Control method of compressor rotation speed and vehicle

Abstract

The present application relates to the technical field of production and manufacture of vehicles, and particularly relates to a compressor rotating speed control method and a vehicle. When the compressor is started, the compressor is operated according to an actual rotating speed through a feedforward rotating speed and an adjusting rotating speed. The actual rotating speed of the compressor is obtained through PI adjustment on the basis of the feedforward rotating speed, so as to control the steady-state performance of the compressor, and the compressor is kept in an optimal state in the operation process, thereby reducing energy consumption. In a fault state, outputting a too high compressor rotating speed can waste energy consumption. The energy waste can be reduced by operating the compressor within a limited rotating speed. Through such a design, the compressor rotating speed is controlled, the steady-state performance of the compressor is controlled, energy consumption is reduced, and the endurance is increased. In a fault state, the compressor is controlled to operate at a limited rotating speed, and the energy waste is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of vehicle production and manufacturing, specifically to a method for controlling compressor speed and a vehicle. Background Technology

[0002] With the widespread adoption of new energy vehicles in daily travel, vehicle energy consumption is receiving increasing attention from users. A superior vehicle thermal management system and control technology make a significant contribution to reducing energy consumption, increasing driving range, and improving overall vehicle range. This is primarily achieved by controlling the compressor to manage the vehicle's thermal management system. Therefore, reducing energy consumption and increasing driving range through compressor control is a crucial technical problem that urgently needs to be solved. Summary of the Invention

[0003] The purpose of this application is to provide a method for controlling the speed of a compressor and a vehicle.

[0004] This application provides a method for controlling compressor speed, comprising: when the compressor is started, obtaining a preset feedforward speed of the compressor based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature; obtaining the target temperature and the real-time actual temperature of the evaporator, and calculating the corresponding adjustment speed based on the target temperature and the actual temperature using a PI converter; obtaining the real-time actual speed based on the sum of the preset feedforward speed and the adjustment speed, and controlling the compressor to run at the actual speed; periodically monitoring the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor at a preset time interval, and controlling the compressor to run at a preset limit speed if any one of the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, or the actual power of the compressor meets the corresponding preset threshold.

[0005] In one exemplary embodiment of this application, when the compressor starts and runs normally at a speed less than or equal to its rated speed, obtaining a preset feedforward speed of the compressor based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature includes: obtaining a real-time preset predicted demand speed of the compressor based on the obtained real-time cooling capacity demand at the evaporator end and the real-time outside temperature; in response to the vehicle refrigeration system switching cooling modes, obtaining the instantaneous speed of the compressor when switching cooling modes, and obtaining a preset compensation speed based on the instantaneous speed and the cooling modes before and after the switching; and obtaining the preset feedforward speed based on the sum of the real-time preset predicted demand speed and the preset compensation speed.

[0006] In one exemplary embodiment of this application, obtaining the preset compensation speed based on the instantaneous speed and the cooling mode before and after the switch includes: obtaining the current cooling mode before and after the switch and the instantaneous speed; querying a pre-stored preset compensation speed table in the database based on the instantaneous speed of the cooling mode before and after the switch, and obtaining the preset compensation speed corresponding to the preset compensation speed table.

[0007] In one exemplary embodiment of this application, the step of obtaining the target temperature and the real-time actual temperature of the evaporator, and calculating the corresponding adjustment speed using PI based on the target temperature and the actual temperature, includes: obtaining the target temperature and the real-time actual temperature of the evaporator, and calculating the temperature difference Δt; obtaining the cooling mode of the vehicle cooling system, and obtaining a preset first coefficient P and a second coefficient I based on the temperature difference Δt, the cooling mode, and the outside temperature; obtaining a first adjustment speed based on the temperature difference and the first coefficient P according to the formula P*Δt; obtaining a second adjustment speed based on the temperature difference and the second coefficient I according to the formula ∑(I*Δt); the adjustment speed is equal to the sum of the first adjustment speed and the second adjustment speed.

[0008] In one exemplary embodiment of this application, obtaining the cooling mode of the vehicle cooling system and obtaining a preset first coefficient P and second coefficient I based on the temperature difference, the cooling mode, and the outside temperature includes: obtaining a table of adjustment speed coefficients corresponding to the cooling mode in a database based on the current cooling mode; and querying the corresponding adjustment speed coefficient table to obtain the pre-stored first coefficient P and second coefficient I based on the temperature difference Δt and the outside temperature.

[0009] In one exemplary embodiment of this application, the step of periodically monitoring the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the power of the compressor according to a preset time period, and controlling the compressor to operate at a preset speed limit in response to any one of the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor satisfying a corresponding preset threshold, includes: the preset thresholds include a preset frosting temperature of the evaporator, a preset outlet pressure of the compressor, a preset inlet pressure of the compressor, and a preset available power of the compressor; when the compressor is running at the actual speed, the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the power of the compressor are periodically monitored according to a preset time period. The compressor's outlet pressure, inlet pressure, and actual power are measured. Simultaneously, the actual temperature of the evaporator is compared with the preset frosting temperature, the compressor's outlet pressure with the preset outlet pressure, the compressor's inlet pressure with the preset inlet pressure, and the compressor's actual power with the preset available power. In response to at least one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the compressor's outlet pressure is higher than the preset outlet pressure, the compressor's inlet pressure is lower than the preset inlet pressure, or the compressor's actual power is greater than the preset available power, the compressor is adjusted to operate at the preset limited speed.

[0010] In one exemplary embodiment of this application, the method further includes: responding to the following conditions: the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, and the actual power of the compressor is lower than or equal to the preset available power; then, in real time or periodically, based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature, the method acquires the preset feedforward speed of the compressor; acquires the target temperature of the evaporator and the real-time actual temperature, and calculates the corresponding adjustment speed using a PI converter based on the target temperature and the actual temperature; obtains the real-time actual speed based on the sum of the preset feedforward speed and the adjustment speed, and controls the compressor to operate at the actual speed.

