Protection method of compressor unit

Abstract

The invention relates to the technical field of compressor unit operation, in particular to a protection method of a compressor unit. The temperature of the first evaporator is analyzed according to a preset temperature threshold value; analyzing the alternating current effective value according to a preset alternating current effective value threshold value; analyzing the current effective value according to a preset current effective value threshold value; analyzing the first bus voltage according to a preset parameter threshold value; generating a protection operation frequency; controlling the compressor unit to operate according to the protection operation frequency; a multi-dimensional protection system is constructed by obtaining key parameters such as the temperature of an evaporator, the system generates protection operation frequency according to reality, the adaptability of a compressor unit to working conditions and environment changes is improved, when all parameters are abnormal, the operation frequency of the compressor unit is regulated and controlled, all monitoring and adjustment are matched with one another, and the parameter problem interleaving condition is solved; the comprehensive instruction is comprehensively regulated and controlled, and safe and efficient operation of the unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor unit operation, and in particular to a compressor unit protection method. Background Art

[0002] In the current field of dehumidifier compressor unit operation technology, as people's requirements for indoor environmental comfort and equipment operational stability continue to increase, existing protection methods have gradually exposed many shortcomings. Traditional protection methods are mostly single-dimensional monitoring, focusing on a single parameter. For example, a dehumidifier only monitors the effective current value of the compressor unit. When other key parameters such as evaporator temperature, AC effective value, and outdoor DC bus voltage show abnormalities, they cannot be detected and effectively responded to in a timely manner, resulting in numerous hidden dangers in the operation of the compressor unit. The previous method of generating adjustment instructions based on a single parameter cannot fully guarantee the stable operation of the unit. Under complex working conditions, if the evaporator temperature rises abnormally, the refrigeration efficiency may be reduced due to failure to adjust and control in time, and even the equipment may be damaged; the unstable effective value of the AC power will affect the normal operation of the motor, increase energy consumption, and may also cause premature aging of the motor windings due to frequent current shocks; abnormal outdoor DC bus voltage may interfere with the dehumidifier's power transmission system, causing the control circuit to malfunction, and making key components such as the compressor and fan unable to work normally. These problems are intertwined and seriously threaten the stable and efficient operation of the dehumidifier compressor unit. The existing technology lacks effective means to comprehensively analyze various key parameters from multiple dimensions and accurately adjust them. Therefore, an innovative multi-dimensional protection method is urgently needed to make up for these defects, improve the safety and reliability of dehumidifier operation, and create a more comfortable and stable indoor environment for users. Summary of the Invention

[0003] In order to solve the above-mentioned shortcomings in the prior art, the present invention proposes a protection method for a compressor unit.

[0004] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0005] A method for protecting a compressor unit includes: obtaining a first evaporator temperature, and analyzing the first evaporator temperature according to a preset temperature threshold to obtain a first analysis result; generating a first adjustment instruction according to the first analysis result; obtaining an AC effective value, and analyzing the AC effective value according to a preset AC effective value threshold to obtain a second analysis result; generating a second adjustment instruction according to the second analysis result; obtaining a current effective value, and analyzing the current effective value according to a preset current effective value threshold to obtain a third analysis result; generating a third adjustment instruction according to the third analysis result; obtaining an outdoor DC bus voltage in an operating state to obtain a first bus voltage; analyzing the first bus voltage according to a preset parameter threshold to obtain a fourth analysis result; generating a fourth adjustment instruction according to the fourth analysis result; generating a protection operating frequency according to the first adjustment instruction, the second adjustment instruction, the third adjustment instruction and the fourth adjustment instruction; and controlling the operation of the compressor unit according to the protection operating frequency.

[0006] Furthermore, the generating of the first adjustment instruction according to the first analysis result includes: performing result analysis on the first analysis result; when the first analysis result is that the first evaporator temperature is greater than the preset first temperature threshold and less than or equal to the preset second temperature threshold, generating a first frequency ramp-up instruction according to the first evaporator temperature; generating a first adjustment instruction according to the first frequency ramp-up instruction; when the first analysis result is that the first evaporator temperature is greater than the preset third temperature threshold and less than or equal to the first temperature threshold, generating a frequency prohibition increase instruction according to the first evaporator temperature; generating a first adjustment instruction according to the frequency prohibition increase instruction; when the first analysis result is that the first evaporator temperature is greater than the preset fourth temperature threshold and less than or equal to the third temperature threshold, generating a first frequency limit and ramp-down control instruction according to the first evaporator temperature. ; Generate a first adjustment instruction based on the first frequency limit and slow-down control instruction; when the first analysis result is that the first evaporator temperature is greater than the preset fifth temperature threshold and less than or equal to the fourth temperature threshold, generate a first frequency limit and speed-down control instruction based on the first evaporator temperature; generate a first adjustment instruction based on the first frequency limit and speed-down control instruction; when the first analysis result is that the first evaporator temperature is greater than the second temperature threshold, generate a first reset instruction; generate a first adjustment instruction based on the first reset instruction; when the first analysis result is that the first evaporator temperature is less than or equal to the fifth temperature threshold, generate a temperature protection instruction based on the preset downtime; generate a first adjustment instruction based on the temperature protection instruction; the fifth temperature threshold is less than the fourth temperature threshold, less than the third temperature threshold, less than the first temperature threshold, less than the second temperature threshold.

[0007] Furthermore, when the first analysis result is that the first evaporator temperature is greater than the preset fourth temperature threshold and less than or equal to the third temperature threshold, a first frequency limiting and slow-down control instruction is generated according to the first evaporator temperature, including: when the first analysis result is that the first evaporator temperature is greater than the fourth temperature threshold and less than or equal to the third temperature threshold, a first slow frequency reduction type is generated according to the first evaporator temperature; a first frequency reduction time is calculated according to the first slow frequency reduction type; a first slow frequency reduction instruction is generated according to the first slow frequency reduction type and the first frequency reduction time; the system operating frequency is obtained to obtain the first operating frequency; the first operating frequency is adjusted according to the slow frequency reduction instruction to obtain the first frequency limiting frequency; it is determined whether the first frequency limiting frequency is equal to the preset frequency limiting frequency threshold; when the first frequency limiting frequency is equal to the frequency limiting frequency threshold, a first frequency limiting and slow-down control instruction is generated according to the first frequency limiting frequency and the first slow frequency reduction instruction.

[0008] Furthermore, when the first analysis result is that the first evaporator temperature is greater than the preset fifth temperature threshold and less than or equal to the fourth temperature threshold, a first frequency limiting and speed reduction control instruction is generated according to the first evaporator temperature, including: when the first analysis result is that the first evaporator temperature is greater than the fifth temperature threshold and less than or equal to the fourth temperature threshold, a first rapid frequency reduction type is generated according to the first evaporator temperature; a second frequency reduction time is calculated according to the first rapid frequency reduction type; a first rapid frequency reduction instruction is generated according to the first rapid frequency reduction type and the second frequency reduction time; the system operating frequency is obtained to obtain the second operating frequency; the second operating frequency is adjusted according to the first rapid frequency reduction instruction to obtain the second frequency limiting frequency; it is determined whether the second frequency limiting frequency is equal to the frequency limiting frequency threshold; when the second frequency limiting frequency is equal to the frequency limiting frequency threshold, a first frequency limiting and speed reduction control instruction is generated according to the second frequency limiting frequency and the first rapid frequency reduction instruction.

[0009] Furthermore, the generating of the first adjustment instruction according to the temperature protection instruction includes: controlling the compressor unit to shut down according to the temperature protection instruction; obtaining the evaporator temperature of the compressor unit in the shutdown state to obtain a second evaporator temperature; judging whether the second evaporator temperature is greater than or equal to a third temperature threshold; when the second evaporator temperature is greater than or equal to the third temperature threshold, generating a second reset instruction; and generating the first adjustment instruction according to the second reset instruction.

[0010] Further, the generating of the second adjustment instruction according to the second analysis result includes: performing result analysis on the second analysis result; when the second analysis result is that the effective value of the alternating current is greater than a preset first alternating current threshold and less than or equal to a preset second alternating current threshold, generating a slow frequency increase instruction according to the effective value of the alternating current; generating a second adjustment instruction according to the slow frequency increase instruction; when the second analysis result is that the effective value of the alternating current is greater than the second alternating current threshold and less than or equal to a preset third alternating current threshold, generating a first frequency locking instruction according to the effective value of the alternating current; generating a second adjustment instruction according to the first frequency locking instruction; when the second analysis result is that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to a preset fourth alternating current threshold, generating a second frequency limiting and slow-down control instruction according to the effective value of the alternating current; A second adjustment instruction is generated according to the second frequency limiting and speed reduction control instruction; when the second analysis result is that the effective value of the AC power is greater than the fourth AC power threshold and less than or equal to the preset fifth AC power threshold, a second frequency limiting and speed reduction control instruction is generated according to the effective value of the AC power; a second adjustment instruction is generated according to the second frequency limiting and speed reduction control instruction; when the second analysis result is that the effective value of the AC power is less than the first AC threshold, a third reset instruction is generated; a second adjustment instruction is generated according to the third reset instruction; when the second analysis result is that the effective value of the AC power is greater than or equal to the fifth AC threshold, an AC protection instruction is generated; a second adjustment instruction is generated according to the AC protection instruction; the first AC threshold is less than the second AC threshold, less than the third AC threshold, less than the fourth AC threshold, less than the fifth AC threshold.

[0011] Further, when the second analysis result is that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to the preset fourth alternating current threshold, a second frequency limiting and slow-down control instruction is generated according to the effective value of the alternating current, including: when the second analysis result is that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to the fourth alternating current threshold, a second slow frequency reduction type is generated according to the effective value of the alternating current; a third frequency reduction time is calculated according to the second slow frequency reduction type; a second slow frequency reduction instruction is generated according to the second slow frequency reduction type and the third frequency reduction time; the system operating frequency is obtained to obtain a third operating frequency; the third operating frequency is adjusted according to the second slow frequency reduction instruction to obtain a third frequency limiting frequency; it is determined whether the third frequency limiting frequency is equal to the frequency limiting frequency threshold; when the third frequency limiting frequency is equal to the frequency limiting frequency threshold, a second frequency limiting and slow-down control instruction is generated according to the third frequency limiting frequency and the second slow frequency reduction instruction.

