Method for detecting compressor rotor state in air conditioning system and air conditioning system

Abstract

The present invention discloses a method for detecting the status of a compressor rotor in an air-conditioning system and the air-conditioning system. The method comprises: when the air-conditioning system is operating in a low-temperature heating mode, real-time monitoring of compressor fault information; determining whether the compressor fault information meets preset fault conditions; and if so, determining the compressor rotor status based on the operating parameters of the air-conditioning system. Compared with existing technologies, the present invention can determine whether a compressor fault is caused by rotor sticking when a compressor fault occurs, accurately locate the compressor fault, and improve subsequent repair efficiency.

Description

Technical Field

[0001] The present invention relates to the field of air conditioning, and in particular to a method for detecting the state of a compressor rotor in an air conditioning system and the air conditioning system. Background Art

[0002] The compressor plays a vital role in the cooling and heating process of the air-conditioning system. It is responsible for energy conversion, heat transfer, system pressure control, etc., and is the core component of the air-conditioning system.

[0003] Under ultra-low temperature conditions, the outdoor ambient temperature is very low, which causes the evaporator temperature to be extremely low. The evaporation rate of the refrigerant in the evaporator slows down, and some liquid refrigerant is sucked into the compressor before it is completely vaporized, resulting in liquid accumulation.

[0004] After the liquid refrigerant enters the compressor, since the liquid is incompressible, when the piston or scroll plate tries to compress the liquid, it will generate a huge impact force, causing damage to the internal parts of the compressor (such as the piston, connecting rod, crankshaft, etc.) and the rotor to get stuck. At this time, related faults will occur when the machine is restarted and it will not be able to start.

[0005] Therefore, how to design a compressor rotor status detection method and air-conditioning system in an air-conditioning system to determine whether the compressor failure is caused by rotor jamming and then locate the specific fault location is a technical problem that needs to be solved urgently in the industry. Summary of the Invention

[0006] In view of the problem in the prior art that when a compressor fails, it is impossible to determine whether the compressor failure is caused by rotor jamming, the present invention proposes a compressor rotor status detection method in an air-conditioning system and an air-conditioning system.

[0007] The technical solution of the present invention is to propose a method for detecting the state of a compressor rotor in an air-conditioning system, comprising: when the air-conditioning system operates in a low-temperature heating condition, real-time monitoring of compressor fault information;

[0008] It is determined whether the fault information of the compressor meets a preset fault condition. If so, the rotor state of the compressor is determined according to the operating parameters of the air-conditioning system.

[0009] Furthermore, the fault information of the compressor includes: the number of times the compressor has an overcurrent fault and a step-out fault;

[0010] Determining whether the fault information of the compressor meets a preset fault condition includes:

[0011] Determine whether the number of times the compressor has experienced out-of-step failures within a first preset time has reached a preset number;

[0012] If so, when an overcurrent fault exists before the compressor loses step fault, it is determined that the fault information of the compressor meets the preset fault condition.

[0013] Furthermore, the operating parameters of the air-conditioning system include: the operating high pressure of the air-conditioning system, the operating low pressure of the air-conditioning system, and the exhaust temperature of the air-conditioning system;

[0014] Determining the rotor state of the compressor according to the operating parameters of the air conditioning system includes:

[0015] Calculating a pressure difference between an operating high pressure of the air conditioning system and an operating low pressure of the air conditioning system, and determining whether the pressure difference is less than a preset threshold;

[0016] If so, determining whether the exhaust temperature of the air conditioning system rises within a second preset time;

[0017] When the exhaust temperature of the air-conditioning system does not rise within a second preset time, it is determined that the rotor of the compressor is stuck.

[0018] Furthermore, when the pressure difference is greater than the preset threshold and / or the exhaust temperature of the air-conditioning system rises within a second preset time, it is determined that a control failure problem occurs in the compressor.

[0019] Furthermore, before real-time monitoring of compressor fault information, the following steps are also included:

[0020] Detecting the ambient temperature of the air conditioning system and determining whether the ambient temperature is less than a low temperature threshold;

[0021] If so, detecting the operating mode of the air conditioning system;

[0022] When the air-conditioning system is in a heating mode, it is determined that the air-conditioning system is operating in a low-temperature heating condition.

