A power board, motor driver and brushless direct current motor driving system

Abstract

The application discloses a power board, a motor driver and a brushless direct current motor driving system, and relates to the technical field of motor drivers, and aims at solving the problem that the motor driver is large in size and weight and cannot meet the requirements of the fields of aviation and spaceflight. The power board comprises a negative electrode connecting terminal, a three-phase inverter assembly and a current sensor assembly which are uniformly surrounded by the negative electrode connecting terminal. The motor driver comprises the power board provided in the technical scheme. The power board, the motor driver and the brushless direct current motor driving system are used for driving a brushless direct current motor.

Description

Technical Field

[0001] This invention relates to the field of motor driver technology, and more particularly to a power board, a motor driver, and a brushless DC motor drive system. Background Technology

[0002] Low-voltage, high-current motor drives are commonly used in aerospace and other fields. Since size and weight are among the core competitive advantages in aerospace and other fields, low-voltage, high-current motor drives are required to be compact, small in size, and lightweight.

[0003] However, in the existing technology, low voltage and high current will cause serious heat generation on the high current traces on the circuit board, resulting in large size and weight of the motor driver, which cannot meet the needs of aerospace and other fields. Summary of the Invention

[0004] The purpose of this invention is to provide a power board, a motor driver, and a brushless DC motor drive system to overcome the problems of severe overheating, large size, and heavy weight of existing motor drivers.

[0005] To achieve the above objectives, the present invention provides a power board. The power board includes: a negative terminal block, and three-phase inverter components and current sensor components uniformly surrounding the negative terminal block. The current sensor components are electrically connected to each phase of the inverter component, and each phase of the inverter component is electrically connected to the negative terminal block.

[0006] Compared with existing technologies, the power board provided by this invention features a three-phase inverter assembly and a current sensor assembly arranged around the negative terminal, resulting in a smaller current loop area, shorter traces, and a more compact structure between the positive and negative terminals. When a large current flows, the small current loop area and short traces between the positive and negative terminals reduce heat generation on the power board's traces, eliminating the need for large-area heat dissipation and thus making the power board smaller and lighter. Furthermore, the small current loop area and short traces between the positive and negative terminals also reduce the stray inductance of the power board's busbars, thereby reducing the surge voltage generated by the three-phase inverter assembly during switching and extending the power board's lifespan.

[0007] The present invention also provides a motor driver, including the power board described above.

[0008] Compared with the prior art, the beneficial effects of the motor driver provided by the present invention are the same as those of the power board described in the above technical solution, and will not be repeated here.

[0009] The present invention also provides a brushless DC motor drive system, including the above-described motor driver.

[0010] Compared with the prior art, the beneficial effects of the brushless DC motor drive system provided by the present invention are the same as those of the power board described in the above technical solution, and will not be repeated here. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0012] Figure 1 This is a schematic diagram of the front structure of the control board in an embodiment of the present invention;

[0013] Figure 2 This is a schematic diagram of the back structure of the control board in an embodiment of the present invention;

[0014] Figure 3 This is a schematic diagram of the driver board in an embodiment of the present invention;

[0015] Figure 4 This is a schematic diagram of the power board structure in an embodiment of the present invention. Figure 1 ;

[0016] Figure 5 This is a schematic diagram of the mounting structure of the driver board and power board in an embodiment of the present invention;

[0017] Figure 6 This is a schematic diagram of the power board structure in an embodiment of the present invention. Figure 2 .

[0018] Figure label:

[0019] 1-Control board, 10-Control board socket;

[0020] 11-Control board mounting hole; 12-Control chip;

[0021] 13-15V drive power supply module, 14-5V control power supply module;

[0022] 15-3.3V linear power supply module, 2-driver board;

[0023] 20 - Driver board mounting hole; 21 - Driver board socket;

[0024] 22-Socket 1, 23-Socket 2;

[0025] 24-Socket 3, 25-Socket 4;

[0026] 26 - Driver chip, 3 - Power board;

[0027] 31 - Power board mounting hole; 32 - Negative terminal block;

[0028] 33 - Three-phase inverter module, 33' - Inverter module per phase;

[0029] 331 - Phase terminal; 332 - First transistor;

[0030] 333 - Second transistor, 334 - Driver terminal;

[0031] 34-Current sensor assembly, 341-Current sensor;

[0032] 342 - Sensor terminal block; 343 - Current signal acquisition terminal block;

[0033] 35 - First capacitor, 36 - Second capacitor;

[0034] Phase current in region 37-A, phase current in region 38-C;

[0035] 40- Bolt. Detailed Implementation

[0036] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0037] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0039] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, 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 this invention.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 according to the specific circumstances.

