Refrigerator and frequency conversion fault processing method

Abstract

The invention discloses a refrigerator and a frequency conversion fault processing method, and the processing method comprises the steps: 1, detecting the voltage U of a power supply after electrification, and executing a step 2 if the voltage U is out of limit; if normal, continuous monitoring is carried out, and the compressor works normally; 2, when the out-of-limit duration t reaches a set first time threshold t1, the machine is stopped immediately, and the step 3 is executed; if not, recording that voltage fluctuation occurs once, taking whether continuous N times of voltage fluctuation occurs in a set time period Ts or not after the current startup as a criterion, if yes, forcibly stopping, and allowing the startup after the protection time length Tp; if not, returning to the step 1; 3, monitoring the U, recording the shutdown protection duration t2 until the U is within a normal range and the duration is set for Tn, and executing the step 4; 4, if t2 reaches the frequency conversion protection time Tf or above, executing the step 5, and if t2 does not reach the frequency conversion protection time Tf, returning to the step 3; and 5, if t2 does not reach Tp, stopping and waiting until Tp is reached, and then allowing to start. And the operation stability and reliability of the refrigerator are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of refrigerators, and more particularly, relates to a refrigerator and a method for processing frequency conversion failures. Background Art

[0002] When a refrigerator is operating at home, the voltage can fluctuate due to the influence of the power supply station. To prevent the inverter board from burning out and malfunctioning, the compressor must stop when a voltage anomaly is detected, triggering inverter fault protection and restarting after the voltage stabilizes. This operation faces many challenges, including but not limited to: 1. The voltage provided by the power supply station is unstable and may fluctuate multiple times in a short period of time. Frequent shutdowns require 10 minutes of protection after each shutdown, which can affect the refrigerator's cooling performance. Therefore, protection logic for frequent voltage fluctuations must be configured. 2. After a shutdown, it is difficult to ensure that the inverter fault protection is completely eliminated and normal operation can resume automatically. Sometimes, users need to contact after-sales personnel for processing, which increases manpower and material expenses.

[0003] Solutions in the prior art include, but are not limited to, using specific voltage protectors and protection circuits to implement frequency conversion fault handling, but changing the hardware involves costs, and it cannot be simply solved for controllers that have been mass-produced, sold, and have after-sales service; solutions in prior art documents also include: in order to prevent instantaneous high current shocks during startup, by adjusting the operating parameters of internal devices at the next startup, the starting current is reduced to less than the current value of the fault report, thereby reducing the fault frequency, but it still cannot solve the self-recovery problem in response to frequent voltage fluctuations and multiple faults occurring simultaneously. Summary of the Invention

[0004] To address the deficiencies in the prior art, the present invention provides a refrigerator and a method for handling inverter faults. By implementing protection judgment logic for frequent voltage fluctuations and comprehensive inverter board fault diagnosis, the stability, safety, and reliability of refrigerator operation are improved.

[0005] The present invention adopts the following technical solutions.

[0006] A first aspect of the present invention provides a method for handling a frequency conversion fault, which is used for a frequency conversion compressor, wherein the frequency conversion compressor includes a frequency conversion board and a compressor. The method includes the following steps:

[0007] Step 1: After power is turned on, the inverter board detects the power supply voltage U. If the power supply voltage exceeds the limit, proceed to step 2; if it is within the normal range, the power supply voltage U is continuously monitored and the inverter compressor operates normally.

[0008] Step 2: If the power supply voltage over-limit duration t reaches or exceeds the set first time threshold t1, the compressor is immediately shut down and step 3 is continued; if the first time threshold t1 is not reached, a voltage fluctuation is recorded, and whether N consecutive voltage fluctuations after the current startup occur within the set time period Ts is used as a continuous fluctuation criterion. If the continuous fluctuation criterion is met, the compressor is forced to shut down for the set compressor protection time Tp before the compressor is allowed to start; if the continuous fluctuation criterion is not met, the process returns to step 1 and continues to monitor the power supply voltage;

[0009] Step 3: Continuously monitor the power supply voltage U and record the shutdown protection duration t2 until the power supply voltage has returned to the normal range and lasts for the set time Tn, and then proceed to step 4;

[0010] Step 4: Determine whether the shutdown protection time t2 has reached or exceeded the frequency conversion protection time Tf. If so, proceed to step 5. If not, return to step 3.

