Method and system for controlling vibrations of variable capacity compressor of refrigeration system

Abstract

A method for vibration control includes receiving a request to change a rotational speed of a variable capacity compressor from a current rotational speed to a reference rotational speed; verifying whether the reference rotational speed needs to minimize compressor vibration; defining a reference rotating speed range, wherein the reference rotating speed is within the range; defining the highest rotating speed in the rotating speed range and the lowest rotating speed in the rotating speed range; comparing the reference rotating speed with the current rotating speed; changing the rotating speed of the compressor; measuring vibration of the compressor in the reference rotating speed range; defining the lowest vibration rotating speed and the highest vibration; defining a vibration difference; establishing a vibration difference reference; comparing the vibration difference with a vibration difference reference; and defining a final speed of operation of the compressor.

Description

Technical Field

[0001] The present invention discloses a method and system for controlling vibration of a variable capacity compressor of a refrigeration system.

[0002] More specifically, the solution of the invention aims at minimizing the vibrations and noise of a refrigeration system equipped with a variable capacity compressor in an active way and using at least one vibration sensor. Background Art

[0003] Currently, most solutions for minimizing vibrations and noise in refrigeration systems equipped with variable capacity compressors are based on an a priori search for the most problematic compressor operating conditions (mainly defined by the rotational speed of the compressor's motor), and then on creating prohibited ranges of operating conditions by defining prohibited RPM ranges, which are fixed for all products of the determined model.

[0004] Document US2020240689A1, entitled “METHOD AND APPARATUS FOR PREVENTINCOMPONENT MALFUNCTION USING ACCELEROMETERS”, published on June 30, 2020, discloses a method for minimizing component failures of a heating, ventilation and air conditioning (HVAC) system, the method comprising: measuring the vibration of at least one component by an accelerometer associated with at least one component of the HVAC system; and receiving actual vibration data reflecting the measured vibration by a controller. The method further comprises: determining, using the controller, whether the actual vibration data is greater than a predefined acceptable baseline vibration data by more than a predefined acceptable amount; and in response to a positive determination in the determining step, adding, by the controller, the operating frequency of at least one component corresponding to the actual vibration data as a deadband frequency.

[0005] Document US2018202679A1, entitled “METHOD AND APPARATUS FOR SYSTEM DIAGNOSTICS USING ACCELEROMETERS”, published on July 19, 2018, discloses a method for monitoring the health of components of a heating, ventilation and air conditioning (HVAC) system. The method includes: measuring the vibration of at least one component by an accelerometer associated with at least one component of the HVAC system; receiving actual vibration data reflecting the measured vibration by a controller; determining by the controller whether the actual vibration data differs from a predefined acceptable baseline vibration data by more than an acceptable amount; and in response to a positive determination in the determining step, forwarding information about the determination by the controller to a monitoring device to monitor the operation of the component.

[0006] Document US2015300684A1, entitled “SOUND LEVEL CONTROL IN A HVAC SYSTEM”, published on October 22, 2015, discloses a system and method for controlling the sound level in a heating, ventilation and air conditioning (HVAC) system. The system includes a refrigeration unit, which includes a compressor, a condenser fan, a controller and a sound controller. The sound controller is configured to keep the sound level of the refrigeration unit within a sound level operating range. A method for controlling a refrigeration unit of a heating, ventilation and air conditioning (HVAC) system is described. The method includes determining, by the controller, a cooling demand for a conditioning space. The controller also determines a sound level operating range for the refrigeration unit. The method further includes the controller applying a cooling setting based on the cooling demand and the sound level operating range.

[0007] Document US2009093911A1, entitled “VIBRATION PROTECTION IN AVARIABLE SPEED COMPRESSOR” and published on April 9, 2009, discloses a vibration protection in a compressor system having a variable speed compressor, which may include: operating the variable speed compressor at multiple frequencies; measuring multiple vibration values ​​associated with the multiple frequencies; determining frequency characteristics of the compressor system based on the multiple vibration values; and identifying prohibited compressor frequencies based on the frequency characteristics.