[0023] Furthermore, the method for detecting an overcurrent fault in the compressor includes:

[0024] monitoring the instantaneous current of the compressor in real time, and determining whether the instantaneous current of the compressor exceeds a current threshold;

[0025] If so, it is determined that an overcurrent fault occurs in the compressor.

[0026] Furthermore, the method for detecting a compressor out-of-step fault includes:

[0027] detecting an actual speed of the compressor during operation, and determining whether the actual speed exceeds a speed threshold range;

[0028] If so, it is determined that the compressor has a step-out fault.

[0029] Furthermore, before determining the rotor state of the compressor according to the operating parameters of the air-conditioning system, the method further includes: controlling the compressor to enter an open-loop drag mode.

[0030] Furthermore, the open-loop drag mode includes:

[0031] A target frequency for the compressor is set, and an external current is applied to the compressor to make the compressor operate at the target frequency.

[0032] The present invention also provides an air-conditioning system, which adopts the above-mentioned method for detecting the state of a compressor rotor in the air-conditioning system.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The compressor rotor status detection method proposed in the present invention can determine whether the compressor has a rotor stuck problem based on the operating parameters of the air-conditioning system, and then accurately locate the compressor fault location, thereby improving subsequent maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is an overall flow chart of the compressor rotor state detection method of the present invention;

[0037] Figure 2 This is a conversion diagram of the compressor in the normal starting state of the present invention;

[0038] Figure 3 This is a conversion diagram of the self-check logic state when a compressor failure occurs in the present invention. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Thus, a feature indicated in this specification is intended to illustrate one of the features of one embodiment of the present invention, rather than to imply that every embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise noted, the described combinations are not intended to be limiting.

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

[0042] When the air conditioning system is running in heating mode at ultra-low temperatures, the evaporation rate of the evaporator slows down, causing liquid refrigerant to enter the compressor, causing damage to the internal parts of the compressor, and causing problems such as the compressor rotor being stuck, resulting in the compressor being unable to start normally;

[0043] However, the compressor stops working due to a variety of reasons. The current technical solution cannot determine the specific fault location of the compressor. As a result, after the compressor stops working due to a fault, subsequent maintenance requires a lot of work to check one by one, affecting the subsequent maintenance efficiency.

[0044] The design idea of ​​the present invention is to determine whether the compressor fault is a rotor jam based on the fault information that occurs when the compressor rotor is stuck, combined with the changes in the operating parameters of the air-conditioning system that controls the compressor to enter the open-loop drag mode, and thus achieve accurate fault location.

[0045] Based on the above design ideas, the present invention proposes a method for detecting the status of a compressor rotor in an air-conditioning system, comprising the following steps:

[0046] When the air conditioning system is operating in low-temperature heating conditions, real-time monitoring of compressor fault information;

[0047] Determine whether the compressor fault information meets the preset threshold condition. If so, determine the compressor rotor status based on the operating parameters of the air-conditioning system.

[0048] As mentioned above, the evaporation rate of the evaporator slows down, causing liquid refrigerant to enter the compressor, which in turn causes the compressor rotor to become stuck. This problem usually occurs in an ultra-low temperature environment. The idea of ​​the present invention is to detect whether the compressor rotor is stuck. Therefore, before performing compressor fault information monitoring, the present invention needs to ensure that the air conditioning system is operating in a low-temperature heating condition (that is, in the ultra-low temperature environment, in the heating mode).

[0049] As for the present invention, the judgment is made by using the fault information of the compressor, which is set according to the operating state of the compressor when the rotor of the compressor is stuck. Here, when the rotor of the compressor is stuck, the operating state of the compressor is:

[0050] When the compressor has a rotor stuck fault, the rotor cannot rotate and the load becomes smaller, which will cause a large current to be generated. The current will exceed the current threshold, and the compressor will first have an overcurrent fault;

[0051] After the overcurrent fault occurs, when the compressor is turned on again, the compressor rotor is stuck and cannot rotate. At this time, the compressor control program will determine that the actual speed of the compressor deviates too much from the set speed. At this time, the out-of-step logic is met and a out-of-step fault is reported. At the same time, because the compressor rotor is stuck, even if the compressor is turned on again, the compressor control program will still determine that the actual speed of the compressor deviates too much from the set speed, that is, multiple out-of-step faults will be reported at this time.

