Method, device and refrigeration system for controlling the speed step of a variable frequency compressor

Abstract

This invention discloses a speed step size control method, apparatus, and refrigeration system for a variable frequency compressor. The variable frequency compressor is applied to environmental testing equipment. The speed step size control method includes: acquiring the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time prior to the current time; determining the difference between the current temperature and the temperature at the preset time, as well as the temperature change rate, based on the current temperature and the temperature at the preset time; and controlling the speed step size of the variable frequency compressor based on the difference, the temperature change rate, a preset speed change step size, and a preset step size correction value. The speed step size control method, apparatus, and refrigeration system for a variable frequency compressor provided by this invention can improve the reliability of speed step size control, prevent excessive energy consumption of the variable frequency compressor, and thus improve energy-saving effects.

Description

Technical Field

[0001] The embodiments of the present invention relate to compressor control technology, and more particularly to a method, device and refrigeration system for controlling the speed step size of a variable frequency compressor. Background Technology

[0002] In production and daily life, many fields require compressors, such as variable frequency compressors, for temperature regulation. For variable frequency compressors, the speed step size needs to be adjusted according to actual needs to meet specific speed and temperature requirements. For example, the speed of the variable frequency compressor can be adjusted by reducing the speed step size.

[0003] Currently, existing speed step control methods for variable frequency compressors suffer from low reliability in adjusting the speed step size, leading to higher energy consumption and impacting the energy-saving performance of the compressor. Summary of the Invention

[0004] This invention provides a method, apparatus, and refrigeration system for controlling the speed step size of a variable frequency compressor, thereby improving the reliability of speed step size control, preventing excessive energy consumption of the variable frequency compressor, and thus improving energy-saving effect.

[0005] In a first aspect, embodiments of the present invention provide a speed step control method for a variable frequency compressor, wherein the variable frequency compressor is applied to environmental testing equipment, and the speed step control method includes:

[0006] Obtain the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time;

[0007] Based on the current temperature and the temperature at the preset time, determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change;

[0008] The speed step size of the variable frequency compressor is controlled based on the difference, the rate of temperature change, the preset speed change step size, and the preset step size correction value.

[0009] Optionally, based on the current temperature and the temperature at a preset time, determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change, including:

[0010] Based on the current temperature and the temperature at the preset time, determine the difference between the current temperature and the temperature at the preset time. The rate of temperature change is the ratio of the difference to the time difference between the current time and the preset time.

[0011] Optionally, the preset step size correction values ​​include a preset first step size correction value, a preset second step size correction value, and a preset third step size correction value;

[0012] Based on the difference, the rate of temperature change, the preset speed change step size, and the preset step size correction value, the speed step size of the variable frequency compressor is controlled, including:

[0013] If the rate of temperature change is less than or equal to the preset temperature rate step size control deviation, and the absolute value of the rate of temperature change, after retaining two decimal places, is greater than or equal to the preset first step size correction value, then the preset minimum adjustment value of the speed step size is adjusted to the product of the preset second step size correction value and the absolute value of the rate of temperature change, after retaining two decimal places.

[0014] If the rate of temperature change is less than or equal to the preset temperature rate step size control deviation, and the absolute value of the rate of temperature change, after retaining two decimal places, is less than the preset first step size correction value, then the preset minimum adjustment value of the speed step size is adjusted to the product of the preset third step size correction value and the absolute value of the rate of temperature change, after retaining two decimal places.

[0015] Adjust the speed step size of the variable frequency compressor according to the preset minimum adjustment value of the speed step size.

[0016] Optionally, the speed step size of the variable frequency compressor can be adjusted according to a preset minimum adjustment value, including:

[0017] If the preset minimum adjustment value of the speed step size is less than or equal to the preset minimum speed change step size, then the preset minimum adjustment value will be adjusted to the preset minimum speed change step size.

[0018] If the preset minimum adjustment value of the speed step is less than or equal to the preset maximum speed change step, then the preset minimum adjustment value at this time will be used as the speed step of the variable frequency compressor.

