another embodiment of the present disclosure, wherein the electric heating element of the electric heating system is arranged between the positive electrode of the power supply and the neutral point of the motor.

[0032] Figure 3 is a connection diagram of an electric heating system in a vehicle electric drive device, wherein the electric heating element is directly connected to the neutral point and the power supply, and the electric heating element is integrated within a housing of the motor.

[0033] Figure 4 is another connection diagram of an electric heating system in a vehicle electric drive device, wherein the electric heating element is connected to the power supply and the neutral point both through the inverter, and the electric heating element is integrated within a chamber in which a busbar assembly between the inverter and the motor is arranged.

[0034] Detailed description

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely in the following in connection with the accompanying drawings of the embodiments of the present disclosure. It should be noted that the described embodiments are a part of the embodiments of the present disclosure, and not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without the need for creative labor fall within the scope of protection of the present disclosure.

[0036] Unless otherwise defined, technical terms or scientific terms used herein shall have the ordinary meaning as understood by a person of ordinary skill in the field to which the present disclosure belongs. The words “a”, “an”, or “the” and the like used in the specification of the patent application and the claims of the present disclosure also do not indicate quantitative limitation, but rather indicate the existence of at least one. Words such as “including” or “comprising” mean that the element or object preceded by the word encompasses the enumerated elements or objects and their equivalents that follow the word, and do not exclude other elements or objects. The words “up”, “down”, “left”, “right”, etc. are only used to indicate relative positional relationships. When the absolute position of the described object is changed, the relative positional relationship may be changed accordingly. For the convenience of description, the accompanying drawings of the present disclosure accordingly simplify or omit parts commonly used in the field, such as external connecting wires and other parts that are not related to the description of the present disclosure. These omitted or simplified components do not affect the understanding of the present disclosure by those skilled in the art.

[0037] The new energy vehicle typically includes an electric motor that drives the vehicle to navigate. The motor may, for example, be a three-phase motor including u, v, and w phase windings. An inverter of the motor control assembly outputs current flowing through the phase windings to generate torque to drive the motor to rotate. The motor is not able to convert electrical energy into kinetic energy with 100 percent efficiency, and some of the electrical energy is consumed in the form of heat. The thermal management system of a vehicle can transfer the heat generated by the motor to other parts of the vehicle through a heat transfer medium, which serves as a heat source for active heating of the vehicle. However, this direct use of the motor winding as a heat-generating element has the following two defects: when the vehicle is moving, the motor's heat-generating power often fails to meet the needs of the vehicle's thermal management, resulting in the need to actively reduce the efficiency of the motor to increase the heat-generating power; when the vehicle is parked, for example, during charging, the distribution of the current on the different windings of the motor and the amount of heat generated is often uneven, generating a difference in temperature within the motor, resulting in the damage to the service life of the motor. The present disclosure addresses the above deficiencies by means of an electric heating system 100 for use in a vehicle.

[0038] FIG. 1 illustrates an electric heating system 100 for use in a vehicle according to an exemplary embodiment of the present disclosure. As shown, said electric heating system 100 comprises a power supply 10, an inverter 20, a motor 30, and an electric heating element 40. The power supply 10, which may be the vehicle's power battery or charging system, comprises a positive and a negative electrode and is adapted to output a direct current. The inverter 20 is part of a motor control assembly of the vehicle for controlling an electrical connection between the power supply 10 and the motor 30. The inverter 20 comprises three phase bridge arms 21, each phase bridge arm 21 comprising an upper bridge arm 21a connected between the positive electrode of said power supply 10 and a midpoint 22 of said phase bridge arm 21 and a lower bridge arm 21b connected between the negative electrode of said power supply 10 and the midpoint 22 of said phase bridge arm 21. The upper bridge arm 21a and the lower bridge arm 21b of the same phase bridge arm 21 are alternately turned on and off. The inverter 20 is capable of converting the direct current output from the power supply 10 into alternating current to drive the motor 30. The motor 30 comprises three phase windings 31, each of said phase windings 31 being connected at one end to the midpoint 22 of a corresponding one of the phase bridge arms 21, and at the other end to a common neutral point 32. The electric heating element 40 is connected at one end to the neutral point 32, and at the other end to the negative electrode of the power supply 10.