[0052] From the above records, it can be seen that after the compressor has a rotor stuck fault, the fault state of the compressor will be: first an overcurrent fault occurs, and then multiple out-of-step faults occur. The present invention uses this part of the characteristics as fault information to determine whether the compressor has a rotor stuck fault;

[0053] However, the out-of-step fault of the compressor is not solely due to the compressor rotor being stuck. If the compressor has a control failure problem, the out-of-step fault problem may also occur. Therefore, when performing the above judgment, the present invention does not directly judge that the compressor rotor is stuck based on the compressor fault information, but further judges the compressor rotor state based on the operating parameters of the air-conditioning system, that is, the compressor rotor state is judged based on the operating parameters of the air-conditioning system as mentioned above;

[0054] The control logic in this case is to inject current into the compressor to make it run. If the compressor can run, it means that the fault of the compressor is control failure. If the compressor cannot run normally, it means that the fault of the compressor is rotor stuck.

[0055] Here, since the operation of the compressor will cause the operating parameters of the air-conditioning system to change accordingly, the present invention can directly determine the rotor state of the compressor based on the operating parameters of the air-conditioning system;

[0056] The above description is also the present invention's "when the air-conditioning system operates in a low-temperature heating condition, real-time monitoring of compressor fault information;

[0057] Determine whether the compressor fault information meets the preset fault conditions. If so, determine the compressor rotor status based on the operating parameters of the air conditioning system.

[0058] From the above analysis, it can be seen that after using the compressor rotor status detection method in the air-conditioning system proposed by the present invention, the present invention can accurately determine whether the compressor has a rotor stuck fault, that is, the present invention can accurately locate the fault position of the compressor, thereby improving the subsequent maintenance efficiency.

[0059] Furthermore, the fault information of the compressor in the present invention includes: the number of times the compressor has experienced overcurrent faults and out-of-step faults;

[0060] Determine whether the compressor fault information meets the preset fault conditions, including:

[0061] Determine whether the number of times the compressor has experienced out-of-step failures within a first preset time has reached a preset number;

[0062] If so, when an overcurrent fault exists before the compressor loses step fault, it is determined that the fault information of the compressor meets the preset fault condition.

[0063] This part of the judgment is the first level of judgment in the present invention, that is, based on the judgment logic of the fault information. As mentioned above, when the compressor encounters a rotor stuck fault, it will first encounter an overcurrent fault and then multiple out-of-step faults. The preset fault conditions in the present invention correspond to this judgment logic. Judging based on this preset fault condition can largely determine that the compressor fault is a rotor stuck;

[0064] The preset number of times here can be set according to actual needs, generally it can be set to 3 times. If the number is set too small, there may be misjudgment. If the number is set too much, the workload of judgment will increase.

[0065] Similarly, the first preset time can also be set according to actual needs, and can generally be set to 15 minutes. If the time is set too short, the compressor may not restart and the out-of-step fault may not be detected.

[0066] The present invention adopts the above-mentioned judgment logic, which can preliminarily filter most fault types, provide convenience for subsequent judgment, and be used for subsequent accurate judgment of whether the compressor has a rotor stuck problem.

[0067] Furthermore, the operating parameters of the air conditioning system in the present invention include: operating high pressure of the air conditioning system, operating low pressure of the air conditioning system, and exhaust temperature of the air conditioning system;

[0068] Determine the compressor rotor status based on the operating parameters of the air conditioning system, including:

[0069] Calculating a pressure difference between an operating high pressure of the air conditioning system and an operating low pressure of the air conditioning system, and determining whether the pressure difference is less than a preset threshold;

[0070] If so, determining whether the exhaust temperature of the air conditioning system rises within a second preset time;

[0071] When the exhaust temperature of the air-conditioning system does not rise within the second preset time, it is determined that the rotor of the compressor is stuck.

[0072] This part of the judgment logic is the second-level judgment in the present invention. As mentioned above, although after the compressor has a rotor stuck problem, its fault information is that first an overcurrent fault occurs, and then multiple out-of-step faults occur, but the compressor presents this fault condition (an overcurrent fault occurs, and then multiple out-of-step faults occur) does not necessarily mean that the compressor has a rotor stuck problem. The compressor out-of-step fault may also be caused by control failure. Because the present invention needs to execute the above-mentioned second-level judgment to further determine that the compressor has a rotor stuck fault.