[0011] In one exemplary embodiment of this application, after controlling the compressor to operate at a preset limited speed, the method further includes: no longer calculating the preset feedforward speed and the adjustment speed, but controlling the compressor to maintain the preset limited speed.

[0012] In one exemplary embodiment of this application, before the compressor starts operating normally at a speed less than or equal to its rated speed, a preset feedforward speed of the compressor is obtained based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature; the process further includes: starting the compressor; simultaneously obtaining the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor; simultaneously comparing and analyzing the actual temperature of the evaporator with a preset frosting temperature, the outlet pressure of the compressor with a preset outlet pressure, the inlet pressure of the compressor with a preset inlet pressure, and the actual power of the compressor being lower than a preset available power; in response to the conditions that the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, and the actual power of the compressor is lower than or equal to the preset available power, the compressor starts operating normally at a speed less than or equal to its rated speed.

[0013] In one exemplary embodiment of this application, the system further includes: in response to at least any one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is higher than the preset available power, the compressor is controlled to start and run at a preset limited speed until the refrigeration system is shut down.

[0014] In one exemplary embodiment of this application, the step of obtaining the real-time preset feedforward speed of the compressor based on the real-time cooling capacity demand at the evaporator end of the compressor and the real-time outside temperature includes: obtaining the real-time cooling capacity demand and the corresponding outside temperature; querying a pre-stored preset feedforward speed table in the database based on the real-time cooling capacity demand and the corresponding outside temperature to obtain the corresponding preset feedforward speed.

[0015] This application also provides a vehicle, including a processor and a memory, the processor being connected to the memory, wherein the memory stores program instructions; the processor is used to execute the program instructions stored in the memory to implement the control method.

[0016] This application discloses a compressor speed control method and vehicle, which has the following beneficial effects: When the compressor starts working, the compressor operates at its actual speed through feedforward speed and regulating speed. Based on the feedforward speed, the actual compressor speed is obtained through PI regulation. PI regulation includes proportional regulation and integral regulation. Proportional regulation reacts proportionally to system deviations; once a deviation occurs, proportional regulation immediately takes effect to reduce it. Integral regulation eliminates steady-state errors and improves error-free performance. This controls the compressor's steady-state performance, ensuring it operates at its optimal state and reducing energy consumption. Simultaneously, the actual evaporator temperature, compressor outlet and inlet pressures, and compressor power are periodically monitored. If any of these parameters falls outside a threshold range, the compressor may be in a fault state. In a fault state, excessively high compressor speeds waste energy. By limiting the compressor's speed, energy waste is reduced. Through this design, controlling the compressor speed controls its steady-state performance, reducing energy consumption and increasing range. Furthermore, limiting the compressor's speed during fault states further reduces energy waste.

[0017] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 This is a first flowchart illustrating a method for controlling compressor speed according to an embodiment of the present invention;

[0021] Figure 2 This is a flowchart of step S100;

[0022] Figure 3 This is a flowchart of step S120;

[0023] Figure 4 This is a flowchart of step S200;

[0024] Figure 5This is a flowchart of step S220;

[0025] Figure 6 This is a flowchart of step S400;

[0026] Figure 7 This is a flowchart illustrating the process prior to step S100;

[0027] Figure 8 This is a structural schematic diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0028] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0029] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0030] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present application, and should not be construed as limiting the present application.

[0031] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0032] With the widespread adoption of new energy vehicles in daily travel, vehicle energy consumption is receiving increasing attention from users. A superior vehicle thermal management system and control technology makes a significant contribution to reducing energy consumption, increasing driving range, and improving overall vehicle range, while also providing system protection. This is primarily achieved by controlling the compressor to manage the vehicle's thermal management system. Therefore, reducing energy consumption, increasing driving range, and achieving system self-protection through compressor control are pressing technical challenges that need to be addressed.

[0033] This application provides a method for controlling the compressor speed in a vehicle refrigeration system, specifically including steps S100 to S400.

[0034] S100: When the compressor starts and runs normally at a speed less than or equal to the rated speed, the preset feedforward speed of the compressor is obtained based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature.

[0035] First, steps S100 to S400 involve starting the compressor and adjusting and controlling it to operate at a reasonable speed within the rated speed range. The rated speed refers to the compressor's speed at its rated power; this is a factory-set value that can be adjusted based on compressor performance and requirements, specifically 8500 rpm.

[0036] Specifically, the compressor starts operating in response to a start command from the refrigeration system. This start command can be issued to the refrigeration system via buttons or voice control. Upon receiving the start command, the refrigeration system activates the compressor. The real-time cooling capacity requirement at the evaporator end is obtained from the real-time interior temperature and the target interior temperature. This means the amount of cooling required to lower the real-time interior temperature to the target interior temperature is determined. The real-time interior temperature and the target interior temperature are collected by sensors installed in the vehicle. The compressor's feedforward speed is then determined based on the real-time cooling capacity requirement and the real-time outside temperature.

[0037] S200: Obtain the target temperature and real-time actual temperature of the evaporator, and calculate the corresponding adjustment speed based on the target temperature and actual temperature using PI.

[0038] In refrigeration systems, the feedforward speed of the compressor cannot ensure that the evaporator reaches the ideal cooling state, resulting in an error between the cooling capacity demanded by the evaporator and the target cooling demand. Within this error range, appropriate compressor control methods are needed to ensure that the refrigeration system maintains steady-state performance while meeting the target cooling demand. Therefore, PI control is used to adjust the compressor speed based on the feedforward speed. PI control combines proportional and integral control. Proportional control responds proportionally to system deviations; once a deviation occurs, proportional control immediately adjusts to reduce it. Integral control eliminates steady-state errors and improves the error-free performance.