[0011] Step 5: Determine whether the shutdown protection duration t2 has reached the compressor protection time Tp. If not, continue to shut down and wait. When the shutdown time reaches the compressor protection time Tp, allow the compressor to start.

[0012] Preferably, during the execution of steps 1 to 5, if a fault other than voltage exceeding the limit occurs on the frequency conversion board, the fault count is increased by 1, and the frequency conversion compressor enters a fault state;

[0013] If the compressor is in the on state at this time, the compressor will stop and wait until the fault state is eliminated before allowing the compressor to start;

[0014] If the compressor is in a stopped state at this time, wait until the fault state is eliminated, and determine whether to allow the compressor to be started based on whether the accumulated number of faults exceeds the fault number threshold.

[0015] Preferably, determining whether to allow the compressor to be started according to whether the cumulative number of failures exceeds a failure number threshold comprises:

[0016] When the shutdown reaches the compressor protection time Tp and the fault state has been eliminated, if the cumulative number of faults is less than the fault number threshold N1, the compressor is allowed to start;

[0017] If the cumulative number of faults is equal to the fault threshold N1, the downtime is extended until it reaches βTp, and the compressor is allowed to start, where β>1;

[0018] If the cumulative number of faults is greater than the fault threshold N1, the compressor is allowed to start only after powering off and then powering on again.

[0019] Preferably, the method of allowing the compressor to start only after power failure and then power-on further includes:

[0020] After the compressor starts up normally, the variable-frequency compressor memorizes the number of times of the last failure until no failure occurs again within the set time period Tcl, and then the number of failure times is cleared.

[0021] The second aspect of the present invention provides a method for handling variable-frequency faults of a refrigerator. Based on the handling method described in the first aspect of the present invention, it includes the following steps:

[0022] In step 1, after the refrigerator is powered on, the variable-frequency board detects the power supply voltage U. If U≥280V or U≤140V, step 2 is continued. If the power supply voltage 140V<U<280V, the power supply voltage U is continuously monitored, and the variable-frequency compressor of the refrigerator operates normally.

[0023] Preferably, in step 2, when the variable-frequency board of the refrigerator detects that the continuous duration t of the power supply voltage U≥280V or U≤140V is t≥5ms, the compressor immediately stops for protection and step 3 is continued;

[0024] If the continuous duration t of the power supply voltage U≥280V or U≤140V is less than 5ms, one voltage fluctuation is recorded, and it is further determined whether three consecutive voltage fluctuations occur within 30 minutes after the compressor is started up this time. If three consecutive voltage fluctuations occur within 30 minutes, the continuous fluctuation criterion is met, and the compressor is forced to stop for the set compressor protection duration of 10 minutes; if not within 30 minutes, step 1 is returned to continue monitoring the power supply voltage.

[0025] Preferably, in step 3, the power supply voltage U is continuously monitored, and the duration t2 of the stop protection is recorded until the power supply voltage has recovered to 140V<U<280V and lasts for 1 minute, and then step 4 is continued.

[0026] Preferably, in step 4, it is determined whether the stop protection time t2 has reached the variable-frequency protection time of 5 minutes. If it is satisfied, step 5 is continued; if not, step 3 is returned.

[0027] Preferably, during the execution of steps 1 to 5, if a fault other than voltage overlimit occurs on the variable-frequency board, and at this time the compressor is in a stopped state due to voltage overlimit protection, when the stop reaches the compressor protection duration of 10 minutes and the fault state has been eliminated, if the cumulative number of fault times is less than 4 times, the compressor is allowed to start; if the cumulative number of fault times is equal to 4 times, the stop time is extended to 15 minutes and then the compressor is allowed to start; if the cumulative number of fault times is greater than 4 times, the compressor is allowed to start only by the method of power failure and then power-on.

[0028] A third aspect of the present invention provides a refrigerator, wherein the variable frequency compressor of the refrigerator comprises a frequency conversion board and a compressor; the frequency conversion board detects the power supply voltage U and executes the processing methods described in the first and second aspects of the present invention.

[0029] Compared with the prior art, the beneficial effects of the present invention include at least:

[0030] 1. Set up protection judgment logic in the case of frequent voltage fluctuations to improve the stability, safety and reliability of refrigerator operation; detect the status of the entire machine and compressor, and after the detection is completed, it can automatically resume normal operation without the user having to contact after-sales personnel to handle it, which increases manpower and material expenditures.

