Fault self-diagnosis method and device for motor and air conditioner

Abstract

The application relates to the technical field of air conditioners, and discloses a fault self-diagnosis method for a motor, which comprises the following steps: acquiring an actual motor temperature, the actual motor temperature comprising an actual bearing temperature and an actual winding temperature, the actual bearing temperature being obtained based on a bearing temperature model and motor input power and running efficiency, and the actual winding temperature being obtained based on a winding resistance; determining a motor early warning strategy in the case that the motor temperature meets a temperature early warning condition; and adjusting motor operation according to the motor early warning strategy to adjust the actual motor temperature. The method can realize real-time fault monitoring of the motor and improve the reliability and safety of motor operation. The application further discloses a fault self-diagnosis device for a motor and an air conditioner.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, for example to a method and device for fault self-diagnosis of a motor, and an air conditioner. BACKGROUND

[0002] At present, the fault self-diagnosis mode of the motor of the air conditioner is to detect the voltage and current, and the rotating speed of the motor in operation by the host computer. If the host computer finds that part or all of the above parameters are abnormal, a fault reminder is given. However, the existing air conditioner does not set a corresponding monitoring scheme for the motor winding temperature and the motor bearing temperature. Therefore, how to realize the fault monitoring of the motor winding temperature and the motor bearing temperature has become a technical problem to be solved urgently.

[0003] In order to realize the fault monitoring of motor winding temperature and motor bearing temperature, the related technology discloses a motor automatic detection protection method, which comprises the following steps: S1: the motor is powered on, the control box controls the motor to work, and the sensor starts to work; S2: when the motor rotor winding temperature sensor detects that the temperature Tz is greater than 45°, a motor starting signal is sent to the control box, and the control box starts the motor working time t0; S3: after the control box receives the motor starting signal, the real-time temperature of the rotor winding temperature sensor is recorded, and the front bearing temperature sensor and the rear bearing temperature sensor are started; S4: the control box records the real-time temperature of the front bearing temperature sensor as Tq, and records the real-time temperature of the rear bearing temperature sensor as Th; S5: the control box respectively monitors the rotor winding sensor temperature Tz, the front bearing temperature sensor temperature Tq and the rear bearing temperature sensor temperature Th, compares the rotor winding temperature sensor temperature Tz with the preset rotor maximum temperature T1, compares the front bearing temperature sensor temperature Tq and the rear bearing temperature sensor temperature Th with the bearing maximum temperature T2 respectively, and controls the motion state of the motor through the motor drive chip according to the following conditions: (5.1) when 45° < Tz≤ T1, the motor works normally, and the maximum rotating speed ωmax is output; (5.2) when Tz > T1, the control box controls the unloading part of the motor output end to work through the motor drive chip, so that the motor output end is disconnected from the load; at the same time, the control box controls the motor to output low rotating speed ωmin through the motor drive chip; (5.2.1) when Tz > T1, the control box sends an abnormal alarm of the motor to the staff; (5.2.1.1) the staff checks the motor, judges that the motor is normal or no abnormality is found, controls the unloading part to stop working through the control box, the motor output end is connected with the load again, and after the connection is restored, the control box controls the motor to restore the maximum rotating speed ωmax through the motor drive chip; (5.2.1.2) the staff checks the motor, finds the abnormality, and controls the motor to be powered off through the control box, and controls the unloading part to stop working through the control box.(5.3) when Tq≤ T2, the motor works normally; (5.4) when Tq > T2, the control box judges that the front bearing temperature is abnormal, and controls the motor drive chip to power off the motor; (5.5) when Th≤ T2, the motor works normally; (5.6) when Th > T2, the control box judges that the front bearing temperature is abnormal, and controls the motor drive chip to power off the motor.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0005] The related art needs to add rotor winding temperature sensors and bearing temperature sensors to detect winding temperature values and bearing temperature values respectively, which not only increases the complexity of the hardware configuration, but also complicates the hardware structure of the fault detection system, and only when the winding temperature value and / or the bearing temperature value is abnormal can it be confirmed that a fault has occurred. Thus, the motor fault diagnosis has a lag, reducing the reliability of the motor operation.

[0006] It should be noted that the information disclosed in the above BACKGROUND section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0007] To provide a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to determine key / important components or delineate the scope of protection of these embodiments, but as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a method, device and air conditioner for self-diagnosis of motor faults, to monitor the motor in real time and improve the reliability and safety of the motor operation.

[0009] In some embodiments, the method comprises: obtaining an actual motor temperature, the actual motor temperature comprising an actual bearing temperature and an actual winding temperature, the actual bearing temperature being obtained based on a bearing temperature model and motor input power and operating efficiency, and the actual winding temperature being obtained based on a winding resistance value; determining a motor warning strategy if the motor temperature satisfies a temperature warning condition; and adjusting the motor operation according to the motor warning strategy to adjust the actual motor temperature.