[0008] Document BRPI0702369A2, published on January 20, 2009 and entitled “SYSTEM AND METHOD OF DIAGNOSIS THROUGH DETECTION OF MECHNICAL WAVES IN REFRIGERATION SYSTEMS AND / OR HOUSEHOLD PLIANCES”, discloses a system and method for diagnosing a refrigeration system and / or household appliances, which determines and notifies the operating conditions of the refrigeration system and / or its components based on multiple detected physical quantities.

[0009] Document EP3535533B1, entitled "REFRIGRRATION DEVICE WITH A NOISE SENSOR" published on September 9, 2019, discloses a refrigeration device having an electrical device component that emits noise during operation. A controller operates the electrical device component within a normal operating power range. The noise sensor detects the intensity of the noise emitted from the electrical device component. The controller is configured to change the operating power of the electrical device component within the normal operating power range, determine the minimum value of the noise intensity detected by the noise sensor, and determine the noise reduction operating power so that the electrical device component operates at the noise reduction operating power.

[0010] Therefore, the disadvantage of the prior art is that the prohibited speed range for the operation of the compressor is defined, and this prohibited range is fixed and does not change according to the conditions of the refrigeration system. Summary of the invention

[0011] The object of the present invention is to provide a method and a system for controlling vibrations of a variable capacity compressor of a refrigeration system which avoids the disadvantages of the prior art.

[0012] This object is achieved by a method for controlling vibrations of a variable capacity compressor of a refrigeration system, the method comprising the following steps:

[0013] receiving a request to change a speed of the variable capacity compressor from a current speed to a reference speed;

[0014] Verify that the reference speed is required to minimize compressor vibration;

[0015] Define a reference speed range, within which the reference speed is located;

[0016] Based on the speed range and the reference speed, a maximum speed within the speed range and a minimum speed within the speed range are defined;

[0017] Compare the reference speed with the current speed;

[0018] changing the speed of the compressor based on a comparison between the reference speed and the current speed;

[0019] Measure compressor vibration within a reference speed range;

[0020] Based on the vibration measured within the speed range, define the lowest vibration, the lowest vibration speed, and the highest vibration;

[0021] Based on the lowest vibration and the highest vibration, the vibration difference is defined;

[0022] Establish a vibration differential baseline;

[0023] comparing the vibration difference to a vibration difference reference; and

[0024] Based on the comparison between the vibration difference and the vibration difference reference, a final operating speed at which the compressor operates is defined.

[0025] In addition, the method according to the present invention discloses that the reference speed is a new speed at which the compressor is requested to operate from the current speed.

[0026] Furthermore, the method according to the invention comprises a step of verifying whether the reference speed is required to minimize the vibration of the compressor, the step further comprising:

[0027] If there is no need to minimize the compressor vibration, the current speed is set as the reference speed.

[0028] In addition, the method according to the present invention discloses a step of defining a rotation speed range, which step further comprises:

[0029] The speed range is the same for all reference speeds; or

[0030] The speed range changes for each base speed.

[0031] In addition, the method according to the present invention comprises the step of defining a minimum rotation speed and a maximum rotation speed, which step further comprises:

[0032] The minimum speed is calculated as RPM_L = RPM_REF-kL.RPM_RG;

[0033] The maximum speed is RPM_H = RPM_REF + kH.RPM_RG; and

[0034] The maximum speed RPM_H and the minimum speed RPM_L are defined symmetrically around or equal to the reference speed, with the multiplier kL being equal to kH, or are defined asymmetrically around or equal to the reference speed, with the multiplier kL being different from kH.

[0035] In addition, the method according to the present invention includes the steps of comparing a reference speed with a current speed and changing the speed of the compressor, and the steps further include: when the reference speed is lower than the current speed, reducing the speed of the compressor at a first rate of change until a highest reference speed within the speed range is reached.