[0012] Furthermore, when the second analysis result is that the effective value of the alternating current is greater than the fourth alternating current threshold and less than or equal to the preset fifth alternating current threshold, a second frequency limiting and speed reduction control instruction is generated according to the effective value of the alternating current, including: when the second analysis result is that the effective value of the alternating current is greater than the fourth alternating current threshold and less than or equal to the fifth alternating current threshold, a second fast frequency reduction type is generated according to the effective value of the alternating current; a fourth frequency reduction time is calculated according to the second fast frequency reduction type; a second fast frequency reduction instruction is generated according to the second fast frequency reduction type and the fourth frequency reduction time; the system operating frequency is obtained to obtain the fourth operating frequency; the fourth operating frequency is adjusted according to the second fast frequency reduction instruction to obtain the fourth frequency limiting frequency; it is determined whether the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold; when the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold, a second frequency limiting and speed reduction control instruction is generated according to the fourth frequency limiting frequency and the second fast frequency reduction instruction.

[0013] Furthermore, the generating of the third adjustment instruction according to the third analysis result includes: performing result analysis on the third analysis result; when the third analysis result is that the effective current value is greater than the preset first current threshold and less than or equal to the preset second current threshold, generating a second frequency ramp-up instruction according to the effective current value; generating a third adjustment instruction according to the second frequency ramp-up instruction; when the third analysis result is that the effective current value is less than the preset second current threshold and less than or equal to the preset third current threshold, generating a second frequency lock instruction according to the effective current value; generating a third adjustment instruction according to the second frequency lock instruction; when the third analysis result is that the effective current value is greater than the third current threshold and less than or equal to the preset fourth current threshold, generating a third slow frequency reduction type according to the effective current value; calculating a fifth frequency reduction time according to the third slow frequency reduction type; generating a third slow frequency reduction instruction according to the third slow frequency reduction type and the fifth frequency reduction time; obtaining the system operating frequency to obtain the fifth operating frequency; adjusting the fifth operating frequency according to the third slow frequency reduction instruction to obtain the fifth frequency limit frequency; judging whether the fifth frequency limit frequency is equal to the frequency limit frequency threshold; and when the fifth frequency limit frequency is equal to the frequency limit frequency threshold, adjusting the fifth frequency limit frequency according to the fifth frequency limit frequency a third frequency limiting and slow-down control instruction based on the third analysis result and the third slow frequency reduction instruction; a third adjustment instruction is generated based on the third frequency limiting and slow-down control instruction; when the third analysis result shows that the effective current value is greater than the fourth current threshold and less than or equal to the preset fifth current threshold, a third fast frequency reduction type is generated based on the effective current value; a sixth frequency reduction time is calculated based on the third fast frequency reduction type; a third fast frequency reduction instruction is generated based on the third fast frequency reduction type and the sixth frequency reduction time; a system operating frequency is obtained to obtain a sixth operating frequency; the sixth operating frequency is adjusted based on the third fast frequency reduction instruction to obtain a sixth frequency limiting frequency; whether the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold is determined; when the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold, a third frequency limiting and speed-down control instruction is generated based on the sixth frequency limiting frequency and the third fast frequency reduction instruction; a third adjustment instruction is generated based on the third frequency limiting and speed-down control instruction; when the third analysis result shows that the effective current value is less than the first current threshold, a fourth reset instruction is generated; a third adjustment instruction is generated based on the fourth reset instruction; when the third analysis result shows that the effective current value is greater than or equal to the fifth current threshold, a current protection instruction is generated; and the third adjustment instruction is generated based on the current protection instruction.

[0014] Furthermore, the generating of the fourth adjustment instruction according to the fourth analysis result includes: performing result analysis on the fourth analysis result; when the fourth analysis result is that the first bus voltage is higher or lower than the preset bus voltage threshold parameter, generating a voltage protection instruction according to the first bus voltage; obtaining the outdoor DC bus voltage within the preset recovery time range according to the voltage protection instruction to obtain the second bus voltage; calculating the first bus voltage threshold and the second bus voltage threshold according to the bus voltage threshold parameter and the empirical value; judging whether the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold; when the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold, generating a fifth reset instruction; and generating the fourth adjustment instruction according to the fifth reset instruction.

[0015] The beneficial effects of the protection method of a compressor unit of the present invention are:

[0016] By simultaneously acquiring key parameters such as evaporator temperature, AC effective value, current effective value and outdoor DC bus voltage, and comprehensively considering the changes in these key parameters, a comprehensive multi-dimensional protection system is established; this system can generate appropriate protection operating frequency according to actual conditions, improve the adaptability of the compressor unit to various complex working conditions and environmental changes, and enhance the adaptability and reliability of the system; when the evaporator temperature rises abnormally, the first adjustment instruction can timely adjust the operating frequency of the compressor unit to prevent the reduction of cooling efficiency and equipment damage; when the AC effective value is unstable, the second adjustment instruction can adjust the operating frequency of the compressor unit to ensure the normal operation of the motor, thereby significantly improving the compressor The operating stability of the unit, the third adjustment instruction is an instruction for regulating and protecting the compressor operating frequency based on the effective value of current, and the fourth adjustment instruction is an instruction for regulating and protecting the compressor unit operating frequency based on the outdoor DC bus voltage in the operating state; the monitoring and adjustment of various parameters cooperate with each other to jointly deal with problems such as abnormal evaporator temperature, fluctuation of AC effective value, abnormal current and abnormal outdoor DC bus voltage, effectively solving the situation where the problems of various parameters are intertwined and threaten the stable and efficient operation of the compressor unit. Finally, by integrating multiple adjustment instructions to generate a protective operating frequency, more precise and comprehensive regulation is achieved to ensure the safe and efficient operation of the compressor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0018] Figure 1 A flow chart of a compressor unit protection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] The terms "first," "second," "third," "fourth," and the like (if any) in the description and claims of the present invention and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0021] This solution builds a comprehensive and sophisticated protection and operation control system around the compressor unit. Protection functions encompass multiple aspects, including indoor evaporator temperature, outdoor compressor AC current, compressor RMS current, and voltage. For example, compressor protection sets different thresholds for freezing protection, AC current, and RMS current in the dehumidifier's indoor heat exchanger. Depending on the relationship between temperature or current and the threshold, normal operation, slow frequency increase, frequency maintenance, slow or rapid frequency reduction, and shutdown protection are implemented. When the system is in a frequency reduction state, the system reduces the frequency by 1Hz at regular intervals. Voltage protection involves bus voltage, monitoring and processing voltage anomalies under different operating conditions.

[0022] In terms of operating mode, taking the dehumidification mode as an example, the compressor startup target frequency, the operating frequency control rules after startup, and the control logic of the compressor operating frequency under the indoor wind speed and indoor temperature during cooling operation are specified in detail to ensure the safe, stable and efficient operation of the compressor unit.

[0023] For ease of understanding, the specific process of the embodiment of the present invention is described below. Figure 1 , an embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0024] 101. Obtain a first evaporator temperature, and analyze the first evaporator temperature according to a preset temperature threshold to obtain a first analysis result;

[0025] 102. Generate a first adjustment instruction according to the first analysis result;

[0026] In this embodiment, the evaporator temperature is the indoor evaporator temperature, and the temperature thresholds include a first temperature threshold (T2_COLD3), a second temperature threshold (T2_COLD4), a third temperature threshold (T2_COLD2), a fourth temperature threshold (T2_COLD1), and a fifth temperature threshold (T2_COLD0). By comparing the indoor evaporator temperature with the temperature thresholds, the operating frequency of the compressor unit is regulated in multiple stages to prevent the indoor evaporator from freezing.

[0027] 103. Obtain an AC effective value, and analyze the AC effective value according to a preset AC effective value threshold to obtain a second analysis result;

[0028] 104. Generate a second adjustment instruction according to the second analysis result;

[0029] In this embodiment, the AC effective value threshold is a key indicator set specifically for AC current protection in the dehumidification mode, and the AC effective value threshold includes a first AC threshold (AcCurLimit_A[0]), a second AC threshold (AcCurLimit_A[1]), a third AC threshold (AcCurLimit_A[2]), a fourth AC threshold (IAcCurLimit_A[3]), and a fifth AC threshold (IAcCurLimit_A[4]); the second adjustment instruction is an instruction for regulating and protecting the operating frequency of the compressor unit based on the AC current effective value in the dehumidification mode;

[0030] 105. Obtain a current effective value, and analyze the current effective value according to a preset current effective value threshold to obtain a third analysis result;

[0031] 106. Generate a third adjustment instruction according to the third analysis result;

[0032] In this embodiment, the AC effective value threshold includes a first current threshold (compCurLimit[0]), a second current threshold (compCurLimit[1]), a third current threshold (compCurLimit[2]), a fourth current threshold (compCurLimit[3]), and a fifth current threshold (compCurLimit[4]); the third adjustment instruction is an instruction for regulating and protecting the operating frequency of the compressor based on the current effective value;

[0033] 107. Acquire the outdoor DC bus voltage in the operating state to obtain a first bus voltage;

[0034] 108. Analyze the first bus voltage according to a preset parameter threshold to obtain a fourth analysis result;

[0035] 109. Generate a fourth adjustment instruction according to the fourth analysis result;

[0036] In this embodiment, the parameter threshold includes a bus voltage threshold parameter and a second bus voltage threshold (ROT_MAX_VBUS_RUN-10) and a first bus voltage threshold (PROT_MIN_VBUS_RUN+10) generated according to the bus voltage threshold parameter and empirical values; the fourth adjustment instruction is an instruction for regulating and protecting the operating frequency of the compressor unit based on the outdoor DC bus voltage in the running state;

[0037] 110. Generate a protection operation frequency according to the first adjustment instruction, the second adjustment instruction, the third adjustment instruction, and the fourth adjustment instruction;

[0038] 111. Control the operation of the compressor unit according to the protection operation frequency;

[0039] In this embodiment, by simultaneously acquiring key parameters such as evaporator temperature, AC effective value, current effective value and outdoor DC bus voltage, and comprehensively considering the changes in these key parameters, a comprehensive multi-dimensional protection system is constructed; the system can generate a suitable protection operating frequency according to actual conditions, thereby improving the adaptability of the compressor unit to various complex working conditions and environmental changes, and enhancing the adaptability and reliability of the system; when the evaporator temperature rises abnormally, the first adjustment instruction can timely adjust the operating frequency of the compressor unit to prevent the reduction of refrigeration efficiency and damage to the equipment; when the AC effective value is unstable, the second adjustment instruction can adjust the operating frequency of the compressor unit to ensure the normal operation of the motor, thereby significantly improving the The operating stability of the compressor unit is improved. The third adjustment instruction is an instruction for regulating and protecting the compressor operating frequency based on the effective value of the current. The fourth adjustment instruction is an instruction for regulating and protecting the compressor operating frequency based on the outdoor DC bus voltage in the running state. The monitoring and adjustment of various parameters cooperate with each other to jointly deal with problems such as abnormal evaporator temperature, fluctuation of the effective value of AC power, abnormal current and abnormal outdoor DC bus voltage, and effectively solve the situation where the problems of various parameters are intertwined and threaten the stable and efficient operation of the compressor unit. Finally, by integrating multiple adjustment instructions to generate a protective operating frequency, more precise and comprehensive regulation is achieved to ensure the safe and efficient operation of the compressor unit.