[0031] 2. For after-sales service, a simple and quick method is needed to solve user needs. The present invention sets relevant logic in the frequency conversion software to facilitate after-sales processing. During maintenance, the method of burning the latest frequency conversion software can be used. Moreover, this logic can solve faults caused by non-controller problems as well as faults caused by controller problems, thus solving a wider range of problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention provides a flowchart for handling refrigerator frequency conversion failure. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] Embodiment 1 of the present invention provides a method for handling a frequency conversion fault, which is used for a frequency conversion compressor. The frequency conversion compressor includes a frequency conversion board and a compressor. The method includes the following steps:

[0035] Step 1: After power is turned on, the inverter board detects the power supply voltage U. If the power supply voltage exceeds the limit, that is, the power supply voltage U is greater than or equal to the upper voltage threshold U1 or the power supply voltage U is less than or equal to the lower voltage threshold U2, then continue to step 2; if the power supply voltage does not exceed the limit and is within the normal range, that is, the power supply voltage U is between the lower voltage threshold U2 and the upper voltage threshold U1, then the power supply voltage U is continuously monitored and the inverter compressor operates normally.

[0036] Step 2: If the power supply voltage exceeds the limit duration t and exceeds the set first time threshold t1, that is, t≥t1, the compressor will stop immediately and continue to step 3;

[0037] If the duration t of the over-limit power supply voltage does not reach the set first time threshold t1, that is, t < t1, then record that a voltage fluctuation has occurred, and continue to judge whether N consecutive voltage fluctuations after the compressor is started this time occur within the set time period Ts, that is, whether the continuous fluctuation criterion t w,i -t w,(i-N+1) ≤ Ts is satisfied, where t w,i represents the moment of the i-th voltage fluctuation, and t w,(i-N+1) represents the moment of the (i - N + 1)-th voltage fluctuation, and i is an integer greater than or equal to N. If the continuous fluctuation criterion is satisfied, the compressor is forced to stop for the set compressor protection duration Tp. After the stop reaches the compressor protection duration Tp, the compressor can determine whether to start according to the working requirements at the current moment. For example, but not limited to, it can decide whether to start according to the heating / cooling requirements; if the continuous fluctuation criterion is not satisfied, return to step 1 and continue to monitor the power supply voltage.

[0038] Step 3: Continuously monitor the power supply voltage U, and record the shutdown protection duration t2 until the power supply voltage has returned to the normal range and lasts for the set duration Tn. Preferably but not restrictively, the set duration Tn is less than the protection duration Tp, and then continue to execute step 4.

[0039] Step 4: Judge whether the shutdown protection time t2 has reached more than the variable frequency protection time Tf, that is, t2 ≥ Tf. If it is satisfied, continue to execute step 5. If it is not satisfied, that is, t2 < Tf, then return to step 3.

[0040] Step 5: Judge whether the shutdown protection duration t2 has reached the compressor protection duration Tp, that is, whether the forced shutdown protection condition t2 ≥ Tp is satisfied. If it is not satisfied, then continue to wait for shutdown. When the shutdown duration reaches the compressor protection duration Tp, the compressor can determine whether to start according to the working requirements at the current moment. For example, but not limited to, it can decide whether to start according to the heating / cooling requirements.

[0041] Preferably but not restrictively, during the execution of steps 1 to 5, if a fault other than the over-limit voltage of the variable frequency board occurs, such as, but not limited to, damage to the IGBT / IPM module, communication fault, overheat, relay / contactor fault, etc., the number of faults +1, and the variable frequency compressor enters the fault state. If the compressor is in the on state at this time, the compressor stops, and the variable frequency board will only allow the compressor to start according to the heating / cooling request of the whole machine after this fault state is eliminated;

[0042] If the compressor is in a shutdown state due to overvoltage protection at this time, when the shutdown duration reaches the compressor protection duration Tp and the fault status has been eliminated, if the cumulative number of faults is less than the fault number threshold N1, the compressor can determine whether to start up according to the working requirements at the current moment; if the cumulative number of faults is equal to the fault number threshold N1, after extending the shutdown time to reach βTp (where β > 1), the compressor can determine whether to start up according to the working requirements at the current moment; if the cumulative number of faults is greater than the fault number threshold N1, the compressor is only allowed to start up by powering off and then powering on again. After the compressor starts up normally, the variable-frequency compressor also needs to remember the number of faults that occurred last time, until no faults occur again within the set duration Tcl, and the number of faults is cleared. Or after powering off and then powering on again at this stage, the number of faults is cleared.