[0039] Referring to FIG. 1, when one of the upper bridge arms 21a of the inverter 20 is turned on, the electric heating element 40 is able to form a connecting circuit with the upper bridge arm 21a and the power supply 10 through the corresponding phase winding 31, generating a heating current flowing through the electric heating element 40, and thus generating heat on the electric heating element 40. As a result, the electric heating element 40 is capable of heating the heat transfer medium circulating in the heat transfer circuit. The heated heat transfer medium flows to the portion of the vehicle, such as the power battery and the air conditioning heat exchanger, that needs to be heated and releases the heat.

[0040] When the vehicle is parked, the motor 30 is not in operation and the inverter 20 is not required to provide AC power to drive the motor 30. Therefore, the upper bridge arms 21a of the three phase bridge arms 21 of the inverter 20 are able to turn on or turn off at the same time. When the three upper bridge arms 21a are simultaneously turned on, the electric heating element 40 is connected to the power supply 10 via the three phase windings 31, and the heating current flowing through the electric heating element 40 is evenly distributed across the three phase windings 31. For instance, the power supply 10 outputs a voltage of about 400 V, the electrical heating element 40 has a resistance of about 20 Q, and the heating current flowing through the electrical heating element 40 is about 20 A, allowing the electrical heating element 40 to provide a heating power of about 8 kW. Then, the current flowing through each of the phase windings 31 is about 6.7 A. The resistance of the phase windings 31 is very small compared to the electric heating element 40, making the heat generated thereon negligible.

[0041] The heating power of the electric heating element 40 is able to be controlled via a PWM control signal. Specifically, the inverter 20 controls the turning on and off of the upper bridge arm 21a and the lower bridge arm 21b via the PWM control signals, thereby controlling the conduction and shutdown of the electrical connection between the electric heating element 40 and the power supply 10. For example, in the example cited above, when the electric heating element 40 is required to provide a heating power of 4 kW, the duty cycle of the PWM control signal is set to 50%, so that the percentage of time during which the upper bridge arm 21a conducts and the electric heating element 40 generates heat is also roughly 50%, resulting in a heating power of 4 kW. Accordingly, the duty cycle of the PWM control signal may be reduced when the heating power of the electric heating element 40 needs to be reduced, and the duty cycle of the PWM control signal may be increased when the heating power of the electric heating element 40 needs to be increased.

[0042] In the conventional scheme of heat generation through phase windings, the motor needs to be heated first, and then other parts of the vehicle (e.g., the battery) are heated by the warmed-up motor through a heat transfer medium. The large mass of the motor is slow to warm up, making it impossible to quickly heat the other parts of the vehicle. In contrast, the electric heating system 100 according to the present disclosure no longer needs to heat the motor first, but can instead heat the motor and the other parts of the vehicle at the same time, such as simultaneously heat the motor and the battery via the heat transfer medium. The electric heating system 100 according to the present disclosure has a faster thermal response, which is particularly advantageous for preheating the battery in cold environments. While the vehicle is in motion, the motor 30 is driven by the inverter 20 and is in an operating state, with an AC drive current (about 400A-600A) of the motor 30 flowing through the phase windings 31. At this time, the electric heating system 100 is able to control the voltage at the neutral 32, which in turn controls the heating power of the electric heating element 40. Optionally, the electric heating system 100 controls the voltage at the neutral point 32 to be half of the output voltage of the power supply 10 via the inverter 20. Referring to the example cited above, the voltage at the neutral point 32 is controlled to be about 200 V, the resistance of the electric heating element 40 is about 20 Q, and the heating current flowing through the electric heating element 40 is about 10 A, allowing the electric heating element 40 to provide a heating power of about 2 kW. The voltage at the neutral point 32 may be decreased when the heating power of the electric heating element 40 needs to be decreased, and the voltage at the neutral point 32 may be increased when the heating power of the electric heating element 40 needs to be increased.

[0043] Alternatively, the electric heating system 100 is also capable of using the current flowing through the electric heating element 40 as a control parameter for controlling the heating power of the electric heating element 40. The current flowing through the electric heating element 40 can be reduced when the heating power of the electric heating element 40 needs to be reduced, and the current flowing through the electric heating element 40 can be increased when the heating power of the electric heating element 40 needs to be increased.

[0044] As described above, when the vehicle is in motion, the motor 30 has a very high drive current on the phase windings 31 and thus can also generate a considerable amount of heat (especially if the RPM of the motor 30 is low or zero). This heat can also be utilized by the vehicle's thermal management system to supplement the reduced heating power of the electric heating elements 40. That is, the heating power of the electric heating system 100 is the sum of the heating power generated by the phase winding 31 and the heating power generated by the electric heating element 40. The heating current flowing through the electric heating element 40 is also superimposed on the phase winding 31. However, since the heating current is much smaller than the driving current, the heating current superimposed on the phase winding 31 has very little effect on the power and efficiency of the motor 30.