[0010] In some embodiments, the motor temperature satisfying the temperature warning condition is determined in the following manner: obtaining a change trend of a temperature difference value within a first preset time period; obtaining a first number of times that the temperature difference value is higher than a temperature difference threshold value within the first preset time period if the change trend indicates that the temperature difference value is continuously increasing; and determining that the motor temperature satisfies the temperature warning condition if the first number of times is greater than a first number threshold value; wherein the temperature difference value represents a difference between the motor temperature and a preset upper temperature threshold value.

[0011] In some embodiments, adjusting the motor operation according to the motor warning strategy comprises: adjusting the current rotating speed to reduce the rotating speed within a preset rotating speed range to reduce the winding temperature; and / or adjusting the unit load to reduce the winding temperature and the bearing temperature.

[0012] In some embodiments, further comprising: in the case that the motor temperature does not satisfy the pre-warning condition, obtaining an electric field parameter value of the motor; and in the case that the electric field parameter value satisfies an electric field pre-warning condition, adjusting the operation of the motor according to a motor pre-warning strategy.

[0013] In some embodiments, the electric field parameter value satisfying the electric field pre-warning condition is determined in the following manner: obtaining a second number of times that the electric field difference value is higher than an electric field difference value threshold in a second preset time period; and in the case that the second number of times is greater than a second number of times threshold, determining that the electric field parameter value satisfies the temperature pre-warning condition; wherein the electric field difference value represents a difference between the electric field parameter value and a preset upper limit threshold of the electric field, and the electric field parameter value comprises a motor voltage or a motor current.

[0014] In some embodiments, obtaining the actual bearing temperature comprises: obtaining a motor input power and a motor operation efficiency; obtaining a motor heat generation according to the motor input power and the motor operation efficiency; obtaining an actual bearing temperature rise value according to the motor heat generation and a bearing temperature model, the bearing temperature model representing a correlation between the motor heat generation and the bearing temperature rise value; and obtaining the actual bearing temperature according to a current environmental temperature and the actual bearing temperature rise value.

[0015] In some embodiments, the motor heat generation is obtained according to the motor input power and the motor operation efficiency, comprising: obtaining a motor heat power P t according to P t = P * (1 - η), wherein P represents the motor input power, η represents the motor operation efficiency, and P t represents the motor heat power; and obtaining the motor heat generation Q by multiplying the motor heat power P t and a cumulative operation time t.

[0016] In some embodiments, the actual winding temperature is obtained in the following manner: controlling the motor to start under a test environmental temperature; obtaining a test parameter value when the motor is normally operated after starting, the test parameter value comprising a test voltage and a test current, a test winding temperature, a test bearing temperature, a test pre-warning voltage, and a test pre-warning current; constructing a correlation between a winding resistance value and a winding temperature by using a preset model to generate a winding resistance value temperature model under the test environmental temperature and the test parameter; and obtaining the actual winding temperature according to the winding resistance value temperature model and an actual winding resistance value.

[0017] In some embodiments, a device comprises a processor and a memory storing program instructions, the processor being configured to execute a method for self-diagnosis of a motor fault when running the program instructions.

[0018] In some embodiments, an air conditioner comprises: an air conditioner body comprising a motor; and a device for self-diagnosis of a motor fault as described above, which is installed in the air conditioner body.

[0019] The method, device and air conditioner for fault self-diagnosis of a motor provided by the embodiments of the present disclosure can achieve the following technical effects.

[0020] The embodiments of the present disclosure obtain the actual bearing temperature based on the bearing temperature model and the motor input power and operating efficiency, and obtain the winding temperature based on the winding resistance, without adding bearing temperature sensors and rotor winding temperature sensors to detect the winding temperature value and the winding temperature value, thereby reducing the complexity of the hardware configuration of the motor. Meanwhile, after obtaining the actual bearing temperature and the actual winding temperature, the embodiments of the present disclosure determine the motor warning strategy when the motor temperature meets the temperature warning condition, and adjust the operation of the motor according to the motor warning strategy, thereby achieving accurate adjustment of the actual bearing temperature and the actual winding temperature value. In this way, the embodiments of the present disclosure can obtain the actual bearing temperature based on the bearing temperature model and the actual winding temperature based on the winding length, can accurately predict the actual motor temperature value, and can timely adjust the operation of the motor according to the motor warning strategy, can perform real-time fault monitoring on the running motor, and can improve the reliability and safety of the operation of the motor.