[0036] In addition, the method according to the invention comprises the step of measuring the vibration of the compressor, which step is performed as follows:

[0037] The rotation speed of the compressor is gradually reduced from the highest rotation speed to the lowest rotation speed at a second change rate and a rotation speed step length;

[0038] In this case, the vibration is measured at each speed step.

[0039] In addition, the method according to the present invention discloses a step of comparing a reference speed with a current speed and a step of changing the reference speed, and the step further includes: when the reference speed is higher than the current speed, increasing the speed of the compressor at a first rate of change until the lowest speed within the speed range is reached.

[0040] Furthermore, the method according to the invention discloses a step of measuring the vibration of the compressor, which is performed as follows:

[0041] The speed of the compressor is gradually increased from the lowest speed to the highest speed at a second change rate and a speed step length;

[0042] In this case, the vibration is measured at each speed step.

[0043] In addition, the method according to the present invention comprises the step of defining a minimum vibration, a minimum vibration speed and a maximum vibration, which step further comprises:

[0044] The lowest vibration is the lowest vibration level measured by at least one vibration sensor within the speed range;

[0045] The minimum vibration speed is a speed that enables the lowest vibration to be achieved within the speed range when the compressor is operated; and

[0046] The highest vibration is the highest vibration level measured by at least one vibration sensor within the rotational speed range.

[0047] In addition, the method according to the present invention includes a step of defining a vibration difference, which step further includes: obtaining the vibration difference by VD=VH-VL; or

[0048] The vibration difference is the percentage of the highest vibration to the lowest vibration.

[0049] In addition, the method according to the present invention discloses a step of establishing a vibration difference reference, which step further comprises:

[0050] The vibration difference reference is the same for all reference speeds; or

[0051] The vibration difference reference is changed for each reference rotation speed.

[0052] In addition, the method according to the present invention discloses the steps of comparing the vibration difference with the vibration difference reference and defining the final operating speed of the compressor operation, the steps further comprising: when the vibration difference is greater than the vibration difference reference, setting the final operating speed to the lowest vibration speed.

[0053] In addition, the method according to the present invention discloses the steps of comparing the vibration difference with a vibration difference reference and defining a final operating speed of the compressor operation, the steps further comprising: when the vibration difference is less than the vibration difference reference, setting the final operating speed to the reference speed.

[0054] The object is also achieved by a system for controlling vibrations of a variable capacity compressor of a refrigeration system, the system comprising:

[0055] a first electronic controller;

[0056] a second electronic controller; and

[0057] and at least one vibration sensor.

[0058] One advantage of the present invention is that the speed of the compressor is defined based on a comparison of vibration levels within a speed range and is not dependent on the absolute value of the vibration level.

[0059] Another advantage of the present invention is that minor changes in compressor operating speed may be made to minimize vibration without compromising other characteristics of the refrigeration system that are dependent on compressor speed, such as cooling capacity and energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The objects and advantages of the present invention will become more apparent from the following detailed description of embodiments and the non-limiting drawings presented at the end of this document:

[0061] Figure 1 A refrigeration system and a control system according to the present invention are disclosed.

[0062] Figure 2 A method according to the invention is disclosed.

[0063] Figure 3 and Figure 4 Practical uses of the methods and systems according to the present invention are disclosed.

[0064] Figure 5 According to the invention, the possibility of using the method is disclosed which is carried out based on time intervals while operating at the same current rotational speed for a longer period of time. DETAILED DESCRIPTION

[0065] The present invention discloses a system and method for vibration control of a variable capacity compressor of a refrigeration system to cool an environment 5 .

[0066] according to Figure 1 , the refrigeration system includes an evaporator 10, a condenser 20 and a variable capacity compressor 30. In addition, there is a system for vibration control of the variable capacity compressor 30 according to the present invention inside the refrigeration system, the control system includes a first electronic controller 40 (e.g., an electronic thermostat), a second electronic controller 50 (e.g., a frequency converter) and at least one vibration sensor 60 (e.g., an accelerometer), the first electronic controller 40 measures the temperature of the environment to be refrigerated; the second electronic controller 50 measures and defines the rotation speed of the compressor 30. At least one vibration sensor 60 is connected to the second electronic controller 50, and the measured vibration or noise is transmitted to the second controller 50.