[0019] Optionally, the speed step size of the variable frequency compressor can be adjusted according to a preset minimum adjustment value, including:

[0020] If the preset minimum adjustment value of the speed step is greater than the preset minimum speed change step and less than or equal to the preset maximum speed change step, then the preset minimum adjustment value at this time will be used as the speed step of the variable frequency compressor.

[0021] If the preset minimum adjustment value of the speed step size is less than or equal to the preset maximum value of the speed change step size, then the preset maximum value of the speed change step size will be used as the speed step size of the variable frequency compressor.

[0022] Optionally, the speed step size of the variable frequency compressor is controlled based on the difference, the rate of temperature change, the preset speed change step size, and the preset step size correction value, including:

[0023] If the rate of temperature change is greater than the preset temperature rate step size control deviation, then the preset minimum adjustment value of the speed step size of the variable frequency compressor is adjusted to 0.

[0024] Adjust the speed step size of the variable frequency compressor according to the adjusted preset minimum adjustment value.

[0025] Optionally, the speed step size of the variable frequency compressor can be adjusted according to the adjusted preset minimum adjustment value, including:

[0026] If the adjusted preset minimum adjustment value is less than or equal to the preset maximum speed change step size, then the preset minimum adjustment value at this time will be used as the speed step size of the variable frequency compressor.

[0027] If the adjusted minimum preset adjustment value is greater than the maximum preset speed change step size, then the maximum preset speed change step size will be used as the speed step size of the variable frequency compressor.

[0028] Secondly, embodiments of the present invention also provide a speed step control device for a variable frequency compressor, wherein the variable frequency compressor is applied to environmental testing equipment, and the speed step control device includes:

[0029] The temperature acquisition module is used to acquire the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time.

[0030] The difference determination module is used to determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change, based on the current temperature and the temperature at the preset time.

[0031] The step size control module is used to control the speed step size of the variable frequency compressor based on the difference, the rate of temperature change, the preset speed change step size, and the preset step size correction value.

[0032] Optionally, the difference determination module is specifically used to determine the difference between the current temperature and the temperature at the preset time, based on the current temperature and the temperature at the preset time. The rate of temperature change is the ratio of the difference to the time difference between the current time and the preset time.

[0033] Thirdly, embodiments of the present invention also provide a refrigeration system, including a controller, a variable frequency compressor, a condenser, and an evaporator. The controller is electrically connected to the variable frequency compressor. The condenser is connected to the evaporator and the variable frequency compressor via pipelines. The evaporator is connected to the variable frequency compressor via pipelines. The speed step control device as described in the second aspect is integrated into the controller.

[0034] The present invention provides a method, apparatus, and refrigeration system for controlling the speed step size of a variable frequency compressor. The variable frequency compressor is applied to an environmental testing device. The method acquires the current temperature of the inner chamber of the environmental testing device and the temperature at a preset time prior to the current time. Based on the current temperature and the temperature at the preset time, the difference between the current temperature and the temperature at the preset time, as well as the temperature change rate, are determined. Based on the difference, the temperature change rate, a preset speed change step size, and a preset step size correction value, the speed step size of the variable frequency compressor is controlled. The method, apparatus, and refrigeration system provided by the present invention, by controlling the speed step size of the variable frequency compressor based on the difference between the current temperature and the temperature at the preset time, the temperature change rate, the preset speed change step size, and the preset step size correction value, can improve the reliability of speed step size control, prevent excessive energy consumption of the variable frequency compressor, and thus improve energy-saving effects. Attached Figure Description

[0035] Figure 1 This is a flowchart of a speed step control method for a variable frequency compressor provided in Embodiment 1 of the present invention;

[0036] Figure 2 This is a structural block diagram of a refrigeration system provided in Embodiment 1 of the present invention;

[0037] Figure 3 This is a flowchart of a speed step control method for a variable frequency compressor provided in Embodiment 2 of the present invention;

[0038] Figure 4 This is a structural block diagram of a refrigeration system provided in Embodiment 2 of the present invention;

[0039] Figure 5 This is a flowchart of another speed step control method for a variable frequency compressor provided in Embodiment 2 of the present invention;

[0040] Figure 6 This is a structural block diagram of a speed step control device for a variable frequency compressor provided in Embodiment 3 of the present invention. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0042] Example 1

[0043] Figure 1This is a flowchart of a speed step size control method for a variable frequency compressor provided in Embodiment 1 of the present invention. This embodiment is applicable to situations where the speed step size of the variable frequency compressor is adjusted, such as by reducing it. The variable frequency compressor is used in environmental testing equipment. This method can be executed by a speed step size control device for the variable frequency compressor. This device can be implemented by software and / or hardware. The device can be integrated into the controller of the refrigeration system. The method specifically includes the following steps:

[0044] Step 110: Obtain the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time.