[0041] With the rapid development of modern power electronics, battery technology, and brushless DC motor technology, a large number of brushless DC motor drive systems powered by low-voltage batteries have emerged, such as electric starting systems for turbines, electric starting systems for small piston engines, and electric door drive systems for aircraft. In these applications, low-voltage, high-current motor drivers are often used, and the motor drivers are required to be compact, small in size, and lightweight.

[0042] Brushless DC motor drivers are the key to electrical energy conversion. Electrical energy conversion refers to the process by which the driver uses power electronic devices to chop low-voltage DC power into three-phase power for the motor. Currently, low-voltage, high-current motor drivers suffer from problems such as severe heat generation from high-current traces on the printed circuit board and high-power transistors, resulting in large size and weight. Furthermore, stray inductance in the bus leads to large turn-off surge voltages in high-power transistors, increasing driver losses.

[0043] Please see Figures 1-4 This invention provides a brushless DC motor drive system, including a brushless DC motor and a motor driver. The motor driver includes a control board 1, a drive board 2, and a power board 3. The control board 1 and drive board 2 are electrically connected, and drive board 2 and power board 3 are concentrically fixed together. It should be noted that drive board 2 can be circular to facilitate the layout of power board 3. Similarly, to reduce the area of ​​power board 3 and facilitate its layout, power board 3 can also be circular. When both drive board 2 and power board 3 are circular, they can be fixed using a double-layer board interlocking structure. Furthermore, the diameter of drive board 2 is smaller than the diameter of power board 3 to ensure that drive board 2 does not affect the layout on power board 3 while minimizing the volume of drive board 2 and the interlocking height between drive board 2 and power board 3.

[0044] As one possible implementation, such as Figure 1 and Figure 2As shown, the control board 1 includes a power module, a control chip 12, and a control board socket 10. The power module is electrically connected to both the control chip 12 and the control board socket 10, and is used to step down the power supply to provide control power to the control board 1 and drive power to the drive board 2. The control chip 12 can be a TMS28035 chip, used to detect the Hall signal and motor current feedback signal from the brushless DC motor, and output a control signal to the drive board 2 after processing by the control algorithm. The drive board 2 receives the control signal, processes it through the drive chip 26 and peripheral circuits (not shown in the figure), and outputs a drive signal to the power board 3. The power board 3 receives the drive signal and inverts the DC power into three-phase power for output to the brushless DC motor.

[0045] Specifically, such as Figure 1 and Figure 2 As shown, the control board 1 has three power supply modules: a 15V drive power supply module 13, a 5V control power supply module 14, and a 3.3V linear power supply module 15. The 15V drive power supply module 13 converts the input low-voltage DC power into a 15V drive power supply to power the drive chip on the drive board 2. The 5V control power supply module 14 converts the input low-voltage DC power into a 5V control power supply to power the relevant components on the control board 1. The 3.3V linear power supply module 15 steps down the 5V control power supply to 3.3V to power the control chip 12. The 15V drive power supply module 13 and the control signals are transmitted to the drive board 2 through the control board socket 10 and corresponding connector wires.

[0046] In practical applications, such as Figure 1 and Figure 2 As shown, the control board 1 may have multiple mounting holes 11. The control board 1 can be fixed to the housing of the motor driver by passing bolts through these mounting holes 11.

[0047] As one possible implementation, such as Figure 3 As shown, the aforementioned driver board 2 has a driver chip 26 and a driver board socket 21. The driver board socket 21 is electrically connected to the driver chip 26, and the driver board socket 21 is electrically connected to the control board socket 10, for receiving drive power and drive signals from the control board 1. Specifically, the control board socket 10 and the driver board socket 21 can be connected together using wires.