[0043] That is to say, when a variable-frequency fault occurs during the shutdown stage, no treatment is performed, but the number of faults is accumulated. If the accumulated number is too large, it proves that the probability of another fault occurring when starting the compressor at this time is very high. In order to avoid faults in the controller and the whole machine and even being burned out, leading to safety accidents, the shutdown time is extended or the power is cut off and then powered on again to protect the controller.

[0044] Embodiment 2 of the present invention provides a method for handling variable-frequency faults of a refrigerator. The variable-frequency compressor of the refrigerator includes a variable-frequency board and a compressor. The protection method includes the following steps:

[0045] Step 1: After the refrigerator is powered on, the variable-frequency board detects the power supply voltage U. If the power supply voltage exceeds the limit, that is, the power supply voltage U is greater than or equal to the voltage upper limit threshold U1 or the power supply voltage U is less than or equal to the voltage lower limit threshold U2. Preferably but not limitedly, the rated value of the power supply voltage U of a domestic refrigerator for domestic sales in normal operation is 220V. The voltage upper limit threshold U1 and the voltage lower limit threshold U2 are, for example but not limited to, the highest and lowest voltages in the laboratory, which are 280V and 140V. If U ≥ 280V or U ≤ 140V, the protection action is immediately started, and then step 2 is continued; if the power supply voltage does not exceed the limit and is within the normal range, that is, 140V < U < 280V, the power supply voltage U is continuously monitored, and the variable-frequency compressor of the refrigerator operates normally.

[0046] Step 2: If the duration t of the over-limited power supply voltage reaches more than the set first time threshold t1, that is, t ≥ t1. Preferably but not limitedly, t1 = 5ms, the variable-frequency board immediately reports overvoltage or undervoltage protection, and the compressor immediately stops, and then step 3 is continued; specifically, when the variable-frequency board of the refrigerator detects that the duration t of the power supply voltage U ≥ 280V or U ≤ 140V is t ≥ 5ms, the compressor immediately stops for protection and then step 3 is continued;

[0047] If the duration t of the over-limit power supply voltage does not reach the set first time threshold t1, that is, the duration t of the power supply voltage U≥280V or U≤140V is less than 5ms, record one voltage fluctuation, and continue to judge whether three consecutive voltage fluctuations after the compressor is turned on this time occur within 30 minutes, that is, use the current latest voltage fluctuation, that is, the time t of the i-th voltage fluctuation w,i subtract the time t of the voltage fluctuation before the voltage fluctuation separated by one time from it w,i-2 , if the time difference is within 30 minutes, the continuous fluctuation criterion is met, and the compressor is forced to stop for the set compressor protection duration Tp. Preferably but not limitedly, Tp is 10 minutes. After the stop reaches the protection duration of 10 minutes, the compressor can determine whether to start according to the working requirements at the current moment. For example but not limited to, determine whether to start according to the heating / cooling requirements; if the continuous fluctuation criterion is not met, that is, three consecutive voltage fluctuations do not occur within 30 minutes, return to step 1 and continue to monitor the power supply voltage.

[0048] It should be noted that if high voltage (current) fluctuations occur multiple times within a period of time, it is very likely that the phenomenon of instantaneous voltage (current) exceeding the limit occurs, and the probability of the controller being burned and short-circuited increases. At this time, it is prompted that the voltage is unstable to prevent controller failures caused by abnormal voltages. No impact will be caused to the refrigerator if a failure occurs after shutdown. If more failures occur during the shutdown time, the shutdown time will be extended to ensure the stability of the refrigerator and the controller.

[0049] Step 3: Continuously monitor the power supply voltage U and record the shutdown protection duration t2 until the power supply voltage has returned to the normal range and lasts for the set duration Tn. Preferably but not limitedly, Tn is 1 minute, and then continue to execute Step 4.

[0050] [[ID=第十三条]]Step 13: Judge whether the shutdown protection time t2 has reached more than the variable frequency protection time Tf, that is, t2≥Tf. Preferably but not limitedly, Tf = 5 minutes. If it is satisfied, continue to execute Step 14. If it is not satisfied, that is, t2<Tf, return to Step 13.