[0040] A second embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0041] 201. Analyze the first analysis result;

[0042] 202. When the first analysis result shows that the first evaporator temperature is greater than a preset first temperature threshold and less than or equal to a preset second temperature threshold, a first frequency slow-increase instruction is generated according to the first evaporator temperature;

[0043] In this embodiment, when the indoor evaporator temperature (T2) satisfies T2>T2_COLD4 (the second temperature threshold), the compressor unit operates normally at a preset default operating frequency to ensure that the refrigeration system works efficiently under suitable temperature conditions; when the indoor evaporator temperature (T2) satisfies T2_COLD3 (the first temperature threshold)<T2≤T2_COLD4 (the second temperature threshold), a first frequency slow increase instruction is generated; this reasonable frequency slow increase mechanism avoids unnecessary high-load operation of the compressor unit when the temperature changes slightly, prevents energy waste, reduces mechanical impact on internal components of the compressor unit, maintains a stable operating state of the compressor unit, and reduces the probability of compressor unit failure; slowly increasing the frequency can gradually increase the cooling capacity according to the actual heat load demand, so that the refrigeration system can maintain good refrigeration performance under different temperature conditions and meet the actual demand of the environment for refrigeration. In the refrigeration mode, the indoor evaporator temperature frequency slow increase time is 30 seconds;

[0044] 203. Generate a first adjustment instruction according to the first frequency slow increase instruction;

[0045] In this embodiment, the compressor unit can be controlled to perform a slow frequency increase according to the first frequency slow increase instruction;

[0046] 204. When the first analysis result shows that the first evaporator temperature is greater than the preset third temperature threshold and less than or equal to the first temperature threshold, a frequency increase prohibition instruction is generated according to the first evaporator temperature;

[0047] In this embodiment, when the indoor evaporator temperature satisfies T2_COLD2 (third temperature threshold) < T2 ≤ T2_COLD3 (first temperature threshold), a frequency increase prohibition instruction is generated;

[0048] 205. Generate a first adjustment instruction according to the frequency increase prohibition instruction;

[0049] In this embodiment, the frequency increase prohibition instruction can be used to control the compressor unit to prohibit frequency increase; by prohibiting frequency increase, the evaporator temperature can be stabilized to avoid the compressor unit from increasing frequency, because if the compressor unit continues to increase frequency at this time, the refrigerant circulation volume may increase, and if the evaporator heat exchange efficiency is insufficient (such as low air volume or dirty fin blockage), the evaporation pressure will drop significantly, causing the evaporation temperature of the evaporator to be lower than 0°C, forming frost or freezing; limiting the frequency increase of the compressor unit by the frequency increase prohibition instruction directly suppresses the excessive increase of the refrigerant circulation volume, avoids the evaporation pressure drop caused by insufficient evaporator heat exchange efficiency (such as low air volume or dirty fin blockage), and ensures that the evaporation temperature is always above the freezing point;

[0050] 206. When the first analysis result shows that the first evaporator temperature is greater than the preset fourth temperature threshold and less than or equal to the third temperature threshold, a first frequency limiting and slow-down control instruction is generated according to the first evaporator temperature;

[0051] In this embodiment, T2_COLD3=(T2_COLD2+T2_COLD4) / 2. When the indoor evaporator temperature satisfies T2_COLD1 (fourth temperature threshold)<T2≤T2_COLD2 (third temperature threshold), a first frequency limiting and slow-down control instruction is generated.

[0052] 207. Generate a first adjustment instruction according to the first frequency limiting and slow-down control instruction;

[0053] In this embodiment, when the indoor evaporator temperature is in the range of T2_COLD1<T2≤T2_COLD2, if the compressor unit still maintains high frequency operation, it will increase the equipment load. The compressor unit can be controlled to slowly reduce the frequency to F1 (an empirical value) according to the first frequency limit and slow-down control instruction, and the compressor unit is limited to operate at F1 all the time. This can prevent the compressor and other equipment from being damaged due to long-term high-load operation, effectively extend the service life of the equipment, and reduce equipment maintenance costs. The frequency limit and slow-down control instruction enables a smooth transition of system parameters and enhances system reliability.

[0054] 208. When the first analysis result shows that the first evaporator temperature is greater than the preset fifth temperature threshold and less than or equal to the fourth temperature threshold, a first frequency-limited and speed-same-drop control instruction is generated according to the first evaporator temperature;

[0055] In this embodiment, when the indoor evaporator temperature satisfies T2_COLD0 (fifth temperature threshold) < T2 ≤ T2_COLD1 (fourth temperature threshold), a first frequency-limited and speed-reduced control instruction is generated;

[0056] 209. Generate a first adjustment instruction according to the first frequency-limited and speed-reduced control instruction;

[0057] In this embodiment, the compressor unit can be controlled to quickly reduce the frequency to F1 (an empirical value) according to the first frequency limit and speed reduction control instruction, and the compressor unit is limited to operate at F1 all the time; when the indoor evaporator temperature is in the range of T2_COLD0<T2≤T2_COLD1, it indicates that the evaporator temperature has become more obviously abnormal (the evaporator is close to the freezing point and is about to frost), then the first frequency limit and speed reduction control instruction is generated to control the compressor unit to quickly reduce the frequency, which can quickly respond to abnormal evaporator temperature, avoid freezing due to too low evaporator temperature, prevent the compressor from being damaged due to overheating, and avoid problems such as decomposition of refrigerant due to high temperature; quickly reducing the frequency of the compressor unit to the empirical value F1 and limiting it to operate at this frequency all the time can help the compressor unit operate in a relatively stable state; F1 is an operating frequency that has been verified in practice to be suitable for the current temperature range, which can ensure that the refrigeration system can still maintain a certain cooling effect under abnormal temperature, and at the same time avoid frequent adjustments of the unit due to excessive frequency fluctuations, reduce equipment loss, and extend equipment service life;

[0058] 210. When the first analysis result indicates that the first evaporator temperature is greater than the second temperature threshold, a first reset instruction is generated;

[0059] In this embodiment, when the indoor evaporator temperature satisfies T2>T2_COLD4 (the second temperature threshold), a first reset instruction is generated;

[0060] 211. Generate a first adjustment instruction according to the first reset instruction;

[0061] In this embodiment, the first reset instruction is an instruction to release all restrictions on the operating frequency of the compressor unit and control the compressor unit to return to the default operating frequency;

[0062] 212. When the first analysis result shows that the first evaporator temperature is less than or equal to a fifth temperature threshold, a temperature protection instruction is generated according to a preset downtime;

[0063] In this embodiment, when the indoor compressor temperature satisfies T2≤T2_COLD0 (the fifth temperature threshold), the evaporator temperature is already below freezing. At this time, to prevent the evaporator from being damaged by freezing at low temperatures, a temperature protection instruction is generated after 5 seconds. According to the temperature protection instruction, the indoor compressor unit can be controlled to stop running and the output of the refrigerant circulation amount can be stopped until the heat absorption on the evaporator side is significantly reduced. This process can effectively prevent the refrigerant in the evaporator from continuing to evaporate and absorb heat, causing the temperature to drop further, and effectively prevent the evaporator from being physically damaged by freezing, such as cracking and deformation.

[0064] 213. Generate a first adjustment instruction according to the temperature protection instruction;

[0065] In this embodiment, the preset downtime is 5 seconds. After 5 seconds, the temperature protection instruction is an instruction to shut down the compressor unit for protection and restore the compressor unit to the default operating mode. During the temperature abnormality period, the compressor unit may deviate from the optimal operating state due to the implementation of control measures such as frequency reduction and frequency limiting, causing the internal components of the equipment to be subjected to additional stress and wear. The reset instruction returns the compressor unit to the default frequency operation, and each component resumes normal working rhythm and load status, thereby reducing unnecessary mechanical wear, extending the service life of the equipment, and reducing equipment maintenance and replacement costs.

[0066] In this embodiment, the current threshold value of the indoor evaporator temperature T2 includes 5 groups;

[0067] T2_COLD0 T2_COLD1 T2_COLD2 T2_COLD3 T2_COLD4 -1℃ 2℃ 4℃ 6.5℃ 7℃

[0068] The fifth temperature threshold is less than the fourth temperature threshold, which is less than the third temperature threshold, which is less than the first temperature threshold, which is less than the second temperature threshold;

[0069] In this embodiment, T2_COLD0 (fifth temperature threshold) < T2_COLD1 (fourth temperature threshold) < T2_COLD2 (third temperature threshold) < T2_COLD3 (first temperature threshold) < T2_COLD4 (second temperature threshold), and the values increase successively, corresponding to different temperature ranges from extremely low to relatively high, and are used to trigger different operating states and protection mechanisms of the system;

[0070] In this embodiment, the operating frequency of the compressor unit is finely controlled through multi-level temperature thresholds and corresponding adjustment instructions, thereby achieving efficient, stable and safe operation of the refrigeration system; when the indoor evaporator temperature is in different ranges, the system generates frequency slow increase, no increase, frequency limit and slow decrease, frequency limit and speed decrease, reset and temperature protection instructions respectively to accurately control the operating frequency of the compressor unit. This mechanism effectively avoids unnecessary high-load operation of the compressor unit when the temperature changes slightly, reduces energy waste and mechanical shock, reduces the probability of failure, and extends the service life of the equipment; at the same time, through measures such as slow or fast frequency reduction, the system can quickly respond to temperature anomalies, prevent equipment damage, and ensure the cooling effect; the reset instruction enables the compressor unit to return to the default frequency after the temperature returns to normal, further optimizes the equipment operation status, and reduces wear; overall, this embodiment significantly improves the adaptability, reliability and economy of the refrigeration system, and meets the actual needs under different temperature conditions.