[0039] S300: The actual speed is obtained in real time based on the sum of the preset feedforward speed and the adjusted speed, and the compressor is controlled to run at the actual speed.

[0040] The refrigeration system obtains the actual speed through feedforward speed and regulating speed, which has good steady-state performance and can meet the target refrigeration demand, keeping the compressor in optimal condition during operation, thereby reducing energy consumption.

[0041] S400: Periodically monitors the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor according to a preset duration. If any one of the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, or the actual power of the compressor meets the corresponding preset threshold, the compressor is controlled to run at the preset limit speed.

[0042] When the compressor is running at its actual real-time speed, the refrigeration system may experience increased energy consumption due to malfunctions. Therefore, it is necessary to periodically monitor the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor. In order to address malfunctions in the refrigeration system by adjusting the compressor speed, the energy consumption under malfunction conditions can be reduced.

[0043] Specifically, in the S400, the refrigeration system monitors the actual evaporator temperature, compressor outlet and inlet pressures, and compressor power at preset intervals (e.g., 0.1s, 0.5s). Monitoring the evaporator temperature determines if frosting has occurred, while monitoring the compressor outlet and inlet pressures and actual power indicates compressor malfunction. For example, excessively low evaporator temperature may indicate frosting; excessively high outlet pressure and / or excessively low inlet pressure may indicate compressor outlet and inlet blockage; excessively high actual power may indicate a short circuit in the refrigeration system or compressor overload. Therefore, monitoring the evaporator temperature, compressor outlet and inlet pressures, and compressor power reduces losses due to malfunctions and allows for limiting compressor speed based on fault diagnosis, further reducing energy loss.

[0044] Therefore, in this application, when the compressor is started and operating, the compressor runs at its actual speed through feedforward speed and regulating speed. The actual compressor speed is obtained through PI regulation based on the feedforward speed. PI regulation includes proportional and integral regulation. Proportional regulation reacts proportionally to system deviations; once a deviation occurs, proportional regulation immediately takes effect to reduce it. Integral regulation eliminates steady-state errors and improves error-free performance, thereby controlling the compressor's steady-state performance and maintaining optimal operation, thus reducing energy consumption. Simultaneously, the actual evaporator temperature, compressor outlet and inlet pressures, and actual compressor power are periodically monitored. If any of these parameters falls outside a threshold range, the compressor may be in a fault state. In a fault state, excessively high compressor speeds waste energy. By operating the compressor within a limited speed range, energy waste is reduced. Through this design, the compressor speed is controlled to maintain steady-state performance, reducing energy consumption and increasing range. Furthermore, by limiting the compressor's speed during fault conditions, energy waste is minimized.

[0045] In some specific embodiments, refer to Figure 2 As shown, Figure 2 This is a flowchart of step S100, which specifically includes steps S110 to S140.

[0046] Step S110: Based on the real-time cooling capacity demand at the evaporator end and the real-time outside temperature, obtain the real-time preset predicted speed of the compressor.

[0047] Based on simulations or extensive actual motion tests, a one-to-one correspondence is obtained between the real-time cooling capacity demand at the evaporator, the real-time outside temperature, and the predicted required engine speed, and this data correspondence is maintained in a database. Preferably, the one-to-one correspondence between the real-time cooling capacity demand at the evaporator, the real-time outside temperature, and the predicted required engine speed can be generated into preset files, tables, etc., and stored in the database for easy access later. The corresponding preset feedforward engine speed can be retrieved from the database based on the real-time cooling capacity demand at the evaporator and the real-time outside temperature.

[0048] Specifically, in one particular embodiment, the correspondence between the real-time cooling capacity demand at the evaporator end, the real-time outside temperature, and the preset predicted required rotational speed is shown in the table below:

[0049]

[0050] It should be noted that the correspondence between the real-time cooling capacity demand at the evaporator end, the real-time outside temperature, and the preset predicted speed demand will vary for different types of vehicles, or even different models of the same type of vehicle. Therefore, the relationship between the real-time cooling capacity demand at the evaporator end, the real-time outside temperature, and the preset predicted speed demand is not limited to the table above. The table above is merely a specific embodiment to facilitate the description of the technical principles of this application.

[0051] According to the table above, for example, when the real-time outside temperature is 20℃ and the real-time cooling demand at the evaporator is 500W, the corresponding preset predicted speed is 1000rpm. The refrigeration system can obtain the real-time outside temperature through sensors; the table lists 10℃, 20℃, 30℃, and 40℃, including but not limited to these values. The real-time cooling demand at the evaporator is obtained by multiplying the evaporator's real-time cooling capacity by time; the table lists 500W and 1000W, including but not limited to these values. It can be understood that if the obtained real-time outside temperature is 15℃ and the real-time cooling demand at the evaporator is 500W, the corresponding preset predicted speed of the compressor can be found in the table as 900rpm. This pattern continues, allowing for the corresponding values ​​of real-time outside temperature, real-time evaporator cooling capacity, and preset predicted speed of the compressor.

[0052] Step S120: In response to the vehicle's refrigeration system switching the refrigeration mode, obtain the instantaneous speed of the compressor when switching the refrigeration mode, and obtain the preset compensation speed based on the instantaneous speed and the refrigeration mode before and after the switch.

