An aircraft motor drive
By employing air cooling in the motor drive of an electric aircraft, utilizing convection during flight to dissipate heat, the heat dissipation problem in existing technologies is solved, resulting in a compact, lightweight, and low-cost motor drive design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI AUTOFLIGHT CO LTD
- Filing Date
- 2022-03-30
- Publication Date
- 2026-07-14
AI Technical Summary
Existing electric aircraft motor drives suffer from heat dissipation problems, resulting in complex structures, increased weight and size, and are unable to meet the power requirements of large aircraft.
The system employs air cooling, which involves placing power components at the edge of the power board and creating airflow channels near the motor to dissipate heat through convection during flight, thus eliminating the need for water cooling.
This reduces the structural complexity and weight of the motor driver, improves its compactness, reduces cost and size, and enhances the power density of the motor driver.
Smart Images
Figure CN114726148B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of drive technology, and more particularly to an aircraft motor driver. Background Technology
[0002] Electric aircraft are aircraft that are propelled by an electric propulsion system rather than an internal combustion engine. In existing electric aircraft, the power board structure of the motor driver is relatively simple, mostly rectangular, with a driver IC on one side and power semiconductors on the other, and the three-phase lines leading out through windows on the side of the board. While this layout meets the needs of small drones and is easy to assemble on the arms, it is not conducive to heat dissipation. The high temperature rise of the power semiconductors limits their performance, resulting in low power density. Because large aircraft are heavier and require higher power output from their propulsion systems, the drawbacks of this conventional layout are particularly pronounced. Therefore, most require separate water-cooling devices for heat dissipation, leading to a more complex aircraft structure and increases in weight, size, and cost to varying degrees. Summary of the Invention
[0003] The purpose of this invention is to provide an aircraft motor driver that can be cooled by air, thereby improving the compactness of the driver structure and reducing the size, weight and structural complexity of the driver and the aircraft.
[0004] To achieve this objective, the present invention adopts the following technical solution:
[0005] An aircraft motor drive, comprising:
[0006] A power board, the power board including a base plate and power components, the power components being located at the edge of the base plate;
[0007] The motor is located near the center of the power board and is electrically connected to the terminals on the base plate. The motor driver has an airflow channel for providing airflow for heat dissipation of the power components.
[0008] Optionally, the power element includes several groups of transistors, each group of transistors and the terminal are connected by copper-clad wires, and conductive strips are soldered onto the copper-clad wires.
[0009] Optionally, the conductive strip is provided on both the front and back sides of the base plate; the conductive strip is disposed opposite to each other on the front and back sides of the base plate.
[0010] Optionally, the conductive strip is a tin-plated copper strip; the tin-plated copper strip is bonded to the copper-clad conductor.
[0011] Optionally, the conductive strip is located on the side of the transistor near the center of the base plate; the terminal is located on the side of the conductive strip near the center of the base plate.
[0012] Optionally, the transistor is vertically positioned on the base plate plane; the heat dissipation surface of the transistor is perpendicular to the base plate plane; and the heat dissipation surface of the transistor faces the outer periphery of the base plate.
[0013] Optionally, the power element further includes several capacitors located on the side of the conductive strip near the center of the base plate; the terminal is located between two adjacent capacitors.
[0014] Optionally, the transistor, the conductive strip, the capacitor, and the terminal are evenly spaced on the base plate.
[0015] Optionally, the base plate has a regular hexagonal or circular structure; the transistor, the conductive strip, and the capacitor are centrally symmetrically distributed with the center of the base plate as the origin.
[0016] Optionally, the power board further includes a positive and a negative power bus for providing DC power, and a signal line for transmitting control signals.
[0017] The beneficial effects of this invention are:
[0018] The aircraft motor driver provided by this invention has power components located at the edge of a power board, and the motor is mounted in the middle of the power board where heat generation is low. Heat dissipation at the edge of the power board is ensured by convective airflow. Compared with water cooling, this design greatly reduces the structural complexity of the motor driver and improves its structural compactness, thereby reducing the cost, size, and weight of the driver and the aircraft. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall structure of the aircraft motor driver described in this invention;
[0020] Figure 2 This is a schematic diagram of the front structure of the power board involved in the embodiment of the present invention;
[0021] Figure 3 This is a schematic diagram of the back structure of the power board involved in the embodiments of the present invention;
[0022] Figure 4 This is a schematic diagram of the front window area of the power board involved in the embodiment of the present invention;
[0023] Figure 5 This is a schematic diagram of the back window area of the power board involved in the embodiment of the present invention.