[0045] The current temperature and the temperature at a preset time before the current time can be collected in real time by a temperature sensor installed inside the environmental test equipment. The speed step control device is electrically connected to the temperature sensor and can obtain and store the real-time temperature collected by the temperature sensor.

[0046] Step 120: Based on the current temperature and the temperature at the preset time, determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change.

[0047] Specifically, the difference between the current temperature TPV(n) and the preset temperature TPV(nx) is TPV(n)-TPV(nx), and the rate of temperature change is [TPV(n)-TPV(nx)] / [t(n)-t(nx)], where t(n) is the current time and t(nx) is the preset time.

[0048] Step 130: Control the speed step of the variable frequency compressor based on the difference, the rate of temperature change, the preset speed change step size, and the preset step size correction value.

[0049] For example, Figure 2 This is a schematic diagram of a refrigeration system provided in Embodiment 1 of the present invention. (Reference) Figure 2 The refrigeration system includes a controller 10, a variable frequency compressor 20, a condenser, and an evaporator 30. The controller 10 is electrically connected to the variable frequency compressor 20. The condenser is connected to the evaporator 30 and the variable frequency compressor 20 via pipelines. The evaporator 30 is also connected to the variable frequency compressor 20 via pipelines. As described in any embodiment of the present invention, the speed step control device is integrated into the controller 10. The controller 10 can control the speed step of the variable frequency compressor 20. For example, when the rate of temperature change is greater than the preset temperature rate step control deviation, the speed step of the variable frequency compressor 20 can be controlled to be zero.

[0050] The variable frequency compressor speed step size control method provided in this embodiment is applied to an environmental testing device. It acquires the current temperature of the inner chamber of the environmental testing device and the temperature at a preset time prior to the current moment. Based on the current temperature and the temperature at the preset time, it determines the temperature difference between the two temperatures and the temperature change rate. Based on the temperature difference, the temperature change rate, a preset speed change step size, and a preset step size correction value, it controls the speed step size of the variable frequency compressor. This method, by controlling the speed step size of the variable frequency compressor based on the temperature difference between the current temperature and the preset time, the temperature change rate, the preset speed change step size, and the preset step size correction value, improves the reliability of speed step size control, prevents excessive energy consumption of the variable frequency compressor, and thus improves energy-saving effects.

[0051] Example 2

[0052] Figure 2 This is a flowchart of a speed step size control method for a variable frequency compressor provided in Embodiment 2 of the present invention. This embodiment is applicable to situations where the speed step size of the variable frequency compressor is adjusted, such as by reducing it. The variable frequency compressor is used in environmental testing equipment. This method can be executed by a speed step size control device for the variable frequency compressor. This device can be implemented by software and / or hardware. The device can be integrated into the controller of the refrigeration system. The method specifically includes the following steps:

[0053] Step 210: Obtain the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time.

[0054] Step 220: Based on the current temperature TPV(n) and the preset temperature TPV(nx), determine the difference between the current temperature and the preset temperature as TPV(n)-TPV(nx), and the temperature change rate dTPV_t_diff is [TPV(n)-TPV(nx)] / [t(n)-t(nx)].

[0055] Where t(n) is the current time and t(nx) is the preset time.

[0056] Step 230: If [TPV(n)-TPV(nx)] / [t(n)-t(nx)]≤dTPV_t_diff_con, and ROUND(ABS(dTPV_t_diff),2)≥TPV_rpm_step_change_corr_1, then f(a,b,c,...)_1 is INT(TPV_rpm_step_change_corr_2*ROUND(ABS(dTPV_t_diff),2)).