[0053] After the compressor starts running, its speed changes in real time according to the actual cooling demand of the refrigeration system to provide the energy required for the cooling effect. In actual use, the actual cooling demand of the refrigeration system, in addition to the desired cooling temperature (the target temperature expected by the user), is also related to the cooling mode. The cooling mode described in this application refers to the area of ​​the vehicle that needs cooling. Depending on the usage needs, the cooling modes of this application include cabin cooling, battery cooling, and simultaneous cabin and battery cooling. Cabin cooling is abbreviated as CabCool; battery cooling is abbreviated as BatCool; and simultaneous cabin and battery cooling is abbreviated as Bat&Cab Cool. Switching the cooling mode of the refrigeration system includes switching from Cab Cool to BatCool, BatCool to Cab Cool, BatCool or Cab Cool to Bat&Cab Cool, and Bat&Cab Cool to BatCool or Cab Cool, etc. Therefore, even if the target temperature requirement remains unchanged, the required compressor speed will differ when the cooling mode changes. Therefore, while keeping the target temperature requirement constant, the preset required speed needs to be adjusted according to the change in cooling mode. Specifically, when the cooling mode changes, the instantaneous speed of the compressor at the time of switching cooling modes is obtained, and the preset compensation speed is obtained based on the instantaneous speed and the cooling modes before and after the switch.

[0054] In some specific embodiments, the compressor speed can be monitored in real time using a channel speed sensor or similar device to obtain the instantaneous speed of the compressor.

[0055] Step S130: Obtain the preset feedforward speed based on the sum of the real-time preset predicted speed and the preset compensation speed.

[0056] By using the sum of the preset predicted demand speed and the preset compensation speed as the preset feedforward speed, energy can be saved when switching between corresponding modes, and the stability of the evaporator and compressor can be protected.

[0057] In this embodiment, during the preset feedforward speed determination stage, the preset compensation speed is determined based on the switching of the cooling mode, thereby enabling the steady-state performance of the refrigeration system to be controlled before PI calculation, and the preset compensation speed can reduce energy consumption.

[0058] Furthermore, refer to Figure 3 As shown, Figure 3 This is a flowchart of step S120, which specifically includes steps S121 and S122.

[0059] Step S121: Obtain the current cooling mode and instantaneous speed before and after the switch.

[0060] In this application, the cooling mode includes any one of Cab Cool, BatCool, and Bat&Cab Cool, depending on the needs of the vehicle's cooling zone. This allows users to select different cooling zones or different target cooling temperatures for different cooling zones as needed.

[0061] Step S122: Based on the cooling mode and instantaneous speed before and after switching, query the pre-stored preset compensation speed table in the database and obtain the corresponding preset compensation speed in the preset compensation speed table.

[0062] When the cooling mode is switched from Cab Cool to Bat&Cab Cool, Bat&Cab Cool to BatCool, or CabCool, the preset compensation speed is 0. Since the cooling capacity is reduced, it is equivalent to no speed compensation is needed, so as to save energy.

[0063] When the cooling mode is switched from Cab Cool to BatCool, BatCool to Cab Cool, and BatCool to Bat&Cab Cool, the preset compensation speed is 0, which means that no speed compensation is required. The speed is gradually increased based on the preset feedforward speed and the adjustment speed calculated by PI, thereby protecting the stability of the evaporator and compressor.

[0064] Based on simulations or extensive actual motion tests, a one-to-one correspondence between instantaneous rotational speed and preset compensation rotational speed is obtained according to the cooling mode before and after the switch, and these data correspondences are maintained in a database. Preferably, based on the one-to-one correspondence between instantaneous rotational speed and preset compensation rotational speed, preset files, tables, etc., can be generated and stored in the database for convenient future use. The corresponding preset compensation rotational speed can be retrieved from the database based on the cooling mode before and after the switch and the instantaneous rotational speed.

[0065] When the cooling mode is switched from Cab Cool to Bat & Cab Cool, the preset compensation speed is obtained based on the instantaneous speed and the cooling mode before and after the switch, as shown in the table below.

[0066]

[0067] It should be noted that the correspondence between the cooling mode, instantaneous speed, and preset compensation speed before and after switching may differ for different types of vehicles, or even different models of the same type of vehicle. Therefore, the relationship between the cooling mode, instantaneous speed, and preset compensation speed before and after switching is not limited to the table above. The table above is merely a specific embodiment to facilitate the description of the technical principles of this application.

[0068] For example, when the instantaneous speed is 1000 rpm, the corresponding preset compensation speed is 600 rpm. The table lists instantaneous speeds of 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 6000 rpm, and 8000 rpm for explanation, including but not limited to 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 6000 rpm, and 8000 rpm. It can be understood that if the instantaneous speed is 1500 rpm, the corresponding preset compensation speed can be found in the table as 750 rpm, and so on, to obtain the corresponding value of each instantaneous speed and preset compensation speed.

[0069] In some specific embodiments, refer to Figure 4 As shown, Figure 4 This is a flowchart of step S200, which specifically includes steps S210 to S250.

[0070] Step S210: Obtain the target temperature and the real-time actual temperature of the evaporator, and calculate the temperature difference Δt.

[0071] The target temperature of the evaporator can include the target temperature of the cockpit and the target temperature of the battery cooling system. The target temperature of the cockpit is generally determined by driving needs; for example, if the driver wants to achieve a temperature of 23°C, then the target temperature of the cockpit is 23°C. The target temperature of the battery cooling system is obtained after feedback from the battery's operating status. Therefore, the target temperature of the evaporator can be considered as a combined value of the target temperature of the cockpit and the target temperature of the battery cooling system. For example, if the final target temperature of the evaporator is 21°C, and the actual real-time temperature of the evaporator is 31°C, then the temperature difference Δt is the difference between the target temperature of the evaporator and the actual real-time temperature of the evaporator, which is 10°C.

[0072] Step S220: Obtain the cooling mode of the vehicle's cooling system, and obtain the preset first coefficient P and second coefficient I based on the temperature difference Δt, the cooling mode, and the outside temperature.

[0073] The cooling modes of the vehicle's cooling system, as described in step S130, include Cab Cool, BatCool, and Bat & Cab Cool. The first coefficient P and the second coefficient I corresponding to different cooling modes can be obtained from the corresponding adjustment speed coefficient table.