[0024] In the picture:
[0025] 10-Power board; 101-Baseboard; 1-RC snubber circuit; 2-Transistor; 3-Positive power bus; 4-Negative power bus; 5-Signal line; 6-Capacitor; 7-Conductive strip; 8-Terminal; 9-Mounting hole; 20-Motor. Detailed Implementation
[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0027] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0029] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.
[0030] Currently, the biggest challenge facing the development of various electric aircraft is the insufficient performance of electric propulsion systems, which cannot meet the requirements of heavy aircraft. In existing technologies, to ensure heat dissipation, power components are mostly distributed on power boards. However, due to the size limitations of electric aircraft, it is difficult to maintain sufficient distance between the power board and the motor for heat dissipation. Since aircraft require large output power, to prevent the power components from being affected by excessive heat, the power board usually needs to be cooled by a separate water-cooling device. However, the addition of a water-cooling device significantly increases the size and weight of the electric aircraft, affecting its performance and increasing its complexity and manufacturing cost. Therefore, this embodiment provides an aircraft motor driver that can dissipate heat through air cooling, has a compact installation structure, and reduces both size and weight.
[0031] like Figure 1 As shown, the aircraft motor driver provided in this embodiment includes a power board 10 and a motor 20. The power board 10 includes a base plate 101, a power element, and three phase wire terminals 8. The power element is located at the edge of the front side of the base plate 101, and the terminals 8 penetrate both the front and back sides of the base plate 101. The motor 20 is located on the back side of the base plate 101, near the center of the power board 10, and is electrically connected to the terminals 8 on the back side of the base plate 101. Preferably, the end size of the motor 20 is smaller than the area of the power board 10, and the outer edge of the power board 10 is located on the outer periphery of the motor 20. A hollow structure is provided around the motor driver, which connects the inside and outside of the driver to form a channel for airflow. During the movement of the aircraft, the airflow enters the internal cavity of the driver through the airflow channel, flows through the edge of the power board 10, and exchanges heat with the power element to achieve the purpose of cooling the edge of the power board 10.
[0032] This aircraft motor driver places high-heat-generating power components on the outer edge of the power board 10, resulting in extremely low heat generation in the center of the power board 10. Therefore, during driver assembly, the motor 20 can be installed close to the center of the power board 10. The power components distributed on the outer edge of the power board 10 can achieve heat dissipation by ensuring airflow at the edge through a perforated structure. Since the power components have the largest distribution perimeter on the power board 10, and the edge position has a weak obstruction effect on airflow, in this embodiment, the temperature of the power board 10 can be maintained within a reliable operating range by relying on convection generated during aircraft flight. This replaces the existing water-cooling structure in aircraft, significantly reducing the weight, volume, and structural complexity of the driver, making it highly suitable for electric aircraft applications. Furthermore, by eliminating the water-cooling structure, the motor 20 can be installed close to the center of the power board 10, further improving the structural compactness of the motor driver and reducing its overall size and assembly difficulty.
[0033] refer to Figure 2 In this embodiment, in addition to the base plate 101, power components, and terminals 8, the power board 10 also includes a positive power bus 3 and a negative power bus 4 soldered to the base plate 101 and connected to the positive and negative terminals of the driver's DC power supply, a signal line 5 connected to the control terminal of the driver or a control module such as a control board to transmit control signals, and an RC absorption circuit 1 for interference suppression. The power components include several transistors 2 and several capacitors 6. In this power board 10, the positive power bus 3, the negative power bus 4, the RC absorption circuit 1, and the signal line 5 are all distributed in the middle of the base plate 101, while the transistors 2, which are the main heat source and noise interference source, are distributed at the edge of the board. In addition to heat dissipation requirements, this also reduces interference to the circuits inside the board.
[0034] As a preferred embodiment, the base plate 101 adopts a regular hexagonal or circular structure, preferably a regular hexagonal structure which is easier to process, and is a double-sided PCB board structure. The regular hexagonal structure is close to a circle in shape, which facilitates the installation of motors and the cooling of the internal air ducts of the aircraft. The material of the PCB board can be aluminum substrate, copper substrate, or ceramic substrate with better thermal conductivity, or new composite substrate, etc., as needed. In this embodiment, all six corners of the base plate 101 are chamfered, and mounting holes 9 are opened at each of the six corners for assembling and fixing the base plate 101.
