Motor drive system and vehicle
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CONTEMPORARY AMPEREX INTELLIGENCE TECHNOLOGY (SHANGHAI) LTD
- Filing Date
- 2024-12-24
- Publication Date
- 2026-06-26
Smart Images
Figure CN122292997A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic technology, and in particular to an electric motor drive system and a vehicle. Background Technology
[0002] Currently, the voltage levels of motor drive systems in vehicles are continuously increasing, and the switching frequency and turn-on / off speed of the switching modules in these systems are also increasing. These changes lead to larger common-mode voltage and common-mode current in the motor drive system, resulting in shaft voltage and shaft current in the motor. This shaft voltage and shaft current can cause electro-corrosion damage, affecting the lifespan of various motor components.
[0003] Currently, common-mode current suppression devices are mainly installed on the three-phase copper busbars of the motor controller to reduce the amplitude of the common-mode current and thus mitigate the degree of electro-corrosion.
[0004] However, the current method has poor common-mode current suppression effect. Summary of the Invention
[0005] This application provides a motor drive system and a vehicle that can improve the suppression of common-mode current, reduce the degree of electro-corrosion, and increase the service life of the motor drive system.
[0006] In a first aspect, this application provides a motor drive system, comprising:
[0007] First shell;
[0008] The motor controller is at least partially housed within the first housing;
[0009] A first capacitor is connected to the first housing and the motor controller;
[0010] Second shell;
[0011] The motor is at least partially housed within the second housing, and the motor controller is electrically connected to the motor;
[0012] The second capacitor connects the second housing and the motor;
[0013] A reflux mechanism is electrically connected to the first housing and the second housing; and
[0014] A suppression component is disposed on the return mechanism and located outside the first housing and outside the second housing. The suppression component is used to suppress common-mode current.
[0015] In this technical solution, by setting a suppression component on the recirculation mechanism, and the suppression component being located outside the first housing and outside the second housing, the problem of the suppression component being unable to dissipate heat quickly during operation and the common-mode current suppression capability being weakened due to rapid temperature rise is avoided by installing the suppression component in the limited housing space. This improves the suppression effect of the suppression component on common-mode current, thereby further reducing the degree of electro-corrosion and increasing the service life of the motor drive system.
[0016] In one possible implementation, a third housing is included, within which the first housing and the second housing are housed.
[0017] In this technical solution, by setting a third housing to accommodate the first and second housings, the suppression component can be prevented from being interfered with by the external environment, thereby further improving the suppression effect of the suppression component on common-mode current.
[0018] In one possible implementation, one of the first housing and the second housing is electrically connected to the third housing;
[0019] An insulating layer is provided between the first housing and the other of the second housing and the third housing, and the third housing is electrically connected to the third housing through the return mechanism.
[0020] In this technical solution, since it is inconvenient to install the suppression component in the third housing, the common-mode current can be prevented from flowing back to the first housing through the third housing by setting an insulating layer. By setting a return current mechanism electrically connected to the third housing, the common-mode current can be allowed to flow back to the first housing through the third housing and the return current mechanism. In this way, the suppression component can be set on the return current mechanism, which makes its installation more convenient and solves the problem that it is inconvenient to install the suppression component in the third housing.
[0021] In one possible implementation, the second housing is in contact with the third housing, and the insulating layer covers at least a portion of the second housing from the outside.
[0022] In this technical solution, by covering the outside of the second housing with an insulating layer, the common-mode current can be prevented from flowing back into the second housing through means other than the return current mechanism, ensuring that the suppression component on the return current mechanism can stably suppress the common-mode current and improve the working stability of the suppression component.
[0023] In one possible implementation, the suppression component is disposed outside the third housing, and a portion of the reflux mechanism is disposed outside the third housing.
[0024] In this technical solution, by placing the suppression component on the outside of the third housing, it is easier for the suppression component to dissipate heat, preventing the suppression component from overheating and improving the suppression effect of the suppression component on common mode current.
[0025] In one possible implementation, the suppression component is disposed inside the third housing.
[0026] In this technical solution, placing the suppression component inside the third housing can play a protective role, preventing the suppression component from being interfered with by the external environment and improving the suppression effect of the suppression component on common-mode current.
[0027] In one possible implementation, the reflux mechanism includes at least one first conductive connector connecting the first housing and the second housing, and the suppression component is disposed on the first conductive connector.
