A motor and a motor control method

Abstract

The present invention belongs to the technical field of motors, and particularly provides a motor and a control method. The motor includes an electrical box, and a PCB board, a power device and a radiator are arranged in the electrical box; the PCB board is fixed in the electrical box; the radiator is assembled on the side wall of the electrical box; the power device is assembled on the PCB board and forms a heat conduction relationship with the radiator. The integrated radiator design of the motor of the present invention increases the effective heat dissipation area, simplifies the assembly of the radiator and the power device, and the radiator is combined with the electrical box to further expand the heat dissipation area and enhance the heat dissipation effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to a motor and a motor control method. Background Art

[0002] A motor is an electrical device that converts electrical energy into mechanical energy, commonly known as a motor. Its main function is to generate a driving torque and serve as a power source for household appliances or small machinery. With the development of technology, motors can be precisely controlled in terms of speed, torque, and position, making motors very widely used in practical applications and can be seen everywhere in life. Motors are also an indispensable part of printers, engraving machines, smart homes, and control machinery, etc.

[0003] When a motor controller converts the control signal of the MCU into a motor drive signal, a large number of power devices are required, such as rectifier bridges, diodes, MOSFETs, IGBTs, and IPMs. During the conversion process of the power devices, current flows through the power devices, generating energy losses and presenting in the form of heat. Specifically, the power devices heat up and the surface temperature rises sharply. Excessive temperature will seriously damage the performance of the power devices, reduce the reliability and service life of the system, and in severe cases, cause device failure and damage to the entire controller.

[0004] Traditional heat dissipation methods involve adding a radiator to each individual power device, which requires a large installation area, occupies a large area of the PCB board, has low installation efficiency, and high usage costs. At the same time, when laying out the power, the volume of a single radiator is large, and the heat dissipation surface is only limited to the radiator itself, and the heat dissipation surface of the electrical box sidewall cannot be utilized for heat dissipation, resulting in low overall heat dissipation efficiency and causing a bottleneck in performance.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] To solve the above technical problems, the first object of the present invention is to propose a motor, including

[0007] An electrical box, in which a PCB board, power devices, and a radiator are provided;

[0008] The PCB board is fixed inside the electrical box;

[0009] The radiator is assembled on the sidewall of the electrical box;

[0010] The power devices are assembled on the PCB board and form a heat conduction relationship with the radiator.

[0011] Further optionally, the radiator includes

[0012] A radiator body, wherein a plurality of mounting grooves facing the inner side of the electrical box are circumferentially spaced along the side wall of the electrical box; there are a plurality of power devices, and the plurality of power devices are spaced and distributed in the plurality of mounting grooves and form a heat conduction relationship with the mounting grooves;

[0013] A plurality of support blocks, the plurality of support blocks are respectively inserted into the plurality of mounting grooves to fix the power devices located in the mounting grooves on the radiator, so that the power devices are closely attached to the radiator.

[0014] Further optionally, the mounting groove penetrates through the top and bottom of the radiator body, and the inner walls on both sides of the mounting groove respectively form a first mounting surface and a second mounting surface; the two sides of the support block form a first mating surface and a second mating surface respectively mating with the first mounting surface and the second mounting surface, and the power devices are respectively arranged between the first mounting surface and the first mating surface and between the second mounting surface and the second mating surface.

[0015] Further optionally, a certain angle is formed between the first mounting surface and the second mounting surface, so that the size of the opening of the mounting groove is larger than the size of the bottom wall of the mounting groove; the angle between the first mating surface and the second mating surface is equal to the angle between the first mounting surface and the second mounting surface.

[0016] Further optionally, the plurality of support blocks are connected in series by a connecting rope.

[0017] Further optionally, a connecting wall is formed between adjacent two mounting grooves, and the heat dissipation device further includes:

[0018] A fixing block, the fixing block is located at the bottom of the connecting wall and is used to fix the radiator on the PCB board. The fixing block is provided with fixing columns, and the fixing columns are matched with the mounting holes on the PCB board.

[0019] Further optionally, a connecting through hole penetrating through the mounting groove is formed in the connecting wall, and the connecting rope is arranged in the connecting through hole to connect the support blocks located in adjacent mounting grooves.

[0020] Further optionally, a mounting through hole is formed in the support block along the depth direction of the mounting groove, and a first mating hole matched with the mounting through hole is formed in the bottom wall of the mounting groove. Connecting screws respectively pass through the first mating hole and the mounting through hole from the side of the radiator close to the electrical box and are tightly fitted with connecting nuts.