[0071] A third embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0072] 301. When the first analysis result shows that the first evaporator temperature is greater than the fourth temperature threshold and less than or equal to the third temperature threshold, generate a first slow frequency reduction type according to the first evaporator temperature;

[0073] 302. Calculate a first frequency reduction time according to the first slow frequency reduction type;

[0074] In this embodiment, different temperature conditions may correspond to different frequency reduction types. Generating a corresponding slow frequency reduction type based on the specific condition of the first evaporator temperature can accurately match the cooling capacity of the compressor unit with the actual heat load demand, avoid over-cooling or under-cooling, ensure that the refrigeration system can operate efficiently under different temperature conditions, and improve the overall performance of the system. The first slow frequency reduction type determines the time interval between each frequency reduction and is a key parameter for achieving slow frequency reduction.

[0075] 303. Generate a first slow frequency reduction instruction according to the first slow frequency reduction type and the first frequency reduction time;

[0076] 304. Acquire a system operating frequency to obtain a first operating frequency;

[0077] 305. Adjust the first operating frequency according to the slow frequency reduction instruction to obtain a first frequency-limiting frequency;

[0078] 306. Determine whether the first frequency limiting frequency is equal to a preset frequency limiting frequency threshold;

[0079] In this embodiment, the first frequency limiting frequency is the frequency adjusted in real time during the frequency reduction process. Whether the first frequency limiting frequency is equal to the preset frequency limiting frequency threshold is determined to determine whether to enter the next frequency limiting stage. This method of gradually adjusting the operating frequency of the compressor unit according to actual working conditions can ensure that the frequency of the compressor unit changes smoothly.

[0080] 307. When the first frequency limiting frequency is equal to the frequency limiting frequency threshold, generating a first frequency limiting and slow frequency reduction control instruction according to the first frequency limiting frequency and the first slow frequency reduction instruction;

[0081] In this embodiment, the first frequency limit and slow frequency reduction control instruction is an instruction to ensure that the system operates at a stable frequency after reaching the frequency limit threshold; when the indoor evaporator temperature satisfies T2_COLD0 (fifth temperature threshold) < T2 ≤ T2_COLD1 (fourth temperature threshold), the system quickly reduces the frequency once at intervals according to the first slow frequency reduction type and the frequency reduction time corresponding to the first slow frequency reduction type until the frequency is reduced to F1, and then operates at F1 all the time, which helps to make the compressor unit operate in a relatively stable state, reduce unnecessary mechanical wear, extend the service life of the equipment, and reduce equipment maintenance and replacement costs;

[0082] In this embodiment, a first slow frequency reduction type is generated according to the first evaporator temperature, and the frequency reduction time is calculated accordingly, so that the refrigeration capacity is accurately matched with the heat load demand, ensuring that the refrigeration system operates efficiently under different working conditions; the system operating frequency is adjusted according to the slow frequency reduction instruction generated according to the frequency reduction type and time, and the relationship between the adjusted first frequency limit frequency and the preset frequency limit frequency threshold is judged in real time during the process to ensure smooth frequency changes; when the frequency limit threshold is reached, a frequency limit and slow reduction control instruction is generated to allow the system to operate stably, and the system slowly reduces the frequency to F1 and maintains it according to a specific interval and frequency reduction type, which greatly reduces the mechanical wear of the equipment, extends the service life of the equipment, and reduces the maintenance and replacement costs; at the same time, accurate matching of the heat load demand avoids excessive or insufficient cooling, improves the overall performance of the system, ensures that refrigeration services can be provided to users stably and efficiently under different temperature conditions, and improves the stability, reliability and economy of the compressor unit operation from many aspects.

[0083] A fourth embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0084] 401. When the first analysis result shows that the first evaporator temperature is greater than the fifth temperature threshold and less than or equal to the fourth temperature threshold, generate a first rapid frequency reduction type according to the first evaporator temperature;

[0085] 402. Calculate a second frequency reduction time according to the first rapid frequency reduction type;

[0086] In this embodiment, the second frequency reduction time determines the interval between each frequency reduction. It is calculated based on factors such as the first rapid frequency reduction type and the system's operating characteristics, and plays a key role in achieving rapid frequency reduction. Rapid frequency reduction can quickly reduce the load on the compressor and the cooling output until the heat absorption on the evaporator side decreases. This process effectively prevents the risk of frost or cracking of the evaporator due to excessively low temperatures.

[0087] 403. Generate a first rapid frequency reduction instruction according to the first rapid frequency reduction type and the second frequency reduction time;

[0088] In this embodiment, the first rapid frequency reduction instruction specifies the specific method and rhythm of frequency reduction, such as the amplitude of each frequency reduction and the time period for completing the frequency reduction, providing a clear execution basis for subsequent adjustment of the system operating frequency. Although the first rapid frequency reduction instruction is an instruction to control the compressor unit to achieve rapid frequency reduction, it is carried out according to a specific time interval (second frequency reduction time) and a specific method (first rapid frequency reduction type). This reduces the impact on the internal mechanical components of the compressor. The compressor will not be subjected to excessive mechanical stress due to frequency mutation during the frequency reduction process, thereby reducing component wear and failure probability, ensuring stable operation of the compressor, and reducing downtime and maintenance costs caused by compressor failure.

[0089] 404. Acquire the system operating frequency to obtain a second operating frequency;

[0090] 405. Adjust the second operating frequency according to the first rapid frequency reduction instruction to obtain a second frequency-limited frequency;

[0091] 406. Determine whether the second frequency limiting frequency is equal to the frequency limiting frequency threshold;

[0092] 407. When the second frequency limiting frequency is equal to the frequency limiting frequency threshold, a first frequency limiting and speed reduction control instruction is generated according to the second frequency limiting frequency and the first fast frequency reduction instruction;

[0093] In this embodiment, the system will gradually reduce the operating frequency of the compressor unit according to the frequency reduction method and time interval specified by the first frequency limit and speed reduction control instruction, so that the operating frequency approaches the frequency limit threshold. After reaching the frequency limit threshold, the system will maintain operation in the frequency limit state to ensure the stability and safety of the system.

[0094] In this embodiment, when the evaporator temperature is greater than the fifth temperature threshold and less than or equal to the fourth temperature threshold, the system generates a first rapid frequency reduction type accordingly, and comprehensively calculates the second frequency reduction time based on factors such as system operating characteristics. The first rapid frequency reduction instruction generated accordingly specifies the frequency reduction amplitude and time, which not only quickly reduces the compressor load and reduces the cooling output, preventing the evaporator from frosting or cracking due to low temperature, but also reduces the impact on the mechanical components of the compressor, reduces wear and the probability of failure, ensures its stable operation, and reduces maintenance costs. In subsequent operations, the system operating frequency is obtained and adjusted according to the instruction, and the relationship between the adjusted frequency limit frequency and the frequency limit frequency threshold is determined. When the frequency limit frequency reaches the frequency limit frequency threshold, a frequency limit and speed reduction control instruction is generated, so that the compressor unit gradually reduces the frequency to the frequency limit frequency threshold in a specified manner and interval and maintains it, ensuring that the system always maintains stable and safe operation under complex operating conditions, greatly improving the reliability, equipment life, and energy utilization efficiency of the refrigeration system, and ensuring the efficient operation of the refrigeration system.

[0095] A fifth embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0096] 501. Control the compressor unit to shut down according to the temperature protection instruction;

[0097] In this embodiment, it is usually because the evaporator temperature is detected to be in an abnormal state (such as frost on the evaporator due to low temperature). Continuing to operate the compressor unit may cause damage to the evaporator, so a temperature protection instruction is generated and the shutdown protection mechanism is activated according to the temperature protection instruction; after the compressor unit is shut down, the indoor evaporator temperature automatically rises due to ambient heat conduction or residual refrigerant flow.

[0098] 502. Obtaining the evaporator temperature of the compressor unit in a shutdown state to obtain a second evaporator temperature;

[0099] 503. Determine whether the temperature of the second evaporator is greater than or equal to a third temperature threshold;

[0100] In this embodiment, the third temperature threshold is a pre-set standard used to measure whether the temperature of the evaporator has recovered to a safe range for restarting the compressor unit;

[0101] 504. When the second evaporator temperature is greater than or equal to a third temperature threshold, a second reset instruction is generated;

[0102] In this embodiment, the second reset instruction is used to control the compressor unit to return to the default operating frequency. The default operating frequency is set according to the design characteristics and optimal operating conditions of the compressor unit. When operating at this frequency, the various components inside the compressor are evenly stressed and operate smoothly, which can effectively reduce component wear and mechanical stress caused by abnormal frequency operation, reduce the probability of equipment failure, extend the service life of the equipment, and reduce the repair and replacement costs caused by equipment damage; in the default mode, the system can operate in sleep mode, silent mode, automatic mode, strong mode and drying mode; the default operating frequency corresponds to the standard cooling capacity output of the compressor unit. When the compressor unit returns to this frequency, it can provide stable and sufficient cooling capacity for the refrigeration system, ensure that the indoor temperature is maintained within the set range, and meet the user's demand for cooling effect; the default operating frequency is a benchmark parameter during the design and commissioning of the refrigeration system. The system's control logic and protection mechanism are usually set based on this frequency. The compressor unit returns to the default operating frequency, making the system control simpler and more accurate, and convenient for operators to monitor and manage;

[0103] 505. Generate a first adjustment instruction according to the second reset instruction;

[0104] In this embodiment, when an abnormal evaporator temperature is detected (such as low temperature frost), a temperature protection instruction is generated to shut down the compressor unit to prevent the evaporator from being damaged due to continuous abnormal operation; after shutdown, the evaporator temperature is obtained to determine whether it has reached the third temperature threshold. If it has reached it, a second reset instruction is generated to restore the compressor unit to the default operating frequency. This frequency is set based on the design system characteristics and the optimal operating conditions, which can reduce component wear, reduce the probability of failure, extend equipment life, and save maintenance costs; at the same time, the default operating frequency ensures stable output of cooling capacity to meet user cooling needs, and is a system design benchmark parameter, which is convenient for operators to accurately monitor and manage based on it, making system control simpler and more accurate, and ensuring efficient and stable operation of the refrigeration system.

[0105] A sixth embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0106] 601. Analyze the second analysis result.

