Control method of compressor and refrigerator

Abstract

The application provides a compressor control method and a refrigerator. The control method comprises the following steps: after a preset time t1 of opening a PFC function, modifying a target rotating speed of the compressor to a target rotating speed n2 of the compressor corresponding to the PFC function, and adjusting a current field weakening parameter or a bus voltage parameter of the compressor according to the target rotating speed n2 to improve the operating efficiency of the compressor. Whether the PFC function is opened is determined according to the rotating speed and the power of the compressor. After the PFC function is opened, the target rotating speed is adjusted. If the target rotating speed is not reached, the current field weakening depth can be adjusted to keep the compressor stably operating at a higher efficiency. When the rotating speed requirement changes again, the field weakening depth can be adjusted first. After the adjustment, if the compressor rotating speed still cannot be increased, the voltage is adjusted again. When the rotating speed reaches the target rotating speed, the field weakening depth can be adjusted again. In this way, the voltage and the field weakening depth of the motor are adjusted, so that the compressor can stably operate at a higher efficiency.

Description

Technical Field

[0001] This invention relates to the field of refrigerator technology, specifically to a compressor control method and a refrigerator. Background Technology

[0002] With the increasing demand in the commercial refrigerator market, the requirements for high-power equipment are also gradually increasing, and the requirements for power factor are becoming more stringent. Therefore, commercial refrigerators are gradually introducing power factor correction (PFC) technology, which maintains an approximately constant phase difference between the input current and the input voltage. By improving the power factor and optimizing the regulation of harmonic currents, the harmful effects of harmonics on power grid stability are reduced.

[0003] Existing PFC control schemes typically employ a single voltage control mode. In this mode, as the voltage is boosted by the PFC circuit, the power loss of the switching transistor increases with the voltage increase. Simultaneously, as the output voltage rises, the system's power and power factor also improve. However, this fixed-boost approach has significant limitations in certain scenarios.

[0004] For example, in situations where the compressor operates at high speeds and requires field weakening control, traditional fixed-voltage boost solutions often fail to meet the overall performance requirements of the system. Single-voltage control and a fixed field weakening depth not only significantly increase the power consumption of the switching transistors but also adversely affect the motor's operating efficiency. In this case, the switching transistors experience greater losses under high loads, while the high-speed operating efficiency of the motor cannot be fully utilized. Summary of the Invention

[0005] In order to solve the technical problem that the PFC control scheme in the prior art usually adopts a single voltage control mode with low efficiency, the present invention proposes a compressor control method and a refrigerator.

[0006] The technical solution adopted in this invention is:

[0007] This invention proposes a compressor control method, comprising the following steps:

[0008] After enabling the PFC function and running for a preset time t1;

[0009] Modify the compressor's target speed to the compressor's target speed n2 after the PFC function is enabled, and adjust the compressor's current field weakening parameters or bus voltage parameters according to the target speed n2 to improve the compressor's operating efficiency.

[0010] Furthermore, the adjustment of the compressor's current field weakening parameters or bus voltage parameters according to the target rotational speed n2 specifically includes:

[0011] Determine whether the compressor speed n is less than the target speed n2;

[0012] If so, increase the compressor speed by adjusting the current magnetic weakening parameter of the compressor to X2;

[0013] If not, maintain the current running status.

[0014] Furthermore, after adjusting the compressor's current magnetic weakening parameter to X2 to increase the compressor speed, it is determined again whether the compressor speed n is less than the target speed n2;

[0015] If so, increase the bus voltage parameter until the compressor speed n equals the target speed n2;

[0016] If not, maintain the current running status.

[0017] The present invention further includes the following steps: after modifying the target speed of the compressor to the target speed n2 of the compressor after the PFC function is turned on, if the compressor obtains a demand for continued speed increase, after reaching the target speed n2 and running for a preset time t2, the target speed of the compressor is modified to the target speed n3 corresponding to the speed increase demand, and then the current magnetic weakening parameter or bus voltage parameter of the compressor is adjusted according to the target speed n3 to improve the operating efficiency of the compressor.

[0018] Furthermore, the adjustment of the compressor's current field weakening parameters or bus voltage parameters based on the compressor's target speed n3 specifically includes:

[0019] Determine whether the compressor speed n is less than the target speed n3;

[0020] If so, adjust the compressor's current magnetic weakening parameter to X3 to increase the compressor speed;

[0021] If not, maintain the current running status.