[0028] In this technical solution, by using a first conductive connector to connect the first housing and the second housing, the first conductive connector can carry common-mode current. The suppression component is set on the first conductive connector, so that the suppression component is not constrained by the internal space of the housing, which facilitates the installation of the suppression component. At the same time, the size of the suppression component can be made larger or more numerous, further improving the suppression effect of the suppression component on common-mode current.
[0029] In one possible implementation, a speed reducer is also included, wherein the speed reducer and the second housing are housed within a fourth housing, and the second housing is in contact with the fourth housing;
[0030] The reflux mechanism is connected to the first housing and the fourth housing.
[0031] In this technical solution, by integrating the reducer, the second housing, and the motor in the second housing into the same fourth housing, the integrity of the motor drive system is ensured, and the installation and disassembly of the motor drive system are facilitated.
[0032] In one possible implementation, the reflux mechanism includes at least one second conductive connector connecting the first housing and the fourth housing, and the suppression component is disposed on the second conductive connector.
[0033] In this technical solution, the common-mode current in the reducer can also flow back to the first housing through the second conductive connector. By setting a suppression component on the second conductive connector, the common-mode current in the reducer can be suppressed, thereby further reducing the degree of electro-corrosion and improving the service life of the motor drive system.
[0034] In one possible implementation, the suppression component includes a magnetic ring fitted onto the return mechanism.
[0035] In this technical solution, the installation is convenient and quick by fitting a magnetic ring onto the reflux mechanism.
[0036] In one possible implementation, a fixing member is included, which secures the magnetic ring to the return mechanism.
[0037] In this technical solution, the magnetic ring is fixed by a fastener, which can improve the working stability of the magnetic ring.
[0038] Secondly, this application provides a vehicle, including a vehicle body and the aforementioned motor drive system, wherein the motor drive system is disposed in the vehicle body. Attached Figure Description
[0039] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.
[0040] Figure 1 A simplified cross-sectional view of the motor drive system provided in the embodiments of this application;
[0041] Figure 2 Equivalent parasitic circuit diagram of common-mode current path provided in the embodiments of this application;
[0042] Figure 3 This is a structural framework diagram of the motor drive system provided in an embodiment of this application;
[0043] Figure 4 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0044] Figure 5 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0045] Figure 6 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0046] Figure 7 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0047] Figure 8 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0048] Figure 9 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0049] Figure 10 An equivalent parasitic circuit diagram of a common-mode current path provided in another embodiment of this application;
[0050] Figure 11 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0051] Figure 12 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0052] Figure 13 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0053] Figure 14 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application;
[0054] Figure 15 An equivalent parasitic circuit diagram of a common-mode current path provided in another embodiment of this application;
[0055] Figure 16 This is a flowchart illustrating the common-mode current suppression provided in an embodiment of this application.
[0056] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation
[0057] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0058] With the rapid development of electric drive systems (EDS) for electric vehicles, the voltage levels of these systems have gradually increased (reaching up to 800 volts). Furthermore, to improve the overall driving range and efficiency of the electric drive system, the switching frequency and turn-on / off speed of the switching modules (such as Insulated Gate Bipolar Transistors (IGBTs) and Silicon Carbide Field-Effect Transistors (SiC MOSFETs) in the electric drive system have been further increased. These changes lead to increased common-mode voltage and common-mode current in the electric drive system. Consequently, components such as the motor rotor shaft bearings suffer electro-corrosion damage due to the shaft voltage and current generated by the common-mode voltage (UCM) and common-mode current (ICM), ultimately reducing the service life of these components.
[0059] For example, Figure 1A simplified cross-sectional view of the motor drive system provided in the embodiments of this application, as shown below. Figure 1 As shown, the motor drive system includes a motor controller 1, a motor 2, and a reducer 3. The motor controller 1 includes components such as a filter 11, a bus capacitor C12, a switching module 13, and a three-phase copper busbar 14. Capacitor Cmotor represents the parasitic capacitance of the motor windings to the stator housing 102 (i.e., the housing of motor 2), capacitor Cmodule represents the parasitic capacitance of the switching module 13 to the motor controller housing 101, and Cy represents the parasitic capacitance of the filter 11 to the motor controller housing 101. Both the motor controller housing 101 and the stator housing 102 are connected to the motor drive system housing 103.
[0060] The common-mode current flows through the above-mentioned components to form a common-mode path (in sequence: three-phase copper busbar 14 → motor winding → capacitor Cmotor → stator housing 102 → motor drive system housing 103 → motor controller housing 101 → capacitor Cmodu le, capacitor Cy).