[0051] Step 14: Judge whether the shutdown protection duration t2 has reached the protection duration of 10 minutes, that is, whether the forced shutdown protection condition t2≥Tp is satisfied. If it is not satisfied, continue to wait for shutdown. When the shutdown duration reaches 10 minutes, the compressor can determine whether to start according to the working requirements at the current moment. For example but not limited to, determine whether to start according to the heating / cooling requirements. ​It is worth noting that in this embodiment, the compressor protection time Tp, i.e. 10 minutes, is the protection time that needs to be waited as long as the compressor stops, to prevent the compressor from frequently starting and stopping and causing failures, and the frequency conversion protection time Tf, i.e. 5 minutes, is the time required for the frequency conversion software to protect when a frequency conversion failure occurs. The frequency conversion does not collect information during this stage.

[0053] After the 5-minute frequency conversion protection time has passed, the voltage is monitored in real time throughout the entire process. Voltage fluctuations caused by power supply stations are generally short-lived and are more likely to occur in the summer. In summer, the ambient temperature is high, and once the compressor is shut down, the room heats up quickly. To prevent excessive temperature rise from affecting food preservation, the voltage needs to be determined in advance. If the voltage is within the normal range, the compressor can be restarted normally after the 10-minute protection time. The preferred, but non-restrictive, rule is to collect data after 5 minutes. The collection time can also be changed based on the ambient temperature. For example, when the ambient temperature is below 30°C, the voltage is tested after the 10-minute shutdown protection.

[0054] Preferably, but not limitatively, during the execution of steps 1 to 5, if a fault other than voltage exceeding the limit occurs on the inverter board, such as, but not limited to, IGBT / IPM module damage, communication failure, overheating, relay / contactor failure, etc., the fault count is increased by 1, and the inverter compressor enters a fault state. If the compressor is in the on state at this time, the compressor is shut down. The inverter board will allow the compressor to be turned on according to the heating / cooling request of the entire machine only after the fault state is eliminated;

[0055] If the compressor is in a shutdown state due to voltage over-limit protection at this time, when the shutdown reaches the compressor protection time of 10 minutes and the fault state has been eliminated, if the cumulative number of faults is less than the fault number threshold N1, preferably but not restrictively, N1 is 4 times, then the compressor can determine whether to start up according to the current working needs; if the cumulative number of faults is equal to 4 times, the shutdown time is extended to 15 minutes, and the compressor can determine whether to start up according to the current working needs; if the cumulative number of faults is greater than 4 times, the compressor is allowed to start only by powering off and then powering on again, and after the compressor starts normally, the variable frequency compressor also needs to remember the number of times the last fault occurred until no fault occurs again within the set 4 hours, and the number of faults is reset.

[0056] Embodiment 3 of the present invention provides a refrigerator, wherein the variable frequency compressor of the refrigerator includes a frequency conversion board and a compressor; the frequency conversion board detects the power supply voltage U, and when the power supply voltage U exceeds the limit or a fault other than the voltage exceeding the limit occurs, the processing method described in Embodiments 1 and 2 is executed.

[0057] Embodiment 4 of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the processing method according to embodiment 1 when loaded into the processor.

[0058] Embodiment 5 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processing method according to embodiment 1 is implemented.

[0059] It is worth noting that in the embodiments of the present invention, "step + number" is only a way of expression to clearly describe the specific implementation method of the processing method, rather than an absolute restriction on the sequence of each step. Under the guidance of the core concept of the present invention, changing the order of implementing these steps to obtain the same or similar technical effects falls within the scope of the present invention.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for handling frequency conversion failure, used for a frequency conversion compressor, wherein the frequency conversion compressor comprises a frequency conversion board and a compressor, characterized in that: The processing method comprises the following steps: Step 1: After power is turned on, the inverter board detects the power supply voltage U. If the power supply voltage exceeds the limit, proceed to step 2; if it is within the normal range, the power supply voltage U is continuously monitored and the inverter compressor operates normally. Step 2: If the power supply voltage over-limit duration t reaches or exceeds the set first time threshold t1, the compressor is immediately shut down and step 3 is continued; if the first time threshold t1 is not reached, a voltage fluctuation is recorded, and whether N consecutive voltage fluctuations after the current startup occur within the set time period Ts is used as a continuous fluctuation criterion. If the continuous fluctuation criterion is met, the compressor is forced to shut down for the set compressor protection time Tp before the compressor is allowed to start; if the continuous fluctuation criterion is not met, the process returns to step 1 and continues to monitor the power supply voltage; Step 3: Continuously monitor the power supply voltage U and record the shutdown protection duration t2 until the power supply voltage has returned to the normal range and lasts for the set time Tn, and then proceed to step 4; Step 4: Determine whether the shutdown protection time t2 has reached or exceeded the frequency conversion protection time Tf. If so, proceed to step 5. If not, return to step 3. Step 5: Determine whether the shutdown protection duration t2 has reached the compressor protection time Tp. If not, continue to shut down and wait. When the shutdown time reaches the compressor protection time Tp, allow the compressor to start.