[0035] Optionally, in this embodiment, the terminal 8 of each phase and the corresponding transistor 2 are connected on the base plate 101 by copper-clad wires. Since the main current loop of the power board 10 is between the transistor 2 and the terminal 8, which generates a lot of heat, in this embodiment, a conductive strip 7 is soldered on the copper-clad wires connecting the transistor 2 and the terminal 8. The conductive strip 7 has a certain width and thickness, which can increase the cross-sectional area of the current conductor, improve the current carrying capacity, and reduce the heat generation. At the same time, the conductive strip 7 and the transistor 2, which generate a lot of heat, are evenly distributed at the edge of the base plate 101 to reduce the heat in the middle of the power board 10.
[0036] refer to Figure 2 and Figure 3 As a preferred embodiment, in this embodiment, conductive strips 7 are attached to both the front and back sides of the base plate 101, and the conductive strips 7 attached to the front and back sides of the base plate 101 are positioned opposite each other. Specifically, the conductive strip 7 is a rectangular tin-plated copper strip. More specifically, in this embodiment, a single rectangular tin-plated copper strip is 23mm long, 6mm wide, and 1.5mm thick. This embodiment reduces the processing difficulty by opening windows and adding tin to the base plate 101, and connecting and fixing the tin-plated copper strip and the copper-clad conductor by integral patch welding. This also allows the tin-plated copper strip and the copper-clad conductor to be completely bonded together.
[0037] In this embodiment, by setting conductive strips 7 on the copper-clad conductors, the cross-sectional area of the high-current conductor is increased, the internal resistance of the conductor is reduced, the current carrying capacity of the conductor is improved, and the heat generation of the conductor is reduced. At the same time, the current conductor changes from a copper-clad conductor covered under the solder mask layer to an exposed tin-plated copper strip, which reduces its heat generation and improves its heat dissipation capacity. Moreover, sufficient area of the base plate 101 for expanding the width of the copper-clad conductor can be reserved for the conductor segments on the line without conductive strips 7, so that the power board 10 can achieve a higher volume utilization rate and power density while ensuring the current carrying capacity and heat dissipation capacity. For example, in this embodiment, the large aircraft motor driver has a volume of 240mm*209.8mm*60mm, a bus voltage input of 288V to 405V, and a peak output current of 500A per phase, which is much higher than that of a general motor drive power board.
[0038] Continue to refer to Figure 2 In this embodiment, transistor 2, conductive strip 7 and capacitor 6 are arranged evenly at equal intervals in a layered manner from the outside to the inside according to the heat generation, so that the power board 10 forms an arrangement pattern in which the heat generation gradually increases from the inside to the outside, so as to further ensure the heat dissipation effect of the power board 10.
[0039] Optionally, in this embodiment, transistor 2 is selected as a low-EMI insulated double-gate transistor (IGBT). This transistor 2 can be vertically positioned at the edge of the base plate 101, with its heat dissipation surface perpendicular to the plane of the base plate 101 and facing the outer periphery of the base plate 101, to facilitate heat dissipation outwards from the base plate 101. In practical use, this heat dissipation surface may be the side where the power semiconductor wafer of transistor 2 is located, the side where the metal heat dissipation surface of transistor 2 is located, or the side of transistor 2 with the largest area, etc.
[0040] As a preferred embodiment, capacitor 6 is a DC-Link capacitor. The capacitors 6 are arranged end-to-end, forming a fan-shaped corner between adjacent capacitors 6. The positive terminal of capacitor 6 is connected to the positive terminal 3 of the power bus, and the negative terminal is connected to the negative terminal 4 of the power bus. The terminal 8 is located within the fan-shaped corner formed by two adjacent capacitors 6. The placement of capacitor 6 is chosen not only for heat dissipation but also for size considerations. Concentrating capacitor 6 in the inner ring allows for the use of a larger standard packaged DC-Link capacitor without requiring additional custom capacitor 6. Furthermore, the DC-Link capacitor has a large capacitance and discharge capacity, providing a margin of safety.
[0041] As another preferred embodiment, in this embodiment, the terminal block 8 is a cylindrical gold-plated copper head, and the terminal block 8 penetrates both the front and back sides of the base plate 101. Replacing the existing edge-opening welding connection method with a gold-plated copper head can reduce heat generation and manufacturing difficulty, and facilitate the connection and disconnection between the power board 10 and the motor 20.