[0067] according to Figure 2 , the start of the method according to the invention comprises the step of the second controller 50 receiving 95 a request to change the compressor speed from the current speed RPM_SET to a reference speed RPM_REF.

[0068] In case it is desired to minimize the vibration of the compressor with respect to the reference speed RPM_REF, the method proceeds to the next step, otherwise, the current speed RPM_SET is set to the reference speed RPM_REF by the second controller 50 .

[0069] When it is desired to minimize the compressor vibrations with respect to the reference speed RPM_REF, the method proceeds to a step of defining 105 by the second controller 50 a speed range RPM_RG within which the reference speed RPM_REF lies.

[0070] The speed range RPM_RG may be a fixed value for any reference speed RPM_REF, or may be changed according to the value of the reference speed RPM_REF. For example, when the reference speed RPM_REF is a lower speed (e.g., 2000RPM), the speed range RPM_RG may be limited to a smaller value (e.g., 200RPM), thereby minimizing the change in the compressor cooling capacity when efficiency is prioritized. On the other hand, when the reference speed RPM_REF is a higher speed value (e.g., 4500RPM), the speed range RPM_RG may also be increased.

[0071] Subsequently, further based on Figure 2 , the method proceeds to a step in which the second controller 50 defines 110 a maximum speed RPM_H within the speed range RPM_RG and a minimum speed RPM_L within the speed range RPM_RG based on the speed range RPM_RG and the reference speed RPM_REF.

[0072] According to the definition 110, the minimum speed RPM_L is calculated as:

[0073] RPM_L=RPM_REF-kL.RPM_RG

[0074] Among them, RPM_REF is the reference speed; kL is the multiplier; and RPM_RG is the speed range.

[0075] In addition, the maximum speed RPM_H is calculated as:

[0076] RPM_H=RPM_REF+kH.RPM_RG

[0077] Where RPM_REF is the reference speed; kH is the multiplier; and RPM_RG is the reference speed range.

[0078] The maximum speed RPM_H and the minimum speed RPM_L are defined symmetrically or asymmetrically around or equal to the reference speed RPM_REF. For example, if the reference speed RPM_REF is 2400RPM and the speed range RPM_RG is 200RPM, the minimum speed RPM_L may be 2300RPM and the maximum speed RPM_H may be 2500RPM, wherein the multipliers kL and kH are equal to 0.5, or the minimum speed RPM_L may be 2350RPM and the maximum speed RPM_H may be 2550RPM, wherein the multiplier kL is equal to 0.25 and the multiplier kH is equal to 0.75, or the minimum speed RPM_L may be 2400RPM and the maximum speed RPM_H may be 2600RPM, wherein the multiplier kL is equal to 0 and the multiplier kH is equal to 1.

[0079] Subsequently, according to Figure 2 , the method proceeds to a step in which the second controller 50 compares 115 the reference speed RPM_REF with the current speed RPM_SET.

[0080] Based on the comparison 115 between the reference speed RPM_REF and the current speed RPM_SET, the second controller 50 decides how the speed of the compressor 30 should be controlled, ie, decreased or increased.

[0081] Therefore, still according to Figure 2 , the method proceeds to a step of changing 120 the speed of the compressor 30 by the second controller 50 based on a comparison 115 between the reference speed RPM_REF and the current speed RPM_SET, as follows: If the reference speed RPM_REF is lower than the current speed RPM_SET, the speed of the compressor 30 is reduced until the highest speed RPM_H in the speed range RPM_RG is reached. On the contrary, if the reference speed RPM_REF is higher than the current speed RPM_SET, the speed of the compressor 30 is increased until the lowest speed RPM_L in the speed range RPM_RG is reached.