[0057] Wherein, the rotation speed step size of the variable-frequency compressor Δrpm_step = Min[(f(a,b,c,...)_1, Δrpm_step_max], where Δrpm_step_max is the preset maximum value of the rotation speed change step size; both Δrpm_step_max and f(a,b,c,...)_1 are greater than or equal to zero; the preset step correction values include a preset first step correction value, a preset second step correction value, and a preset third step correction value. dTPV_t_diff_con is the preset temperature rate step control deviation, TPV_rpm_step_change_corr_1 is the preset first step correction value, and TPV_rpm_step_change_corr_2 is the preset second step correction value.

[0058] Step 240: If [TPV(n)-TPV(n-x)] / [t(n)-t(n-x)]≤dTPV_t_diff_con, and ROUND(ABS(dTPV_t_diff),2)<TPV_rpm_step_change_corr_1, then f(a,b,c,...)_1 is INT(ROUND(TPV_rpm_step_change_corr_3*ABS(dTPV_t_diff),2)).

[0059] Wherein, TPV_rpm_step_change_corr_3 is the preset third step correction value.

[0060] Step 250: If f(a,b,c,...)_1≤Δrpm_step_min, adjust f(a,b,c,...)_1 to Δrpm_step_min.

[0061] Wherein, Δrpm_step_min is the preset minimum value of the rotation speed change step size, and Δrpm_step_min is greater than or equal to zero.

[0062] Step 260: If f(a,b,c,...)_1≤Δrpm_step_max, take the current f(a,b,c,...)_1 as the rotation speed step size Δrpm_step of the variable-frequency compressor.

[0063] Step 270: If Δrpm_step_min<f(a,b,c,...)_1≤Δrpm_step_max, take the current f(a,b,c,...)_1 as the rotation speed step size Δrpm_step of the variable-frequency compressor.

[0064] Wherein, Δrpm_step_min is the preset minimum value of the rotation speed change step size;

[0065] Step 280: If f(a,b,c,...)_1>△rpm_step_max, then △rpm_step_max is used as the speed step size △rpm_step of the variable frequency compressor.

[0066] Step 290: If [TPV(n)-TPV(nx)] / [t(n)-t(nx)]>dTPV_t_diff_con, then adjust f(a,b,c,...)_1 in the speed step size △rpm_step of the variable frequency compressor to 0.

[0067] Wherein, dTPV_t_diff_con is the preset temperature rate step size control deviation.

[0068] It should be noted that each preset value in each embodiment can be set according to the actual speed step size control requirements, and is not limited here.

[0069] Step 291: If the adjusted f(a,b,c,...)_1 ≤ △rpm_step_max, then take the current f(a,b,c,...)_1 as the speed step △rpm_step of the variable frequency compressor.

[0070] Wherein, △rpm_step_min is the preset minimum step size for speed change.

[0071] Step 292: If the adjusted f(a,b,c,...)_1>△rpm_step_max, then △rpm_step_max is used as the speed step size △rpm_step of the variable frequency compressor.

[0072] For example, Figure 4 This is a schematic diagram of a refrigeration system provided in Embodiment 2 of the present invention. The controller 10 in the refrigeration system controls the speed step size of the variable frequency compressor 20, for example, controlling the speed step size of the variable frequency compressor 20 to be Δrpm_step_max.

[0073] Figure 5 This is a flowchart of another speed step control method for a variable frequency compressor provided in Embodiment 2 of the present invention. (See reference) Figure 5 The method includes the following steps:

[0074] Step 1: Obtain the current temperature TPV(n) of the inner chamber of the environmental test equipment and the temperature TPV(nx) at a preset time before the current time.

[0075] Step 2: Determine the difference between the current temperature and the temperature at the preset time as TPV(n)-TPV(nx), and the temperature change rate dTPV_t_diff as [TPV(n)-TPV(nx)] / [t(n)-t(nx)].

[0076] Where t(n) is the current time and t(nx) is the preset time.

[0077] Step 3: Determine whether [TPV(n)-TPV(nx)] / [t(n)-t(nx)] is less than or equal to dTPV_t_diff_con; if yes, proceed to step 4; if no, proceed to step 12.