[0061] Figure 2 The equivalent parasitic circuit diagram of the common-mode current path provided in the embodiments of this application, combined with Figure 1 and Figure 2 ,Original Figure 1 The motor winding Cmotor can be decomposed into parasitic capacitances such as Cws, Cwr, Crs, Cb,nde, and Cb,de. The common-mode current ICM generated by the common-mode voltage UCM flows from the three-phase copper busbar 14 and motor winding 21 into the electronic rotor 22, rotor shaft bearing 23, and motor drive end bearing 24 in the motor 2, and flows through these parasitic capacitances through the stator housing 102, motor drive system housing 103, and motor controller housing 101 back to the motor controller side. To suppress the common-mode current ICM and reduce bearing electro-corrosion, a three-phase common-mode current suppression component 15 is typically installed on the three-phase copper busbar 14 to reduce the amplitude of the common-mode current, thereby mitigating the degree of electro-corrosion of components such as the motor rotor shaft bearing 23 and the motor drive end bearing 24, and improving the durability and service life of the bearings.
[0062] but Figure 2The proposed solution has the following problems: The three-phase common-mode current suppression component 15 is installed inside the motor controller or motor. Due to space constraints, the size of the three-phase common-mode current suppression component 15 is also limited. In addition, the high ambient temperature inside the motor controller or motor causes the three-phase common-mode current suppression component 15 to have the following problems: (1) After the common-mode current flows, the three-phase common-mode current suppression component 15 generates heat due to losses. After reaching the Curie temperature, the performance of the three-phase common-mode current suppression component 15 decreases, and the common-mode suppression capability weakens; (2) The heat generated by the three-phase common-mode current suppression component 15 will cause the plastic parts fixing the magnetic ring to fail due to heat; (3) The three-phase common-mode current suppression component 15 gradually reaches the core saturation under common-mode current, thereby reducing the common-mode suppression capability. Due to the above problems, the common-mode current suppression effect of the three-phase common-mode current suppression component 15 is poor, and the motor rotor shaft bearings and other components still have electro-corrosion problems, resulting in a reduction in their durability and service life.
[0063] To address the aforementioned issues, this application provides a motor drive system, a position determination method, and a vehicle. By adjusting the return path of the common-mode current generated in the motor drive system and readjusting the position of the common-mode current suppression component, the aforementioned problems existing in the use of the common-mode current suppression component can be solved, the suppression capability of the common-mode current suppression component for common-mode current can be improved, and the problem of reduced durability and service life of components such as motor rotor shaft bearings due to electro-corrosion can be prevented.
[0064] For example, Figure 3 This is a structural framework diagram of the motor drive system provided in the embodiments of this application, such as... Figure 3 As shown, the motor drive system 30 includes at least a motor controller and a motor. The motor controller may be partially disposed in the first housing 301, and the motor may be partially disposed in the second housing 302.
[0065] The motor controller is electrically connected to the motor, and is used to output electrical control signals to the motor to control the motor. The return mechanism is electrically connected to the first housing and the second housing. The return mechanism is equipped with a suppression component, which is located outside the first housing and outside the second housing.
[0066] In this embodiment, the first housing, the return mechanism, and the second housing are all conductive. That is, after the common-mode current I cm flows through the motor, it continues to flow from the second capacitor C2 to the second housing 302, then continues to flow through the return mechanism to the first housing 301, and finally flows back into the motor controller through the first capacitor C1.
[0067] Here, the first capacitor C1 and the second capacitor C2 can refer to one or more capacitors. For example, refer to the above. Figure 1The first capacitor C1 can include capacitor Cy and capacitor Cmodule, and the second capacitor can include capacitor Cmotor. Capacitors Cy, Cmodule, and Cmotor can refer to parasitic capacitance. Parasitic capacitance refers to capacitance that exists parasitically between wirings, even when no physical capacitors are actually present. In other words, capacitors Cy, Cmodule, and Cmotor can be non-physical; that is, there are no physical capacitors between the first housing and the motor controller, or between the second housing and the motor. Instead, they exist parasitically, resulting in equivalent parasitic capacitance.
[0068] In this embodiment, the common-mode current will flow through at least the rotor shaft and rotor shaft bearings in the motor, causing electro-corrosion in both the rotor shaft and bearings. The larger the amplitude of the common-mode current, the more severe the electro-corrosion, which will shorten the durability and service life of the motor.