[0074] Step S230: Based on the temperature difference and the first coefficient P, the first regulating speed is obtained according to the formula P*Δt.

[0075] In step S220, the temperature difference and the corresponding first coefficient P have been obtained. The first adjustment speed can be obtained according to the formula P*Δt. The first adjustment speed is to adjust the speed of the compressor according to a certain ratio.

[0076] Step S240: Based on the temperature difference and the second coefficient I, the second regulating speed is obtained according to the formula ∑(I*Δt).

[0077] In step S220, the temperature difference and the corresponding second coefficient I have been obtained. The second adjustment speed can be obtained according to the formula ∑(I*Δt). The second adjustment speed can eliminate the steady-state error of speed adjustment by integral method.

[0078] Step S250: Adjust the rotation speed to be equal to the sum of the first and second adjustment speeds.

[0079] By using the sum of the first and second regulating speeds as the regulating speed, the first regulating speed proportionally reflects the deviation of the system. Once a deviation occurs in the system, the proportional regulation immediately takes effect to reduce the deviation; the second regulating speed eliminates steady-state error and improves the error-free degree.

[0080] In this embodiment, the PI calculation has an anti-saturation function. That is, when the final actual output compressor target speed is not the compressor speed required by the PI calculation function (it is restricted), it can be adjusted according to the actual output compressor speed in combination with the second adjustment speed. This allows the compressor speed to be continuously calculated based on the instantaneous speed when the restriction is lifted, and finally the adjustment speed of the compressor can be obtained.

[0081] In some specific embodiments, refer to Figure 5 As shown, Figure 5 This is a flowchart of step S220, which specifically includes steps S221 and S222.

[0082] Step S221: Based on the current cooling mode, obtain the adjustment speed coefficient table corresponding to the cooling mode from the database.

[0083] Cooling modes include Cab Cool, BatCool, and Bat&Cab Cool. If the current cooling mode is Cab Cool, the corresponding speed adjustment coefficient table for Cab Cool will be obtained from the database.

[0084] Step S222: Based on the temperature difference Δt and the outside temperature, retrieve the pre-stored first coefficient P and second coefficient I from the corresponding adjustment speed coefficient table.

[0085] Based on simulations or extensive actual motion tests, a one-to-one correspondence between temperature difference Δt, outside temperature, and the first coefficient P, or a one-to-one correspondence between temperature difference Δt, outside temperature, and the second coefficient I, can be obtained, and these data correspondences are maintained in a database. Preferably, based on the one-to-one correspondence between temperature difference Δt, outside temperature, and the first coefficient P, or based on the one-to-one correspondence between temperature difference Δt, outside temperature, and the second coefficient I, preset files, tables, etc., can be generated and stored in the database for convenient subsequent use. The corresponding preset feedforward speed can be retrieved from the database based on the temperature difference Δt, outside temperature, first coefficient P, and second coefficient I.

[0086] When the cooling mode is Cab Cool, the first coefficient P is shown in the following figure:

[0087] When the cooling mode is Cab Cool, the second coefficient I is shown in the following figure:

[0088] When the cooling mode is BatCool, the first coefficient P is shown in the following figure:

[0089] When the cooling mode is BatCool, the second coefficient I is shown in the following figure:

[0090] When the cooling mode is Bat & Cab Cool, the first coefficient P is shown in the following figure:

[0091]

[0092] When the cooling mode is Bat & Cab Cool, the second coefficient I is shown in the following figure:

[0093]

[0094] It should be noted that the relationship between temperature difference Δt, outside temperature, and the first coefficient P may differ for different types of vehicles, or even for different models of the same type of vehicle. Similarly, the relationship between temperature difference Δt, outside temperature, and the second coefficient I may also differ. Therefore, the relationship between temperature difference Δt, outside temperature, the first coefficient P, and the second coefficient I is not limited to the table above. The table above is merely a partial embodiment to facilitate the description of the technical principles of this application.

[0095] Taking the Cab Cool cooling mode as an example, when the outside temperature is 20℃ and the temperature difference is 20℃, the corresponding first coefficient P is 100. The cooling system can obtain the real-time outside temperature through sensors. The table lists 10℃, 20℃, and 30℃, including but not limited to these values. The table also lists temperature differences of 0℃ and 20℃, including but not limited to these values. It can be understood that if the obtained real-time outside temperature is 15℃ and the temperature difference is 20℃, the corresponding first coefficient P can be found to be 50 by looking up the table. This pattern continues to yield the corresponding value of the first coefficient P for each outside temperature, temperature difference, and the given temperature.

[0096] The table above provides the first coefficient P and the second coefficient I for different modes. The same method used to obtain the first coefficient P and the second coefficient I for other cooling modes can be used when the cooling mode is Cab Cool. This will not be elaborated on here.

[0097] In some specific embodiments, refer to Figure 6 As shown, Figure 6 This is a flowchart of step S400, which specifically includes steps S410 to S450.

[0098] Step S410: The preset thresholds include the preset frosting temperature of the evaporator, the preset outlet pressure of the compressor, the preset inlet pressure of the compressor, and the preset available power of the compressor.

[0099] Specifically, the preset frosting temperature of the evaporator is 3℃; the preset outlet pressure of the compressor is 22 bar; the preset inlet pressure of the compressor is 2.95 bar; and the preset available power of the compressor is the difference between the rated power and 1 kW. For example, if the rated power is 7 kW, then the preset available power of the compressor is 6 kW. Depending on regional or vehicle differences, the preset frosting temperature of the evaporator, the preset outlet pressure of the compressor, the preset inlet pressure of the compressor, and the preset available power of the compressor can be set according to actual needs.

[0100] Step S420: While the compressor is running at its actual speed, the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor are acquired periodically according to a preset time period.