[0073] In order to screen out the problem of control failure of the compressor, the solution of the present invention is to inject a current into the compressor, so that the compressor is dragged in an open loop. In this case, the compressor is equivalent to being forced to run. Therefore, if the compressor can work normally in this case, it indicates that the fault of the compressor is control failure. Otherwise, it can be determined that the fault of the compressor is rotor stuck.

[0074] As can be seen from the above description, the normal operation of the compressor will affect the operating parameters of the air conditioning system. Therefore, when performing the second-level judgment, the present invention directly uses the operating parameters of the air conditioning system to make a judgment;

[0075] Here, the operating parameters of the air conditioning system used in the present invention include: the operating high pressure of the air conditioning system, the operating low pressure of the air conditioning system, and the exhaust temperature of the air conditioning system;

[0076] The above operating parameters are parameters that will change under normal operation of the compressor, such as the operating high pressure of the air conditioning system and the operating low pressure of the air conditioning system. These two parameters can correspond to the pressure difference of the air conditioning system. If the compressor operates normally, the pressure difference will change. Here, the changed value is recorded as PΔa. Therefore, the present invention only needs to determine whether the change in the pressure difference reaches PΔa to determine whether the compressor is operating normally. PΔa is also the preset threshold value.

[0077] Similarly, when the compressor is operating normally, the exhaust temperature of the air conditioning system will rise. Therefore, the present invention can also directly determine whether the compressor can operate normally at this time by whether the exhaust temperature of the air conditioning system rises, thereby eliminating the problem of rising control failure.

[0078] The present invention sets the judgment logic of the pressure difference and the exhaust temperature in a progressive relationship to avoid misjudgment. Only when both the pressure difference and the exhaust temperature indicate that the compressor is not running can it be determined that the compressor rotor is stuck, thereby ensuring the accuracy of the judgment.

[0079] Since the pressure difference corresponding to the air-conditioning system (the difference between the operating high pressure of the air-conditioning system and the operating low pressure of the air-conditioning system) will exceed the preset threshold when the compressor is operating normally, it can be determined that the compressor is not operating when the pressure difference is less than the preset threshold;

[0080] Similarly, when the compressor is operating normally, the corresponding exhaust temperature of the air conditioning system will rise. Therefore, it can be determined that the compressor is not operating by the fact that the exhaust temperature does not rise;

[0081] When both of the rising judgment logics determine that the compressor is not running, it is determined that the fault of the compressor at this time is a stuck rotor.

[0082] Based on the logic for determining whether the compressor rotor is stuck, the present invention can also provide a logic for determining whether the compressor control fails, which is the opposite of the logic for determining whether the compressor rotor is stuck, that is:

[0083] When the exhaust temperature of the air-conditioning system rises within the second preset time, it is determined that a control failure problem occurs in the compressor.

[0084] Based on the above judgment logic, the present invention can accurately determine whether the compressor has a rotor stuck fault, and can also determine whether the compressor has a control failure problem, thereby accurately determining the location of the compressor fault to improve subsequent maintenance efficiency.

[0085] Furthermore, as can be seen from the foregoing description, the present invention provides a current to the compressor to drive the compressor to operate when further determining whether the compressor has a rotor stuck fault or a control failure fault. This part of the control is also referred to as the foregoing part of the present invention: before determining the rotor state of the compressor based on the operating parameters of the air-conditioning system, it also includes: controlling the compressor to enter an open-loop drive mode;

[0086] The open-loop drag mode here is to provide a current to the compressor as mentioned above, thereby driving the compressor to run.

[0087] The purpose of the present invention controlling the compressor to enter the open-loop drag mode is to ensure the normal operation of the compressor. When the compressor fails to control, the compressor is essentially not running. The present invention controls the operation of the compressor through the open-loop drag mode, thereby avoiding the influence of the control failure of the compressor on the above judgment. At this time, whether the compressor operates normally is only related to whether the rotor of the compressor is stuck, that is, at this time, it can be directly judged whether the compressor has a rotor stuck fault based on the operating parameters of the air-conditioning system.

[0088] The specific actions of the open-loop drag mode are as follows:

[0089] A target frequency for the compressor is set, and an external current is applied to the compressor to make the compressor operate at the target frequency.

