Driving motor cooling system, control method and new energy pure electric road roller

Abstract

The invention discloses a driving motor cooling system, a control method and a new energy pure electric road roller, and belongs to the technical field of electric control of motors, the driving motor cooling system adopts phase change of a refrigerant in a compressor, a cooling mechanism and a condensation mechanism to realize rapid cooling of a driving motor, and the driving motor cooling system is simple in structure and convenient to operate. Meanwhile, a cooling medium channel for cooling the driving motor is formed in the stator of the driving motor by utilizing a plurality of passages of the cooling mechanism and the liquid collecting area, so that the aim of cooling a coil from the inner wall of the stator is fulfilled, the influence of the wall thickness on the heat conduction speed of single-side contact type heat dissipation is avoided, the uniform cooling of the stator is also realized, and the service life of the stator is prolonged. The situation that the local temperature of the stator is too high is eradicated, the driving motor can be rapidly cooled, the response speed is high, and the problems that a current new energy pavement mechanical driving motor is poor in heat dissipation effect and low in response speed are solved.

Description

Technical Field

[0001] The present invention relates to a driving motor cooling system, a control method and a new energy pure electric road roller, belonging to the technical field of motor electronic control. Background Art

[0002] Excessive temperature rise inside the motor is extremely harmful. It will accelerate the aging of the insulating material inside the motor, shorten the service life and reduce the operating efficiency, and then lead to a continuous increase in heat generation, forming a vicious cycle, seriously threatening the life and operating safety of the motor; At present, the heat dissipation methods of the driving motors of new energy road machinery on the market mainly include air cooling, indirect coolant cooling and direct oil cooling; although air cooling has the advantages of simplicity and portability, its cooling effect is poor and the heat dissipation efficiency is extremely low, and it is only applicable to small driving motors with a power within 10kw; although the cooling efficiency of coolant cooling and oil cooling is higher than that of air cooling and can control the temperature of the driving motor to a certain extent, the cooling efficiency is still limited and difficult to meet the heat dissipation requirements of high torque density motors. In addition, the indirect cooling method has a large thermal resistance and a slow response speed. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a driving motor cooling system, a control method and a new energy pure electric road roller, which can quickly cool down the driving motor, have a fast response speed, and solve the problems of poor heat dissipation effect and slow response speed of the driving motors of current new energy road machinery.

[0004] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions: On the one hand, the present invention provides a driving motor cooling system, including: A cooling medium container filled with a refrigerant; A compressor connected to the cooling medium container; A cooling mechanism provided on the driving motor; wherein, the cooling mechanism is provided with multiple passages and a liquid collecting area connected to the multiple passages on the stator of the driving motor, and a cooling medium channel for dissipating heat from the driving motor is formed inside the stator of the driving motor through the multiple passages and the liquid collecting area; A first cooling pipeline respectively connected to the compressor and the cooling mechanism; A second cooling pipeline respectively connected to the cooling mechanism and the compressor; A condensing mechanism for condensing the refrigerant passing through the cooling mechanism; A third cooling pipeline respectively connected to the compressor and the condensing mechanism; A fourth cooling pipeline respectively connected to the condensing mechanism and the cooling medium container; A sensor group including multiple temperature sensors, and the multiple temperature sensors are respectively arranged on the cooling mechanism and the stator of the driving motor; A controller, which is electrically connected to a compressor, a condensing mechanism, and a sensor group respectively.

[0005] Optionally, the cooling mechanism includes a plurality of through holes formed in the stator of the driving motor; Wherein, the stator of the driving motor is stacked by a plurality of stator silicon steel sheets, and the plurality of through holes respectively form a plurality of paths among the plurality of stator silicon steel sheets.

[0006] Optionally, the cooling medium channel further includes a plurality of heat dissipation pipelines arranged in the paths, and both ends of the heat dissipation pipelines are connected to the liquid collection area.