[0107] 602. When the second analysis result shows that the AC effective value is greater than the preset first AC threshold and less than or equal to the preset second AC threshold, a slow frequency increase instruction is generated according to the AC effective value;

[0108] In this embodiment, AC power is the energy supply basis of the compressor unit and is the value for monitoring the power supply quality; when the AC current effective value IAC of the outdoor compressor unit meets the condition of AcCurLimit_A[0] (first AC threshold) < IAC ≤ AcCurLimit_A[1] (second AC threshold); it proves that the AC current effective value IAC of the compressor unit is slightly higher than the normal range, but still within the controllable range, so a slow frequency increase measure is taken to adjust the system operation state; so that the operating frequency of the compressor unit gradually increases, and the work efficiency is improved based on the current relatively good power supply conditions;

[0109] 603. Generate a second adjustment instruction according to the slow frequency increase instruction;

[0110] 604. When the second analysis result shows that the effective value of the alternating current is greater than the second alternating current threshold and less than or equal to a preset third alternating current threshold, a first frequency lock instruction is generated according to the effective value of the alternating current;

[0111] In this embodiment, when the effective value of the AC current IAC of the outdoor compressor unit satisfies the condition of IAcCurLimit_A[1] (the second AC threshold) <IAC ≤ AcCurLimit_A[2] (the third AC threshold), it indicates that the system is in a relatively stable working state, and the cooling or heating performance and energy consumption of the system at the current operating frequency are in a relatively reasonable matching state. Maintaining the current operating frequency helps to maintain the optimal balance of the system in terms of performance and energy consumption; the first frequency lock instruction can lock the operating frequency of the compressor unit to prevent unnecessary changes in the operating frequency of the compressor unit due to slight fluctuations in the AC power. The stability of the frequency enables the compressor unit to operate continuously and stably, avoiding brief shutdowns or operation interruptions that may be caused by frequency changes;

[0112] 605. Generate a second adjustment instruction according to the first frequency locking instruction;

[0113] 606. When the second analysis result shows that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to the preset fourth alternating current threshold, a second frequency limiting and slow-down control instruction is generated according to the effective value of the alternating current;

[0114] In this embodiment, when the effective value of the AC current of the outdoor compressor unit satisfies the condition of IAcCurLimit_A[2] (third AC threshold) < IAC ≤ IAcCurLimit_A[3] (fourth AC threshold), this indicates that the effective value of the AC current is high, and the system needs to gradually reduce the operating frequency to the preset frequency limit by slowly reducing the frequency to reduce the system load and prevent overload;

[0115] 607. Generate a second adjustment instruction according to the second frequency limiting and slow-down control instruction;

[0116] 608. When the second analysis result shows that the AC effective value is greater than the fourth AC threshold and less than or equal to the preset fifth AC threshold, a second frequency-limited and speed-reduced control instruction is generated according to the AC effective value;

[0117] In this embodiment, when the effective value of the AC current of the outdoor compressor unit satisfies IAcCurLimit_A[3] (the fourth AC threshold) <IAC ≤ IAcCurLimit_A[4] (the fifth AC threshold), a second frequency-limited and speed-reduced control instruction is generated; the compressor unit can be controlled to quickly reduce the frequency to F1 (an empirical value) according to the second frequency-limited and speed-reduced control instruction, and the compressor unit is limited to operate at F1 all the time: when the effective value of the AC current is in the range of IAcCurLimit_A[3] <IAC ≤ IAcCurLimit_A[4], it means that the compressor If the compressor has problems such as unstable motor speed, decreased output power, and decreased efficiency, a first frequency-limited and speed-reduced control instruction is generated at this time to control the compressor unit to quickly reduce the frequency, which can quickly respond to abnormal AC parameters of the compressor unit and avoid problems such as grid voltage fluctuations, unstable motor speed, decreased output power of the compressor unit, reduced working efficiency of the compressor unit, and abnormal AC parameters supplied to the compressor unit. The compressor unit is quickly reduced to the empirical value F1 and is restricted to operate at this frequency all the time, which helps to make the compressor unit operate in a relatively stable state and improve the operating performance of the compressor unit motor.

[0118] 609. Generate a second adjustment instruction according to the second frequency-limited and speed-reduced control instruction;

[0119] 610. When the second analysis result shows that the AC effective value is less than the first AC threshold, generate a third reset instruction;

[0120] In this embodiment, when the effective current value Icom of the outdoor compressor unit satisfies Icom<compCurLimit[0] (the first current threshold), the system is operating normally and is in a normal operating state, or the effective AC value of the compressor unit is within a normal range, a third reset instruction is generated; the third reset instruction is used to control the compressor unit to return to the default operating frequency. When the compressor unit returns to the frequency, the motor can run smoothly, reduce the friction and impact of mechanical components caused by unstable speed, reduce the wear of components such as the compressor piston and connecting rod, reduce equipment failures, and reduce maintenance costs; under the default operating frequency, the compressor unit can output relatively stable power, improve the problem of output power drop caused by too low voltage, ensure the normal operation of the cooling or heating system, and meet the user's demand for temperature regulation;

[0121] 611. Generate a second adjustment instruction according to the third reset instruction;

[0122] 612. When the second analysis result shows that the AC effective value is greater than or equal to the fifth AC threshold, an AC protection instruction is generated;

[0123] 613. Generate a second adjustment instruction according to the AC protection instruction;

[0124] The first AC threshold is smaller than the second AC threshold, smaller than the third AC threshold, smaller than the fourth AC threshold, smaller than the fifth AC threshold;

[0125] In this embodiment, when the effective value of the AC current of the outdoor unit reaches IAC≥compCurLimit[4] (the fifth current threshold), it means that the AC voltage supplied to the compressor unit is too high. The fifth AC threshold is set based on the upper limit of the AC voltage at which the compressor unit can operate safely and stably. When the AC voltage is too high, if it is not controlled in time, the failure of the compressor unit may cause a chain failure of the entire refrigeration or heating system. For example, a compressor failure may cause a pressure imbalance in the system, thereby affecting the normal operation of other components such as the condenser and evaporator. By implementing the AC protection instruction and the second adjustment instruction, the spread of the fault can be curbed, the stability of the system can be maintained, and the system can be guaranteed to maintain some functions in a complex voltage environment or to be able to quickly resume normal operation after the fault is resolved.

[0126] In this embodiment, when the effective value of the alternating current is slightly lower than the normal range but controllable, a slow frequency increase instruction is generated, which takes advantage of the relatively good power supply conditions of the compressor unit, gradually increases the operating frequency of the compressor unit, effectively improves work efficiency, and taps the potential of the system; when the effective value of the alternating current is in a relatively stable current range, the operating frequency of the compressor unit is locked by the first frequency lock instruction, maintaining an optimized balance between cooling or heating performance and energy consumption, and ensuring continuous and stable operation of the compressor unit; when the effective value of the alternating current is in a higher current range, the second frequency limit and slow frequency reduction control instruction come into play, reducing the system load by slowly reducing the frequency, preventing equipment overload, protecting the safe operation of the equipment, and extending the service life of the equipment; if the effective value of the alternating current is too high, the second frequency limit and speed reduction control instruction respond quickly, quickly reducing the compressor The unit frequency is reduced to the empirical value F1 and locked, which can effectively deal with problems such as unstable motor speed, reduced power and efficiency, improve motor performance, and ensure normal system operation; when the effective value of AC power is lower than the normal range, the third reset instruction restores the compressor unit to the default frequency, which reduces the friction and impact of mechanical parts, reduces wear, reduces equipment failure rate and maintenance costs, and stabilizes the output power, ensuring the normal operation of the cooling or heating system and meeting the user's temperature adjustment needs; once the effective value of AC power exceeds the safety upper limit, the AC protection instruction takes effect immediately, which can quickly curb the spread of the fault, prevent the compressor unit failure from triggering a chain reaction in the entire cooling or heating system, maintain system stability, and quickly return to normal after the fault is resolved, safeguarding the stable, efficient and safe operation of the compressor unit and related systems.

[0127] A seventh embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0128] 701. When the second analysis result shows that the AC effective value is greater than the third AC threshold and less than or equal to the fourth AC threshold, generate a second slow frequency reduction type according to the AC effective value;

[0129] 702. Calculate a third frequency reduction time according to the second slow frequency reduction type;

[0130] In this embodiment, the third frequency reduction time determines the interval between each frequency reduction. It is calculated based on factors such as the second slow frequency reduction type, the inertia of the motor, the response speed of the system, and the need to avoid shock to the equipment caused by excessive frequency reduction. The second slow frequency reduction type determines information such as the frequency reduction mode and amplitude of the compressor unit.

[0131] 703. Generate a second slow frequency reduction instruction according to the second slow frequency reduction type and the third frequency reduction time;

[0132] 704. Acquire the system operating frequency to obtain a third operating frequency;

[0133] 705. Adjust the third operating frequency according to the second slow frequency reduction instruction to obtain a third frequency-limiting frequency;

[0134] 706. Determine whether the third frequency limiting frequency is equal to the frequency limiting frequency threshold;

[0135] 707. When the third frequency limiting frequency is equal to the frequency limiting frequency threshold, generating a second frequency limiting and slow frequency reduction control instruction according to the third frequency limiting frequency and the second slow frequency reduction instruction;

[0136] In this embodiment, the second slow frequency reduction instruction specifies the specific method and rhythm of frequency reduction, such as the amplitude of each frequency reduction and the time required to complete the frequency reduction, providing guidance for adjusting the system operating frequency. The second frequency limit and slow frequency reduction control instruction comprehensively considers the current frequency limit and the slow frequency reduction requirements, ensuring that the compressor unit can stably maintain a safe frequency range during subsequent operation.

[0137] In this embodiment, through precise analysis of the effective value of the alternating current, a targeted second slow frequency reduction type is generated, and the third frequency reduction time is comprehensively calculated in combination with factors such as motor inertia and system response speed, and then a detailed second slow frequency reduction instruction is generated. The instruction clarifies the specific amplitude and rhythm of the frequency reduction, making the adjustment of the system operating frequency more accurate and stable; at the same time, by judging whether the third frequency limiting frequency reaches the threshold, and generating the second frequency limiting and slow frequency reduction control instruction accordingly, it is further ensured that the compressor unit can stably remain within the safe frequency range in subsequent operation. This process improves the operating stability and safety of the system, optimizes the operating efficiency of the system, enhances the system's adaptability to different working conditions, and provides a strong guarantee for the efficient and stable operation of the compressor unit.