[0090] This step is to inject current into the compressor, set the current loop target value, set the target frequency, without position observer (speed loop open loop), and drive the motor. Figure 3 In this case, the specific state switching process of the present invention is standby → bias voltage calculation → bootstrap capacitor charging → open-loop operation → end.

[0091] See Figure 2 Under normal circumstances, the state switching process of the compressor is standby → bias voltage calculation → bootstrap capacitor charging → positioning → high frequency injection start → operation;

[0092] The control method of the present invention is adjusted for the high-frequency injection start-up step. Therefore, when the compressor fails to control, the high-frequency injection start-up action of the upper computer will not be able to normally control the start-up of the compressor. The present invention utilizes the above-mentioned open-loop operation method to inject current and drive the motor to run, which can drive the normal operation of the compressor to determine whether the rotor of the above-mentioned compressor is stuck.

[0093] This setting of the present invention is used to ensure that the compressor can operate normally, thereby avoiding the impact of compressor control failure on the above judgment. At this time, whether the compressor operates normally is only related to whether the compressor rotor is stuck, that is, at this time, it can be directly judged based on the operating parameters of the air-conditioning system whether the compressor has a rotor stuck fault.

[0094] See Figure 1 , which is the overall control flow of the present invention, wherein ta is the fault judgment time, that is, the first preset time mentioned above, which is used to judge whether the number of out-of-step faults of the compressor reaches the preset number;

[0095] iPhsmiscnt is the number of times the compressor has lost-step faults;

[0096] PmLimit is the preset number of times;

[0097] iOccnt is the number of times the compressor has an overcurrent fault;

[0098] tb is a second preset time, which is a delay time for obtaining the pressure difference and exhaust temperature of the air conditioning system, and is used to determine whether the exhaust temperature rises and whether the pressure difference is less than a preset threshold;

[0099] See Figure 1 , the specific steps are:

[0100] Determine whether the system is in ultra-low temperature heating mode; the ultra-low temperature heating mode here refers to the low temperature heating condition mentioned above. This step also refers to the determination of whether the ambient temperature of the air conditioning system is less than the low temperature threshold before real-time monitoring of the compressor fault information mentioned above;

[0101] At time ta, it is determined that iPhsmiscnt>PmLimit; here ta is the first preset time,

[0102] iPhsmiscnt is the number of times the compressor has lost step, and PmLimit is the preset number. This step is the same as the above step of determining whether the number of times the compressor has lost step reached the preset number within the first preset time.

[0103] Determine if iOccnt is true; here, iOccnt is the number of times the compressor has an overcurrent fault. If iOccnt is true, it means that an overcurrent fault has occurred. This step is the same as the determination of the existence of an overcurrent fault before the compressor has a step-out fault in the previous text.

[0104] After receiving the power-on command again, the compressor is operated in the open-loop drag mode. This step is the same as the above step of controlling the compressor to enter the open-loop drag mode before determining the rotor state of the compressor according to the operating parameters of the air-conditioning system.

[0105] After time tb, it is determined whether the system high-low pressure difference and the exhaust temperature difference meet the threshold setting; the high-low pressure difference here actually corresponds to the pressure difference between the operating high pressure and the operating low pressure of the air-conditioning system, and the exhaust temperature difference is a value used to indicate whether the exhaust temperature of the air-conditioning system has increased. If the exhaust temperature difference is greater than zero, it indicates that the exhaust temperature of the air-conditioning system has increased; otherwise, it indicates that the exhaust temperature of the air-conditioning system has decreased. This step is the same as the above-mentioned determination of whether the pressure difference is less than the preset threshold and whether the exhaust temperature of the air-conditioning system has increased within the second preset time;

[0106] When the judgment is yes, the function enters the compound rotor stuck feature, the digital tube displays the corresponding fault code, the fault is not restored, and the machine does not start; this step also determines that the compressor has a rotor stuck fault. After the rotor stuck fault occurs, the digital tube displays the fault code corresponding to the rotor stuck fault, which is used to inform the compressor of the fault type. Since the compressor has a rotor stuck fault at this time, the compressor is controlled not to start running to avoid the fault from worsening.

[0107] In the present invention, if any of the above judgment logics determines to be yes or no, the judgment logic of not meeting the rotor jam is entered, and it is handled in the same way as other faults, without any special processing actions; this is because the design concept of the present invention is mainly aimed at detecting compressor rotor jams, and does not mean that other fault types of the compressor cannot be judged based on the concept of the present invention. According to the previous records, it can be easily found that the present invention can at least determine whether the compressor has a control failure problem.