[0007] Optionally, an insulating layer is further provided between the heat dissipation pipeline and the path.

[0008] Optionally, the liquid collection area includes a first sealing end cover and a second sealing end cover. The first sealing end cover is provided with a cooling medium inlet, and the second sealing end cover is provided with a cooling medium outlet; The cooling medium inlet is connected to a first cooling pipeline, and the cooling medium outlet is connected to a second cooling pipeline; The first sealing end cover and the second sealing end cover are respectively located at both ends of the heat dissipation pipeline and are connected and communicated with the heat dissipation pipeline.

[0009] Optionally, the refrigerant includes R1234yf.

[0010] On the other hand, the present invention provides a control method for a driving motor cooling system. The method is based on the above driving motor cooling system, and the method includes: Obtain the coil winding temperature of the stator of the driving motor; Determine the true heating power of the stator of the driving motor according to the coil winding temperature; Based on the true heating power of the stator of the driving motor, control the rotation speed of the compressor by using a pre-constructed temperature control model, change the mass flow rate of the refrigerant, and reduce the temperature of the stator of the driving motor.

[0011] Further, the pre-constructed temperature control model includes: The temperature control model is represented by the following formula: ; ; ; Wherein: represents the true heating power of the stator of the driving motor; represents the mass flow rate of the refrigerant, , represents the rotation speed of the compressor, represents the displacement of the compressor, represents the volumetric efficiency of the compressor; represents the temperature of the cooling medium inlet, represents the temperature of the cooling medium outlet; represents the heat power carried away by the refrigerant, represents the mass flow rate of the refrigerant, represents the specific heat capacity of the refrigerant; represents the heat stored in the drive motor, represents the specific heat capacity of the drive motor stator, represents the ambient temperature, t represents time, represents the average temperature change rate of the drive motor itself.

[0012] Furthermore, determining the true heat generation power of the drive motor stator according to the coil winding temperature includes: Calculating the heat generation power of the drive motor stator coil winding by the following formula: ; Where: represents the heat generation power of the drive motor stator; represents the specific heat capacity of the drive motor stator, represents the ambient temperature, t represents time, represents the average temperature change rate of the drive motor itself, represents the thermal resistance of the drive motor; represents the coil winding temperature of the drive motor stator, , represents the front-end coil winding temperature of the drive motor stator, represents the rear-end coil winding temperature of the drive motor stator; Compare the heat generation power of the front-end coil winding of the drive motor stator with the heat generation power of the rear-end coil winding of the drive motor stator, and take the maximum value as the true heat generation power of the drive motor stator.

[0013] The present invention also provides a new energy pure voltage road roller, including the drive motor cooling system as described above.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention: 1. The present invention realizes the rapid cooling of the drive motor by the phase change of the refrigerant in the compressor, the cooling mechanism, and the condensing mechanism. At the same time, multiple channels of the cooling mechanism and the liquid collection area form a cooling medium channel for dissipating heat from the drive motor inside the stator of the drive motor, achieving the purpose of dissipating heat from the inner wall of the stator to the coil, avoiding the influence of the wall thickness on the heat conduction speed of the single-sided contact type heat dissipation, and also realizing the uniform cooling of the stator, eliminating the situation of excessive local temperature of the stator, being able to quickly cool the drive motor, with a fast response speed, solving the problems of poor heat dissipation effect and slow response speed of the drive motor of the current new energy road machinery.

[0015] 2. Based on the actual heating power of the stator of the drive motor, the present invention controls the rotational speed of the compressor through a pre-constructed temperature control model, changes the mass flow rate of the refrigerant, reduces the temperature of the stator of the drive motor, and can dynamically adjust the rotational speed of the compressor according to the actual heating power of the stator of the drive motor, improving the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of a drive motor cooling system provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the distribution position of through holes provided by an embodiment of the present invention; Figure 3 is a schematic top view structural diagram of the stator of the drive motor provided by an embodiment of the present invention; Figure 4 is a flowchart of a control method for a drive motor cooling system provided by an embodiment of the present invention.