[0069] Optionally, in some embodiments, the motor controller and the motor can be electrically connected via the three-phase copper busbar mentioned above.
[0070] Optionally, in some embodiments, the return mechanism can be a wire harness or a support column, etc. The wire harness has greater flexibility than the support column, making it suitable for scenarios requiring bending, such as when a partition exists between the first and second housings, causing the return mechanism to bend. The support column, on the other hand, provides support and fixation, suitable for scenarios requiring support force between the first and second housings. For example, when external forces are applied, using a support column to connect the first and second housings can prevent relative displacement between them, improving stability.
[0071] In this embodiment, the suppression component suppresses common-mode current through filtering, reducing the amplitude of the common-mode current and minimizing electro-erosion caused by it. In other words, the suppression component can refer to a component with filtering capabilities. Optionally, the suppression component can be a magnetic ring, or it can be composed of both a magnetic ring and a capacitor.
[0072] In this embodiment, the installation method of the suppression component is not limited. For example, the suppression component can be sleeved on the return current mechanism, which facilitates its installation. Alternatively, when the return current mechanism is a wire harness, the suppression component may include a capacitor disposed on the wire harness, and a magnetic ring may also be disposed on the wire harness.
[0073] In this embodiment, by setting a suppression component on the return current mechanism, and placing the suppression component outside the first housing and the second housing, the space is not limited by the internal space of the housing, allowing for a larger volume or number of suppression components. This improves the common-mode current suppression capability, facilitates installation, and enhances the stability of the suppression component, preventing it from falling off due to the failure of the fixing components caused by excessive temperature rise. Furthermore, the suppression component is exposed outside the housing, which facilitates heat dissipation and allows for the flexible addition of other auxiliary heat dissipation methods. The larger external space of the housing allows for a wider variety of auxiliary heat dissipation options, avoiding the problem of rapid temperature rise and deterioration of suppression performance when suppressing common-mode current, thus improving the common-mode current suppression effect.
[0074] Figure 4 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 4 As shown, the motor drive system includes a third housing 40, and a first housing 401 and a second housing 402 are at least partially disposed in the third housing 40.
[0075] To achieve better sealing, the motor controller can be entirely housed in the first housing 401, and the motors can be entirely housed in the second housing 402, thus improving the overall sealing of the motor drive system. The return flow mechanism is entirely located inside the third housing 40. The suppression component is also located inside the third housing 40.
[0076] For example, Figure 5 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 5 As shown, Figure 5 and Figure 4 The difference lies in the fact that the return current mechanism can be partially located outside the third housing 40, allowing the suppression component to also be positioned outside the third housing 40. This arrangement facilitates the suppression component's contact with the external environment, enabling rapid heat dissipation and preventing rapid temperature rise during operation that could lead to a decrease in current suppression effectiveness due to overheating. This improves the suppression component's ability to suppress common-mode current. Furthermore, the size of the suppression component is not limited by the space of the third housing, allowing for a larger size and / or number of components to address the issue of common-mode current oversaturation. Additionally, placing the suppression component outside the third housing 40 facilitates installation and removal. This also frees up space within the third housing 40 for other components, such as a speed reducer.
[0077] In this embodiment, by integrating the first housing and the second housing into the third housing, the first housing and the second housing can be protected from damage caused by external influences, thereby improving the reliability of the motor drive system and reducing the space occupied by the entire motor drive system.
[0078] Furthermore, in some embodiments, the third housing may be conductive. In this case, in order to improve the utilization of the internal space of the third housing, the first housing or the second housing may be placed close to the third housing (i.e., there will be an electrical connection between the first housing or the second housing and the third housing).
[0079] Optionally, in some embodiments, if there is an electrical connection between the first housing and the third housing, in order to prevent the common-mode current from flowing back to the first housing through the third housing, an insulating layer needs to be provided between the second housing and the third housing, and then a return current mechanism needs to be provided between the second housing and the first housing. In this way, the common-mode current flows back to the first housing through the return current mechanism, ensuring that the suppression component can achieve the effect of suppressing the common-mode current.
[0080] For example, Figure 6 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 6 As shown, after the first housing 401 and the third housing 40 are at least partially in contact and electrically connected, an insulating layer 403 can be provided between the second housing 402 and the third housing 40. The insulating layer 403 prevents the electrical connection between the second housing 402 and the third housing 40, causing the common-mode current to flow through the first housing 401, through the third housing 40, and then back to the second housing 402 through the third housing 40 (in this case, because the common-mode current does not flow through the return mechanism, the suppression component will fail).