[0082] Subsequently, further based on Figure 2, the method proceeds to a step of measuring 125 the vibration of the compressor within the speed range RPM_RG by at least one vibration sensor 60, the steps being as follows: if the reference speed RPM_REF is lower than the current speed RPM_SET, the speed of the compressor 30 is reduced to a maximum reference speed RPM_H at a first rate of change RPM_ROUT, wherein the first rate of change RPM_ROUT (change in RPM per second) is generally high to change the speed faster. The first rate of change RPM_ROUT is a predefined value set by the user, which depends on the application of the method. The user defines the first rate of change RPM_ROUT according to the speed at which the method must be executed. Once the maximum reference speed RPM_H is reached, the speed of the compressor 30 is gradually reduced from the maximum speed RPM_H to the minimum speed RPM_L at a second rate of change RPM_RIN, wherein the rate is generally low to ensure that the vibration sensor 60 can measure the vibration from RPM_H to RPM_L at each speed step RPM_S. The second rate of change RPM_RIN is a predefined value set by the user, which depends on the application of the method. The user defines the second rate of change RPM_RIN according to the speed at which the method must be executed. On the contrary, if the reference speed RPM_REF is higher than the current speed RPM_SET, the speed of the compressor 30 is increased to the minimum speed RPM_L at the first rate of change RPM_ROUT. Once the minimum speed RPM_L is reached, the speed of the compressor 30 is gradually increased from the minimum speed RPM_L to the maximum speed RPM_H at the second rate of change RPM_RIN, wherein at least one vibration sensor 60 measures vibration at each speed step RPM_S. The speed step RPM_S is a predefined value set by the user, and the user defines the speed step RPM_S according to the speed at which the method must be executed.

[0083] Subsequently, still according to Figure 2 , the method proceeds to a step of defining 130 a lowest vibration VL, a lowest vibration rotational speed RPM_VL, and a highest vibration VH based on the vibration measured 125 in the rotational speed range RPM_RG by the second controller 50. The lowest vibration VL is the lowest vibration level measured by at least one vibration sensor 60 in the rotational speed range RPM_RG, the lowest vibration rotational speed RPM_VL is a rotational speed that enables the lowest vibration VL to be achieved in the rotational speed range RPM_RG when the compressor 30 is operated, and the highest vibration VH is the highest vibration level measured by at least one vibration sensor 60 in the rotational speed range RPM_RG.

[0084] After definition 130, according to Figure 2 , the method proceeds to a step of defining 135 a vibration difference VD based on the lowest vibration VL and the highest vibration VH by the second controller 50. The vibration difference VD is calculated as follows:

[0085] VD=VH-VL

[0086] Wherein VH is the highest vibration within the speed range RPM_RG; and VL is the lowest vibration within the speed range RPM_RG.

[0087] Alternatively, the vibration difference VD can be expressed as a percentage of the highest vibration VH to the lowest vibration VL as follows:

[0088]

[0089] Subsequently, the method proceeds to the step of establishing 140 a vibration difference reference VD_REF by the second controller 50 .

[0090] The vibration difference reference VD_REF is a value fixed for all reference rotation speeds RPM_REF, for example, 20%, which means that the highest vibration VH is 20% higher than the lowest vibration VL. Optionally, the vibration difference reference VD_REF changes for different reference rotation speeds RPM_REF, for example, if the reference rotation speed RPM_REF is less than 2000RPM, the vibration difference reference VD_REF is 20%, or if the reference rotation speed RPM_REF is greater than 2000RPM, the vibration difference reference VD_REF is 10%.

[0091] Subsequently, according to Figure 2 The method compares 145 the vibration difference VD with a vibration difference reference VD_REF by the second controller 50 .

[0092] Finally, still according to Figure 2 , the method defines 150 a final operating speed RPM_RSET at which the compressor 30 operates based on a comparison between the vibration difference VD and a vibration difference reference VD_REF by the second controller 50 .