[0045] Specifically, when the motor 30 is in an operating state, the driving current on the phase winding 31 of the motor 30 includes a direct-axis current Id for controlling the magnetic field strength and a quadrature-axis current Iq for controlling the torque. By maximizing the direct-axis current Id flowing through the phase winding 31 and controlling the quadrature-axis current Iq so that the motor 30 outputs the required torque (which can be zero, that is, the RPM of the motor 30 is zero), the electric heating system 100 can maximize the current flowing through the phase winding 31 while meeting the torque requirement, thereby maximizing the heat generated on the phase winding 31 of the motor 30. Simultaneously, the electric heating system 100 can also control the heating power of the electric heating element 40 by controlling the voltage at the neutral point 32 or controlling the current flowing through the electric heating element 40. Since the heat generated on the phase winding 31 of the motor 30 is maximized, the heating power of the electric heating element 40 can be reduced, that is, the heating demand of the vehicle can be met by a small-sized electric heating element.

[0046] In summary, the electric heating system 100 according to the present disclosure is capable of controlling the heating power of the electric heating elements 40 to meet the thermal management needs of the vehicle, both when the motor 30 is operating (e.g., when the vehicle is moving) and when the motor 30 is not operating (e.g., when the vehicle is parked).

[0047] The electric heating element 40 of the electric heating system 100 is, for example, a heating element in a coolant heater for vehicle. Compared to providing a separate coolant heater in the vehicle, the electric heating system 100 according to the present disclosure requires only an additional provision of the electric heating element, and uses the inverter of the motor control assembly of the vehicle as an electronic control unit, eliminating a number of electrical components such as a power switch, a HV-LV insulation assembly, a high voltage power connector, a signaling connector and the like, thus substantially reducing the cost. The coolant may be water, water glycol, oil or any other suitable coolant. In particular, the coolant may also be the air flowing through the electric heating element 40.

[0048] Preferably, said electric heating system 100 is provided with an additional switching element 1. The switching element 1 is capable of controlling the electrical connection of the electric heating elements 40 in cooperation with the inverter 20. The switching element 1 may be a MOS device or an IGBT device, or a relay. In the embodiment shown in figure 1, the switching element 1 is arranged between the electric heating element 40 and the negative electrode of the power supply 10. Optionally, said switching element 1 is also capable of being arranged between the neutral point 32 and the electric heating element 40.

[0049] In order to detect the operating state of the electric heating element 40, the electric heating system 100 further comprises a plurality of electrical sensors. Referring to Figure 1, each of the three phase bridge arms 21 of the inverter 20 is provided with a current sensor 23. The current sensor 23 is capable of measuring the current flowing through the neutral point 22 of the corresponding phase bridge arm 21, which in turn is used to determine the current flowing through the electric heating element 40. The current sensor 23 is a conventional built-in sensor of the inverter 20, rather than being specifically provided for this purpose, and thus does not increase the cost of parts for the vehicle. Furthermore, in case there is a need to enhance the safety features of the vehicle, additional current sensors 2 are provided specifically in the electric heating system 100 for measuring the current flowing through said electric heating element 40. In the embodiment shown in figure 1 , the additional current sensor 2 is arranged between the electric heating element 40 and the power supply 10. Optionally, the additional current sensor 2 can also be arranged between the neutral point 32 and the electric heating element 40, or the additional current sensor 2 can also be arranged between said power supply 10 and said inverter 20. By means of the additional current sensor 2, the electric heating system 100 is able to measure the current flowing through the electric heating element 40 even in case of malfunction, thus in- creasing the safety of the vehicle. In particular, the electric heating system 100 incorporating the additional current sensor 2 is able to be classified as the the highest level of Automotive Safety Integrity Level certification (ASIL-D).

[0050] FIG. 2 illustrates an electrical heating system 100 according to another embodiment of the present disclosure. The electrical heating system 100 illustrated in FIG. 2 differs from the electrical heating system 100 illustrated in FIG. 1 mainly in that the electrical heating elements 40 are arranged in a different position in this electrical heating system 100.

[0051] In the embodiment shown in FIG. 2, the electric heating element 40 is arranged between the positive electrode of the power supply 10 and the neutral point 32 of the motor 30. When one lower bridge arm 21b of the inverter 20 is turned on , the electric heating element 40 is able to form a connecting circuit with that lower bridge arm 21b and the power supply 10 through a corresponding phase winding 31, and when that lower bridge arm 21b is turned off, the electric heating element 40 is not able to connect with the power supply 10 through the corresponding phase winding 31. When all three lower bridge arms 21b of the inverter 20 are turned off, the electrical connection between the electric heating element 40 and the power supply 10 is turned off.