[0081] The location of the reflux mechanism is unrestricted, see reference. Figure 6 The reflux mechanism can be located in the third housing 40, or similar to the one described above. Figure 5 It is located outside the third housing 40.
[0082] Optionally, in some embodiments, if there is an electrical connection between the second housing and the third housing, in order to prevent the common-mode current from flowing back to the first housing through the third housing, an insulating layer needs to be provided between the first housing and the third housing, and then a return current mechanism needs to be provided between the second housing and the first housing. In this way, the common-mode current flows back to the first housing through the return current mechanism, ensuring that the suppression component can achieve the effect of suppressing the common-mode current.
[0083] For example, Figure 7 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 7As shown, after the second housing 402 and the third housing 40 are at least partially in contact and electrically connected, an insulating layer 403 can be provided between the first housing 401 and the third housing 40 to prevent electrical connection between the first housing 401 and the third housing 40.
[0084] Furthermore, in some embodiments, after the first housing and the third housing are electrically connected, the second housing and the third housing are in contact through an insulating layer. This insulating layer can cover a portion of the second housing from the outside, or it can completely cover the second housing. Referring again to the above, as exemplarily... Figure 6 The insulating layer 403 can completely cover the second housing 402, which can effectively avoid the electrical connection between the second housing 402 and the third housing 40 (assuming that the insulating layer 403 is only set on the left side of the second housing 402, if the second housing 402 is displaced to the right, it may cause the right side of the second housing 402 to come into contact with the third housing 40, resulting in an electrical connection). This ensures that the common-mode current flows back from the first housing 401 to the second housing 402 only through the return mechanism, thus guaranteeing the suppression effect of the suppression component on the common-mode current.
[0085] Furthermore, based on the third housing described in the above embodiments, in some embodiments, the third housing may also accommodate other components of the motor drive system. For example, taking a speed reducer as one of these other components... Figure 8 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 8 As shown, the motor, motor controller, and reducer are all at least partially housed within the third housing 80. Specifically, the reducer housing 801, motor housing 802, and motor controller housing 803 are all partially housed within the third housing 80, thus highly integrating the entire motor drive system into a unified whole.
[0086] When the third housing 80, reducer housing 801, motor housing 802, and motor controller housing 803 are all conductive, in order to ensure the normal operation of the suppression component and reduce costs, an insulating layer 804 can be provided only on the outside of the motor controller housing 803. This isolates the motor controller housing 803 from the third housing 80, reducer housing 801, and motor housing 802, preventing electrical connections. Then, a separate return current mechanism is provided to connect the motor controller housing 803 and the motor housing 802, so that the common-mode current flows from the motor through the motor housing 802 and then through the return current mechanism, ensuring that the suppression component can suppress the common-mode current.
[0087] The location of the reflux mechanism is unrestricted and can be, for example... Figure 8The suppression component is located on the outside of the third housing 80. This allows for heat dissipation, and the size of the suppression component is not limited by the internal space of the third housing 80. This prevents the suppression component from gradually reaching core saturation under common-mode current due to volume constraints, thus avoiding a reduction in common-mode suppression capability.
[0088] In other embodiments, the reflux mechanism may also be disposed inside the third housing 80. For example, Figure 9 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 9 As shown, with Figure 8 The difference is that the entire reflux mechanism is located inside the third housing 80, and the suppression component is also located inside the third housing 80. This is mainly because the suppression component is located outside the third housing 80 and is easily affected by the external environment, which may cause the suppression component to fail (for example, after the suppression component is fixed to the reflux mechanism, the influence of external environmental factors may cause the suppression component to fall off the reflux mechanism).
[0089] The purpose of setting the insulating layer is described in detail below with reference to the accompanying drawings.
[0090] Figure 10 An equivalent parasitic circuit diagram of a common-mode current path provided in another embodiment of this application is shown below. Figure 10 As shown, before the insulation layer is installed, the motor controller housing 101 and the stator housing 102 are electrically connected through the third housing 103. This makes the common-mode current return path change to: motor → parasitic capacitance (including parasitic capacitance Cb,nde, Crs, Cb,de, etc.) → stator housing 102 → third housing 103 → motor controller housing 101. That is, the common-mode current no longer flows back to the motor controller through the return mechanism, causing the suppression component to fail. However, by installing the insulation layer, the common-mode path of stator housing 102 → third housing 103 → motor controller housing 101 is cut off. The common-mode current can no longer flow back to the motor controller housing 101 through the third housing 103, but can only flow back to the motor controller housing 101 through the return mechanism. At this time, the suppression component on the return mechanism can suppress the common-mode current.