[0042] Continue to refer to Figure 2 In this embodiment, the capacitor 6, conductive strip 7 and transistor 2 are divided into 6 groups with the same composition structure. The 6 groups of composition structure are evenly distributed on the 6 edges of the base plate 101 in a fan-shaped arrangement of 60° with the center of the base plate 101 as the origin, so that the capacitor 6, conductive strip 7 and transistor 2 form a centrally symmetrical layout.
[0043] Specifically, in this embodiment, there are 6 capacitors 6, 6 conductive strips 7, and 36 transistors 2. Each power board 10 consists of 6 components, with one capacitor 6, one conductive strip 7, and a bridge arm composed of 6 parallel transistors 2.
[0044] The power board 10, through its centrally symmetrical layout, ensures that the current loop impedance of the three phases and the six bridge arms of the power board 10 is consistent, thereby guaranteeing the current sharing effect of the power board 10. This avoids uneven current and heat generation caused by uneven current, which could cause the transistor 2 with high current to exceed its temperature limit when the power is high, thus triggering temperature protection, reducing the performance release of the transistor 2, or even causing the transistor 2 to fail directly.
[0045] refer to Figure 4 and Figure 5 In this embodiment, each of the six bridge arms on the power board 10 is composed of multiple transistors 2 connected in parallel. Adjacent bridge arms are connected end-to-end by conductive strips 7. The terminals 8 are located on the inner ring of the junction of two sets of conductive strips 7, and are connected to the junction of the two connected bridge arms as close as possible. The terminals 8 of each phase are connected to the drive motor. The two ends of the two connected bridge arms are respectively connected to the positive terminal 3 and the negative terminal 4 of the power bus. The on / off state of the three-phase bridge arms can be controlled by the transistors 2. The transistors 2 are controlled by the drive control module, which can selectively control the connection or disconnection of the terminals 8 and the drive DC power module. In this embodiment, the bridge arms formed by multiple transistors 2 connected in parallel can serve as current shunting, thereby reducing the heat generated by a single transistor 2 and preventing the transistor 2 from failing due to overheating.
[0046] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. An aircraft motor driver, characterized in that, include: A power board (10) includes a base plate (101) and power components, the power components being located at the edge of the front side of the base plate (101); The motor (20) is located near the center of the power board (10) and is electrically connected to the terminal (8) on the base plate (101). The motor driver has an airflow channel to provide airflow for heat dissipation of the power components. The motor (20) is located on the back side of the base plate (101). The terminal (8) passes through both the front and back sides of the base plate (101) to electrically connect the power board (10) and the motor (20). The power element includes several groups of transistors (2), and each group of transistors (2) and the terminal (8) are connected by copper-clad wires, and conductive strips (7) are soldered on the copper-clad wires; The power element also includes several capacitors (6), which are located on the side of the conductive strip (7) near the center of the base plate (101); the terminal (8) is located between two adjacent capacitors (6); The transistor (2), the conductive strip (7), the capacitor (6), and the terminal (8) are all equally spaced on the base plate (101); The base plate (101) has a regular hexagonal or circular structure; the transistor (2), the conductive strip (7) and the capacitor (6) are centrally symmetrically distributed with the center of the base plate (101) as the origin.
2. The aircraft motor driver according to claim 1, characterized in that, The conductive strip (7) is provided on both the front and back sides of the base plate (101); the conductive strip (7) is disposed opposite to each other on the front and back sides of the base plate (101).
3. The aircraft motor driver according to claim 1, characterized in that, The conductive strip (7) is a tin-plated copper strip; the tin-plated copper strip is bonded to the copper-clad conductor.
4. The aircraft motor driver according to claim 1, characterized in that, The conductive strip (7) is located on the side of the transistor (2) near the center of the base plate (101); the terminal (8) is located on the side of the conductive strip (7) near the center of the base plate (101).
5. The aircraft motor driver according to claim 1, characterized in that, The transistor (2) is placed vertically on the plane of the base plate (101); the heat dissipation surface of the transistor (2) is perpendicular to the plane of the base plate (101); the heat dissipation surface of the transistor (2) faces the outer periphery of the base plate (101).
6. The aircraft motor driver according to claim 1, characterized in that, The power board (10) also includes a power bus positive terminal (3) and a power bus negative terminal (4) for providing DC power to it, as well as a signal line (5) for transmitting control signals.