[0093] In this sense, the definition 150 made by the second controller 50 is as follows: if the vibration difference VD is greater than the vibration difference reference VD_REF, the second controller 50 sets the final operating speed RPM_RSET to be equal to the lowest vibration speed RPM_VL. On the contrary, if the vibration difference VD is less than the vibration difference reference VD_REF, the second controller 50 sets the value of the final operating speed RPM_RSET to be equal to the requested reference speed RPM_REF.

[0094] [Practical Example of Use of the Preferred Embodiment of the Present Invention]

[0095] The practical use of the present invention is described in detail below.

[0096] according to Figure 3 and Figure 4, the second controller 50 receives a request to change the speed of the variable capacity compressor from the current speed RPM_SET 3600RPM to a lower reference speed RPM_REF 2400RPM.

[0097] Subsequently, according to Figure 2 and Figure 3 If it is desired to minimize the vibration of the compressor 30 around the reference speed RPM_REF, the controller defines 105 a speed range RPM_REF 200RPM between 2300RPM and 2500RPM (multipliers kL and kH equal to 0.5), within which the reference speed RPM_REF is located.

[0098] Subsequently, according to Figure 3 In the method, the second controller 50 defines 110 a maximum reference speed RPM_H of 2500 RPM within the speed range RPM_RG and a minimum reference speed RPM_L of 2300 RPM within the speed range RPM_RG.

[0099] Then, according to Figure 4 The method compares 115 the reference speed RPM_REF with the current speed RPM_SET by the second controller 50. When the reference speed RPM_REF 2400RPM is lower than the current speed 3600RPM, the method changes 120 the speed of the compressor 30 by reducing the speed of the compressor 30 until the maximum reference speed RPM_H 2500RPM is reached.

[0100] Subsequently, according to Figure 4 , at least one vibration sensor 60 measures 125 the vibration of the compressor within the speed range RPM_RG. When the reference speed RPM_REF 2400RPM is lower than the current speed RPM_REF 3600RPM, the speed of the compressor 30 is gradually reduced from 2500RPM by a speed step of RPM_S20RPM until the lowest reference speed RPM_L 2300RPM is reached. At least one vibration sensor 60 measures the vibration of the compressor 30 at each step RPM_S.

[0101] Subsequently, based on the vibrations measured 125 , the method defines 130 a lowest vibration VL 0.95 mm / s, a lowest vibration rotation speed RPM_VL 2340 RPM, and a highest vibration VH 1.90 mm / s.

[0102] Based on the definition 130 of the lowest vibration VL and the highest vibration VH, the method defines 135 a vibration difference VD of 0.95 mm / s. Alternatively, the vibration difference VD may be expressed as a percentage of the highest vibration VH to the lowest vibration VL, in this example VD being 100%.

[0103] The method establishes 140 a vibration difference reference VD_REF by the second controller 50 , wherein the vibration difference reference VD_REF may be a fixed value for any rotational speed, or have different values ​​for different rotational speed ranges. In this example, the vibration difference reference VD_REF is expressed as a percentage of the highest vibration VH to the lowest vibration VL.

[0104] The method compares 145 the vibration difference VD with a vibration difference reference VD_REF by the second controller 50 .

[0105] When the vibration difference VD is higher than the vibration difference reference VD_REF, for example, the vibration difference reference VD_REF is defined as 50%, the method defines 150 a final operating speed RPM_RSET for the operation of the compressor 30 based on a comparison between the vibration difference VD and the vibration difference reference VD_REF by the second controller 50, wherein the final operating speed RPM_RSET is the lowest vibration speed RPM_VL.

[0106] The comparison between the vibration difference VD and the vibration difference reference VD_REF is performed to measure the degree of change of the vibration level within the speed range RPM_RG. Alternatively, for the example given here, the vibration difference VD can be lower than the vibration difference reference VD_REF, 20% and 40% as examples respectively. In this case, the second controller 50 will define the final operating speed RPM_RSET with the same reference speed RPM_REF requested at the beginning of the method.