[0138] An eighth embodiment of a compressor unit protection method according to an embodiment of the present invention includes:

[0139] 801. When the second analysis result shows that the AC RMS value is greater than the fourth AC threshold and less than or equal to the fifth AC threshold, generate a second fast frequency reduction type according to the AC RMS value;

[0140] 802. Calculate a fourth frequency reduction time according to the second fast frequency reduction type;

[0141] In this embodiment, the second frequency reduction time determines the interval between each frequency reduction. It is calculated based on factors such as the second rapid frequency reduction type and the system's operating characteristics. The second rapid frequency reduction type includes key information such as the frequency reduction mode and target frequency range set for the current AC power anomaly. The system's operating characteristics include factors such as the motor's moment of inertia, the compressor's mechanical response speed, and the system's thermal inertia. By comprehensively calculating these factors, the fourth frequency reduction time ensures that the frequency reduction process can both quickly respond to current anomalies and ensure safe operation of all system components.

[0142] 803. Generate a second rapid frequency reduction instruction according to the second rapid frequency reduction type and the fourth frequency reduction time;

[0143] In this embodiment, the operating frequency of the compressor unit is controlled by generating and executing a second rapid frequency reduction instruction, so that it can quickly respond to abnormal increases in grid voltage. This allows the compressor unit to maintain a relatively stable operating state in a complex and changeable grid environment. Whether in areas with frequent voltage fluctuations or in situations where grid faults cause voltage abnormalities, the compressor unit can adapt to grid changes through its own adjustment mechanism, thereby improving the adaptability and reliability of the system and expanding the scope of use of the equipment.

[0144] 804. Obtain a system operating frequency to obtain a fourth operating frequency;

[0145] 805. Adjust the fourth operating frequency according to the second fast frequency reduction instruction to obtain a fourth frequency limiting frequency;

[0146] 806. Determine whether the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold;

[0147] 807. When the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold, a second frequency limiting and speed reduction control instruction is generated according to the fourth frequency limiting frequency and the second fast frequency reduction instruction;

[0148] In this embodiment, the system gradually reduces the operating frequency of the compressor unit according to the frequency reduction method and time interval specified by the second frequency limit and speed reduction control instruction, so that the operating frequency approaches the frequency limit threshold. After reaching the frequency limit threshold, the system maintains operation in the frequency limit state to ensure system stability and safety.

[0149] In this embodiment, when the effective value of the alternating current is greater than the fourth and less than or equal to the fifth alternating current threshold, the system generates a second rapid frequency reduction type based on the effective value of the alternating current. This type covers the frequency reduction mode and target frequency range for the current abnormal AC power; at the same time, combined with system operating characteristics such as motor rotational inertia, compressor mechanical response speed, and system thermal inertia, the fourth frequency reduction time is calculated, and then a second rapid frequency reduction instruction is generated; by executing the second rapid frequency reduction instruction, the compressor unit can quickly respond to the abnormal increase in grid voltage, so that the compressor unit can maintain stable operation in a complex grid environment, improve the system adaptability and reliability, and expand the scope of equipment use; the system gradually adjusts the operating frequency of the compressor unit to the frequency limit threshold according to the frequency reduction method and time interval of the second frequency limit and speed reduction control instruction, and maintains frequency limit operation to ensure system stability and safety.

[0150] A ninth embodiment of a method for protecting a compressor unit according to an embodiment of the present invention includes:

[0151] 901. Analyze the third analysis result.

[0152] 902. When the third analysis result shows that the effective current value is greater than the preset first current threshold and less than or equal to the preset second current threshold, a second frequency slow increase instruction is generated according to the effective current value;

[0153] In this embodiment, the effective value of the current can intuitively reflect the load condition of the compressor unit. When the load borne by the compressor unit changes, its operating current will also change accordingly. For example, if the cooling or heating demand increases, the compressor needs to output more power, and the effective value of the current will increase, indicating that the load has increased. On the contrary, when the load is reduced, the effective value of the current decreases. By monitoring the effective value of the current, the operating parameters can be reasonably adjusted. When the effective value of the outdoor compressor unit current Icom meets the condition of compCurLimit[0] (first current threshold) < Icom ≤ compCurLimit[1] (second current threshold), it indicates that the load of the compressor unit has increased slightly. By slowly increasing the operating frequency of the compressor unit, the compressor current limit slow frequency increase time is 30 seconds, which can steadily increase the compressor output power to adapt to the load change and avoid the impact of frequency mutation on the equipment.

[0154] 903. Generate a third adjustment instruction according to the second frequency slow increase instruction;

[0155] 904. When the third analysis result shows that the effective current value is less than the preset second current threshold and less than or equal to the preset third current threshold, a second frequency lock instruction is generated according to the effective current value;

[0156] In this embodiment, when the effective value of the outdoor compressor unit current Icom satisfies the condition of compCurLimit[1] (second current threshold) < Icom ≤ compCurLimit[2] (third current threshold), it indicates that the current compressor unit is in a relatively stable working state, and the performance of the compressor at the current operating frequency is reasonably matched with the energy consumption. Maintaining the current operating frequency can ensure the optimal balance of the system in terms of performance and energy consumption. The second frequency lock instruction locks the current operating frequency to ensure that the compressor unit continues to operate at the operating frequency, thereby maintaining the optimal balance of the system in terms of performance and energy consumption, avoiding performance degradation or energy consumption increase due to frequency fluctuations, improving energy utilization efficiency, and reducing operating costs.

[0157] 905. Generate a third adjustment instruction according to the second frequency locking instruction;

[0158] 906. When the third analysis result shows that the effective current value is greater than the third current threshold and less than or equal to the preset fourth current threshold, generate a third slow frequency reduction type according to the effective current value;

[0159] In this embodiment, when the effective value of the outdoor compressor current Icom satisfies the condition of compCurLimit[2] (third current threshold) < Icom ≤ compCurLimit[3] (fourth current threshold), it indicates that the load of the compressor unit has increased and exceeded the reasonable range of the current operating frequency. A third slow frequency reduction type can be generated based on the effective value of the current. The third slow frequency reduction type determines the frequency reduction mode, amplitude and other information of the compressor unit.

[0160] 907. Calculate a fifth frequency reduction time according to the third slow frequency reduction type;

[0161] In this embodiment, the third frequency reduction time determines the time interval between each frequency reduction. It is calculated based on factors such as the third slow frequency reduction type, the inertia of the motor, the response speed of the system, and the need to avoid shock to the equipment caused by excessive frequency reduction. The third slow frequency reduction type determines the frequency reduction mode, amplitude, and other information of the compressor unit.

[0162] 908. Generate a third slow frequency reduction instruction according to the third slow frequency reduction type and the fifth frequency reduction time;

[0163] 909. Obtain the system operating frequency to obtain a fifth operating frequency;

[0164] In this embodiment, the system operating frequency is a key parameter reflecting the current working state of the compressor unit. Obtaining this parameter is crucial for implementing corresponding control strategies for the compressor unit.

[0165] 910. Adjust the fifth operating frequency according to the third slow frequency reduction instruction to obtain a fifth frequency-limiting frequency;

[0166] 911. Determine whether the fifth frequency limiting frequency is equal to the frequency limiting frequency threshold;

[0167] 912. When the fifth frequency limiting frequency is equal to the frequency limiting frequency threshold, generating a third frequency limiting and slow frequency reduction control instruction according to the fifth frequency limiting frequency and the third slow frequency reduction instruction;

[0168] In this embodiment, the system gradually reduces the operating frequency of the compressor unit according to the frequency reduction method and time interval specified by the third frequency limit and slow reduction control instruction, so that the operating frequency approaches the frequency limit threshold. After reaching the frequency limit threshold, the system maintains operation in the frequency limit state to ensure system stability and safety.

[0169] 913. Generate a third adjustment instruction according to the third frequency limiting and slow-down control instruction;

[0170] 914. When the third analysis result shows that the effective current value is greater than the fourth current threshold and less than or equal to the preset fifth current threshold, generate a third fast frequency reduction type according to the effective current value;

[0171] In this embodiment, when the effective value of the outdoor compressor current Icom satisfies the condition of compCurLimit[3] (fourth current threshold) < Icom ≤ compCurLimit[4] (fifth current threshold), it indicates that the compressor unit is facing a high load pressure. When the compressor unit faces a high load pressure, the motor current will increase sharply, causing the motor winding to heat up. If it continues in this high current state, the motor insulation layer may be damaged due to overheating, causing serious faults such as short circuits. It is necessary to quickly reduce the operating frequency of the compressor unit to protect the equipment; the third fast frequency reduction type includes key information such as the frequency reduction mode and target frequency range set for the current abnormal current situation;

[0172] 915. Calculate a sixth frequency reduction time according to the third rapid frequency reduction type;

[0173] In this embodiment, the sixth frequency reduction time is calculated based on key information such as the frequency reduction mode and target frequency range included in the third rapid frequency reduction type. This enables the frequency reduction process to be precisely controlled based on the actual load of the current compressor unit, ensuring that while the frequency is rapidly reduced, the equipment is not adversely affected by overly fast or slow frequency reduction.

[0174] 916. Generate a third rapid frequency reduction instruction according to the third rapid frequency reduction type and the sixth frequency reduction time;

[0175] In this embodiment, the third rapid frequency reduction instruction specifies the specific method and rhythm of frequency reduction, such as the amplitude of each frequency reduction and the time period for completing the frequency reduction. This provides a clear execution basis for subsequent adjustment of the system operating frequency. Although the third rapid frequency reduction instruction controls the compressor unit to achieve rapid frequency reduction, it is executed at a specific time interval (the sixth frequency reduction time) and in a specific manner (the third rapid frequency reduction type). This reduces the impact on the internal mechanical components of the compressor. The compressor will not be subjected to excessive mechanical stress due to sudden frequency changes during the frequency reduction process, thereby reducing component wear and the probability of failure, ensuring stable operation of the compressor, and reducing downtime and repair costs caused by compressor failure.

[0176] 917. Obtain the system operating frequency to obtain a sixth operating frequency;

[0177] 918. Adjust the sixth operating frequency according to the third fast frequency reduction instruction to obtain a sixth frequency-limited frequency;

[0178] 919. Determine whether the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold;

[0179] 920. When the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold, a third frequency limiting and speed reduction control instruction is generated according to the sixth frequency limiting frequency and the third fast frequency reduction instruction;

[0180] In this embodiment, the system gradually reduces the operating frequency of the compressor unit according to the frequency reduction method and time interval specified by the third frequency-limited and speed-reduced control instruction, so that the operating frequency approaches the frequency-limited threshold. After reaching the frequency-limited threshold, the system maintains operation in the frequency-limited state to ensure system stability and safety.