[0108] From the attached Figure 1 It can be clearly seen that the compressor rotor status detection method in the air-conditioning system proposed by the present invention can accurately determine whether the compressor has a rotor stuck fault, thereby accurately locating the compressor fault position and improving subsequent maintenance efficiency.

[0109] According to the above description, it can be found that when the present invention determines the fault information, it is necessary to record the number of times the compressor has an overcurrent fault and the number of times the compressor has a step-out fault. That is, when the present invention performs the above steps, it is actually necessary to determine whether the compressor has an overcurrent fault and a step-out fault. To this end, the present invention provides corresponding detection methods for the compressor overcurrent fault and the compressor step-out fault, respectively, for detecting the number of times the compressor has an overcurrent fault and the number of times the compressor has a step-out fault.

[0110] Specifically, the method for detecting an overcurrent fault in a compressor according to the present invention is as follows:

[0111] Monitor the instantaneous current of the compressor in real time to determine whether the instantaneous current of the compressor exceeds the current threshold;

[0112] If so, it is determined that the compressor has an overcurrent fault;

[0113] The essence of this overcurrent fault is that the instantaneous current of the compressor increases, exceeds the current threshold, and thus affects the operation of the compressor. Therefore, in the present invention, only the instantaneous current of the compressor is monitored in real time to determine whether the compressor has an overcurrent fault;

[0114] Regarding the number of times the compressor overcurrent fault occurs in the above text, it can be judged based on the number of times the instantaneous current exceeds the current threshold. Each time the current threshold is exceeded, an overcurrent fault is recorded. The present invention can well record the number of times the compressor overcurrent fault occurs according to this method, and then use it to judge whether the preset fault condition is met.

[0115] Similarly, the method for detecting a compressor out-of-step fault in the present invention is:

[0116] Detect the actual speed of the compressor during operation and determine whether the actual speed exceeds the speed threshold range;

[0117] If so, it is determined that the compressor has a step-out fault.

[0118] The out-of-step fault is when the compressor suddenly cannot detect the rotor position during operation or the actual speed deviates too much from the set speed during operation. The present invention is set based on the large deviation between the actual speed and the set speed during operation. The speed threshold interval here is the set speed. If the compressor has a rotor stuck fault, the speed of the compressor will become zero and will definitely not be within the speed threshold interval. Therefore, the present invention can determine whether the compressor has an out-of-step fault based on whether the actual speed exceeds the speed threshold interval.

[0119] The number of times the compressor has a loss of step failure mentioned above can be set according to the number of times the actual speed of the compressor is detected. Each time the actual speed of the compressor exceeds the speed threshold range, a loss of step failure is recorded. The present invention can well record the number of times the compressor has a loss of step failure based on this method, and then use it to judge whether the preset fault conditions are met.

[0120] The present invention utilizes the above-mentioned overcurrent fault detection and out-of-step fault detection methods to respectively obtain the number of out-of-step faults that occur within the first preset time and whether an overcurrent fault occurs before the out-of-step fault occurs, thereby determining whether the compressor fault information meets the preset fault conditions.

[0121] In addition, since the compressor rotor state detection method in the air-conditioning system proposed in the present invention needs to be performed under low-temperature heating conditions, the present invention also provides a judgment logic for the low-temperature heating condition, which is as follows:

[0122] Detect the ambient temperature of the air conditioning system and determine whether the ambient temperature is lower than the low temperature threshold;

[0123] If so, the operating mode of the air conditioning system is detected;

[0124] When the air-conditioning system is in the heating mode, it is determined that the air-conditioning system is operating in a low-temperature heating condition.

[0125] Based on this configuration, the present invention can ensure that the air-conditioning system enters a low-temperature heating operating condition, thereby ensuring the accuracy of the above-mentioned compressor rotor stuck judgment.

[0126] Based on the above method for detecting the state of a compressor rotor in an air-conditioning system, the present invention further proposes an air-conditioning system, which has the above method for detecting the state of a compressor rotor in an air-conditioning system.