[0021] Further optionally, at least a second mating hole is formed at a position on the side wall of the electrical box corresponding to the first mating holes at both ends of the radiator, and the connecting screw passes through the second mating hole, the first mating hole, and the mounting through hole from the outside of the electrical box and is tightly fitted with the connecting nut.

[0022] Further optionally, heat dissipation fins are provided at a position on the side wall of the electrical box corresponding to the radiator.

[0023] Further optionally, the motor further includes:

[0024] A temperature detection module, including a first temperature detection device and a second temperature detection device, the first temperature detection device is arranged on the radiator, and the second temperature detection device is arranged at a position on the side wall of the electrical box corresponding to the radiator;

[0025] A control module, which judges the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device and determines the control strategy of the motor accordingly.

[0026] The present invention also provides a control method for any one of the above motors, and the control method includes:

[0027] Judging the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device and determining the control strategy of the motor accordingly.

[0028] Further optionally, the step of judging the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device and determining the control strategy of the motor accordingly includes:

[0029] Obtaining a first temperature value Ta detected by the first temperature detection device and a second temperature value Tb detected by the second temperature detection device;

[0030] Respectively comparing the magnitude of the first temperature value Ta with a first set temperature Tmin and a second set temperature Tmax;

[0031] Comparing the magnitude of the difference Ta - Tb between the first temperature value Ta and the second temperature value Tb with a set temperature difference;

[0032] Determining the control strategy of the motor power and / or the motor current according to the comparison results;

[0033] Wherein, the first set temperature Tmin is the maximum temperature value for the power device to meet the usage requirements; the second set temperature Tmax is the limit temperature value of the operating temperature range of the power device, and the first set temperature Tmin < the second set temperature Tmax.

[0034] Further optionally, respectively compare the first temperature value Ta with the first set temperature Tmin and the second set temperature Tmax, compare the difference Ta - Tb between the first temperature value Ta and the second temperature value Tb with the set temperature difference, and determine the control strategy of the motor power and / or the motor current according to the comparison results, including:

[0035] When Ta < Tmin and Ta - Tb ≤ the set temperature difference, allow the motor to operate at the maximum power Pmax and the maximum current Imax;

[0036] When Ta < Tmin and Ta - Tb > the set temperature difference, allow the motor to operate at the maximum power Pmax with the current not higher than the rated current Imid;

[0037] When Tmax > Ta > Tmin and Ta - Tb ≤ the set temperature difference, determine the allowable power range and / or current range according to the operating voltage of the motor;

[0038] When Tmax > Ta > Tmin and Ta - Tb > the set temperature difference, allow the motor to operate at the first set multiple of the current not higher than the rated current Imid;

[0039] When Ta > Tmax, allow the motor to operate at the second set multiple of the current not higher than the rated current Imid, and the first set multiple is greater than the second set multiple.

[0040] Further optionally, the determining the allowable power range and / or current range according to the operating voltage of the motor includes

[0041] Obtain the operating voltage U of the motor;

[0042] When the operating voltage U = the rated voltage U 额 , allow the motor to operate at the rated power Pmid with the current not higher than the rated current Imid;

[0043] When the operating voltage U > the rated voltage U 额 , allow the motor to operate at the maximum power Pmax with the current not higher than the maximum current Imax;

[0044] When the operating voltage U < the rated voltage U 额 , allow the motor to operate at the rated power Pmid with the current not higher than the rated current Imid.

[0045] Further optionally, after allowing the motor to operate at the first set multiple of the current not higher than the rated current Imid when Tmax > Ta > Tmin and Ta - Tb > the set temperature difference, it further includes:

[0046] Record the first duration t1 when Ta > Tmin;

[0047] When the time t1 reaches the first set time, determine whether the following condition is met: Ta - Tb > the set temperature difference. If it is met, adjust the allowable current range of the motor to operate at a second set multiple of the current not higher than the rated current Imid.

[0048] Further optionally, when Ta > Tmax, after allowing the motor to operate at a second set multiple of the current not higher than the rated current Imid, it further includes:

[0049] Record the second duration t2 when Ta > Tmax. When the time t2 reaches the second set time, execute the shutdown instruction.

[0050] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0051] 1. The radiator of the present invention can further utilize the heat dissipation surface of the electrical box for heat dissipation by being fixed on the side of the electrical box, which can expand the heat dissipation area;

[0052] 2. Through the integrated radiator design of the present invention, the heat dissipation area can be effectively increased, and the heat dissipation effect can be improved; at the same time, the occupied area is small, saving the area of the PCB board, simplifying the installation process, saving installation time, being beneficial to reducing the volume of the system and saving costs; at the same time, the installation firmness is improved, being able to resist the strong vibration brought by the high-speed operation of the motor, and avoiding the reduction of heat dissipation performance caused by the detachment of the middle heat dissipation sticker;

[0053] 3. At the contact position between the radiator and the electrical box of the present invention, heat dissipation fins are added to the electrical box to increase the contact area between the metal and the air, further improving the heat dissipation efficiency.