[0101] The preset timeout period for the refrigeration system can be set to 0.1 seconds, 0.5 seconds, etc. Every preset timeout, the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor must be acquired. Specifically, during operation, a temperature sensor monitors the evaporator temperature, a pressure sensor monitors the outlet and inlet pressures of the compressor, and a power meter simultaneously monitors the actual power of the compressor, thereby obtaining real-time data on the evaporator temperature, compressor outlet pressure, compressor inlet pressure, and compressor power. As needed, these sensors can periodically or in real-time transmit the real-time data to the controller, allowing the controller to compare and analyze these data with the preset frosting temperature of the evaporator, the preset outlet pressure of the compressor, the preset inlet pressure of the compressor, and the preset available power of the compressor.

[0102] Step S430: Simultaneously compare and analyze the actual temperature of the evaporator with the preset frosting temperature, the outlet pressure of the compressor with the preset outlet pressure, the inlet pressure of the compressor with the preset inlet pressure, and the actual low power of the compressor with the preset available power.

[0103] The refrigeration system is considered normal when all of the following conditions are met: the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor. In this state, a normally functioning refrigeration system can reduce energy consumption and prevent further damage. However, if any one of these conditions is abnormal, it may lead to system malfunction (i.e., system failure). Therefore, it is necessary to simultaneously compare and analyze the actual temperature of the evaporator with the preset frosting temperature, the outlet pressure of the compressor with the preset outlet pressure, the inlet pressure of the compressor with the preset inlet pressure, and the actual power of the compressor with the preset available power.

[0104] When the refrigeration system malfunctions, step S441 is executed, which means: in response to at least any one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is greater than the preset available power, the compressor is adjusted to operate at the preset limited speed.

[0105] Specifically, evaporator frosting occurs when the actual temperature of the evaporator is lower than or equal to the preset frosting temperature; compressor outlet pressure is abnormal when it is higher than the preset outlet pressure; compressor inlet pressure is abnormal when it is lower than or equal to the preset inlet pressure; and the compressor load is abnormal when its actual power exceeds its preset available power. Any of these conditions—evaporator frosting, abnormal compressor outlet pressure, abnormal compressor inlet pressure, or abnormal load—indicates a potential malfunction in the refrigeration system. In this case, the compressor should not operate at its actual speed but should be adjusted to operate at the preset limit speed.

[0106] When the refrigeration system is normal, step S442 is executed, that is: in response to the actual temperature of the evaporator being higher than or equal to the preset frosting temperature, the outlet pressure of the compressor being lower than or equal to the preset outlet pressure, the inlet pressure of the compressor being higher than or equal to the preset inlet pressure, and the actual power of the compressor being lower than or equal to the preset available power, steps S100 to S300 are executed as needed, either in real time or periodically.

[0107] Specifically, when the actual temperature of the evaporator is higher than the preset frosting temperature, the evaporator does not frost; when the outlet pressure of the compressor is lower than or equal to the preset outlet pressure of the compressor, the outlet pressure of the compressor is normal; when the inlet pressure of the compressor is higher than the preset inlet pressure of the compressor, the inlet pressure of the compressor is normal; when the actual power of the compressor is lower than or equal to the preset available power of the compressor, the load is normal. When the evaporator does not frost, the outlet pressure of the compressor is normal, the inlet pressure of the compressor is normal, and the load is normal, the refrigeration system is normal, and steps S100 to S300 are executed in real time or periodically.

[0108] In some embodiments, when the evaporator is frosted and the load is abnormal, the preset limiting speed is between 1000 rpm and 8500 rpm. 8500 rpm is the rated speed; the limiting speed of 1000 rpm can be obtained by defining the preset feedforward speed as 0 and then calculating it using PI, as described in step S200.

[0109] In some embodiments, when the outlet pressure and inlet pressure of the evaporator compressor are abnormal, the preset limiting speed is between 1000 rpm and 8500 rpm; where 8500 rpm is the rated speed; the limiting speed of 1000 rpm can be obtained by defining the preset feedforward speed as 0 and then calculating it using PI, referring to step S200. Alternatively, the rate of increase of the compressor speed can be limited to approximately 30% of the original rate according to actual needs.

[0110] Step S450: Instead of calculating the preset feedforward speed and the adjustment speed, the compressor is controlled to maintain the preset limit speed.

[0111] In other words, if at least one of the following four conditions is met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is higher than the preset available power, it indicates that the refrigeration system is malfunctioning. At this time, steps S100 to S300 to adjust the compressor speed are no longer performed. Instead, the compressor is directly controlled to operate at the preset limited speed until the refrigeration system is shut down. Generally, when the compressor operates at the preset limited speed, the desired cooling effect may not be achieved, but it will not cause further damage to the refrigeration system. However, the refrigeration system needs to be inspected and maintained at an appropriate time according to the vehicle's usage requirements.

[0112] In this embodiment, the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the power of the compressor are periodically monitored and compared with preset frosting temperature, preset outlet pressure, preset inlet pressure, and preset available power. When faults such as evaporator frosting, abnormal outlet pressure, abnormal inlet pressure, or abnormal load occur, the compressor is adjusted to operate at a preset limited speed. Operating at the preset limited speed ensures that the compressor operates within the preset speed limit, preventing further damage to the refrigeration system.

[0113] In some specific embodiments, refer to Figure 7 As shown, Figure 7 This is a flowchart before step S100. Steps S10 to S40 are also included before step S100.

[0114] Step S10: Start the compressor.

[0115] After a refrigeration system is shut down, it may experience abnormal startup due to factors such as weather or blockage in the pipes. Therefore, it is necessary to monitor the status of the refrigeration system during startup.

[0116] Step S20: Simultaneously acquire the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor.

[0117] The actual temperature of the evaporator at startup, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor are obtained by referring to the method in step S420.

[0118] Step S30: Simultaneously compare and analyze the actual temperature of the evaporator with the preset frosting temperature, the outlet pressure of the compressor with the preset outlet pressure, the inlet pressure of the compressor with the preset inlet pressure, and the actual power of the compressor being lower than the preset available power.