[0091] It should be noted that because the third housing 103 is relatively large (it needs to accommodate both the motor housing and the motor controller housing), it is not convenient to install suppression components on the third housing 103. Instead, insulation is used to prevent common-mode current from flowing back to the motor controller housing 101 through the third housing 103, and an additional return current mechanism is provided so that the common-mode current flows back to the motor controller housing 101 through this return current mechanism. The return current mechanism can be smaller than the third housing 103, thus facilitating the installation of suppression components.
[0092] In this embodiment, by first constructing an insulating layer, common-mode current can be prevented from flowing back from the third housing to the first housing of the motor controller. This ensures that the common-mode current can only flow back to the first housing through the return current mechanism, thereby enabling the suppression component on the return current mechanism to suppress the common-mode current. Compared to the current practice of setting a common-mode current suppression device on the three-phase copper busbar, this embodiment solves both the problem that the common-mode current can flow back to the first housing through the third housing, making it impossible to suppress the common-mode current on the third housing, and the problem that the suppression component on the current three-phase copper busbar has a poor common-mode current suppression effect.
[0093] Furthermore, the housings of the motor and the motor controller can be independent of each other. For example, the first housing and the second housing can be connected only by at least one first conductive connector, with a suppression component provided on the first conductive connector. This allows the common-mode current to flow from the second housing through the first conductive connector and then back to the first housing. The suppression component on the first conductive connector effectively suppresses the common-mode current.
[0094] For example, Figure 11 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 11 As shown, the first housing 1101 and the second housing 1102 can be connected by at least one first conductive connector 1103, and a suppression component 1104 is provided on the first conductive connector 1103.
[0095] In some embodiments, the motor drive system may also include other components, such as a reducer. In this case, the reducer and the second housing, which at least partially houses the motor, can be housed together within the fourth housing. The second and fourth housings can be in contact with each other to achieve electrical connection. In this case, the return current mechanism can be directly connected to the first and fourth housings. Thus, after the common-mode current flows out from the second housing, it can pass through the fourth housing, flow into the return current mechanism, and then return to the first housing through the return current mechanism.
[0096] For example, the recirculation mechanism may include at least one second conductive connector. Figure 12 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 12 As shown, the first housing 1201 and the fourth housing 1203, which house the motor controller, are directly connected by at least one second conductive connector 1205. The second housing 1202 of the motor is at least partially housed within the fourth housing 1203 and is in contact with the fourth housing to achieve electrical connection.
[0097] For example, the second conductive connector can be a rigid connection mounting angle. After the first housing and the fourth housing are connected through the connection mounting angle, the positions of the first housing and the fourth housing are relatively fixed to avoid relative displacement.
[0098] In this embodiment, the fourth housing may be conductive. That is, when the second housing 1202 of the motor comes into contact with the fourth housing and is electrically connected, it is equivalent to the second housing 1202 also being electrically connected to the second conductive connector 1205. This allows the common-mode current to flow from the second housing 1202 through the fourth housing and then back to the first housing 1201 through the second conductive connector 1205.
[0099] In other embodiments, the fourth housing may not be conductive, in which case the second conductive connector needs to be directly connected to the first housing 1201 of the motor controller and the second housing 1202 of the motor.
[0100] For example, when the motor drive system also includes other components, such as in Figure 12 When the motor also includes a speed reducer, the second housing 1202 of the motor can be at least partially housed within the fourth housing 1203 along with the speed reducer housing 1204, while the first housing 1201, which partially houses the motor controller, is electrically connected to the fourth housing 1203 via at least one second conductive connector 1205.
[0101] For example, the aforementioned reflux mechanism may include Figure 12 At least one second conductive connector 1205 in the process. The suppression component 1206 in the reflux mechanism can be provided... Figure 12 On the second conductive connector 1205.
[0102] For example, an insulating element may also be provided between the first housing and the fourth housing. Figure 13 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 13 As shown, in addition to providing a second conductive connector 1305 and a suppression component 1306, an insulating component 1307 may also be provided between the first housing 1301 and the fourth housing 1303. The second housing 1302 and the housing that accommodates other components (e.g., the reducer housing 1304) are provided in the fourth housing 1303.