[0048] As one possible implementation, such as Figure 5 and Figure 6As shown, the power board 3 includes a negative terminal 32, a three-phase inverter assembly 33, and a current sensor assembly 34. When the power board 3 is circular, the negative terminal 32 can be located at the center of the power board 3, i.e., the center of the circle, to ensure that the distance from the negative terminal 32 to each phase inverter assembly 33' and the current sensor assembly 34 is as equal as possible. This reduces the current loop area, reduces the stray inductance of the bus, shortens the wiring on the power board 3, reduces the size and weight of the power board 3, and makes the heat generation and heat dissipation on the power board 3 more uniform. Each phase inverter assembly 33' is electrically connected to the driver chip 26 of the driver board 2 to receive the drive signal from the driver chip 26 and respond to the drive signal.

[0049] In practical applications, such as Figure 5 and Figure 6 As shown, in order to better dissipate heat, the power board 3 can be made of a single-layer aluminum substrate. At the same time, there are multiple mounting holes 31 on the power board 3. By using bolts through the mounting holes 31, the power board 3 can be mounted on the housing of the motor driver or the heat sink. While achieving installation and fixation, the heat on the power board 3 can be transferred to the housing of the driver, which helps the power board 3 dissipate heat.

[0050] In one possible implementation, such as Figures 3-5 As shown, the aforementioned driver board 2 has multiple sockets for transmitting power and current feedback signals. These sockets are arranged in a cross shape around the driver board. In practical applications, socket 1 22, socket 23, socket 3 24, and socket 4 25 are located at the respective ends of the cross shape on the driver board.

[0051] In one possible implementation, such as Figures 3-5 As shown, the power board 3 has multiple pins corresponding to multiple sockets on the driver board 2, and these pins are arranged in a "cross" structure around the power board 3. The mounting orientation of the driver board 2 and the power board 3 is uniquely determined by the sockets on the driver board 2 and the pins between them, thus providing a reverse insertion prevention function.

[0052] In practical applications, such as Figures 3-5As shown, the drive board 2 has multiple mounting holes 20, and the power board 3 has multiple patch nuts (not shown in the figure) corresponding to the mounting holes 20 on the drive board 2. The two boards can be fixed together using bolts 40, simplifying installation. This plug-in structure makes the motor driver more compact, smaller, and lighter. After fixing the drive board 2 and power board 3 together using bolts 40, the sockets of the drive board 2 and the pins of the power board 3 are soldered together for transmitting the corresponding drive current, current feedback signal, and power supply. Specifically, after the drive board socket 21 receives the drive power and drive signal from the control board 1, the drive signal is conditioned and amplified by the drive chip 26 and peripheral circuitry (not shown in the figure), and then transmitted through the sockets of the drive board 2 to the pins of the power board 3, thereby driving the three-phase inverter assembly of the power board 3.

[0053] like Figure 5 and Figure 6 As shown, the three-phase inverter components 33 are evenly arranged around the negative terminal 32, and each phase inverter component 33' is electrically connected to the negative terminal 32. Each phase inverter component 33' can be a surface-mount packaged component, making the power board 3 more compact, reducing heat transfer paths, and increasing heat dissipation efficiency.

[0054] In one possible implementation, such as Figure 5 and Figure 6 As shown, each phase inverter assembly 33' includes a phase terminal 331, a first transistor 332 and a second transistor 333 connected in parallel, and a drive terminal 334 (i.e., a pin). The drive terminal 334 is electrically connected to the control terminals of the first transistor 332 and the second transistor 333. The current sensor assembly 34 is electrically connected to the input terminal of the first transistor 332, the output terminal of the first transistor 332 is electrically connected to the phase terminal 331, the input terminal of the second transistor 333 is electrically connected to the phase terminal 331, and the output terminal of the second transistor 333 is electrically connected to the negative terminal 32. It should be noted that the number of first transistors 332 and second transistors 333 in each phase inverter assembly 33' is, but is not limited to, two. The number of first transistors 332 and the number of second transistors 333 are multiples of two. For example, the number of first transistors 332 can be two, and the number of second transistors 333 can be two; or, for example, the number of first transistors 332 can be four, and the number of second transistors 333 can be four, etc. It should also be noted that the first transistor 332 can be the upper transistor and the second transistor 333 can be the lower transistor. Of course, it is also possible that the first transistor 332 is the lower transistor and the second transistor 333 is the upper transistor.