[0119] The refrigeration system is considered normal when all of the following conditions are met: the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor. In this state, a normally functioning refrigeration system can reduce energy consumption and prevent further damage. However, if any one of these conditions is abnormal, it may lead to system malfunction (i.e., system failure). Therefore, it is necessary to simultaneously compare and analyze the actual temperature of the evaporator with the preset frosting temperature, the outlet pressure of the compressor with the preset outlet pressure, the inlet pressure of the compressor with the preset inlet pressure, and the actual power of the compressor with the preset available power.

[0120] When the refrigeration system malfunctions, step S41 is executed, which means that in response to the following conditions: the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, and the actual power of the compressor is lower than or equal to the preset available power, the compressor starts and runs normally at a speed less than or equal to the rated speed. At this time, steps S100-S400 are executed and cycled in real time or periodically.

[0121] Specifically, when the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the evaporator is not frosted; when the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the outlet pressure of the compressor is normal; when the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, the inlet pressure of the compressor is normal; when the actual power of the compressor is lower than or equal to the preset available power, the load is normal. When the evaporator is not frosted, the outlet pressure of the compressor is normal, the inlet pressure of the compressor is normal, and the load is normal, the compressor starts and runs normally at a speed less than or equal to the rated speed, indicating that the refrigeration system is normal, and steps S100-S400 are executed and cycled in real time or periodically.

[0122] When the refrigeration system malfunctions, step S42 is executed, which means: in response to at least any one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is higher than the preset available power, the compressor is controlled to start at a preset limited speed. Furthermore, in this case, because the refrigeration system has malfunctioned, steps S100-S400 are no longer executed and repeated; instead, the compressor is directly controlled to start at the preset limited speed and maintain operation at the preset limited speed until the user shuts off the refrigeration system.

[0123] Specifically, the evaporator will frost when its actual temperature is lower than the preset frosting temperature; it will also frost when the compressor's outlet pressure is higher than the preset outlet pressure; it will frost when the compressor's inlet pressure is lower than the preset inlet pressure; and it will frost when the compressor's actual power is higher than the preset available power. If any of these abnormalities occur—evaporator frosting, compressor outlet pressure abnormality, compressor inlet pressure abnormality, or load abnormality—it indicates a refrigeration system malfunction, and the compressor will be controlled to operate at a preset limited speed.

[0124] In some embodiments, when the evaporator is frosted and the load is abnormal, the preset limiting speed is between 1000 rpm and 8500 rpm. 8500 rpm is the rated speed; the limiting speed of 1000 rpm can be obtained by defining the preset feedforward speed as 0 and then calculating it using PI, as described in step S200.

[0125] In some embodiments, when the outlet pressure and inlet pressure of the evaporator compressor are abnormal, the preset limiting speed is between 1000 rpm and 8500 rpm; where 8500 rpm is the rated speed; the limiting speed of 1000 rpm can be obtained by defining the preset feedforward speed as 0 and then calculating it using PI, referring to step S200. Alternatively, the rate of increase of the compressor speed can be limited to approximately 30% of the original rate according to actual needs.

[0126] In some specific embodiments, refer to Figure 8 As shown, Figure 8 This is a structural schematic diagram of a vehicle according to an embodiment of the present invention.

[0127] This application also provides a vehicle 10, including a processor 11 and a memory 12, wherein the processor 11 is connected to the memory 12, and the memory 12 stores program instructions; the processor 11 is used to execute the program instructions stored in the memory 12 to implement the above-mentioned control method.

[0128] Processor 11 is used to control itself and its memory to implement the steps in any of the compressor speed control method embodiments described above. Processor 11 can also be referred to as a CPU (Central Processing Unit). Processor 11 may be an integrated circuit chip with signal processing capabilities. Processor 11 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. General-purpose processor 11 can be a microprocessor or any conventional processor. Furthermore, processor 11 can be implemented using integrated circuit chips.

[0129] The memory 12 can be a medium that can store program instructions, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. Alternatively, it can be a server that stores the program instructions, which can send the stored program instructions to other devices for execution or execute the stored program instructions itself.

[0130] In this embodiment, the compressor speed is controlled to control the steady-state performance of the compressor, thereby reducing energy consumption and increasing range. Furthermore, the compressor speed is limited to reduce energy waste by controlling it under fault conditions.

[0131] In this application, unless otherwise expressly specified and limited, the terms "set up (provided)" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0132] In the description of this specification, references to terms such as "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0133] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A method for controlling the speed of a compressor, used to control the speed of a compressor in a vehicle refrigeration system, characterized in that, include: When the compressor starts and runs normally at a speed less than or equal to the rated speed, the preset feedforward speed of the compressor is obtained based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature. The target temperature and the real-time actual temperature of the evaporator are obtained, and the corresponding adjustment speed is calculated by PI based on the target temperature and the actual temperature. The real-time actual speed is obtained based on the sum of the preset feedforward speed and the adjusted speed, and the compressor is controlled to operate at the actual speed. The actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor are monitored periodically according to a preset time period. In response to any one of the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the actual power of the compressor satisfying the corresponding preset threshold, the compressor is controlled to operate at a preset limited speed.

2. The compressor speed control method according to claim 1, characterized in that, When the compressor starts and runs normally at a speed less than or equal to its rated speed, the preset feedforward speed of the compressor is obtained based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature, including: Based on the real-time cooling capacity demand at the evaporator end and the real-time outside temperature, the preset predicted speed of the compressor in real time is obtained. In response to the vehicle refrigeration system switching refrigeration mode, the instantaneous speed of the compressor at the time of switching refrigeration mode is obtained, and a preset compensation speed is obtained based on the instantaneous speed and the refrigeration mode before and after switching. The preset feedforward speed is obtained by summing the real-time preset predicted demand speed and the preset compensation speed.