[0103] In other embodiments, the positions of the second housing and the reducer housing within the fourth housing can be varied, for example... Figure 14 This is a schematic diagram of the structure of a motor drive system provided in another embodiment of this application, as shown below. Figure 14As shown, the first housing 1401 and the fourth housing 1405 are connected by at least one second conductive connector 1403, and a suppression component 1402 is provided on the second conductive connector 1403. At this time, the reducer housing 1404 is located on the left side inside the fourth housing 1405, and the second housing 1406 is located on the right side inside the fourth housing 1405.
[0104] In this embodiment of the application, after adding the fourth housing, the housings of other components and the second housing that at least partially houses the motor can be flexibly adjusted inside the fourth housing, which improves the wiring flexibility of the motor drive system.
[0105] Figure 15 An equivalent parasitic circuit diagram of a common-mode current path provided in another embodiment of this application is shown below. Figure 15 As shown, the common-mode current ICM generated by the common-mode voltage UCM flows from the motor controller 1 and the motor winding 21 into the electronic rotor 22, rotor shaft bearing 23 and motor drive end bearing 24 in the motor 2, and flows through these parasitic capacitors (including capacitors Cws, Cwr, Crs, Cb,nde, Cb,de, etc.) and flows back to the motor controller side through the stator housing 102, the motor drive system housing 103, the return mechanism 10 and the motor controller housing 101.
[0106] In this embodiment, by providing a fourth housing, other components of the motor drive system and at least part of the second housing that houses the motor are all housed in the fourth housing. This allows the common-mode current generated by other components and the motor to flow back to the first housing through the fourth housing and the return mechanism. The suppression component on the return mechanism can suppress the common-mode current in other components (e.g., the reducer), thereby further reducing the electro-corrosion of other components and improving the service life of the motor drive system.
[0107] Based on the above embodiments, in some other embodiments, the suppression component can be a magnetic ring. The magnetic ring can be fitted onto the return current mechanism, facilitating installation while ensuring effective suppression of common-mode current.
[0108] In this embodiment, the magnetic ring offers greater freedom of installation. Furthermore, because the magnetic ring is installed on the outer side of both the first and second housings, it dissipates heat quickly, preventing excessive temperature rise. This also improves the temperature rise of the fixing components, preventing overheating and ensuring the magnetic ring is stably fixed to the reflux mechanism. For example, the fixing components can be made of plastic.
[0109] The shape of the magnetic ring is unrestricted; for example, it can be rectangular or elliptical. Furthermore, the material of the magnetic ring is also unrestricted, as is the installation method between the magnetic ring and the reflux mechanism.
[0110] In this embodiment, by sleeved on the reflux mechanism, which is located outside the first housing and outside the second housing, the magnetic ring dissipates heat quickly and the temperature rise is not too high. This prevents the plastic parts that fix the magnetic ring from failing due to the temperature rise, thus improving the convenience of fixing the magnetic ring.
[0111] The process of suppressing common-mode current is described below through some examples. Figure 16 The common-mode current suppression flowchart provided in the embodiments of this application is as follows: Figure 16 As shown, it includes the following steps:
[0112] Step S1601: Based on the information of components such as the motor controller and motor in the motor drive system, identify the relevant parasitic parameters of the common-mode voltage and common-mode current.
[0113] Specifically, parasitic parameters may include parasitic capacitance, as mentioned above.
[0114] Step S1602: Based on the spatial structure layout of each component of the motor drive system, identify the connection relationship between the motor controller housing, the motor housing, and the gearbox housing, and determine the connection path between the motor controller housing, the motor housing, and the gearbox housing.
[0115] This connection path is used for the flow of common-mode current.
[0116] Step S1603: Based on the parasitic parameters and connection paths, create the equivalent circuit diagrams for the common-mode voltage and common-mode current.
[0117] Step S1604: Based on the equivalent circuit diagram, determine the common-mode current return path of the motor side through the parasitic parameters, flowing through the motor housing and then returning to the motor controller housing.
[0118] Step S1605: Equivalent the return path to the physical motor drive system and determine whether a suppression component can be added to the physical system.
[0119] Step S1606: If it is not convenient to add a suppression component to the physical object, then cut off the return path on the physical object, rebuild the return mechanism as the return path, and set the suppression component on the return mechanism to suppress the common mode current.
[0120] Step S1607: If it is convenient to add a suppression component to the physical object, the suppression component can be directly configured on the physical object to suppress the common-mode current.