[0107] according to Figure 5 The method can be executed not only when there is a request for the reference speed RPM_REF, but also from time to time to ensure that compressor vibrations can be reduced even after a longer operation at the same current speed RPM_SET.

[0108] Figure 5 A time T_VIB is described at which the second controller 50 periodically performs a check 155. Once the time T_VIB is reached, the method is performed as described above and, if the comparison between the vibration difference VD and the vibration difference reference VD_REF shows that the vibration difference VD is higher than the vibration difference reference VD_REF, the compressor speed is adjusted to the minimum vibration speed RPM_VL.

[0109] In addition to the embodiments presented above, the same inventive concept can be applied to other alternatives or possibilities of using the invention, for example, a noise sensor can be used instead of a vibration sensor.

[0110] Although the present invention has been described in conjunction with preferred embodiments, it should be understood that the present invention is not intended to limit the present invention to those specific embodiments. On the contrary, the present invention is intended to cover all possible alternative embodiments, modified embodiments and equivalent embodiments within the spirit and scope of the present invention defined by the appended claims.

Claims

1. A method for controlling vibration of a variable capacity compressor (30) of a refrigeration system, characterized in that: The following steps are involved: receiving (95) a request to change the speed of the variable capacity compressor (30) from a current speed (RPM_SET) to a reference speed (RPM_REF); Verifying (100) whether a reference speed (RPM_REF) is required to minimize compressor vibration; defining (105) a reference speed range (RPM_RG), the reference speed (RPM_REF) being within the range (RPM_RG); Based on the speed range (RPM_RG) and the reference speed (RPM_REF), define (110) a maximum speed (RPM_H) within the speed range (RPM_RG) and a minimum speed (RPM_L) within the speed range (RPM_RG); Compare the reference speed (RPM_REF) with the current speed (RPM_SET) (115); changing (120) a speed of the compressor (30) based on a comparison between a reference speed (RPM_REF) and a current speed (RPM_SET); Measuring (125) compressor vibration within a reference speed range (RPM_RG); Based on the vibration measured within the speed range (RPM_RG), defining (130) a lowest vibration (VL), a lowest vibration speed (RPM_VL), and a highest vibration (VH); Based on the lowest vibration (VL) and the highest vibration (VH), define (135) a vibration difference (VD); Establishing (140) a vibration difference reference (VD_REF); comparing the vibration difference (VD) to a vibration difference reference (VD_REF) (145); and Based on the comparison between the vibration difference (VD) and the vibration difference reference (VD_REF), a final operating speed (RPM_RSET) at which the compressor (30) operates is defined (150).

2. The method according to claim 1, characterized in that The reference speed (RPM_REF) is a new speed at which the compressor (30) is requested to operate from the current speed (RPM_SET).

3. The method according to claim 1, characterized in that The step of verifying (100) whether a reference speed (RPM_REF) is required to minimize compressor vibration further comprises: If it is not necessary to minimize the compressor vibration, the current speed (RPM_SET) is set to the reference speed (RPM_REF).

4. The method according to claim 1, characterized in that The step of defining (105) a speed range (RPM_RG) further comprises: The speed range (RPM_RG) is the same for all reference speeds (RPM_REF); or The rotation speed range (RPM_RG) changes for each reference rotation speed (RPM_REF).

5. The method according to claim 1, characterized in that The step of defining (110) a minimum speed (RPM_L) and a maximum speed (RPM_H) further comprises: The minimum speed (RPM_L) is calculated as RPM_L = RPM_REF - kL.RPM_RG; The maximum speed (RPM_H) is RPM_H=RPM_REF+kH.RPM_RG; and The maximum speed RPM_H and the minimum speed RPM_L are defined symmetrically around or equal to the reference speed (RPM_REF), with the multiplier kL being equal to kH, or are defined asymmetrically around or equal to the reference speed (RPM_REF), with the multiplier kL being different from kH.