[0054] 4. The motor and motor control method of the present invention improve the heat dissipation performance by dissipating heat and controlling the temperature of the power devices, reasonably controlling the surface temperature of the power devices, which can greatly improve the practical performance of the power devices and the reliability of the system, and extend the service life of the system.

[0055] The following further describes in detail the specific implementation manners of the present invention with reference to the accompanying drawings. Description of the Drawings

[0056] The accompanying drawings, as part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the accompanying drawings in the following description are only some embodiments, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the accompanying drawings:

[0057] Figure 1 : Schematic assembly diagram of the electrical box, radiator, power device and PCB board in Embodiment 1 of the present invention;

[0058] Figure 2 : is Figure 1 Top view of

[0059] Figure 3 : Schematic structural diagram of the radiator in Embodiment 1 of the present invention;

[0060] Figure 4 : Another perspective view of the radiator in Embodiment 1 of the present invention;

[0061] Figure 5 : Schematic structural diagram of the support block in Embodiment 1 of the present invention;

[0062] Figure 6 : Schematic assembly diagram of the radiator, power device and PCB board in Embodiment 1 of the present invention;

[0063] Figure 7 : is Figure 6 Front view of

[0064] Figure 8 : is Figure 6 Top view of

[0065] Figure 9 : Appearance view of the electrical box in Embodiment 1 of the present invention;

[0066] Figure 10 : Schematic assembly diagram of the electrical box, radiator, power device and PCB board in Embodiment 2 of the present invention;

[0067] Figure 11 , Assembly diagram of the radiator and power device in Embodiment 2 of the present invention;

[0068] Figure 12 : Control logic diagram in Embodiment 4 of the present invention.

[0069] Wherein: 1 - electrical box; 2 - radiator; 3 - PCB board; 4 - power device; 11 - second mating hole; 12 - heat dissipation fin; 21 - installation groove; 22 - support block; 23 - fixing block; 24 - connecting wall; 25 - first mating hole; 51 - first temperature detection device; 52 - second temperature detection device; 6 - connecting screw; 221 - connecting rope; 222 - installation through hole; 231 - fixing post.

[0070] It should be noted that these drawings and text descriptions are not intended to limit the scope of the concept of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0071] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "inner" and "outer" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0072] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection", "contact", and "communication" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] This embodiment provides a motor, as Figures 1-9 shown, including an electrical box 1 and a PCB board 3, a power device 4, and a radiator 2 disposed inside the electrical box 1. The power device can be an IPM or a rectifier bridge. The radiator 2 is assembled on the side wall of the electrical box 1. The PCB board 3 can be optionally disposed at the bottom or top of the electrical box 1. The power device 4 is assembled on the PCB board 3 and forms a heat conduction relationship with the radiator 2. Before designing the PCB board 3 of this embodiment, first, the placement position of the power device 4 needs to be determined. Because the power device 4 generates heat, if the heat energy generated by it is not controlled, the service performance of the motor controller will be severely restricted or damaged. The power device 4 is placed near the side of the electrical box 1, and the heat dissipation surface of the side wall of the electrical box 1 is used for further heat dissipation to improve the overall heat dissipation efficiency. In some embodiments, the radiator 2 is an independent component assembled on the side wall of the electrical box 1. The joint surface of the radiator 2 and the electrical box 1 matches the side wall of the electrical box 1. If the side wall of the electrical box 1 is a plane, the joint surface of the radiator 2 and the electrical box 1 is a plane. If the side wall of the electrical box 1 is a curved surface, the joint surface of the radiator 2 and the electrical box 1 is a curved surface. In some other embodiments, the radiator and the electrical box can be integrally formed, that is, the radiator is directly formed on the side wall of the electrical box.

[0074] The radiator of this embodiment can further utilize the heat dissipation surface of the electrical box for heat dissipation by being fixed on the side of the electrical box, and can expand the heat dissipation area; by fixing the radiator on the side wall of the electrical box, the firmness of the radiator installation can be improved, and it can resist the strong vibration brought by the high-speed operation of the motor, avoiding the reduction of heat dissipation performance caused by the detachment of the intermediate heat dissipation sticker.