[0022] Furthermore, after adjusting the current magnetic weakening parameter of the compressor to X3, it is determined whether the compressor speed n has reached the target speed n3;

[0023] If so, maintain the current running state;

[0024] If not, increase the bus voltage parameter to the preset value to increase the compressor speed.

[0025] Furthermore, after maintaining the current operating state, the current field weakening parameters and the motor operating efficiency close to the current field weakening parameters are calculated. The field weakening parameters corresponding to the maximum operating efficiency of the motor are obtained, and the current field weakening parameters of the compressor are adjusted to the field weakening parameters corresponding to the maximum operating efficiency of the motor.

[0026] Furthermore, after increasing the bus voltage parameter by a preset value to increase the compressor speed, it is determined whether the compressor speed n has reached the target speed n3;

[0027] If so, maintain the current running state;

[0028] If not, continue adjusting the current magnetic weakening parameters of the compressor and running for a preset time t3. If the compressor speed still does not reach the target speed n3, continue increasing the bus voltage parameters until the compressor speed n equals the target speed n3.

[0029] Furthermore, calculating the current field weakening parameters and the motor's operating efficiency under parameters close to the current field weakening parameters specifically includes:

[0030] Obtain the current field weakening parameters and the electromagnetic torque Te corresponding to the current field weakening parameters respectively, calculate the motor output power P1 = Te * n, obtain the motor input power P2, and calculate the motor operating efficiency η = P1 / P2 using P1 and P2.

[0031] When the compressor speed n is greater than or equal to the preset speed n1, or the compressor input power P is greater than or equal to the preset power P1, the PFC function is activated to improve the power factor.

[0032] The present invention also proposes a refrigerator that uses the above-described compressor control method to improve compressor operating efficiency.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1. After entering the PFC function, this invention directly increases the target speed of the compressor, avoiding increased losses of the switching transistor caused by operating the PFC mode at low speed and low power; and adjusts the field weakening parameters or bus voltage according to whether the target speed is reached, so that the speed is close to the target speed, improving the flexibility of field weakening control and improving the operating efficiency of the compressor.

[0035] 2. When the speed requirement increases again, the field weakening depth can be adjusted first. If the compression speed still cannot be increased after adjustment, the voltage can be adjusted again. When the speed reaches the target speed, the field weakening depth can be readjusted. This cycle of adjusting the voltage and the field weakening depth of the motor can be repeated to allow the compressor to operate stably at a higher efficiency. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart of an embodiment of the present invention;

[0038] Figure 2 This is a flowchart of the first embodiment of the present invention;

[0039] Figure 3 This is a flowchart of a further embodiment of the present invention. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0041] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0042] For example, in situations where the compressor operates at high speeds and requires field weakening control, traditional fixed-voltage boost solutions often fail to meet the overall performance requirements of the system. Single-voltage control and a fixed field weakening depth not only significantly increase the power consumption of the switching transistors but also adversely affect the motor's operating efficiency. In this case, the switching transistors experience greater losses under high loads, while the high-speed operating efficiency of the motor cannot be fully utilized.

[0043] To address the above issues, existing compressor control methods need further optimization to reduce switching losses and improve motor efficiency at high speeds, while also meeting the higher power factor and energy efficiency requirements of modern commercial refrigerators.

[0044] like Figure 1 As shown, this invention proposes a compressor control method, including the following steps:

[0045] Set the target speed n2 of the compressor according to the corresponding power factor correction (PFC) function to ensure that the compressor operating parameters match the target state after the PFC function is enabled;

[0046] After enabling the PFC function and running for a preset time t1;

[0047] Modify the compressor's current target speed to the compressor's target speed n2 after the PFC function is enabled, in order to adapt to the requirements of the PFC operation mode; adjust the compressor's current field weakening parameters or bus voltage parameters according to the target speed n2 to improve the compressor's operating efficiency.

[0048] After entering the PFC function, this invention directly increases the target speed of the compressor, avoiding increased losses of the switching transistors caused by operating the PFC mode at low speed and low power. Furthermore, it adjusts the field weakening parameters or bus voltage according to whether the target speed has been reached, so that the speed is close to the target speed, improving the flexibility of field weakening control and increasing the operating efficiency of the compressor.

[0049] In specific embodiments, such as Figure 2 As shown, adjusting the compressor's current field weakening parameters or bus voltage parameters according to the target speed n2 includes the following steps:

[0050] Determine whether the current compressor speed n is less than the target speed n2;

[0051] If the current speed n is less than the target speed n2, the compressor speed is increased by adjusting the current field weakening parameter of the compressor to a new parameter value X2, so as to ensure that it gradually approaches the target speed n2.