[0181] 921. Generate a third adjustment instruction according to the third frequency-limited and speed-reduced control instruction;

[0182] 922. When the third analysis result is that the effective current value is less than the first current threshold, generate a fourth reset instruction;

[0183] 923. Generate a third adjustment instruction according to the fourth reset instruction;

[0184] In this embodiment, when the effective value of the outdoor compressor current Icom satisfies the condition that Icom < compCurLimit[0] (the first current threshold), it indicates that the load of the compressor unit is extremely low and may be in a light load or near no-load state, and a fourth reset instruction is generated to restore the system operating parameters to the initial or default state to optimize system performance and energy consumption;

[0185] 924. When the third analysis result shows that the effective current value is greater than or equal to the fifth current threshold, a current protection instruction is generated;

[0186] In this embodiment, when the effective value of the outdoor compressor current Icom satisfies the condition of Icom ≥ compCurLimit[4] (the fifth current threshold), the compressor unit faces a serious overload risk, which may cause irreversible damage to the equipment. A current protection instruction is generated, and protective measures such as shutdown are immediately taken to ensure the safety of the equipment.

[0187] 925. Generate a third adjustment instruction according to the current protection instruction;

[0188] In this embodiment, the current threshold value of the effective current value Icom includes 5 groups, and all 5 groups can be modified accordingly according to the compressor parameters;

[0189]

[0190] The first current threshold is less than the second current threshold, less than the third current threshold, less than the fourth current threshold, and less than the fifth current threshold;

[0191] In this embodiment, in terms of equipment protection, the risk of equipment damage is reduced by monitoring the effective value of the current and taking corresponding measures. When the effective value of the current is in different current threshold ranges, different protection strategies are corresponding. For example, in the high current range, if the current is greater than the fourth current threshold and less than or equal to the fifth current threshold, the third fast frequency reduction type and instruction are generated to quickly reduce the operating frequency, reduce the heating of the motor winding, avoid damage to the motor insulation layer due to long-term high current, and effectively prevent serious faults such as short circuits. At the same time, the wear and impact of mechanical components under high loads are reduced, the overall service life of the equipment is extended, and maintenance costs and downtime are reduced. When the current is greater than or equal to the fifth current threshold, a current protection instruction is immediately generated, and measures such as shutdown are taken to prevent the equipment from suffering irreversible damage; the system performance optimization has achieved remarkable results. When the effective value of the current shows a load change, the operating frequency can be accurately adjusted to improve energy utilization efficiency. For example, if the effective value of the current is between the first current threshold and the second current threshold, and the load increases slightly, a second frequency slow increase instruction is generated to slowly increase the frequency so that the compressor output power increases steadily, which not only meets the load demand but also avoids energy waste caused by frequency mutation. When the current is between the second current threshold and the third current threshold, a second frequency lock instruction is generated to lock the current reasonable operating frequency, maintain an optimized balance between system performance and energy consumption, reduce energy consumption, and save operating costs; when the load increases beyond the reasonable range of the current frequency, such as if the effective value of the current is between the third current threshold and the fourth current threshold, a third slow frequency reduction instruction is generated. The frequency is adjusted according to the calculated reasonable time interval and frequency reduction mode to ensure that the system operates stably while reducing the load, guaranteeing the cooling or heating effect and improving the user experience; the system adaptability is greatly enhanced, and this solution can flexibly respond to various complex working conditions according to the real-time changes in the effective value of the current, and can respond quickly whether the load changes gradually or suddenly fluctuates greatly; for example, when the load of the compressor unit increases, strategies such as slow increase, slow decrease or fast frequency decrease are adopted according to different degrees; when the load of the compressor unit is extremely low, a fourth reset instruction is generated to restore the system parameters to their initial state and optimize the system performance; in addition, the generation of various instructions in this solution is based on clear thresholds and is adjusted according to actual conditions, so that it can be widely applied to compressor units of different models and working environments, improving versatility and scalability, ensuring the stable operation of the system in various scenarios, expanding the scope of equipment use, and enhancing the reliability and stability of the system.

[0192] A tenth embodiment of a method for protecting a compressor unit according to an embodiment of the present invention includes:

[0193] 1001. Analyze the fourth analysis result;

[0194] 1002. When the fourth analysis result indicates that the first bus voltage is higher or lower than a preset bus voltage threshold parameter, a voltage protection instruction is generated according to the first bus voltage;

[0195] In this embodiment, it is a protection mechanism for the outdoor compressor unit in the operating state. When the DC bus voltage (first bus voltage) of the outdoor compressor unit is higher than PROT_MAX_VBUS_RUN (bus voltage threshold parameter) or lower than PROT_MIN_VBUS_RUN (bus voltage threshold parameter), it is determined that a voltage fault occurs. The bus voltage threshold parameter is set according to the voltage range that the equipment can withstand during normal operation. During operation, the compressor unit has higher requirements for voltage stability because all components in the compressor unit are running at this time. Abnormal voltage may directly affect the normal operation of the equipment. For example, excessive voltage may cause excessive current around the compressor unit, accelerating the aging of various components in the insulation compressor unit; excessively low voltage may cause insufficient motor output torque, resulting in reduced working efficiency of the compressor unit, or even jamming. After determining a voltage fault, the system generates a voltage protection instruction according to the specific situation of the DC bus voltage (first bus voltage);

[0196] 1003. Acquire the outdoor DC bus voltage within a preset recovery time range according to the voltage protection instruction to obtain a second bus voltage;

[0197] In this embodiment, the recovery time range is ±30 seconds, and may also be other empirical values;

[0198] 1004. Calculate a first bus voltage threshold and a second bus voltage threshold according to the bus voltage threshold parameter and an empirical value;

[0199] In this embodiment, the bus voltage threshold parameters are stored in the memory. The first bus voltage threshold is (bus voltage threshold parameter) ROT_MAX_VBUS_RUN+10 (empirical value), and the second bus voltage threshold is (bus voltage threshold parameter). This calculation method combines the bus voltage threshold parameters preset by the compressor unit itself and the appropriate fluctuation range summarized in past actual operation, taking into account the individual characteristics of the equipment and the actual operating environment factors, so that the threshold setting is more in line with the actual operation of the equipment.

[0200] 1005. Determine whether the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold;

[0201] 1006. When the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold, generate a fifth reset instruction;

[0202] 1007. Generate a fourth adjustment instruction according to the fifth reset instruction;

[0203] In this embodiment, the recovery determination mechanism sets a certain time delay and voltage hysteresis interval. When the DC bus voltage of the outdoor compressor unit returns to normal, the system returns to the default operating state, ensuring that the outdoor compressor unit operates within a safe DC bus voltage range, thereby improving the reliability and stability of the overall equipment.

[0204] In this embodiment, the protection mechanism of the DC bus voltage provides a reliable guarantee for the stable operation of the outdoor compressor unit; when the first bus voltage is abnormal, a voltage protection instruction is generated, which effectively avoids problems such as aging of the motor winding of the compressor unit and insufficient output torque due to excessively high or low voltage, and ensures that the compressor unit can still operate safely under abnormal DC bus voltage; at the same time, by setting a reasonable recovery time range and threshold calculation method, and comprehensively considering the equipment preset parameters and actual operating experience, the accuracy and adaptability of voltage protection are improved; in addition, when the DC bus voltage returns to normal, the system restores the default operating state through reset and adjustment instructions, further ensuring the stable operation of the compressor unit within the safe voltage range, significantly improving the reliability and stability of the equipment, extending the service life of the equipment, reducing maintenance costs, and providing users with a safer, more efficient and reliable operating environment.

[0205] The present invention and its embodiments are described above. This description is not restrictive. What is shown in the accompanying drawings is only one of the embodiments of the present invention, and the actual content is not limited to this. In short, if ordinary technicians in this field are inspired by it and do not depart from the purpose of the invention, they can creatively design structural methods and embodiments similar to the technical solution, which should all fall within the scope of protection of the present invention.

Claims

1. A method for protecting a compressor unit, characterized in that: include: Acquiring a first evaporator temperature, and analyzing the first evaporator temperature according to a preset temperature threshold to obtain a first analysis result; generating a first adjustment instruction according to the first analysis result; Acquiring an effective value of alternating current (AC), and analyzing the AC effective value according to a preset AC effective value threshold to obtain a second analysis result; generating a second adjustment instruction according to the second analysis result; Acquiring a current effective value, and analyzing the current effective value according to a preset current effective value threshold to obtain a third analysis result; generating a third adjustment instruction according to the third analysis result; Acquire the outdoor DC bus voltage in the operating state to obtain a first bus voltage; Analyzing the first bus voltage according to a preset parameter threshold to obtain a fourth analysis result; generating a fourth adjustment instruction according to the fourth analysis result; generating a protection operating frequency according to the first adjustment instruction, the second adjustment instruction, the third adjustment instruction, and the fourth adjustment instruction; Control the operation of the compressor unit according to the protection operation frequency.

2. A method for protecting a compressor unit according to claim 1, characterized in that: Generating a first adjustment instruction according to the first analysis result includes: performing result analysis on the first analysis result; When the first analysis result shows that the first evaporator temperature is greater than a preset first temperature threshold and less than or equal to a preset second temperature threshold, a first frequency ramp-up instruction is generated according to the first evaporator temperature; generating a first adjustment instruction according to the first frequency slow increase instruction; When the first analysis result shows that the first evaporator temperature is greater than the preset third temperature threshold and less than or equal to the first temperature threshold, a frequency increase prohibition instruction is generated according to the first evaporator temperature; generating a first adjustment instruction according to the frequency prohibition instruction; When the first analysis result shows that the first evaporator temperature is greater than the preset fourth temperature threshold and less than or equal to the third temperature threshold, a first frequency limiting and slow-down control instruction is generated according to the first evaporator temperature; Generate a first adjustment instruction according to the first frequency limiting and slow-down control instruction; When the first analysis result shows that the first evaporator temperature is greater than the preset fifth temperature threshold and less than or equal to the fourth temperature threshold, a first frequency-limited and speed-reduced control instruction is generated according to the first evaporator temperature; Generate a first adjustment instruction according to the first frequency-limited and speed-reduced control instruction; When the first analysis result is that the first evaporator temperature is greater than the second temperature threshold, generating a first reset instruction; generating a first adjustment instruction according to the first reset instruction; When the first analysis result shows that the first evaporator temperature is less than or equal to a fifth temperature threshold, a temperature protection instruction is generated according to a preset downtime; generating a first adjustment instruction according to the temperature protection instruction; The fifth temperature threshold is smaller than the fourth temperature threshold, smaller than the third temperature threshold, smaller than the first temperature threshold, and smaller than the second temperature threshold.