[0075] Embodiment 1

[0076] As Figures 3-5As shown, the heat sink 2 includes a heat sink body 2 and a plurality of support blocks 22. The heat sink body 2 is circumferentially and spaced apart along the side wall of the electrical box 1 to form a plurality of mounting grooves 21 facing the inside of the electrical box. There are a plurality of power devices 4, and the plurality of power devices 4 are spaced and distributed in the plurality of mounting grooves 21 and form a heat conduction relationship with the mounting grooves 21. The plurality of support blocks 22 correspond to the mounting grooves 21 one by one. The plurality of support blocks 22 are respectively inserted into the plurality of mounting grooves 21 to fix the power devices 4 located in the mounting grooves 21 on the heat sink 2, so that the power devices 4 are closely attached to the heat sink 2. The mounting groove 21 penetrates through the top and bottom of the heat sink body 2. The inner walls on both sides of the mounting groove 21 respectively form a first mounting surface and a second mounting surface. The two sides of the support block 22 form a first mating surface and a second mating surface that respectively cooperate with the first mounting surface and the second mounting surface. The power devices 4 are respectively provided between the first mounting surface and the first mating surface, and between the second mounting surface and the second mating surface. By inserting the support block 22 into the mounting groove 21, the power devices 4 on both sides are clamped between the mating surface of the support block 22 and the mounting surface of the heat sink 2. Before the circuit design in the PCB board 3, it is first necessary to determine the placement positions of the power devices 4, and place the heat sink 2 according to the actual placement positions of the power devices 4. Two power devices 4 can be arranged in each mounting groove 21, so as to integrate all the power devices 4 that need to be arranged on the PCB into the heat sink 2, avoiding adding a heat sink 2 for each power device 4 and occupying a large area of the PCB board 3.

[0077] Further optionally, as Figure 6 shown, a certain angle is formed between the first mounting surface and the second mounting surface, so that the size of the opening of the mounting groove 21 is larger than the size of the bottom wall of the mounting groove 21. The angle between the first mating surface and the second mating surface is equal to the angle between the first mounting surface and the second mounting surface. When the support block 22 is inserted into the mounting groove 21 at the same angle, as the insertion depth of the support block 22 increases, the gap between the heat dissipation surface of the power device 4 and the mounting surface of the heat sink 2 can be effectively controlled, which can be controlled between 0.5 mm and 1 mm. Optionally, the mounting groove 21 is a V-shaped groove, and the heat dissipation surfaces of the two power devices 4 are respectively close to the first mounting surface and the second mounting surface of the V-shaped groove of the heat sink 2. A thermally conductive silicone material is filled in the gap between the mounting groove 21 and the heat dissipation surface of the power device 4. Since air is a poor conductor of heat, by replacing the air in the gap with a silicone material with good thermal conductivity, it is beneficial to enhance the heat dissipation performance.

[0078] Further optionally, as Figure 7As shown, a connecting wall 24 is formed between two adjacent mounting grooves 21, a connecting through hole penetrating the mounting grooves 21 is provided in the connecting wall 24, a connecting rope 221 is passed through the connecting through hole, and the connecting rope 221 connects the support blocks 22 located in the adjacent mounting grooves 21. The connecting rope 221 connects a plurality of support blocks 22 in series to form an integrated support block 22, which can realize convenient and quick installation and avoid the loss of scattered support blocks 22. The connecting rope 221 can be a plastic rope.

[0079] Further optionally, if Figure 5 and Figure 6 As shown, the inside of the support block 22 is provided with a mounting through hole 222 along the depth direction of the mounting groove 21, and the bottom wall of the mounting groove 21 is provided with a first matching hole 25 matching with the mounting through hole 222. The connecting screw 6 passes through the first matching hole 25 and the mounting through hole 222 from the side of the radiator 2 close to the electrical box 1 and is fastened with the connecting nut. The integrated support block 22 can fix all the power devices 4 on the radiator 2. First, one end of the screw is passed through the first matching hole 25 through the inside of the radiator 2 into the mounting through hole 222 inside the support block 22 and extends out to be fastened with the connecting nut to install the integrated support block 22 and the radiator 2 together. The integrated support block 22 is used to tightly and firmly hold the power device 4 and the integrated heat dissipation block together. When fastening, the screw will squeeze the heat-conducting silicone material filled between the heat dissipation surface of the power device 4 and the radiator 2, so that the heat-conducting silicone can be fully distributed in the gap between the two, squeeze out the air, shorten the heat dissipation distance, and facilitate full heat dissipation.