[0052] If the current speed n is not less than the target speed n2, the compressor's current operating state is maintained to preserve system stability and operating efficiency.

[0053] This invention enables the compressor to flexibly adapt to different operating conditions by dynamically adjusting the field weakening parameters, thereby effectively improving the accuracy and response speed of speed control. At the same time, it avoids the additional power loss that may be caused by unnecessary field weakening adjustments or bus voltage adjustments, further improving the compressor's operating efficiency.

[0054] In a specific embodiment, after adjusting the compressor's current field weakening parameter to X2 to increase the compressor speed, the following steps are performed again:

[0055] Determine whether the current compressor speed n is still less than the target speed n2;

[0056] If the current speed n is less than the target speed n2, then the bus voltage parameter is further increased to gradually increase the compressor speed until the compressor speed n equals the target speed n2.

[0057] If the current speed n is not less than the target speed n2, then maintain the current operating state to ensure stable system operation and avoid unnecessary parameter adjustments.

[0058] If adjusting the field weakening parameters fails to increase the compressor to the target speed, the speed can be increased by increasing the bus voltage, thereby improving the compressor's operating efficiency.

[0059] like Figure 3 As shown, the present invention also proposes an embodiment, specifically as follows:

[0060] The compressor's target speed is set to n2, corresponding to the operating requirements after the power factor correction (PFC) function is enabled. After the PFC function is activated, the compressor runs to the target speed n2 and maintains it for a preset time t2. During this period, the compressor's field weakening parameters or bus voltage parameters are adjusted to ensure that the compressor can operate efficiently and achieve the expected performance.

[0061] When a speed increase demand is detected during compressor operation, the target speed is adjusted from n2 to a new target speed n3 corresponding to the speed increase demand. Then, based on the compressor's target speed n3, the current field weakening parameters or bus voltage parameters are adjusted to improve compressor operating efficiency.

[0062] This embodiment improves the compressor's responsiveness to speed increase demands and shortens the response time for speed adjustments by setting target speeds in stages and optimizing dynamic parameters. Optimization of the field weakening parameters and coordinated adjustment of the bus voltage effectively reduce power losses in the switching transistors while ensuring the compressor's operating efficiency at different target speeds. This method adapts to various operating conditions while improving the compressor's energy efficiency, and is particularly suitable for scenarios with high power factor correction requirements.

[0063] In a further embodiment, after the target speed of the compressor is adjusted to n3, the current field weakening parameters or bus voltage parameters of the compressor are optimized and adjusted according to the target speed n3. Specifically, this includes the following operations:

[0064] Determine whether the current speed n of the compressor is less than the target speed n3;

[0065] If the current speed n is less than the target speed n3, the compressor's magnetic weakening parameter will be adjusted to a new setting value X3 to increase the compressor speed and gradually bring it closer to the target speed n3.

[0066] If the current speed n has reached or exceeded the target speed n3, the current operating state is maintained, and no additional adjustments are made to the field weakening parameters or bus voltage parameters, thereby avoiding efficiency reduction or unstable operation caused by unnecessary parameter changes.

[0067] This embodiment improves the flexibility and accuracy of speed regulation by monitoring the compressor's current speed and adjusting the field weakening parameters or bus voltage parameters according to the target speed requirement. Optimization of the field weakening parameters effectively reduces the power loss of the switching transistor, ensuring efficient and stable compressor operation at the target speed. It is suitable for operating conditions where the compressor needs frequent speed adjustments, providing crucial assurance for the overall system's operational reliability and energy efficiency.

[0068] In a further embodiment, after adjusting the compressor's current field weakening parameter to X3, it is determined again whether the compressor's current speed n has reached the target speed n3. If the current speed n has reached the target speed n3, the current operating state is maintained, and the current field weakening parameter and bus voltage parameter are maintained to ensure system stability and efficient operation.

[0069] If the current rotational speed n does not reach the target rotational speed n3, the bus voltage parameter is further increased to the preset value. By increasing the voltage driving force, the compressor speed is increased, gradually bringing it closer to the target rotational speed n3. This adjustment process ensures that even with insufficient adjustment of the field weakening parameter, the system can still achieve the target rotational speed requirement through optimization of the bus voltage.

