Motor controller dc bus power supply structure

Abstract

The utility model relates to a kind of motor controller direct current bus power supply structure, belong to motor controller technical field;Including insulating substrate, positive pole conductive row, negative pole conductive row and at least one electrolytic capacitor;The positive pole conductive row and negative pole conductive row are respectively located at the both sides of insulating substrate, form the layered structure of clamping insulating substrate, the insulating substrate has oppositely arranged first surface and second surface, the first surface is equipped with first conductive layer, the second surface is equipped with second conductive layer, the positive pole of electrolytic capacitor is connected with first conductive layer, negative pole is connected with second conductive layer;Positive pole conductive row and negative pole conductive row one end are connected with input power line, the other end is connected with the power module of motor controller, power current is transmitted through positive pole conductive row and negative pole conductive row, does not flow through the insulating substrate.Aiming at the defects that the cost of laminated busbar is high in prior art, the electromagnetic interference of traditional electrolytic capacitor scheme is big, to realize the synergistic optimization of low cost, high space utilization and low electromagnetic interference.

Description

Technical Field

[0001] This utility model relates to a DC bus power supply structure for a motor controller, and belongs to the field of motor controller technology. Background Technology

[0002] With the development of power electronics technology, motor drive systems are widely used in new energy vehicles, industrial equipment, and other fields, placing higher demands on the power density, electromagnetic compatibility, and cost of controllers. Currently, there are two main types of DC bus power supply schemes for motor controllers: Laminated busbar solution: A compact structure is achieved through multiple layers of insulated conductive busbars, resulting in low electromagnetic interference, but it has problems such as high development cost, complex manufacturing process, and long cycle time. Traditional parallel electrolytic capacitor solution: Electrolytic capacitors are directly soldered onto the PCB board, which is inexpensive, but the printed circuit of the PCB board has weak current carrying capacity and large parasitic inductance, resulting in serious heat generation, strong electromagnetic interference, and low space utilization.

[0003] Existing technologies cannot simultaneously meet the requirements of low cost, high power density, and low electromagnetic interference. Therefore, there is an urgent need for a power supply structure that combines compact structure, low cost, and electromagnetic compatibility. Utility Model Content

[0004] In view of the shortcomings of existing technologies such as high cost of stacked busbars and large electromagnetic interference of traditional electrolytic capacitor solutions, this utility model aims to provide a DC bus power supply structure for motor controllers to achieve synergistic optimization of low cost, high space utilization and low electromagnetic interference.

[0005] The DC bus power supply structure for the motor controller of this utility model includes an insulating substrate, a positive conductive bus, a negative conductive bus, and at least one electrolytic capacitor. The positive and negative conductive buses are located on both sides of the insulating substrate, forming a layered structure that clamps the insulating substrate. The insulating substrate has a first surface and a second surface arranged opposite to each other. The first surface is provided with a first conductive layer, and the second surface is provided with a second conductive layer. The positive terminal of the electrolytic capacitor is connected to the first conductive layer, and the negative terminal is connected to the second conductive layer. The positive and negative conductive buses are used to connect the input power supply and the power module of the motor controller. The power current is transmitted through the positive and negative conductive buses and does not flow through the insulating substrate.

[0006] Preferably, the insulating substrate is a PCB board, and the first conductive layer and the second conductive layer are copper-plated layers on the surface of the PCB board.

[0007] Preferably, the positive electrode conductive bus and the negative electrode conductive bus are fixed to the insulating substrate by fasteners. The insulating substrate is provided with insulating holes for the fasteners to pass through. The insulating holes include insulating clearance holes for positive electrode screws and insulating clearance holes for negative electrode screws. An insulating medium is provided in the insulating holes to isolate the fasteners from the first conductive layer and the second conductive layer.

[0008] Preferably, the fastener includes a positive electrode busbar fixing screw and a negative electrode busbar fixing screw. The positive electrode busbar fixing screw passes through the positive electrode screw insulation clearance hole and is connected to the positive electrode busbar, and the negative electrode busbar fixing screw passes through the negative electrode screw insulation clearance hole and is connected to the negative electrode busbar.

[0009] Preferably, the positive electrode busbar fixing screw and the negative electrode busbar fixing screw are provided with solder pads, the solder pads are conductive, and a shim is placed above the solder pads so that the solder pads are in contact with the positive electrode busbar and the negative electrode busbar and have good conductivity.

[0010] Preferably, the positive electrode busbar and the negative electrode busbar are respectively provided with a first interface and a second interface on their exteriors.

[0011] Preferably, the materials of the positive electrode and the negative electrode are copper, aluminum, or their alloys.

[0012] Preferably, the electrolytic capacitor is fixed to the first conductive layer and the second conductive layer by welding.