[0078] Step 4: Determine whether ROUND(ABS(dTPV_t_diff),2) is greater than or equal to TPV_rpm_step_change_corr_1; if yes, proceed to step 5; if no, proceed to step 6.

[0079] Step 5: Adjust the speed step size △rpm_step of the variable frequency compressor to f(a,b,c,...)_1 as INT(TPV_rpm_step_change_corr_2*ROUND(ABS(dTPV_t_diff),2)), and then execute Step 7.

[0080] Step 6: Adjust the speed step size △rpm_step of the variable frequency compressor to f(a,b,c,...)_1 as INT(ROUND(TPV_rpm_step_change_corr_3*ABS(dTPV_t_diff),2)).

[0081] Step 7: Determine whether f(a,b,c,...)_1 is less than or equal to Δrpm_step_min; if yes, proceed to step 8; if no, proceed to step 9.

[0082] Step 8: Adjust f(a,b,c,...)_1 to Δrpm_step_min.

[0083] Step 9: Determine whether f(a,b,c,...)_1 is less than or equal to Δrpm_step_max; if yes, proceed to step 10; if no, proceed to step 11.

[0084] Step 10: Use f(a,b,c,...)_1 at this time as the speed step size Δrpm_step of the variable frequency compressor.

[0085] Step 11: Use △rpm_step_max as the speed step size △rpm_step of the variable frequency compressor.

[0086] Step 12: Adjust f(a,b,c,...)_1 to 0, and return to Step 9.

[0087] The variable frequency compressor speed step size control method provided in this embodiment controls the speed step size of the variable frequency compressor based on the difference between the current temperature and the temperature at a preset time, as well as the temperature change rate, a preset speed change step size, and a preset step size correction value. This improves the reliability of speed step size control, prevents the variable frequency compressor from consuming too much energy, and thus improves energy saving.

[0088] Example 3

[0089] Figure 6 This is a structural block diagram of a speed step control device for a variable frequency compressor provided in Embodiment 3 of the present invention. The variable frequency compressor is applied to an environmental testing equipment. The speed step control device includes: a temperature acquisition module 310, a difference determination module 320, and a step control module 330. The temperature acquisition module 310 is used to acquire the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time prior to the current time. The difference determination module 320 is used to determine the difference between the current temperature and the temperature at the preset time, as well as the temperature change rate, based on the current temperature and the temperature at the preset time. The step control module 330 is used to control the speed step of the variable frequency compressor based on the difference, the temperature change rate, a preset speed change step, and a preset step correction value.

[0090] Optionally, the difference determination module is specifically used to determine the difference between the current temperature TPV(n) and the preset temperature TPV(nx) based on the current temperature TPV(n) and the preset temperature TPV(nx), and the temperature change rate dTPV_t_diff is [TPV(n)-TPV(nx)] / [t(n)-t(nx)]; where t(n) is the current time and t(nx) is the preset time.

[0091] Optionally, the rotational speed step △rpm_step of the variable frequency compressor = Min[(f(a,b,c,...)_1, △rpm_step_max], where △rpm_step_max is the preset maximum value of the rotational speed variation step; the preset step correction values include a preset first step correction value, a preset second step correction value, and a preset third step correction value; the step control module 330 includes: a first adjustment unit, a second adjustment unit, and a step control unit; wherein the first adjustment unit is configured to: if [TPV(n)-TPV(n-x)] / [t(n)-t(n-x)]≤dTPV_t_diff_con, and ROUND(ABS(dTPV_t_diff),2)≥TPV_rpm_step_change_corr_1, then adjust f(a,b,c,...)_1 in the rotational speed step △rpm_step of the variable frequency compressor to INT(TPV_rpm_step_change_corr_2*ROUND(ABS(dTPV_t_diff),2)); wherein dTPV_t_diff_con is the preset temperature rate step control deviation, TPV_rpm_step_change_corr_1 is the preset first step correction value, and TPV_rpm_step_change_corr_2 is the preset second step correction value; the second adjustment unit is configured to: if the temperature variation rate [TPV(n)-TPV(n-x)] / [t(n)-t(n-x)]≤dTPV_t_diff_con, and ROUND(ABS(dTPV_t_diff),2)<TPV_rpm_step_change_corr_1, then f(a,b,c,...)_1 is INT(ROUND(TPV_rpm_step_change_corr_3*ABS(dTPV_t_diff),2)); wherein TPV_rpm_step_change_corr_3 is the preset third step correction value; the step control unit is configured to adjust the rotational speed step △rpm_step of the variable frequency compressor according to f(a,b,c,...)_1.