3. The compressor speed control method according to claim 2, characterized in that, The step of obtaining the preset compensation speed based on the instantaneous speed and the cooling mode before and after the switch includes: Obtain the cooling mode and instantaneous rotation speed before and after the current switch; Based on the cooling mode and instantaneous speed before and after the switch, query the pre-stored preset compensation speed table in the database to obtain the preset compensation speed corresponding to the preset compensation speed table.

4. The compressor speed control method according to claim 1, characterized in that, The process of acquiring the target temperature and the real-time actual temperature of the evaporator, and calculating the corresponding adjustment speed using a PI converter based on the target temperature and the actual temperature, includes: The target temperature and the real-time actual temperature of the evaporator are obtained, and the temperature difference Δt is calculated. Obtain the cooling mode of the vehicle cooling system, and obtain a preset first coefficient P and a second coefficient I based on the temperature difference Δt, the cooling mode and the outside temperature of the vehicle. Based on the temperature difference and the first coefficient P, the first adjustment speed is obtained according to the formula P*Δt; Based on the temperature difference and the second coefficient I, the second regulating speed is obtained according to the formula ∑(I*Δt); The adjustment speed is equal to the sum of the first adjustment speed and the second adjustment speed.

5. The compressor speed control method according to claim 4, characterized in that, The step of obtaining the cooling mode of the vehicle cooling system, and obtaining a preset first coefficient P and a second coefficient I based on the temperature difference, the cooling mode, and the outside temperature, includes: Based on the current cooling mode, obtain the adjustment speed coefficient table corresponding to the cooling mode from the database; Based on the temperature difference Δt and the outside temperature, the pre-stored first coefficient P and second coefficient I are retrieved from the corresponding adjustment speed coefficient table.

6. The method for controlling compressor speed according to any one of claims 1-5, characterized in that, The step of periodically monitoring the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, and the power of the compressor according to a preset time interval, and controlling the compressor to operate at a preset speed limit when any one of the actual temperature of the evaporator, the outlet and inlet pressures of the compressor, or the actual power of the compressor meets a corresponding preset threshold, includes: The preset thresholds include the preset frosting temperature of the evaporator, the preset outlet pressure of the compressor, the preset inlet pressure of the compressor, and the preset available power of the compressor. When the compressor is running at the actual speed, the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor are acquired simultaneously and periodically according to a preset time period. Simultaneously, the actual temperature of the evaporator is compared with the preset frosting temperature, the outlet pressure of the compressor is compared with the preset outlet pressure, the inlet pressure of the compressor is compared with the preset inlet pressure, and the actual power of the compressor is compared with the preset available power. In response to at least one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is greater than the preset available power, the compressor is adjusted to operate at the preset limited speed.

7. The compressor speed control method according to claim 6, characterized in that, Also includes: In response to the following conditions: the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, and the actual power of the compressor is lower than or equal to the preset available power; The preset feedforward speed of the compressor is obtained in real time or periodically based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature. The target temperature and the real-time actual temperature of the evaporator are obtained, and the corresponding adjustment speed is calculated by PI based on the target temperature and the actual temperature. The real-time actual speed is obtained by summing the preset feedforward speed and the adjusted speed, and the compressor is controlled to run at the actual speed.

8. The compressor speed control method according to claim 6, characterized in that, After controlling the compressor to operate at a preset speed limit, the method further includes: Instead of calculating the preset feedforward speed and adjusting speed, the compressor is controlled to maintain the preset limit speed.

9. The method for controlling compressor speed according to any one of claims 1-5, characterized in that, When the compressor starts and runs normally at a speed less than or equal to its rated speed, the preset feedforward speed of the compressor is obtained based on the real-time cooling capacity demand at the evaporator end of the refrigeration system and the real-time outside temperature; prior to this, it also includes: Start the compressor; Simultaneously, the actual temperature of the evaporator, the outlet pressure of the compressor, the inlet pressure of the compressor, and the actual power of the compressor are obtained; Simultaneously, the actual temperature of the evaporator is compared with the preset frosting temperature, the outlet pressure of the compressor is compared with the preset outlet pressure, the inlet pressure of the compressor is compared with the preset inlet pressure, and the actual power of the compressor is lower than the preset available power. In response to the following conditions being met: the actual temperature of the evaporator is higher than or equal to the preset frosting temperature, the outlet pressure of the compressor is lower than or equal to the preset outlet pressure, the inlet pressure of the compressor is higher than or equal to the preset inlet pressure, and the actual power of the compressor is lower than or equal to the preset available power, the compressor starts and operates normally at a speed less than or equal to the rated speed.

10. The method for controlling compressor speed according to claim 9, characterized in that, Also includes: In response to at least one of the following conditions being met: the actual temperature of the evaporator is lower than the preset frosting temperature, the outlet pressure of the compressor is higher than the preset outlet pressure, the inlet pressure of the compressor is lower than the preset inlet pressure, or the actual power of the compressor is higher than the preset available power, the compressor is controlled to start and run at a preset limited speed until the refrigeration system is shut down.

11. The method for controlling compressor speed according to claim 1, characterized in that, The step of obtaining the real-time preset feedforward speed of the compressor based on the real-time cooling capacity demand at the evaporator end of the compressor and the real-time outside temperature includes: Obtain real-time cooling capacity requirements and corresponding outside temperature; Based on the real-time cooling capacity requirement and the corresponding outside temperature, the system queries the pre-stored preset feedforward speed table in the database to obtain the corresponding preset feedforward speed.

12. A vehicle, characterized in that, The device includes a processor and a memory, the processor being connected to the memory, wherein the memory stores program instructions; the processor is configured to execute the program instructions stored in the memory to implement the control method as described in any one of claims 1-11.

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