[0013] Compared with existing technologies, the DC bus power supply structure for the motor controller of this utility model has the following advantages: Utilizing the characteristic of printed circuits on both sides of a PCB board with insulation in between, the front side is defined as the positive terminal of the busbar, and the back side as the negative terminal. The positive terminal of the electrolytic capacitor is soldered to the front side of the PCB board, and the negative terminal is soldered to the back side. Positive and negative conductive copper busbars contact the corresponding polarity surfaces of the PCB board and are connected by bolts, forming a "sandwich" structure of positive and negative copper busbars sandwiching the PCB board. The conductive copper busbars are planar structures, requiring no stamping or bending, simplifying the manufacturing process. During controller operation, current flows through the conductive copper busbars to the power devices; only a small amount of current generated by voltage fluctuations flows through the PCB board into and out of the capacitors. Parasitic inductance is low, and electromagnetic interference is significantly suppressed. Both the conductive copper busbars and the PCB board are planar structures, connected via planar contact, without complex three-dimensional structures, resulting in minimal space occupation and high space utilization.

[0014] This solution combines the space advantages of laminated busbars with the advantage of low manufacturing costs. Motor controllers using this solution are small in size and have high volumetric density. Utilizing the inherent insulating properties of PCBs saves on insulating materials, further reducing manufacturing costs. Optimizing current paths reduces the current flowing through the PCB, thereby minimizing parasitic inductance and reducing electromagnetic interference. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a structural diagram of one side of the insulating substrate in this utility model; Figure 3 This is a structural diagram of the other side of the insulating substrate in this utility model; In the diagram: 1. Insulating substrate; 2. Electrolytic capacitor; 3. Conductive busbar; 4. First conductive layer; 5. Positive conductive busbar; 6. Negative screw insulation clearance hole; 7. Second conductive layer; 8. Negative conductive busbar fixing screw; 9. Positive screw insulation clearance hole; 10. Negative conductive busbar; 11. First interface; 12. Second interface; 13. Positive conductive busbar fixing screw. Detailed Implementation

[0016] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0017] Example 1: like Figures 1-3 As shown, this embodiment discloses a DC bus power supply structure for a motor controller, including an insulating substrate 1, a positive electrode bus 5, a negative electrode bus 10, and at least one electrolytic capacitor 2. The positive electrode bus 5 and the negative electrode bus 10 are located on both sides of the insulating substrate 1, forming a layered structure that clamps the insulating substrate 1. The insulating substrate 1 has a first surface and a second surface disposed opposite to each other. The first surface is provided with a first conductive layer 4, and the second surface is provided with a second conductive layer 7. The positive electrode of the electrolytic capacitor 2 is connected to the first conductive layer 4, and the negative electrode is connected to the second conductive layer 7. The positive electrode bus 5 and the negative electrode bus 10 are used to connect the input power supply and the power module of the motor controller. The power current is transmitted through the positive electrode bus 5 and the negative electrode bus 10 and does not flow through the insulating substrate 1.

[0018] The insulating substrate 1 is a PCB board, and the first conductive layer 4 and the second conductive layer 7 are copper-plated layers on the surface of the PCB board.

[0019] The positive electrode conductive bus 5 and the negative electrode conductive bus 10 are fixed to the insulating substrate 1 by fasteners. The insulating substrate 1 is provided with insulating holes for the fasteners to pass through. The insulating holes include positive electrode screw insulating clearance holes 9 and negative electrode screw insulating clearance holes 6. The insulating holes are provided with insulating medium to isolate the fasteners from the first conductive layer 4 and the second conductive layer 7.

[0020] The fasteners include a positive electrode busbar fixing screw 13 and a negative electrode busbar fixing screw 8. The positive electrode busbar fixing screw 13 passes through the positive electrode screw insulation clearance hole 9 and is connected to the positive electrode busbar 5. The negative electrode busbar fixing screw 8 passes through the negative electrode screw insulation clearance hole 6 and is connected to the negative electrode busbar 10.

[0021] The positive electrode busbar fixing screw 13 and the negative electrode busbar fixing screw 8 are provided with pads. The pads are conductive and a shim is placed on top of the pads so that the pads can contact the positive electrode busbar 5 and the negative electrode busbar 10 and conduct electricity well.

[0022] The positive electrode busbar 5 and the negative electrode busbar 10 are respectively provided with a first interface 11 and a second interface 12.

[0023] The positive electrode busbar 5 and the negative electrode busbar 10 are made of copper, aluminum or their alloys.

[0024] The electrolytic capacitor 2 is fixed to the first conductive layer 4 and the second conductive layer 7 by welding.

[0025] In this embodiment, the insulating substrate 1 is a PCB board. The first surface (top layer) is copper-plated to form the first conductive layer 4 (bus positive electrode), and the second surface (bottom layer) is copper-plated to form the second conductive layer 7 (bus negative electrode). The layers are insulated by the substrate. The PCB board has positive electrode screw insulation clearance holes 9 and negative electrode screw insulation clearance holes 6 at the corresponding screw positions. The holes are filled with epoxy resin insulating medium to ensure that the screws do not contact the conductive layers.