[0127] To achieve the above-mentioned detection of the compressor rotor status, the air conditioning system has at least the following modules:

[0128] Detection module: It is used to detect the operating high pressure of the air-conditioning system, the operating low pressure of the air-conditioning system, the exhaust temperature of the air-conditioning system, the instantaneous current of the compressor, and the actual speed of the compressor;

[0129] a judgment module for judging whether the compressor has an overcurrent fault based on the instantaneous current of the compressor and recording the number of overcurrent faults; judging whether the compressor has a step-out fault based on the actual speed of the compressor and recording the number of step-out faults; and judging whether the compressor has a rotor stuck fault by calculating a pressure difference based on the operating high pressure and the operating low pressure of the air-conditioning system and combining it with the exhaust temperature of the air-conditioning system;

[0130] The main control module is used to integrate the information of the detection module and the judgment module, and perform corresponding control on the compressor, such as shutting down, maintaining operation, adjusting the actual speed, etc.

[0131] According to the above configuration, the air-conditioning system proposed in the present invention can execute the compressor rotor state detection method in the air-conditioning system as described above, thereby accurately locating the compressor fault position.

[0132] In summary, compared with the prior art, the present invention has at least the following beneficial effects:

[0133] The compressor rotor status detection method proposed in the present invention can determine whether the compressor has a rotor stuck problem based on the operating parameters of the air-conditioning system, and then accurately locate the compressor fault location, thereby improving subsequent maintenance efficiency.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting the state of a compressor rotor in an air-conditioning system, characterized in that: include: When the air conditioning system is operating in a low-temperature heating condition, real-time monitoring of compressor fault information; determining whether the fault information of the compressor meets a preset fault condition, and if so, determining the rotor state of the compressor according to the operating parameters of the air-conditioning system; The fault information of the compressor includes: the number of times the compressor has experienced overcurrent faults and out-of-step faults; Determining whether the fault information of the compressor meets a preset fault condition includes: Determine whether the number of times the compressor has experienced out-of-step failures within a first preset time has reached a preset number; If so, when an overcurrent fault exists before the compressor loses step fault, it is determined that the fault information of the compressor meets the preset fault condition.

2. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 1, wherein: The operating parameters of the air-conditioning system include: the operating high pressure of the air-conditioning system, the operating low pressure of the air-conditioning system, and the exhaust temperature of the air-conditioning system; Determining the rotor state of the compressor according to the operating parameters of the air conditioning system includes: Calculating a pressure difference between an operating high pressure of the air conditioning system and an operating low pressure of the air conditioning system, and determining whether the pressure difference is less than a preset threshold; If so, determining whether the exhaust temperature of the air conditioning system rises within a second preset time; When the exhaust temperature of the air-conditioning system does not rise within a second preset time, it is determined that the rotor of the compressor is stuck.

3. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 2, wherein: When the pressure difference is greater than the preset threshold or the exhaust temperature of the air-conditioning system rises within a second preset time, it is determined that a control failure problem occurs in the compressor.

4. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 1, wherein: Before real-time monitoring of compressor fault information, it also includes: Detecting the ambient temperature of the air conditioning system and determining whether the ambient temperature is less than a low temperature threshold; If so, detecting the operating mode of the air conditioning system; When the air-conditioning system is in a heating mode, it is determined that the air-conditioning system is operating in a low-temperature heating condition.

5. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 1, wherein: The method for detecting an overcurrent fault in the compressor comprises: monitoring the instantaneous current of the compressor in real time, and determining whether the instantaneous current of the compressor exceeds a current threshold; If so, it is determined that an overcurrent fault occurs in the compressor.

6. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 1, wherein: The method for detecting a compressor out-of-step fault comprises: detecting an actual speed of the compressor during operation, and determining whether the actual speed exceeds a speed threshold range; If so, it is determined that the compressor has a step-out fault.

7. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 1, wherein: Before determining the rotor state of the compressor according to the operating parameters of the air-conditioning system, the method further includes: controlling the compressor to enter an open-loop drag mode.

8. The method for detecting the state of a compressor rotor in an air-conditioning system according to claim 7, wherein: The open-loop drag mode includes: A target frequency for the compressor is set, and an external current is applied to the compressor to make the compressor operate at the target frequency.

9. An air conditioning system, characterized in that: The air-conditioning system adopts the method for detecting the state of a compressor rotor in an air-conditioning system according to any one of claims 1 to 8.

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