2. The method for handling a frequency conversion failure according to claim 1, wherein: During the execution of steps 1 to 5, if the inverter board has a fault other than voltage exceeding the limit, the fault count is increased by 1 and the inverter compressor enters the fault state; If the compressor is in the on state at this time, the compressor will stop and wait until the fault state is eliminated before allowing the compressor to start; If the compressor is in a stopped state at this time, wait until the fault state is eliminated, and determine whether to allow the compressor to be started based on whether the accumulated number of faults exceeds the fault number threshold.

3. The method for handling frequency conversion failure according to claim 2, characterized in that: The step of determining whether to allow the compressor to be started according to whether the cumulative number of failures exceeds a failure number threshold comprises: When the shutdown reaches the compressor protection time Tp and the fault state has been eliminated, if the cumulative number of faults is less than the fault number threshold N1, the compressor is allowed to start; If the cumulative number of faults is equal to the fault threshold N1, the downtime is extended until it reaches βTp, and the compressor is allowed to start, where β>1; If the cumulative number of faults is greater than the fault threshold N1, the compressor is allowed to start only after powering off and then powering on again.

4. The method for handling frequency conversion failure according to claim 3, characterized in that: The method of allowing the compressor to start only after power is turned off and then turned on again also includes: After the compressor starts normally, the variable frequency compressor will memorize the number of faults that occurred last time. If no fault occurs again within the set time Tcl, the number of faults will be cleared.

5. A method for handling refrigerator frequency conversion failure, characterized in that: The processing method according to any one of claims 1 to 4 comprises the following steps: In step 1, after the refrigerator is powered on, the variable frequency board detects the power supply voltage U. If U≥280V or U≤140V, step 2 is continued. If the power supply voltage 140V < U < 280V, the power supply voltage U is continuously monitored and the refrigerator variable frequency compressor operates normally.

6. A method for handling variable frequency faults of a refrigerator according to claim 5, characterized in that: In step 2, when the duration t for which the refrigerator variable frequency board detects that the power supply voltage U≥280V or U≤140V is t≥5ms, the compressor immediately stops for protection and step 3 is continued; If the duration t for which the power supply voltage U≥280V or U≤140V is less than 5ms, one voltage fluctuation is recorded, and it is continued to determine whether three consecutive voltage fluctuations after the compressor is started this time occur within 30 minutes. If three consecutive voltage fluctuations occur within 30 minutes, the continuous fluctuation criterion is met, and the compressor is forced to stop for the set compressor protection duration of 10 minutes; if it does not occur within 30 minutes, step 1 is returned to continue monitoring the power supply voltage.

7. A method for handling variable frequency faults of a refrigerator according to claim 5, characterized in that: In step 3, the power supply voltage U is continuously monitored and the shutdown protection duration t2 is recorded until the power supply voltage has recovered to 140V < U < 280V and lasts for 1 minute, and step 4 is continued.

8. A method for handling variable frequency faults of a refrigerator according to claim 5, characterized in that: In step 4, it is determined whether the shutdown protection time t2 has reached the variable frequency protection time of 5 minutes. If it is satisfied, step 5 is continued; if it is not satisfied, step 3 is returned.

9. A method for handling variable frequency faults of a refrigerator according to claim 5, characterized in that: During the execution of steps 1 to 5, if a fault other than voltage overlimit occurs in the variable frequency board, and at this time the compressor is in a shutdown state due to voltage overlimit protection, when the shutdown reaches the compressor protection duration of 10 minutes and the fault state has been eliminated, if the cumulative number of faults is less than 4 times, the compressor is allowed to start; If the cumulative number of faults is equal to 4 times, the shutdown time is extended to 15 minutes and then the compressor is allowed to start; 10. A refrigerator, wherein the variable frequency compressor of the refrigerator comprises a frequency conversion board and a compressor; the frequency conversion board detects the power supply voltage U, characterized in that: If the cumulative number of faults is greater than 4 times, the compressor is allowed to start only by powering off and then powering on again. Execute the handling method according to any one of claims 1 to 9.

Images