[0026] Taking the negative electrode as an example, copper is deposited on the top layer of the PCB board for the negative electrode. A pad is placed at the location of the negative electrode busbar fixing screw 8. The pad is conductive, while other areas are insulated. A copper washer is placed above the pad to ensure good contact and conductivity between the pad on the PCB board and the negative electrode busbar 10. The fixing screw 8 for the negative electrode busbar has threads, and it passes through the bottom layer of the PCB board, locking into the threads on the negative electrode busbar 10. This ensures that the negative electrode busbar 10 makes tight contact and good conductivity with the pad on the PCB board through the copper washer. Copper is deposited on the bottom layer of the PCB board for the positive electrode. An insulating clearance hole 6 for the negative electrode screw is cut out at the location of the negative electrode busbar fixing screw 8 to ensure that the screw does not contact the positive electrode copper and to ensure good insulation.

[0027] The positive electrode busbar 5 and the negative electrode busbar 10 are copper plates with tin plating on the surface. They are fixed to the PCB board by the positive electrode busbar fixing screw 13 and the negative electrode busbar fixing screw 8, respectively. Working principle: When the motor controller is running, one end of the positive conductor 5 and the negative conductor 10 are connected to the input power line, and the other end is connected to the power module of the motor controller. The power current is input to the power module from the power line through the positive conductor 5 and the negative conductor 10 without passing through the PCB board. Taking advantage of the conductive properties of the copper on the surface of the PCB board and the insulation properties of the upper and lower layers, only a small amount of ripple current caused by voltage fluctuations flows into or out of the electrolytic capacitor through the PCB board. Therefore, the copper on the positive and negative terminals of the PCB board does not need to be very thick, and there is no need to consider the impedance.

[0028] The driving current does not flow through the PCB board; when the voltage fluctuates, a small amount of ripple current flows through the first conductive layer 4 and the second conductive layer 7 into and out of the electrolytic capacitor 2, thus stabilizing the voltage. Since the PCB copper plating only transmits small currents, there is no need to consider the issue of heat generation from large currents.

[0029] This embodiment combines the low inductance of multilayer busbars with the low cost of electrolytic capacitors through the collaborative design of planar busbars and PCBs. It is suitable for variable frequency drives such as AC asynchronous motors and permanent magnet synchronous motors, and is especially suitable for new energy vehicles and industrial servo applications where size and cost are sensitive.

[0030] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A DC bus power supply structure for a motor controller, characterized in that, The device includes an insulating substrate (1), a positive electrode busbar (5), a negative electrode busbar (10), and at least one electrolytic capacitor (2). The positive electrode busbar (5) and the negative electrode busbar (10) are located on both sides of the insulating substrate (1) to form a layered structure that clamps the insulating substrate (1). The insulating substrate (1) has a first surface and a second surface that are disposed opposite to each other. The first surface is provided with a first conductive layer (4), and the second surface is provided with a second conductive layer (7). The positive electrode of the electrolytic capacitor (2) is connected to the first conductive layer (4), and the negative electrode is connected to the second conductive layer (7). The positive electrode busbar (5) and the negative electrode busbar (10) are used to connect the input power supply and the motor controller power module. The power current is transmitted through the positive electrode busbar (5) and the negative electrode busbar (10) and does not flow through the insulating substrate (1).

2. The DC bus power supply structure for the motor controller according to claim 1, characterized in that, The insulating substrate (1) is a PCB board, and the first conductive layer (4) and the second conductive layer (7) are copper-plated layers on the surface of the PCB board.

3. The DC bus power supply structure for the motor controller according to claim 1, characterized in that, The positive electrode conductive bus (5) and the negative electrode conductive bus (10) are fixed to the insulating substrate (1) by fasteners. The insulating substrate (1) is provided with insulating holes for the fasteners to pass through. The insulating holes include positive electrode screw insulating clearance holes (9) and negative electrode screw insulating clearance holes (6). The insulating holes are provided with insulating medium to isolate the fasteners from the first conductive layer (4) and the second conductive layer (7).

4. The DC bus power supply structure for the motor controller according to claim 3, characterized in that, The fasteners include a positive electrode busbar fixing screw (13) and a negative electrode busbar fixing screw (8). The positive electrode busbar fixing screw (13) passes through the positive electrode screw insulation clearance hole (9) and is connected to the positive electrode busbar (5). The negative electrode busbar fixing screw (8) passes through the negative electrode screw insulation clearance hole (6) and is connected to the negative electrode busbar (10).

5. The DC bus power supply structure for the motor controller according to claim 4, characterized in that, The positive electrode busbar fixing screw (13) and the negative electrode busbar fixing screw (8) are provided with pads. The pads are conductive and a shim is placed above the pads so that the pads can contact the positive electrode busbar (5) and the negative electrode busbar (10) and conduct electricity well.

6. The DC bus power supply structure for the motor controller according to claim 1, characterized in that, The positive electrode conductive bus (5) and the negative electrode conductive bus (10) are respectively provided with a first interface (11) and a second interface (12).

7. The DC bus power supply structure for the motor controller according to claim 1 or 6, characterized in that, The positive electrode busbar (5) and the negative electrode busbar (10) are made of copper, aluminum or their alloys.

8. The DC bus power supply structure for the motor controller according to claim 1, characterized in that, The electrolytic capacitor (2) is fixed to the first conductive layer (4) and the second conductive layer (7) by welding.

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