[0017] In the figure: 1. Cooling medium container; 2. Compressor; 3. Cooling mechanism; 301. Through hole; 302. Heat dissipation pipeline; 303. First sealing end cover; 3031. Cooling medium inlet; 304. Second sealing end cover; 3032. Cooling medium outlet; 4. Condensing mechanism; 5. First cooling pipeline; 6. Second cooling pipeline; 7. Third cooling pipeline; 8. Fourth cooling pipeline; 9. Insulation layer; 10. Stator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0019] Embodiment 1 As Figure 1 shown, a drive motor cooling system includes: a cooling medium container 1, a compressor 2, a cooling mechanism 3, a condensing mechanism 4, a sensor group, and a controller; Among them, a refrigerant is added to the cooling medium container 1. In this embodiment, the refrigerant is R1234yf, and the compressor 2 is connected to the cooling medium container 1; The compressor 2 is also electrically connected to the controller; The cooling mechanism 3 is provided with multiple passages and a liquid collecting area connected to the multiple passages in the drive motor stator 10. The cooling medium channels for dissipating heat from the drive motor are formed inside the drive motor stator 10 through the multiple passages and the liquid collecting area. Specifically: As Figure 2 And Figure 3 As shown, the cooling mechanism 3 includes a plurality of through holes 301 formed in the drive motor stator 10; among them, the drive motor stator 10 is stacked by a plurality of stator 10 silicon steel sheets, and the plurality of through holes 301 respectively form multiple passages among the plurality of stator 10 silicon steel sheets; The cooling medium channels include a plurality of heat dissipation pipelines 302 arranged in the passages, and both ends of the heat dissipation pipelines 302 are connected to the liquid collecting area; The liquid collecting area includes a first sealing end cover 303 and a second sealing end cover 304. The first sealing end cover 303 and the second sealing end cover 304 are respectively located at both ends of the heat dissipation pipeline 302 and are connected and communicated with the heat dissipation pipeline 302; The first sealing end cover 303 is provided with a cooling medium inlet 3031, and the second sealing end cover 304 is provided with a cooling medium outlet 3032. The cooling medium inlet 3031 is communicated with a first cooling pipeline 5, and the other end of the first cooling pipeline 5 is connected to the compressor 2. The cooling medium outlet 3032 is communicated with a second cooling pipeline 6, and the other end of the second cooling pipeline 6 is connected to the compressor 2; By using the multiple passages of the cooling mechanism 3 and the liquid collecting area to form cooling medium channels for dissipating heat from the drive motor inside the drive motor stator 10, the purpose of dissipating heat from the inner wall of the stator 10 to the coil is achieved, avoiding the influence of the wall thickness on the heat conduction speed of the single-sided contact type heat dissipation, and also realizing uniform cooling of the stator 10, eliminating the situation of over-high local temperature of the stator 10; The compressor 2 is also connected to a third cooling pipeline 7, and the third cooling pipeline 7 is connected to the condensing mechanism 4; The condensing mechanism 4 is also connected to a fourth cooling pipeline 8, and the fourth cooling pipeline 8 is connected to the cooling medium container 1; The condensing mechanism 4 is electrically connected to the controller. In this embodiment, the condensing mechanism 4 is a condenser; The sensor group includes a plurality of temperature sensors, and the plurality of temperature sensors are all electrically connected to the controller; Multiple temperature sensors are respectively installed at the cooling medium inlet 3031, the cooling medium outlet 3032, the front-end winding of the coil of the drive motor stator 10, the rear-end winding of the coil of the drive motor stator 10, and on the drive motor housing, and can obtain the temperature of the cooling medium inlet 3031, the temperature of the cooling medium outlet 3032, the temperature of the front-end winding of the coil of the drive motor stator 10, the temperature of the rear-end winding of the coil of the drive motor stator 10, and the ambient temperature; In order to protect the coil, an insulating layer 9 is also filled between the heat dissipation pipeline 302 and the passage.