[0055] Specifically, such as Figure 5 and Figure 6As shown, when the first transistor 332 is turned on, the phase current transmitted by the first transistor 332 based on the current sensor assembly 34 is transmitted to the brushless DC motor through the phase terminal 331. When the second transistor 333 is turned on, the phase terminal 331 transmits the phase current from the brushless DC motor to the second transistor 333, and the second transistor 333 transmits the phase current from the brushless DC motor to the negative terminal 32. The phase terminal 331 is placed close to the first transistor 332 and the second transistor 333 connected in parallel to achieve short high-current traces on the power board 3, reduce the heat generation of the traces on the power board 3, thereby reducing the area and weight of the power board 3.

[0056] In practical applications, such as Figure 6 As shown, the left area is called "Area A", the right area is called "Area C", and the areas between "Area A" and "Area C" are "Area B" and "Area D", respectively, where "Area D" is the current sensor area. Taking the inverter components in Area A and Area C as examples, at this time, the first transistor 332 in Area A is turned on, and the phase current 37 in Area A flows into the DC bus, passes through the first transistor 332 in Area A, and then flows into the motor through the phase terminal 331 in Area A. The second transistor 333 in Area C is turned on, and the phase current 38 in Area C flows from the brushless DC motor into the phase terminal 331 in Area C, passes through the second transistor 333 in Area C, and then flows into the DC bus. Since the phase terminal 331 in Area C is close to the first transistor 332 and the second transistor 333 in Area C, the large phase current generated by chopping is limited to Area C, reducing the heat generated by the large current on the power board 3.

[0057] In one possible implementation, such as Figure 5 and Figure 6 As shown, the aforementioned current sensor assembly 34 is evenly arranged around the negative terminal 32, and the current sensor assembly 34 is electrically connected to each phase inverter assembly 33'. The current sensor assembly 34 can be a surface-mount packaged element, making the power board 3 more compact, reducing the heat transfer path, and increasing heat dissipation efficiency.

[0058] Specifically, such as Figure 5 and Figure 6As shown, the aforementioned current sensor assembly 34 may include a current sensor 341, a sensor terminal block 342, and a current signal acquisition terminal block 343 (i.e., a pin). The current sensor 341 is electrically connected to each phase inverter assembly 33'. The current signal acquisition terminal block 343 is electrically connected to both the current sensor 341 and the sensor terminal block 342. The sensor terminal block 342 is electrically connected to the current sensor 341. The sensor terminal block 342 is placed close to the current sensor 341 to achieve short high-current traces on the power board 3, reducing heat generation from the power board 3's traces, thereby reducing the area and weight of the power board 3.

[0059] As one possible implementation, such as Figure 5 and Figure 6 As shown, the power board 3 also includes multiple parallel-connected first capacitors 35 and multiple parallel-connected second capacitors 36. The multiple parallel-connected first capacitors 35 are distributed around adjacent two-phase inverter components 33, and the multiple parallel-connected second capacitors 36 are distributed around the two-phase inverter components 33 adjacent to the current sensor component 34 and the current sensor component 34. This distributed arrangement of the multiple parallel-connected first capacitors 35 and multiple parallel-connected second capacitors 36 reduces stray inductance of the DC bus, lowers the risk of surge voltage breakdown when the first transistor 332 or the second transistor 333 is turned off, and results in low equivalent series resistance and low capacitor heat generation, increasing their lifespan. The multiple parallel-connected first capacitors 35 and multiple parallel-connected second capacitors 36 can be surface-mount packaged components, making the power board 3 more compact, with a smaller heat transfer path and higher heat dissipation efficiency.

[0060] In practical applications, such as Figure 5 and Figure 6 As shown, the aforementioned multiple parallel first capacitors 35 can also be distributed between the parallel first transistors 332 and second transistors 333 of each phase inverter component 33' to reduce the stray inductance of the DC bus, thereby reducing the risk of surge voltage breakdown of the parallel first transistors 332 and second transistors 333 when they are turned off.

[0061] As one possible implementation, such as Figure 5 and Figure 6 As shown, each phase inverter component 33' and current sensor component 34 are arranged in a "cross" structure around the negative terminal 32. This ensures that the distance from each phase inverter component 33' to the negative terminal 32 is equal, thereby reducing the stray inductance of the DC bus.