[0121] Referring to the structural description of the motor drive system in the above embodiments, when the common-mode current return path is detected to be on the third housing, because the third housing is relatively large, it is usually impossible to arrange suppression components to filter and suppress the common-mode current. Therefore, according to step S1606, the return path between the first and third housings is disconnected by using an insulation method (such as the insulation layer mentioned above), and a new return path (such as a return mechanism) is built on the first and third housings. Filtering measures such as 16-magnetic rings are arranged on the newly built return path to suppress the common-mode current and reduce bearing electro-corrosion.
[0122] In the motor drive system, the arrangement of various components (motor controller, motor, and gearbox, etc.) is unrestricted, and the components can be combined and arranged in the same housing. Their arrangement and combination are not restricted.
[0123] The method steps in this embodiment can be found in the description of the motor drive system structure in the above embodiment, and will not be repeated here.
[0124] In this embodiment, by providing a reflux mechanism on the outer side of the first housing and the outer side of the second housing, and by setting a suppression component on the reflux mechanism, greater spatial freedom can be achieved. This facilitates the use of more cooling methods to cool and dissipate heat from the suppression component (which generates heat during common-mode current suppression), preventing the suppression component from overheating and causing a decrease in common-mode current suppression performance. It also facilitates the installation of the suppression component, preventing overheating failure of the plastic parts fixing the suppression component due to temperature rise, and preventing the suppression component from detaching. Furthermore, the greater spatial freedom allows for a larger size and / or number of suppression components that can be arranged; for example, several suppression components can be arranged in parallel to solve the common-mode current oversaturation problem.
[0125] In addition, this application also provides a vehicle, which includes a vehicle body and a motor drive system described in any of the above embodiments, wherein the motor drive system is disposed in the vehicle body.
[0126] The vehicle can be a new energy vehicle, such as a pure electric vehicle or a hybrid electric vehicle.
[0127] It should be understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this application, and are not intended to limit the scope of the embodiments of this application.
[0128] It should also be understood that, in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0129] It should also be understood that the various implementation methods described in this specification can be implemented individually or in combination, and the embodiments of this application are not limited in this respect.
[0130] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A motor drive system, characterized in that, include: First shell; The motor controller is at least partially housed within the first housing; A first capacitor is connected to the first housing and the motor controller; Second shell; The motor is at least partially housed within the second housing, and the motor controller is electrically connected to the motor; The second capacitor connects the second housing and the motor; The reflux mechanism is electrically connected to the first housing and the second housing; as well as A suppression component is disposed on the return mechanism and located outside the first housing and outside the second housing. The suppression component is used to suppress common-mode current.
2. The motor drive system according to claim 1, characterized in that, It includes a third housing, within which the first housing and the second housing are housed.
3. The motor drive system according to claim 2, characterized in that, One of the first housing and the second housing is electrically connected to the third housing; An insulating layer is provided between the first housing and the other of the second housing and the third housing, and the third housing is electrically connected to the third housing through the return mechanism.
4. The motor drive system according to claim 3, characterized in that, The second housing is in contact with the third housing, and the insulating layer covers at least a portion of the second housing from the outside.
5. The motor drive system according to any one of claims 2-4, characterized in that, The suppression component is disposed on the outside of the third housing, and a portion of the reflux mechanism is disposed on the outside of the third housing.
6. The motor drive system according to any one of claims 2-4, characterized in that, The suppression component is disposed inside the third housing.
7. The motor drive system according to claim 1, characterized in that, The reflux mechanism includes at least one first conductive connector, which connects the first housing and the second housing, and the suppression component is disposed on the first conductive connector.
8. The motor drive system according to claim 1, characterized in that, It also includes a speed reducer, which and the second housing are housed within a fourth housing, with the second housing in contact with the fourth housing; The reflux mechanism is connected to the first housing and the fourth housing.
9. The motor drive system according to claim 8, characterized in that, The reflux mechanism includes at least one second conductive connector, which connects the first housing and the fourth housing, and the suppression component is disposed on the second conductive connector.
10. The motor drive system according to any one of claims 1-9, characterized in that, The suppression component includes a magnetic ring, which is sleeved on the return mechanism.
11. The motor drive system according to claim 10, characterized in that, It includes a fixing member that fixes the magnetic ring to the return mechanism.
12. A vehicle, characterized in that, The vehicle includes a vehicle body and a motor drive system as described in any one of claims 1-11, wherein the motor drive system is disposed in the vehicle body.