[0070] This embodiment improves the compressor's speed-up response and efficiency by progressively optimizing the coordinated adjustment of the field weakening parameters and the bus voltage parameters. When the adjustment of the field weakening parameters fails to meet the target speed requirements, the increase in the bus voltage parameters provides additional drive protection, avoiding performance loss or instability caused by insufficient adjustment of a single parameter during the adjustment process.

[0071] In a further embodiment, after adjusting the current field weakening parameter of the compressor to X3 and making the compressor speed n reach the target speed n3, while entering the running state holding stage, the motor running efficiency optimization step is performed, which specifically includes: calculating the current field weakening parameter and the running efficiency of the motor (compressor motor) under the current field weakening parameter and close to the current field weakening parameter, obtaining the maximum running efficiency of the motor, and determining the field weakening parameter value corresponding to the maximum running efficiency of the motor.

[0072] After obtaining the field weakening parameters corresponding to the maximum operating efficiency of the motor, the current field weakening parameters of the compressor are adjusted to these optimal parameters. This ensures that the compressor can not only operate smoothly at the target speed n3, but also achieve the optimal efficiency of the motor. Through this optimization process, energy consumption is further reduced while meeting the target speed, thus improving the overall economic efficiency of the compressor operation.

[0073] This embodiment achieves dynamic optimization of motor operating efficiency. Under the condition that the speed meets the target, the field weakening parameter can be precisely optimized according to the motor efficiency to avoid potential efficiency losses, ensuring that the compressor maintains its optimal performance point during long-term operation. This method is particularly suitable for applications with high energy efficiency requirements.

[0074] In a further embodiment, after increasing the bus voltage parameter to a preset value to increase the compressor speed, it is first determined whether the current speed n of the compressor has reached the target speed n3;

[0075] If the compressor speed has reached the target speed n3, the system maintains the current operating state to ensure that the compressor operates stably at the target speed;

[0076] If the compressor speed n does not reach the target speed n3, the current field weakening parameter of the compressor is adjusted, and the system is run for a preset time t3 to further increase the compressor speed. After running for the preset time t3, it is checked again whether the compressor speed has reached the target speed n3. If the target speed n3 is still not reached, the bus voltage parameter is increased until the compressor speed reaches the target speed n3, or the field weakening parameter is adjusted again after increasing the bus voltage parameter. This process is repeated until the target speed n3 is reached.

[0077] This embodiment ensures the compressor reaches the target speed by combining a cyclic adjustment mechanism of bus voltage and field weakening parameters. After initially increasing the bus voltage, if the target speed is not achieved, the system optimizes the speed-up process by adjusting the field weakening parameters, avoiding over-reliance on a single parameter. Ultimately, by gradually increasing the bus voltage, the compressor successfully reaches the expected speed, improving system stability and response speed. This method effectively reduces energy loss during the adjustment process while meeting the target speed requirements, ensuring efficient and stable operation of the compressor under different operating conditions. It is suitable for high-efficiency and energy-saving applications requiring rapid speed adjustments.

[0078] Specifically, calculating the current field weakening parameters and the motor's operating efficiency under parameters close to the current field weakening parameters includes:

[0079] Obtain the current field weakening parameter X3 and the electromagnetic torque Te corresponding to the current field weakening parameter respectively. Calculate the motor output power P1 = Te * n. Obtain the motor input power P2, which can be calculated from the motor input voltage and current. Then, calculate the motor operating efficiency η = P1 / P2 using P1 and P2.

[0080] After the motor reaches the target speed, the load torque Tl and electromagnetic torque Te of the motor can be considered to be approximately equal. The output power P1 of the motor can be calculated from the speed and electromagnetic torque. The input power P2 of the motor can be calculated from the input voltage and current of the motor. The operating efficiency η = P1 / P2 of the motor can be calculated from P1 and P2.

[0081] Taking a rotational speed of n3 as an example, the field weakening parameter at this time is c (the specific value of the field weakening parameter X3), and the corresponding electromagnetic torque is Te. Field weakening parameters c1, c2, c3, c4, c5, and c6 can be selected and can fluctuate around c. The range can be selected according to the requirements. The electromagnetic torques corresponding to the above field weakening parameters are Te1, Te2, Te3, Te4, Te5, and Te6, respectively. The output power of the motor at this time is calculated by formula P1 = Te * n, and then the input power P2 of the motor is calculated. Finally, the operating efficiency under different field weakening parameters is calculated by formula η = P1 / P2. The field weakening parameter corresponding to the highest operating efficiency is selected as the field weakening parameter for the current motor operation.