[0080] Further optionally, as shown in Figure 9, at least a second mating hole 11 is opened at a position on the side wall of the electrical box 1 corresponding to the first mating hole 25 located at both ends of the radiator 2, and the connecting screw 6 passes through the second mating hole 11, the first mating hole 25, and the mounting through hole 222 from the outside of the electrical box 1 to be fastened with the connecting nut. Only the second mating hole 11 is opened on the side wall of the electrical box 1 corresponding to the first through holes located at both ends of the radiator 2. The radiator 2 can be fixed to the side wall of the electrical box 1 only through these two holes, thereby improving the assembly efficiency between the electrical box 1 and the radiator 2.

[0081] Further optionally, if Figure 6 and Figure 7 As shown, the heat dissipation device further includes a fixing block 23, which is located at the bottom of the connecting wall 24 and is used to fix the heat sink 2 on the PCB board 3. The fixing block 23 is provided with a fixing column 231, and the fixing column 231 cooperates with the mounting hole on the PCB board 3. The fixing block 23 is provided at the bottom of the connecting arm to raise the heat sink 2, so that the pins of the power module are inserted into the corresponding position of the PCB. A supporting column is added to the fixing block 23, and the supporting column passes through the hole on the PCB board 3. The supporting column and the PCB board 3 are combined together to fix the heat sink 2 on the PCB board 3.

[0082] During assembly, the PCB board 3 assembled with the radiator 2 and the power device 4 is placed into the electrical box 1. First, the PCB board 3 is fixed to the bottom of the electrical box 1, and then the fixation of the radiator 2 is started. Screws are sequentially passed through the second mating holes 11 and the first mating holes 25 from the outside of the electrical box 1 and into the radiator 2 and the integrated support block 22. The penetrating ends of the screws are fixed in the nuts within the integrated support column grooves. A heat-conducting silicone material is filled in the gap between the radiator 2 and the electrical box 1, and the screw-nut combination is tightened. The screws will squeeze the heat-conducting silicone material filled between the radiator 2 and the electrical box 1, enabling the heat-conducting silicone to be fully distributed in the gap between the two, squeezing out air, shortening the heat dissipation distance, facilitating the radiator 2 to dissipate the heat generated by the power device 4 into the external space, reducing the temperature of the power device 4, thereby controlling the temperature of the power device 4, reducing the surface temperature of the power device 4, improving the service performance of the power device 4, and enhancing the reliability and service life of the system.

[0083] Further optionally, as Figure 9 shown, heat dissipation fins 12 are provided at the positions on the side wall of the electrical box 1 corresponding to the radiator 2. At the positions where the integrated heat dissipation block contacts the electrical box 1, heat dissipation fins 12 are added to the outer surface of the electrical box 1. The heat dissipation fins 12 are evenly distributed on the surface of the electrical box 1. By using the heat dissipation fins 12, the contact area between the surface of the electrical box 1 and the air can be increased. In the flowing air, the larger the contact area, the better the heat dissipation effect.

[0084] Embodiment 2

[0085] This embodiment is different from Embodiment 1 in the form of its radiator 2. As Figure 10 and Figure 11 shown, the radiator 2 is arranged on the electrical box 1, and the power device 4 is arranged on the radiator 2 and located between the radiator 2 and the electrical box 1; the joint surface between the radiator 2 and the electrical box 1 matches the side wall of the electrical box 1. If the side wall of the electrical box 1 is a plane, then the joint surface between the radiator 2 and the electrical box 1 is a plane. If the side wall of the electrical box 1 is an arc surface, then the joint surface between the radiator 2 and the electrical box 1 is an arc surface. Alternatively, the radiator 2 and the side wall of the electrical box 1 are integrally formed, that is, directly formed by the side wall of the radiator 2. The joint surface between the radiator 2 and the power device 4 (such as IPM or rectifier bridge) matches the heat dissipation surface of the power device 4. For example, when the power device 4 is a flat IPM, the joint surface between the radiator 2 and the IPM is a planar type, as Figure 11 shown.

[0086] Embodiment 3

[0087] This embodiment adds a temperature detection module and a control module on the basis of the motors in Embodiment 1 and Embodiment 2.

[0088] Since existing motors lack temperature monitoring of the temperature of power devices and the temperature of electrical boxes, lack active heat dissipation control, use static temperature to evaluate the heat dissipation effect, and lack measures to further improve system performance, the motor of this embodiment is also provided with a temperature detection module and a control module. As Figure 1 and Figure 2 shown, the temperature detection module includes a first temperature detection device 51 and a second temperature detection device 52. The first temperature detection device 51 is arranged on the radiator 2, and the second temperature detection device 52 is arranged on the side wall of the electrical box 1. Since the heat loss is very small when the heat generated by the power device 4 is transferred to the radiator 2, the temperature value detected by the first temperature detection device 51 can directly reflect the temperature of the power device 4. The installation position of the first temperature detection module can be optionally set at the junction of the radiator 2 and the power device 4. The second temperature detection device 52 is the temperature of the electrical box 1. The first temperature detection device 51 and the second temperature detection device 52 transmit the detected temperature values to the control module. The control module determines the allowable operating parameter range of the motor according to the temperature values detected by the first temperature detection device 51 and the second temperature detection device 52, and controls the motor to operate within the allowable operating parameter range. The first temperature detection device 51 and the second temperature detection device 52 can be optionally thermistors. Further optionally, as Figure 2 shown, in order to avoid the temperature value detected by the second temperature detection device 52 being interfered by the heat of the radiator 2, the second temperature detection device 52 can be optionally arranged at a position on the side wall of the electrical box 1 opposite to the radiator 2.