6. The method according to claim 1, characterized in that The steps of comparing (115) a reference speed (RPM_REF) with a current speed (RPM_SET) and changing (120) the speed of the compressor (30) further include: when the reference speed (RPM_REF) is lower than the current speed (RPM_SET), reducing the speed of the compressor (30) at a first change rate (RPM_ROUT) until a maximum reference speed (RPM_H) within a speed range (RPM_RG) is reached.

7. The method according to claim 1, characterized in that The steps for measuring (125) the compressor vibration are performed as follows: The rotation speed of the compressor (30) is gradually reduced from a maximum rotation speed (RPM_H) to a minimum rotation speed (RPM_L) at a second change rate (RPM_RIN) and a rotation speed step length (RPM_S); Therein, the vibration is measured at each speed step (RPM_S).

8. The method according to claim 1, characterized in that The steps of comparing (115) the reference speed (RPM_REF) with the current speed (RPM_SET) and changing (120) the reference speed (RPM_REF) further include: when the reference speed (RPM_REF) is higher than the current speed (RPM_SET), increasing the speed of the compressor (30) at a first change rate (RPM_ROUT) until reaching the lowest speed (RPM_L) within the speed range (RPM_RG).

9. The method according to claim 1, characterized in that: The steps for measuring (125) the compressor vibration are performed as follows: gradually increasing the speed of the compressor (30) from a minimum speed (RPM_L) to a maximum speed (RPM_H) at a second change rate (RPM_RIN) and a speed step (RPM_S); Therein, the vibration is measured at each speed step (RPM_S).

10. The method according to claim 1, characterized in that The step of defining (130) the minimum vibration (VL), the minimum vibration speed (RPM_VL) and the maximum vibration (VH) further comprises: The lowest vibration (VL) is the lowest vibration level measured by at least one vibration sensor (60) within the speed range (RPM_RG); The minimum vibration rotation speed (RPM_VL) is a rotation speed that enables the minimum vibration (VL) to be achieved within the rotation speed range (RPM_RG) when the compressor (30) is operated; and The maximum vibration (VH) is the highest vibration level measured by at least one vibration sensor (60) within the rotation speed range (RPM_RG).

11. The method according to claim 1, characterized in that: The step of defining (135) the vibration difference (VD) further comprises: obtaining the vibration difference (VD) by VD=VH-VL; or The vibration difference (VD) is the percentage of the highest vibration (VH) to the lowest vibration (VL) and is calculated as 12. The method according to claim 1, characterized in that The step of establishing (140) a vibration difference reference (VD_REF) further comprises: The vibration difference reference (VD_REF) is the same for all reference speeds (RPM_REF); or The vibration difference reference (VD_REF) changes for each reference rotation speed (RPM_REF).

13. The method according to claim 1, characterized in that The steps of comparing (145) the vibration difference (VD) with a vibration difference reference (VD_REF) and defining (150) a final operating speed (RPM_RSET) at which the compressor (30) operates further include setting the final operating speed (RPM_RSET) to a minimum vibration speed (RPM_VL) when the vibration difference (VD) is greater than the vibration difference reference (VD_REF).

14. The method according to claim 1, characterized in that The steps of comparing (145) the vibration difference (VD) with a vibration difference reference (VD_REF) and defining (150) a final operating speed (RPM_RSET) at which the compressor (30) operates further include setting the final operating speed (RPM_RSET) to the reference speed (RPM_REF) when the vibration difference (VD) is less than the vibration difference reference (VD_REF).

15. The method according to claim 1, characterized in that The steps of receiving (95) a request to change the speed of the variable capacity compressor (30) from a current speed (RPM_SET) to a reference speed (RPM_REF) and verifying (100) whether the reference speed (RPM_REF) is required to minimize compressor vibration are replaced by the following steps: Check (155) whether the time (T_VIB) has arrived.

16. A system for controlling vibration of a variable capacity compressor of a refrigeration system, comprising: A first electronic controller (40); A second electronic controller (50); as well as and at least one vibration sensor (60), characterized in that it performs the method according to claim 1.

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