[0082] In a specific embodiment, when the compressor speed n is greater than or equal to the preset speed n1, or the compressor input power P is greater than or equal to the preset power Pz, the PFC function is activated to improve the power factor.

[0083] Since turning on PFC at low speed and low power not only increases the loss of the switching transistor, but also does not significantly improve the efficiency of the compressor, thus wasting resources, the PFC function should only be turned on when the compressor speed exceeds a certain speed.

[0084] The present invention also proposes a refrigerator that uses the above-described compressor control method to improve compressor operating efficiency.

[0085] Refrigerators using this control method can determine the voltage requirement based on whether the PFC function is enabled and the compressor (or motor) speed, and adjust the field weakening depth under different voltages, thereby improving the flexibility of field weakening control, increasing the compressor's operating efficiency, and enhancing the product's competitiveness.

[0086] It should be noted that the terminology used above is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0087] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0088] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0089] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0090] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling a compressor, characterized in that, Including the following steps: After enabling the PFC function and running for a preset time t1; Modify the compressor's target speed to the compressor's target speed n2 after the PFC function is enabled, and adjust the compressor's current field weakening parameters or bus voltage parameters according to the target speed n2 to improve the compressor's operating efficiency. The adjustment of the compressor's current field weakening parameters or bus voltage parameters based on the target rotational speed n2 specifically includes: Determine whether the compressor speed n is less than the target speed n2; If so, increase the compressor speed by adjusting the current magnetic weakening parameter of the compressor to X2; If not, maintain the current running status; After increasing the compressor speed by adjusting the current magnetic weakening parameter of the compressor to X2, it is determined again whether the compressor speed n is less than the target speed n2; If so, increase the bus voltage parameter until the compressor speed n equals the target speed n2; If not, maintain the current running status.

2. The compressor control method as described in claim 1, characterized in that, The process also includes the following steps: After modifying the compressor's target speed to the compressor's target speed n2 corresponding to the PFC function being enabled, if the compressor obtains a demand for further speed increase, after reaching the compressor's target speed n2 and running for a preset time t2, the compressor's target speed is modified to the target speed n3 corresponding to the speed increase demand. Then, based on the compressor's target speed n3, the compressor's current field weakening parameters or bus voltage parameters are adjusted to improve the compressor's operating efficiency.

3. The compressor control method as described in claim 2, characterized in that, The adjustment of the compressor's current field weakening parameters or bus voltage parameters based on the compressor's target speed n3 specifically includes: Determine whether the compressor speed n is less than the target speed n3; If so, adjust the compressor's current magnetic weakening parameter to X3 to increase the compressor speed; If not, maintain the current running status.

4. The compressor control method as described in claim 3, characterized in that, After adjusting the compressor's current magnetic weakening parameter to X3, determine whether the compressor speed n has reached the target speed n3; If so, maintain the current running state; If not, increase the bus voltage parameter to the preset value to increase the compressor speed.

5. The compressor control method as described in claim 4, characterized in that, After maintaining the current operating state, calculate the current field weakening parameters and the motor operating efficiency under field weakening parameters close to the current field weakening parameters, obtain the field weakening parameters corresponding to the maximum operating efficiency of the motor, and adjust the current field weakening parameters of the compressor to the field weakening parameters corresponding to the maximum operating efficiency of the motor.

6. The compressor control method as described in claim 4, characterized in that, After increasing the bus voltage parameter by a preset value to increase the compressor speed, it is determined whether the compressor speed n has reached the target speed n3. If so, maintain the current running state; If not, continue adjusting the current magnetic weakening parameters of the compressor and running for a preset time t3. If the compressor speed still does not reach the target speed n3, continue increasing the bus voltage parameters until the compressor speed n equals the target speed n3.

7. The compressor control method as described in claim 5, characterized in that, The calculation of the motor's operating efficiency under the current field weakening parameters and field weakening parameters close to the current field weakening parameters specifically includes: Obtain the current field weakening parameters and the electromagnetic torque Te corresponding to the field weakening parameters that are close to the current field weakening parameters. Calculate the motor output power P1=Te*n, obtain the motor input power P2, and calculate the motor operating efficiency η= P1 / P2 using P1 and P2.

8. The compressor control method as described in claim 1, characterized in that, When the compressor speed n is greater than or equal to the preset speed n1, or the compressor input power P is greater than or equal to the preset power P1, the PFC function is activated to improve the power factor.

9. A refrigerator, characterized in that, The compressor operating efficiency is improved by using the compressor control method according to any one of claims 1 to 8.

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