[0089] In this embodiment, by dissipating heat and controlling the temperature of the power device 4, the heat dissipation performance is improved, the surface temperature of the power device 4 is reasonably controlled, by detecting the temperature of the power device 4 and the electrical box 1, using different heat dissipation coefficients, adopting different control strategies, the heat dissipation efficiency is improved, the performance of the power device 4 can be better utilized, the output power of the system is increased, and at the same time, the practical performance of the power device 4 can be greatly improved, the reliability of the system can be improved, and the service life of the system can be extended.

[0090] Embodiment 4

[0091] The motor control method proposed in this embodiment is based on the motor of Embodiment 3. As Figure 12 shown in the control flow chart, the control method includes: judging the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device, and determining the control strategy of the motor accordingly.

[0092] It includes the following steps:

[0093] S1. Obtain the first temperature value Ta detected by the first temperature detection device and the second temperature value Tb detected by the second temperature detection device;

[0094] S2. Compare the magnitudes of the first temperature value Ta with the first set temperature Tmin and the second set temperature Tmax respectively;

[0095] S3. Compare the magnitude of the difference Ta - Tb between the first temperature value Ta and the second temperature value Tb with the set temperature difference;

[0096] S4. Determine the allowable power range and / or current range based on the comparison results;

[0097] Among them, the first set temperature Tmin is the maximum temperature value at which the power device can be used; the second set temperature Tmax is the limit temperature value of the operating temperature range of the power device, and the first set temperature Tmin < the second set temperature Tmax. The temperature signal Ta represents the surface temperature of the power device, and the temperature signal Tb represents the temperature of the electrical box itself; Tmin is the maximum temperature value at which the power device can be used, generally 95°C, and the value of Tmax is the limit value of the operating temperature range of the power device. Different power devices have different operating ranges. The operating temperature of IGBT and MOSFET is -55 to 175°C; the operating temperature of IPM is -20 to 120°C; the operating temperature of the diode is -55 to 175°C; the operating temperature of the rectifier bridge is -40 to 150°C. In a specific embodiment, step S2 and step S3 can be carried out synchronously, or step S3 can be carried out first, and then step S2.

[0098] Specifically, when Ta < Tmin and Ta - Tb ≤ the set temperature difference, the motor is allowed to operate at the maximum power Pmax and the maximum current Imax; in a specific embodiment, the set temperature difference can be selected as 20°C. When the temperature values of the first temperature detection device and the second temperature detection device meet the above conditions, it indicates that the power device is in a good heat dissipation state and the power device is in the best operating state. When controlling the motor, the power limit and current limit can be released, and it can operate at Pmax (maximum power) and Imax (maximum current), giving priority to meeting the high power and large current operating states required for motor operation.

[0099] When Ta < Tmin and Ta - Tb > the set temperature difference, the motor is allowed to operate at the maximum power Pmax and the current not higher than the rated current Imid; when the temperature values of the first temperature detection device and the second temperature detection device meet the above conditions, it indicates that the power device is in a relatively good heat dissipation state, and the heat generation of the power device is mainly affected by the magnitude of the current. It can operate at Pmax (maximum power), and the motor is restricted to operate below Imid (rated current).

[0100] When Tmax > Ta > Tmin and Ta - Tb ≤ the set temperature difference, determine the allowable power range and / or current range according to the operating voltage of the motor; when the temperature values of the first temperature detection device and the second temperature detection device meet the above conditions, it indicates that the power device is in a relatively high temperature range. At the same time, under the condition of good heat dissipation, different control methods are selected according to different operating voltages. Specifically, obtain the operating voltage U of the motor; when the operating voltage U = U rated, it can operate at Pmid (rated power), and the motor is restricted to operate below Imid (rated current); when the operating voltage U > U rated, it can operate at Pmax (maximum power), and the motor is restricted to operate below Imax (maximum current); when the operating voltage U < U rated, it can operate at Pmid (rated power), and the motor is restricted to operate below Imid (rated current).