[0052] Furthermore, in the embodiment shown in figure 2, the electric heating system 100 comprises a switching element 1 arranged between the electric heating element 40 and the positive electrode of the power supply 10, and comprises an additional current sensor 2 arranged between the electric heating element 40 and the neutral point and a voltage sensor 3 for measuring the voltage applied to the electric heating element 40. By means of this voltage sensor 3, the electric heating system 100 is able to more accurately determine the heating power of said electric heating element 40 and improve safety.

[0053] In addition to the above differences, the electric heating system 100 shown in FIG. 2 is similar to the corresponding components of the electric heating system 100 shown in FIG. 1 and will not be described in detail.

[0054] FIG. 3 and FIG. 4 show a schematic diagram of the connection of the electric heating system 100 in the electric drive device of the vehicle. In FIG. 3 and FIG. 4, the dotted lines represent the housings of the components of the electric drive device, and the solid lines represent the electrical connections between the components of the electric heating system 100.

[0055] As shown in FIG3, the electric heating element 40 is arranged inside the housing of the motor 30, for example, directly mounted on the housing of the motor 30. FIG. 3 also shows a connection chamber 101 between the inverter 20 and the motor 30, in which a busbar assembly that electrically connects the inverter 20 to the motor 30 is arranged. The electrical connection between the phase winding 31 of the motor 30 and the midpoint 22 of the phase bridge arm of the inverter 20 is integrated in the busbar assembly. The connection chamber 101 can be a separate chamber attached to the outside of the housing of the motor 30 or a part of the gearbox of the electric drive device. In FIG. 3, the electric heating element 40 is directly connected to the power source 10, and is directly connected to the neutral point 32 of the motor 30. That is, the electric heating element 40 is connected to the power supply 10 and the neutral point 32 through a separately provided electrical connection cable.

[0056] In the embodiment shown in FIG. 4, the electric heating element 40 is mounted outside the housing of the motor 30 and is arranged in the connection chamber 101 of the busbar assembly between the inverter 20 and the motor 30. It is understandable that the electric heating element 40 can also be arranged outside the connection chamber 101. In FIG. 4, the electric heating element 40 is connected to the power source 10 through the inverter 20, and is connected to the neutral point 32 of the power supply 10 through the inverter 20, and the electrical connection between the electric heating element 40 and the inverter 20 is also integrated into the busbar assembly. Specifically, the electric heating element 40 is connected to the inverter 20 through the busbar assembly, and then connected to the power supply 10 and the neutral point 32 through the inverter 20. This design improves the integration of the electrical connection of the electric heating system 100.

[0057] In an optional embodiment not shown in the drawings, the electric heating element 40 may also be directly connected to one of the power source 10 and the neutral point 32, and connected to the other of the power source 10 and the neutral point 32 via the inverter 20 through the busbar assembly.

[0058] According to another aspect of the present disclosure, a vehicle is provided which comprises the electric heating system 100 as described hereinbefore, said vehicle may be an Electrified Vehicle (EV), such as a pure electric vehicle (BEV, Battery Electric Vehicle), a hybrid electric vehicle (HEV), Plug-in Hybrid Electric Vehicle (PHEV), Range-extended Electric Vehicle, Fuel Cell Vehicle (FCEV). Said vehicle may also be a hydrogen energy vehicle. It should be understood that the aforementioned electric heating system 100 is not intended to cover all electric heating devices included in the vehicle. Electric heating devices that are not part of the aforementioned electric heating system 100 may be included in the vehicle.

[0059] Certain features, structures or characteristics in one or more embodiments of the present disclosure may be appropriately combined.

[0060] It is to be understood that the structures described above and shown in the drawings are merely examples of the invention which may be replaced by other structures which exhibit the same or similar functions for obtaining the desired final result. In addition, it is to be understood that the embodiments described above and shown in the drawings are to be construed as constituting only non-limiting examples of the invention and may be modified in numerous ways within the scope of the patent claims.