[0062] In one alternative approach, such as Figure 5 and Figure 6As shown, the drive terminals 334 of each phase inverter component and the current signal acquisition terminals 343 of the current sensor component are arranged in a "cross" shape around the negative terminal 32. This ensures that the distances from the drive terminals 334 and current signal acquisition terminals 343 of each phase inverter component 33' to the negative terminal 32 are equal, thereby reducing the current loop and the stray inductance of the DC bus. Furthermore, the distances from the drive terminals 334 and current signal acquisition terminals 343 of each phase inverter component to the negative terminal 32 are less than the distances from the phase terminals 331 and sensor terminals 342 of each phase inverter component 33' to the negative terminal 32. This facilitates the layout and installation of the drive board 2.

[0063] In summary, in the power board provided by this embodiment of the invention, the three-phase inverter assembly and the current sensor assembly are arranged around the negative terminal, resulting in a small current loop area, short traces, and a more compact structure between the positive and negative terminals. When a large current flows, the small current loop area and short traces between the positive and negative terminals reduce the heat generated by the power board's traces, thus eliminating the need for large-area heat dissipation and making the power board smaller and lighter. Furthermore, the small current loop area and short traces between the positive and negative terminals also reduce the stray inductance of the power board's busbars, thereby reducing the surge voltage generated by the three-phase inverter assembly during switching and extending the service life of the power board.

[0064] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power board, characterized in that, include: The negative terminal and a three-phase inverter assembly and a current sensor assembly uniformly surrounding the negative terminal, wherein the current sensor assembly is electrically connected to each phase of the inverter assembly, and each phase of the inverter assembly is electrically connected to the negative terminal. Each phase of the inverter assembly includes a phase terminal, a first transistor and a second transistor connected in parallel, and a drive terminal, wherein the drive terminal is electrically connected to the control terminals of the first transistor and the second transistor. The current sensor assembly is electrically connected to the input terminal of the first transistor, the output terminal of the first transistor is electrically connected to the phase terminal, the input terminal of the second transistor is electrically connected to the phase terminal, and the output terminal of the second transistor is electrically connected to the negative terminal. The current sensor assembly includes a current sensor, a sensor terminal, and a current signal acquisition terminal. The current sensor is electrically connected to each phase of the inverter assembly, the sensor terminal is electrically connected to the current sensor, and the current signal acquisition terminal is electrically connected to both the current sensor and the sensor terminal. When the first transistor is turned on, the phase current transmitted by the first transistor based on the current sensor assembly is transmitted to the motor through the phase terminal. When the second transistor is turned on, the phase terminal transmits the phase current from the motor to the second transistor, and the second transistor transmits the phase current of the motor to the negative terminal.

2. The power board according to claim 1, characterized in that, The power board also includes a plurality of first capacitors and a plurality of second capacitors connected in parallel. The plurality of first capacitors connected in parallel are distributed in a ring around the inverter components in two adjacent phases, and the plurality of second capacitors connected in parallel are distributed in a ring around the inverter components and the current sensor components in two adjacent phases.

3. The power board according to claim 1, characterized in that, The inverter assembly and the current sensor assembly of each phase are arranged in a "cross" structure around the negative terminal.

4. The power board according to claim 1, characterized in that, The drive terminals of each phase of the inverter component and the current signal acquisition terminals of the current sensor are arranged in a "cross" shape around the negative terminal; and / or, The distances from the drive terminal of each phase inverter component and the current signal acquisition terminal of the current sensor to the negative terminal are all equal.

5. The power board according to claim 1, characterized in that, Each phase of the inverter assembly and the current sensor assembly uses surface-mount packaged components.

6. The power board according to claim 1, characterized in that, The power board is made of a single-layer aluminum substrate; and / or, The power board is circular in shape.

7. A motor driver, characterized in that, Includes the power board as described in any one of claims 1 to 6.

8. The motor driver according to claim 7, characterized in that, The motor driver also includes a drive board and a control board. The drive board is fixed concentrically with the power board, and the control board and the drive board are electrically connected. The drive board has a drive chip and a drive board socket, the drive board socket and the drive chip are electrically connected, and the drive chip is electrically connected to each phase of the inverter component; The control board has a power module, a control chip, and a control board socket. The control board socket and the drive board socket are electrically connected. The power module is electrically connected to both the control chip and the control board socket.

9. A brushless DC motor drive system, characterized in that, Includes the motor driver as described in claim 7 or 8.

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