[0101] When Tmax > Ta > Tmin and Ta - Tb > the set temperature difference, allow the motor to operate with a current not higher than the first set multiple of the rated current Imid; when the temperature values of the first temperature detection device and the second temperature detection device meet the above conditions, it indicates that the power device is in a relatively high temperature range. At the same time, under the condition of poor heat dissipation, the power device enters a rapid heating state, and the operating current of the controller is restricted to operate at the first set multiple of Imid (rated current). The first set multiple can be selected as 0.8. At the same time, record the first duration t1 of Ta > Tmin; when the time t1 reaches the first set time, judge whether it satisfies: Ta - Tb > the set temperature difference. If it is satisfied, adjust the allowable current range of the motor to operate with a current not higher than the second set multiple of the rated current Imid. At the same time, record the time t when Ta > Tmin is entered. When the time t reaches the first set time, such as 30 min, judge the difference between Ta and Tb. If it is greater than or equal to the set temperature difference, further restrict the current to operate at the second set multiple of Imid (rated current). The second set multiple can be selected as 0.6 to reduce the temperature of the power device until it is judged that the difference between Ta and Tb is less than or equal to the set temperature difference, and enter the previous state;

[0102] When Ta > Tmax, allow the motor to operate with a current not higher than the second set multiple of the rated current Imid, and the first set multiple is greater than the second set multiple. When Ta > Tmax, restrict the current of the power device to operate below the second set multiple of Imid (rated current). Further record the second duration t2 of Ta > Tmax. When the time t2 reaches the second set time, execute the shutdown instruction. For example, if the current state running time is less than 5 min and Ta > Tmax after 5 min, execute the shutdown instruction, otherwise enter the previous state.

[0103] The motor of this embodiment has good heat dissipation performance, which can keep the surface temperature of the power device 4 within a relatively low level range, enabling the power device 4 to operate within a suitable temperature range for a long time, reducing the requirements of the system for the performance indicators of the power device 4. Even when using a low-cost power device 4, a relatively high operating power can still be obtained, enhancing the competitiveness of the product cost.

[0104] The above are only the preferred embodiments of the present invention, and there is no any form of limitation to the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent can make some changes or modifications to equivalent embodiments by using the technical content prompted above within the scope of the technical solution of the present invention. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the present invention.

Claims

1. A motor, characterized in that, including an electrical box, wherein a PCB board, power devices and a radiator are arranged inside the electrical box; the PCB board is fixed inside the electrical box; the radiator is assembled on the side wall of the electrical box, and the power devices are assembled on the PCB board and form a heat conduction relationship with the radiator; the radiator is arranged inside the electrical box, and the joint surface between the radiator and the electrical box matches the side wall of the electrical box; the radiator includes: a radiator main body, wherein a plurality of mounting grooves facing the inner side of the electrical box are formed at intervals along the circumferential direction of the side wall of the electrical box; there are a plurality of the power devices, and the plurality of power devices are distributed at intervals in the plurality of mounting grooves and form a heat conduction relationship with the mounting grooves; the mounting grooves penetrate through the top and bottom of the radiator main body, and first mounting surfaces and second mounting surfaces are respectively formed on the inner walls on both sides of the mounting grooves; a plurality of support blocks, the plurality of support blocks are respectively inserted into the plurality of mounting grooves to fix the power devices located in the mounting grooves on the radiator, so that the power devices are closely attached to the radiator; first mating surfaces and second mating surfaces which respectively cooperate with the first mounting surface and the second mounting surface are formed on both sides of the support block, and the power devices are respectively arranged between the first mounting surface and the first mating surface and between the second mounting surface and the second mating surface.

2. The motor according to claim 1, characterized in that, a certain angle is formed between the first mounting surface and the second mounting surface, so that the size of the opening of the mounting groove is larger than the size of the bottom wall of the mounting groove; the angle between the first mating surface and the second mating surface is equal to the angle between the first mounting surface and the second mounting surface.

3. The motor according to claim 1, characterized in that, the plurality of support blocks are connected in series by a connecting rope.

4. The motor according to claim 3, characterized in that, a connecting wall is formed between two adjacent mounting grooves, and the radiator further includes: a fixing block, the fixing block is located at the bottom of the connecting wall and is used for fixing the radiator on the PCB board; a fixing column is arranged on the fixing block, and the fixing column is matched with the mounting hole on the PCB board.

5. The motor according to claim 4, characterized in that, a connecting through hole penetrating through the mounting groove is formed in the connecting wall, and the connecting rope is arranged in the connecting through hole to connect the support blocks located in the adjacent mounting grooves.