Claims

CLAIMS1. An electric heating system (100) for vehicles, characterized in that the electric heating system (100) comprises: a power supply (10) comprising a positive electrode and a negative electrode; an inverter (20), comprising three phase bridge arms (21), each phase bridge arm (21) comprising an upper bridge arm (21a) connected between the positive electrode of the power supply (10) and a midpoint (22) of the phase bridge arm (21) and a lower bridge arm (21b) connected between the negative electrode of the power supply (10) and the midpoint (22) of the phase bridge arm (21), wherein the upper bridge arm (21a) and the lower bridge arm (21b) of the same phase bridge arm (21) are alternately turned on and off; a motor (30) being driven by the inverter (20) and comprising three phase windings (31), each phase winding (31) being connected at one end to the midpoint (22) of a corresponding one of the phase bridge arms (21), and at the other end to a common neutral point (32), an electric heating element (40), the electric heating element (40) connected at one end to the neutral point (32) and at the other end to the positive electrode or the negative electrode of the power supply (10).

2. The electrical heating system (100) according to claim 1, characterized in that a switching device (1) is connected between the electric heating element (40) and the positive electrode or the negative electrode of the power supply (10), or a switching device (1) is connected between the common neutral point (32) and the electric heating element (40).

3. The electric heating system (100) according to claim 2, characterized in that the switching device (1) is a MOS device or an IGBT device, or the switching element (1) is a relay.

4. The electric heating system (100) according to any one of claims 1 to 3,characterized in that the electric heating system (100) can control the heating power of the electric heating element (40) both when the motor (30) is in operation and when it is not in operation.

5. The electrical heating system (100) according to any one of the preceding claims, characterized in that the electric heating system (100) is configured to control the voltage at the neutral point (32) to control the heating power of the electric heating element (40) when the motor (30) is in operation.

6. The electrical heating system (100) according to any one of claims 1 to 4, characterized in that the electric heating system (100) is configured to control the current flowing through the electric heating element (40) to control the heating power of the electric heating element (40) when the motor (30) is in operation.

7. The electrical heating system (100) according to any one of claims 4 to 6, characterized in that the heating power of the electric heating system (100) is the sum of the heating power generated by the phase windings (31) of the motor (30) and the heating power generated by the electric heating element (40) when the motor (30) is in operation.

8. The electric heating system (100) according to any one of the preceding claims, characterized in that, the electric heating system (100) is configured to maximize the direct- axis current flowing through the phase winding (31) of the motor (30) and control the torque generated by the motor (30), and simultaneously control the current flowing through the electric heating element (40) or control the voltage at the neutral point (32), so as to control the heating power generated by the electric heating element (40).

9. The electric heating system (100) according to any one of the preceding claims, characterized in that the electric heating system (100) is configured to control the turning on andoff of the upper bridge arm (21a) and the lower bridge arm (21b) by means of PWM signals to control the heating power of the electric heating element (40) when the motor (30) is not in operation.

10. The electrical heating system (100) according to any one of the preceding claims, characterized in that the three phase bridge arms (21) of the inverter (20) are each provided with a first current sensors (23) for measuring the current flowing through the midpoint (22) of the corresponding phase bridge arm (21) for determining the current flowing through the electric heating element (40).

11. The electrical heating system (100) according to claim 10, characterized in that the electric heating system (100) further comprises an additional current sensor (2) for measuring the current flowing through the electric heating element (40).

12. The electrical heating system (100) according to claim 11, characterized in that the additional current sensor (2) is arranged between the electric heating element (40) and the power supply (10), or the additional current sensor (2) is arranged between the neutral point (32) and the electric heating element (40), or the additional current sensor (2) is arranged between the power supply (10) and the inverter (20).

13. The electric heating system (100) according to any one of the preceding claims, characterized in that the electric heating system (100) further comprises a voltage sensor (3) for measuring a voltage applied to the electric heating element (40).

14. The electric heating system (100) according to any one of the preceding claims, characterized in that the electric heating element (40) is used to heat a heat transfer medium circulating in a heat transfer circuit.

15. The electric heating system (100) according to any one of claims 1 to 3,characterized in that the electric heating element (40) is directly connected to the neutral point (32), or the electric heating element (40) is connected to the neutral point (32) through the inverter (20), and the electric heating element (40) is directly connected to the power source (10), or the electric heating element (40) is connected to the power source (10) through the inverter (20).

16. The electric heating system (100) according to any one of the preceding claims, characterized in that the electrical connection between the phase winding (31) and the midpoint (22) of the phase bridge arm (21) is integrated into a busbar assembly arranged between the inverter (20) and the motor (30), and the electrical connection between the electric heating element (40) and the inverter (20) is also integrated into the busbar assembly.

17. A vehicle, characterized in that the vehicle comprises an electrical heating system (100) according to any one of claims 1 to 16.

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