[0020] Working principle The low-temperature and low-pressure liquid refrigerant in the compressor enters the first sealing end cover 303 from the cooling medium inlet 3031 through the first cooling pipeline 5, and then enters the multiple heat dissipation pipelines 302 from the first sealing end cover 303. The low-temperature and low-pressure liquid refrigerant absorbs a large amount of heat in the heat dissipation pipeline 302 and vaporizes and enters the second sealing end cover 304. The vaporized refrigerant enters the compressor 2 through the second cooling pipeline 6, and becomes a high-pressure and high-temperature gaseous refrigerant through the compression of the compressor 2. The high-pressure and high-temperature gaseous refrigerant enters the condensation mechanism 4 through the third cooling pipeline 7 to perform heat exchange with the external atmosphere, and turns into a low-temperature and high-pressure refrigerant. The low-temperature and high-pressure refrigerant returns to the cooling medium container 1 through the fourth cooling pipeline 8.

[0021] Embodiment 2 Such as Figure 4 As shown, a control method for a drive motor cooling system, the method is based on the drive motor cooling system in Embodiment 1, and the control method for the drive motor cooling system includes: Obtain the temperature of the coil winding of the drive motor stator; According to the temperature of the coil winding, determine the actual heat generation power of the drive motor stator. Specifically: Calculate the heat generation power of the coil winding of the drive motor stator through the following formula: ; represents the heat generation power of the drive motor stator; represents the specific heat capacity of the drive motor stator, represents the ambient temperature, t represents time, represents the average temperature change rate of the drive motor itself, represents the thermal resistance of the drive motor; represents the temperature of the coil winding of the drive motor stator, , represents the temperature of the front-end winding of the coil of the drive motor stator, Represents the temperature of the rear-end winding of the coil of the drive motor stator; Compare the heating power of the front-end winding of the drive motor stator coil with the heating power of the rear-end winding of the drive motor stator coil, and take the maximum value as the true heating power of the drive motor stator.

[0022] Based on the true heating power of the drive motor stator, use the pre-constructed temperature control model to control the compressor speed, change the mass flow rate of the refrigerant, and reduce the temperature of the drive motor stator; among them, the pre-constructed temperature control model includes: the temperature control model is represented by the following formula: ; ; ; Represents the true heating power of the drive motor stator; Represents the mass flow rate of the refrigerant, , Represents the compressor speed, Represents the compressor displacement, Represents the compressor volumetric efficiency; Represents the temperature of the cooling medium inlet, Represents the temperature of the cooling medium outlet; Represents the heat power carried away by the refrigerant, Represents the mass flow rate of the refrigerant, Represents the specific heat capacity of the refrigerant; Represents the heat stored in the drive motor.

[0023] Embodiment 3 A new energy pure voltage road roller includes the drive motor cooling system as described above.

[0024] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and 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, and therefore cannot be understood as a limitation of the present invention. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. 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 situations.

[0026] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A driving motor cooling system, characterized in that, Comprising: A cooling medium container (1) filled with a refrigerant; A compressor (2) connected to the cooling medium container (1); A cooling mechanism (3) provided for the driving motor; wherein, the cooling mechanism (3) has a plurality of passages and a liquid collecting area connected to the plurality of passages in the driving motor stator (10), and a cooling medium passage for dissipating heat from the driving motor is formed inside the driving motor stator (10) through the plurality of passages and the liquid collecting area; A first cooling pipeline (5) respectively connected to the compressor (2) and the cooling mechanism (3); A second cooling pipeline (6) respectively connected to the cooling mechanism (3) and the compressor (2); A condensing mechanism (4) for condensing the refrigerant passing through the cooling mechanism (3); A third cooling pipeline (7) respectively connected to the compressor (2) and the condensing mechanism (4); A fourth cooling pipeline (8) respectively connected to the condensing mechanism (4) and the cooling medium container (1); A sensor group including a plurality of temperature sensors respectively provided on the cooling mechanism (3) and the driving motor stator (10); A controller electrically connected to the compressor (2), the condensing mechanism (4), and the sensor group respectively.