6. The motor according to claim 1, characterized in that, a mounting through hole is formed in the support block along the depth direction of the mounting groove, and a first mating hole matched with the mounting through hole is formed in the bottom wall of the mounting groove; a connecting screw respectively passes through the first mating hole and the mounting through hole from the side of the radiator close to the electrical box and is tightly matched with a connecting nut.

7. The motor according to claim 6, characterized in that, at least second mating holes are formed at positions on the side wall of the electrical box corresponding to the first mating holes at both ends of the radiator, and the connecting screw respectively passes through the second mating hole, the first mating hole and the mounting through hole from the outside of the electrical box and is tightly matched with the connecting nut.

8. The motor according to claim 1, characterized in that, heat dissipation fins are arranged at positions on the side wall of the electrical box corresponding to the radiator.

9. The motor according to any one of claims 1-8, characterized in that, the motor further includes: The temperature detection module includes a first temperature detection device and a second temperature detection device. The first temperature detection device is arranged on the radiator, and the second temperature detection device is arranged at a position corresponding to the radiator on the side wall of the electrical box. The control module determines the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device, and determines the control strategy of the motor based on this.

10. A control method for the motor according to claim 9, characterized in that, The control method includes: Determining the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device, and determining the control strategy of the motor based on this.

11. The control method for the motor according to claim 10, characterized in that, The step of determining the heat dissipation effect of the power device according to the temperature values detected by the first temperature detection device and the second temperature detection device, and determining the control strategy of the motor based on this includes: Obtaining the first temperature value Ta detected by the first temperature detection device and the second temperature value Tb detected by the second temperature detection device. Respectively comparing the magnitude of the first temperature value Ta with the first set temperature Tmin and the second set temperature Tmax. Comparing the magnitude of the difference Ta - Tb between the first temperature value Ta and the second temperature value Tb with the set temperature difference. Determining the control strategy of the motor power and / or the motor current according to the comparison results. Wherein, the first set temperature Tmin is the maximum temperature value at which the power device can be used; the second set temperature Tmax is the limit temperature value of the operating temperature range of the power device, and the first set temperature Tmin < the second set temperature Tmax.

12. The control method for the motor according to claim 11, characterized in that, The steps of respectively comparing the magnitude of the first temperature value Ta with the first set temperature Tmin and the second set temperature Tmax, comparing the magnitude of the difference Ta - Tb between the first temperature value Ta and the second temperature value Tb with the set temperature difference, and determining the operating strategy of the motor power and / or the motor current according to the comparison results include: When Ta < Tmin and Ta - Tb ≤ the set temperature difference, the motor is allowed to operate at the maximum power Pmax and the maximum current Imax. When Ta < Tmin and Ta - Tb > the set temperature difference, the motor is allowed to operate at the maximum power Pmax and the current not higher than the rated current Imid. When Tmax > Ta > Tmin and Ta - Tb ≤ the set temperature difference, determining the allowable power range and / or current range according to the operating voltage of the motor. When Tmax > Ta > Tmin and Ta - Tb > the set temperature difference, the motor is allowed to operate at the first set multiple of the current not higher than the rated current Imid. When Ta > Tmax, the motor is allowed to operate at the second set multiple of the current not higher than the rated current Imid, and the first set multiple is greater than the second set multiple.

13. A control method for a motor according to claim 12, wherein, The step of determining the allowable power range and / or current range according to the operating voltage of the motor includes Obtaining the operating voltage U of the motor. When the working voltage U = rated voltage U 额 , the motor is allowed to operate at the rated power Pmid with a current not higher than the rated current Imid; When the working voltage U > the rated voltage U 额 , the motor is allowed to operate at the maximum power Pmax with the current not exceeding the maximum current Imax; When the working voltage U < rated voltage U 额 , the motor is allowed to operate at the rated power Pmid with a current not higher than the rated current Imid.

14. A control method for a motor according to claim 12, wherein, After allowing the motor to operate at the first set multiple of the current not higher than the rated current Imid when Tmax > Ta > Tmin and Ta - Tb > the set temperature difference, it further includes: Recording the first duration t1 when Ta > Tmin. When the time t1 reaches the first set time, it is judged whether the following condition is satisfied: Ta - Tb > the set temperature difference. If it is satisfied, the allowable current range of the motor is adjusted to operate at a second set multiple of the current not higher than the rated current Imid.

15. A control method for a motor according to claim 12, wherein, When Ta > Tmax, after allowing the motor to operate at a second set multiple of the current not higher than the rated current Imid, it further includes: Recording the second duration t2 of Ta > Tmax, and when the time t2 reaches the second set time, executing a shutdown instruction.

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