3. A method for protecting a compressor unit according to claim 2, characterized in that: When the first analysis result shows that the first evaporator temperature is greater than the preset fourth temperature threshold and less than or equal to the third temperature threshold, generating a first frequency limiting and slow-down control instruction according to the first evaporator temperature includes: When the first analysis result is that the first evaporator temperature is greater than the fourth temperature threshold and less than or equal to the third temperature threshold, a first slow frequency reduction type is generated according to the first evaporator temperature; Calculate a first frequency reduction time according to the first slow frequency reduction type; Generate a first slow frequency reduction instruction according to the first slow frequency reduction type and the first frequency reduction time; Obtaining a system operating frequency to obtain a first operating frequency; Adjusting the first operating frequency according to the slow frequency reduction instruction to obtain a first frequency-limiting frequency; Determining whether the first frequency limiting frequency is equal to a preset frequency limiting frequency threshold; When the first frequency limiting frequency is equal to the frequency limiting frequency threshold, a first frequency limiting and slow frequency reduction control instruction is generated according to the first frequency limiting frequency and the first slow frequency reduction instruction.

4. A method for protecting a compressor unit according to claim 3, characterized in that: When the first analysis result shows that the first evaporator temperature is greater than the preset fifth temperature threshold and less than or equal to the fourth temperature threshold, generating a first frequency-limited and speed-reduced control instruction according to the first evaporator temperature includes: When the first analysis result is that the first evaporator temperature is greater than the fifth temperature threshold and less than or equal to the fourth temperature threshold, generating a first rapid frequency reduction type according to the first evaporator temperature; Calculating a second frequency reduction time according to the first rapid frequency reduction type; Generate a first rapid frequency reduction instruction according to the first rapid frequency reduction type and the second frequency reduction time; Acquiring the system operating frequency to obtain a second operating frequency; Adjusting the second operating frequency according to the first rapid frequency reduction instruction to obtain a second frequency-limiting frequency; Determining whether the second frequency limiting frequency is equal to the frequency limiting frequency threshold; When the second frequency limiting frequency is equal to the frequency limiting frequency threshold, a first frequency limiting and speed reduction control instruction is generated according to the second frequency limiting frequency and the first fast frequency reduction instruction.

5. A compressor unit protection method according to claim 2, characterized in that: Generating a first adjustment instruction according to the temperature protection instruction includes: Control the compressor unit to shut down according to the temperature protection instruction; Obtaining the evaporator temperature of the compressor unit in a shutdown state to obtain a second evaporator temperature; determining whether the second evaporator temperature is greater than or equal to a third temperature threshold; When the second evaporator temperature is greater than or equal to a third temperature threshold, a second reset instruction is generated; A first adjustment instruction is generated according to the second reset instruction.

6. A method for protecting a compressor unit as claimed in claim 3, characterized in that: Generating a second adjustment instruction according to the second analysis result includes: performing result analysis on the second analysis result; When the second analysis result shows that the effective value of the alternating current is greater than the preset first alternating current threshold and less than or equal to the preset second alternating current threshold, a slow frequency increase instruction is generated according to the effective value of the alternating current; generating a second adjustment instruction according to the slow frequency increase instruction; When the second analysis result is that the effective value of the alternating current is greater than the second alternating current threshold and less than or equal to a preset third alternating current threshold, a first frequency locking instruction is generated according to the effective value of the alternating current; generating a second adjustment instruction according to the first frequency locking instruction; When the second analysis result is that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to the preset fourth alternating current threshold, a second frequency limiting and slow-down control instruction is generated according to the effective value of the alternating current; generating a second adjustment instruction according to the second frequency limiting and slow-down control instruction; When the second analysis result shows that the effective value of the alternating current is greater than the fourth alternating current threshold and less than or equal to the preset fifth alternating current threshold, a second frequency-limited and speed-reduced control instruction is generated according to the effective value of the alternating current; Generate a second adjustment instruction according to the second frequency-limited and speed-reduced control instruction; When the second analysis result is that the AC effective value is less than the first AC threshold, a third reset instruction is generated; generating a second adjustment instruction according to the third reset instruction; When the second analysis result is that the AC effective value is greater than or equal to the fifth AC threshold, an AC protection instruction is generated; generating a second adjustment instruction according to the AC protection instruction; The first AC threshold is smaller than the second AC threshold, smaller than the third AC threshold, smaller than the fourth AC threshold, and smaller than the fifth AC threshold.

7. A method for protecting a compressor unit according to claim 6, characterized in that: When the second analysis result is that the effective value of the alternating current is greater than the third alternating current threshold and less than or equal to the preset fourth alternating current threshold, a second frequency limiting and slow-down control instruction is generated according to the effective value of the alternating current, including: When the second analysis result is that the AC effective value is greater than the third AC threshold and less than or equal to the fourth AC threshold, a second slow frequency reduction type is generated according to the AC effective value; Calculate a third frequency reduction time according to the second slow frequency reduction type; generating a second slow frequency reduction instruction according to the second slow frequency reduction type and the third frequency reduction time; Obtaining the system operating frequency to obtain a third operating frequency; Adjusting the third operating frequency according to the second slow frequency reduction instruction to obtain a third frequency-limiting frequency; Determining whether the third frequency limiting frequency is equal to the frequency limiting frequency threshold; When the third frequency limiting frequency is equal to the frequency limiting frequency threshold, a second frequency limiting and slow frequency reduction control instruction is generated according to the third frequency limiting frequency and the second slow frequency reduction instruction.

8. A method for protecting a compressor unit according to claim 6, characterized in that: When the second analysis result shows that the effective value of the alternating current is greater than the fourth alternating current threshold and less than or equal to the preset fifth alternating current threshold, generating a second frequency-limited and speed-reduced control instruction according to the effective value of the alternating current includes: When the second analysis result is that the AC effective value is greater than the fourth AC threshold and less than or equal to the fifth AC threshold, generating a second fast frequency reduction type according to the AC effective value; Calculating a fourth frequency reduction time according to the second fast frequency reduction type; generating a second rapid frequency reduction instruction according to the second rapid frequency reduction type and the fourth frequency reduction time; Obtaining the system operating frequency to obtain a fourth operating frequency; adjusting the fourth operating frequency according to the second fast frequency reduction instruction to obtain a fourth frequency limiting frequency; Determining whether the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold; When the fourth frequency limiting frequency is equal to the frequency limiting frequency threshold, a second frequency limiting and speed reduction control instruction is generated according to the fourth frequency limiting frequency and the second fast frequency reduction instruction.

9. A compressor unit protection method according to claim 1, characterized in that: Generating a third adjustment instruction according to the third analysis result includes: performing result analysis on the third analysis result; When the third analysis result is that the effective current value is greater than the preset first current threshold and less than or equal to the preset second current threshold, a second frequency slow increase instruction is generated according to the effective current value; generating a third adjustment instruction according to the second frequency ramp-up instruction; When the third analysis result is that the effective current value is less than the preset second current threshold and less than or equal to the preset third current threshold, a second frequency lock instruction is generated according to the effective current value; generating a third adjustment instruction according to the second frequency locking instruction; When the third analysis result is that the effective current value is greater than the third current threshold and less than or equal to the preset fourth current threshold, a third slow frequency reduction type is generated according to the effective current value; A fifth frequency reduction time is calculated according to the third slow frequency reduction type; generating a third slow frequency reduction instruction according to the third slow frequency reduction type and the fifth frequency reduction time; Obtaining the system operating frequency to obtain a fifth operating frequency; adjusting the fifth operating frequency according to the third slow frequency reduction instruction to obtain a fifth frequency-limiting frequency; Determining whether the fifth frequency limiting frequency is equal to the frequency limiting frequency threshold; When the fifth frequency limiting frequency is equal to the frequency limiting frequency threshold, a third frequency limiting and slow frequency reduction control instruction is generated according to the fifth frequency limiting frequency and the third slow frequency reduction instruction; generating a third adjustment instruction according to the third frequency limiting and slow-down control instruction; When the third analysis result is that the effective current value is greater than the fourth current threshold and less than or equal to the preset fifth current threshold, a third fast frequency reduction type is generated according to the effective current value; Calculating a sixth frequency reduction time according to the third fast frequency reduction type; generating a third rapid frequency reduction instruction according to the third rapid frequency reduction type and the sixth frequency reduction time; Obtaining the system operating frequency to obtain a sixth operating frequency; adjusting the sixth operating frequency according to the third fast frequency reduction instruction to obtain a sixth frequency-limited frequency; Determining whether the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold; When the sixth frequency limiting frequency is equal to the frequency limiting frequency threshold, a third frequency limiting and speed reduction control instruction is generated according to the sixth frequency limiting frequency and the third fast frequency reduction instruction; generating a third adjustment instruction according to the third frequency-limited and speed-reduced control instruction; When the third analysis result is that the effective current value is less than the first current threshold, a fourth reset instruction is generated; generating a third adjustment instruction according to the fourth reset instruction; When the third analysis result is that the effective current value is greater than or equal to the fifth current threshold, a current protection instruction is generated; generating a third adjustment instruction according to the current protection instruction; The first current threshold is smaller than the second current threshold, smaller than the third current threshold, smaller than the fourth current threshold, and smaller than the fifth current threshold.

10. A compressor unit protection method according to claim 1, characterized in that: Generating a fourth adjustment instruction according to the fourth analysis result includes: performing result analysis on the fourth analysis result; When the fourth analysis result is that the first bus voltage is higher or lower than a preset bus voltage threshold parameter, a voltage protection instruction is generated according to the first bus voltage; Obtaining the outdoor DC bus voltage within a preset recovery time range according to the voltage protection instruction to obtain a second bus voltage; The first bus voltage threshold and the second bus voltage threshold are calculated according to the bus voltage threshold parameter and the empirical value; Determining whether the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold; When the second bus voltage is higher than the first bus voltage threshold and lower than the second bus voltage threshold, generating a fifth reset instruction; A fourth adjustment instruction is generated according to the fifth reset instruction.

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