2. The drive motor cooling system according to claim 1, characterized in that The cooling mechanism (3) includes a plurality of through holes (301) formed in the driving motor stator (10); Wherein, the driving motor stator (10) is stacked by a plurality of stator (10) silicon steel sheets, and the plurality of through holes (301) respectively form a plurality of passages between the plurality of stator (10) silicon steel sheets.

3. The drive motor cooling system according to claim 1, wherein, The cooling medium passage further includes a plurality of heat dissipation pipelines (302) provided in the passages, and both ends of the heat dissipation pipelines (302) are connected to the liquid collecting area.

4. The drive motor cooling system according to claim 3, wherein An insulating layer (9) is further provided between the heat dissipation pipeline (302) and the passage.

5. The drive motor cooling system according to claim 3, wherein, The liquid collecting area includes a first sealing end cover (303) and a second sealing end cover (304), the first sealing end cover (303) is provided with a cooling medium inlet (3031), and the second sealing end cover (304) is provided with a cooling medium outlet (3032); The cooling medium inlet is connected to the first cooling pipeline (5), and the cooling medium outlet (3032) is connected to the second cooling pipeline (6); The first sealing end cover (303) and the second sealing end cover (304) are respectively located at both ends of the heat dissipation pipeline (302) and are connected and communicated with the heat dissipation pipeline (302).

6. The drive motor cooling system according to claim 1, wherein, The refrigerant includes R1234yf.

7. A control method for a drive motor cooling system, characterized in that, The method is based on the driving motor cooling system according to any one of claims 1 to 6, and the method includes: Obtaining the coil winding temperature of the driving motor stator; Determining the true heat generation power of the driving motor stator according to the coil winding temperature; Based on the true heat generation power of the driving motor stator, controlling the rotational speed of the compressor by using a pre-constructed temperature control model, changing the mass flow rate of the refrigerant, and reducing the temperature of the driving motor stator.

8. The control method of the drive motor cooling system according to claim 7, wherein The pre-constructed temperature control model includes: The temperature control model is represented by the following formula: ； ； ； Wherein: Indicates the true heating power of the drive motor stator; represents the mass flow rate of the refrigerant, , represents the rotational speed of the compressor, represents the displacement of the compressor, represents the volumetric efficiency of the compressor; represents the temperature of the cooling medium inlet, represents the temperature of the cooling medium outlet; represents the heat power carried away by the refrigerant, represents the specific heat capacity of the refrigerant; represents the thermal power stored in the drive motor, represents the specific heat capacity of the stator of the drive motor, represents the ambient temperature, t represents time, represents the average temperature change rate of the drive motor itself.

9. The control method of the drive motor cooling system according to claim 7, characterized in that The step of determining the true heat generation power of the driving motor stator according to the coil winding temperature includes: Calculating the heat generation power of the driving motor stator coil winding by the following formula: ； Wherein: Indicates the heating power of the drive motor stator; represents the specific heat capacity of the drive motor stator, represents the ambient temperature, t represents time, represents the average temperature change rate of the drive motor itself, represents the thermal resistance of the drive motor; Indicates the temperature of the coil winding of the drive motor stator, , Indicates the temperature of the front-end winding of the coil of the drive motor stator, Indicates the temperature of the rear-end winding of the coil of the drive motor stator; Compare the heating power of the front-end winding of the drive motor stator coil with that of the rear-end winding of the drive motor stator coil, and take the maximum value as the true heating power of the drive motor stator.

10. A new energy pure voltage road roller, characterized in that, It includes the drive motor cooling system according to any one of claims 1 to 6.

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