[0092] Preferably, the above step control unit includes: a first adjustment subunit and a second adjustment subunit; wherein the first adjustment subunit is configured to: if f(a,b,c,...)_1≤△rpm_step_min, then adjust f(a,b,c,...)_1 to △rpm_step_min, where △rpm_step_min is the preset minimum value of the rotational speed variation step; the second adjustment subunit is configured to: if f(a,b,c,...)_1≤△rpm_step_max, then take the current f(a,b,c,...)_1 as the rotational speed step △rpm_step of the variable frequency compressor.

[0093] Preferably, the above step size control unit comprises: a first step size control subunit and a second step size control subunit; wherein the first step size control subunit is configured to, if △rpm_step_min<f(a,b,c,...)_1≤△rpm_step_max, take f(a,b,c,...)_1 at this time as the rotational speed step size △rpm_step of the variable-frequency compressor, where △rpm_step_min is the preset minimum value of the rotational speed variation step size; the second step size control subunit is configured to, if f(a,b,c,...)_1>△rpm_step_max, take △rpm_step_max as the rotational speed step size △rpm_step of the variable-frequency compressor.

[0094] Optionally, the rotational speed step size of the variable-frequency compressor △rpm_step=Min[(f(a,b,c,...)_1, △rpm_step_max], where △rpm_step_max is the preset maximum value of the rotational speed variation step size; the step size control module 330 comprises: a third adjustment unit and a step size adjustment unit; wherein the third adjustment unit is configured to, if [TPV(n)-TPV(n-x)] / [t(n)-t(n-x)]>dTPV_t_diff_con, adjust f(a,b,c,...)_1 in the rotational speed step size △rpm_step of the variable-frequency compressor to 0, where dTPV_t_diff_con is the preset temperature rate step size control deviation; the step size adjustment unit is configured to adjust the rotational speed step size △rpm_step of the variable-frequency compressor according to the adjusted f(a,b,c,...)_1.

[0095] Preferably, the above step size adjustment unit comprises a first step size adjustment subunit and a second step size adjustment subunit; wherein the first step size adjustment subunit is configured to, if the adjusted f(a,b,c,...)_1≤△rpm_step_max, take the adjusted f(a,b,c,...)_1 at this time as the rotational speed step size △rpm_step of the variable-frequency compressor, where △rpm_step_min is the preset minimum value of the rotational speed variation step size; the second step size adjustment subunit is configured to, if the adjusted f(a,b,c,...)_1>△rpm_step_max, take △rpm_step_max as the rotational speed step size △rpm_step of the variable-frequency compressor.

[0096] The rotational speed step size control device for a variable-frequency compressor provided in this embodiment shares the same inventive concept as the rotational speed step size control method for a variable-frequency compressor provided in any embodiment of the present invention, and has corresponding beneficial effects. For technical details not exhaustively described in this embodiment, reference may be made to the rotational speed step size control method for a variable-frequency compressor provided in any embodiment of the present invention.

[0097] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for controlling the speed step size of a variable frequency compressor, characterized in that, The variable frequency compressor is used in environmental testing equipment, and the speed step control method includes: Obtain the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time; Based on the current temperature and the temperature at the preset time, determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change; The speed step size of the variable frequency compressor is controlled based on the difference, the temperature change rate, the preset speed change step size, and the preset step size correction value. The preset step size correction value includes a preset first step size correction value, a preset second step size correction value, and a preset third step size correction value; The step of controlling the speed step of the variable frequency compressor based on the difference, the temperature change rate, the preset speed change step size, and the preset step size correction value includes: If the temperature change rate is less than or equal to the preset temperature rate step size control deviation, and the absolute value of the temperature change rate, after retaining two decimal places, is greater than or equal to the preset first step size correction value, then the preset minimum adjustment value of the rotation speed step size is adjusted to the product of the preset second step size correction value and the absolute value of the temperature change rate, after retaining two decimal places. If the temperature change rate is less than or equal to the preset temperature rate step size control deviation, and the absolute value of the temperature change rate, after retaining two decimal places, is less than the preset first step size correction value, then the preset minimum adjustment value of the rotation speed step size is adjusted to the product of the preset third step size correction value and the absolute value of the temperature change rate, after retaining two decimal places. The speed step size of the variable frequency compressor is adjusted according to the preset minimum adjustment value of the speed step size.

2. The speed step size control method according to claim 1, characterized in that, The step of determining the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change, based on the current temperature and the temperature at the preset time, includes: Based on the current temperature and the temperature at the preset time, the difference between the current temperature and the temperature at the preset time is determined, and the rate of temperature change is the ratio of the difference to the time difference between the current time and the preset time.

3. The speed step size control method according to claim 1, characterized in that, The step of adjusting the speed step of the variable frequency compressor according to the preset minimum adjustment value of the speed step includes: If the preset minimum adjustment value of the speed step size is less than or equal to the preset minimum speed change step size, then the preset minimum adjustment value is adjusted to the preset minimum speed change step size. If the preset minimum adjustment value of the speed step is less than or equal to the preset maximum speed change step, then the preset minimum adjustment value at this time is taken as the speed step of the variable frequency compressor.

4. The speed step size control method according to claim 1, characterized in that, The step of adjusting the speed step size of the variable frequency compressor according to the preset minimum adjustment value includes: If the preset minimum adjustment value of the speed step is greater than the preset minimum speed change step and less than or equal to the preset maximum speed change step, then the preset minimum adjustment value at this time is taken as the speed step of the variable frequency compressor. If the preset minimum adjustment value of the speed step is less than or equal to the preset maximum value of the speed change step, then the preset maximum value of the speed change step is used as the speed step of the variable frequency compressor.

5. The speed step size control method according to claim 1, characterized in that, The step of controlling the speed step of the variable frequency compressor based on the difference, the temperature change rate, the preset speed change step size, and the preset step size correction value includes: If the rate of temperature change is greater than the preset temperature rate step size control deviation, then the preset minimum adjustment value of the speed step size of the variable frequency compressor is adjusted to 0. The speed step size of the variable frequency compressor is adjusted according to the preset minimum adjustment value.

6. The speed step size control method according to claim 5, characterized in that, The step of adjusting the speed step size of the variable frequency compressor according to the adjusted preset minimum adjustment value includes: If the adjusted preset minimum adjustment value is less than or equal to the preset maximum speed change step size, then the preset minimum adjustment value at this time is taken as the speed step size of the variable frequency compressor. If the adjusted preset minimum adjustment value is greater than the preset maximum speed change step size, then the preset maximum speed change step size is used as the speed step size of the variable frequency compressor.

7. A speed step control device for a variable frequency compressor, used to execute the speed step control method for a variable frequency compressor as described in any one of claims 1-6, characterized in that, The variable frequency compressor is used in environmental testing equipment, and the speed step control device includes: The temperature acquisition module is used to acquire the current temperature of the inner chamber of the environmental testing equipment and the temperature at a preset time before the current time. The difference determination module is used to determine the difference between the current temperature and the temperature at the preset time, as well as the rate of temperature change, based on the current temperature and the temperature at the preset time. The step size control module is used to control the speed step size of the variable frequency compressor based on the difference, the temperature change rate, the preset speed change step size, and the preset step size correction value.

8. The speed step size control device according to claim 7, characterized in that, The difference determination module is specifically used to determine the difference between the current temperature and the temperature at the preset time based on the current temperature and the temperature at the preset time, wherein the temperature change rate is the ratio of the difference to the time difference between the current time and the preset time.

9. A refrigeration system, characterized in that, The device includes a controller, a variable frequency compressor, a condenser, and an evaporator. The controller is electrically connected to the variable frequency compressor. The condenser is connected to the evaporator and the variable frequency compressor via a pipeline. The evaporator is connected to the variable frequency compressor via a pipeline. The speed step control device as described in any one of claims 7-8 is integrated into the controller.

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