[0021] The foregoing general description and the following description are only exemplary and explanatory, and are not intended to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute a limitation on the embodiments, elements with the same reference numerals in the drawings are shown as similar elements, the drawings do not constitute a proportional limitation, and wherein:

[0023] Figure 1 is a schematic diagram of a method for fault self-diagnosis of a motor provided by the embodiments of the present disclosure;

[0024] Figure 2 is a schematic diagram of another method for fault self-diagnosis of a motor provided by the embodiments of the present disclosure;

[0025] Figure 3 is a schematic diagram of another method for fault self-diagnosis of a motor provided by the embodiments of the present disclosure;

[0026] Figure 4 is a schematic diagram of another method for fault self-diagnosis of a motor provided by the embodiments of the present disclosure;

[0027] Figure 5 is a schematic diagram of a device for fault self-diagnosis of a motor provided by the embodiments of the present disclosure;

[0028] Figure 6 is a schematic diagram of an air conditioner provided by the embodiments of the present disclosure. DETAILED DESCRIPTION

[0029] In order to enable more detailed understanding of the features and technical contents of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure is described in detail below, and the attached drawings are used for reference only, and are not used to limit the embodiments of the present disclosure. In the following technical description, in order to facilitate explanation, through multiple details, a sufficient understanding of the disclosed embodiments is provided. However, one or more embodiments can still be implemented without these details. In other cases, in order to simplify the drawings, well-known structures and devices can be simplified.

[0030] The terms "first", "second", and the like in the description and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0031] Unless otherwise specified, the term "multiple" means two or more.

[0032] In the embodiments of the present disclosure, the character " / " represents a "or" relationship between the objects before and after it. For example, A / B represents: A or B.

[0033] The term "and / or" is a description of the association between objects, which means that there can be three relationships. For example, A and / or B, which means: A or B, or, A and B, three relationships.

[0034] The term "corresponding" can refer to an association or binding relationship, A corresponding to B means that there is an association or binding relationship between A and B.

[0035] In combination Figure 1 As shown, the embodiments of the present disclosure provide a fault self-diagnosis method for a motor, comprising:

[0036] S01, the processor acquires the actual motor temperature, the actual motor temperature including the actual bearing temperature and the actual winding temperature, the actual bearing temperature being obtained based on the bearing temperature model and the motor input power and the running efficiency, and the actual winding temperature being obtained based on the winding resistance.

[0037] S02, the processor determines the motor warning strategy when the motor temperature meets the temperature warning condition.

[0038] S03, the processor adjusts the motor operation according to the motor warning strategy to adjust the actual motor temperature.

[0039] With the method for fault self-diagnosis of the motor provided in the embodiment of the present disclosure, the actual bearing temperature is obtained based on the bearing temperature model and the motor input power and operation efficiency, and the winding temperature is obtained based on the winding resistance, without adding bearing temperature sensors and rotor winding temperature sensors to detect the bearing temperature value and the winding temperature value, thereby reducing the complexity of the hardware configuration of the motor. Meanwhile, after obtaining the actual bearing temperature and the actual winding temperature, when the motor temperature meets the temperature warning condition, the motor warning strategy is determined and the operation of the motor is adjusted according to the motor warning strategy, so as to accurately adjust the actual bearing temperature and the actual winding temperature value. In this way, the actual bearing temperature can be obtained based on the bearing temperature model and the actual winding temperature can be obtained based on the winding length, the actual motor temperature value can be accurately predicted, and the operation of the motor can be adjusted in time according to the motor warning strategy, so that the running motor can be monitored in real time, and the reliability and safety of the motor operation are improved.

[0040] It should be noted that the embodiment of the present disclosure can be applied to the power-on stage of the motor, and can also be applied to the running stage of the motor. In addition, the execution subject of the embodiment of the present disclosure is a processor, which can be configured in an air conditioner or a server in communication connection with the air conditioner. The embodiment of the present disclosure can not be specifically limited.

[0041] Optionally, in combination with Figure 2 , the processor determines that the motor temperature meets the temperature warning condition in the following manner:

[0042] S11, the processor obtains the change trend of the temperature difference value in the first preset time length.

[0043] In this step, the processor obtains the change trend of the temperature difference value in the first preset time length, including: the processor periodically obtains the motor temperature values T N , T w1 ,... T w2 at different times t1, t2,... t wN in the first preset time length according to a sampling period P; the processor obtains a preset upper temperature threshold T wthre ; the processor obtains the temperature difference values ΔT1, ΔT2,... ΔT N at different times in the first preset time length by subtracting T wthre from the motor temperature values at different times; and the processor obtains the change trend of the temperature difference value in the first preset time length according to the temperature difference values ΔT1, ΔT2,... ΔT N at different times. Wherein, ΔT1=T w1 -T wthre , ΔT2=T w2 -T wthre , ΔT N =TwN -T wthre The sampling period P represents the time difference between any adjacent time points. N represents the number of sampled motor temperature values within the first preset time period. It should be noted that the specific value of N can be set according to the operation of the motor. The embodiments of the present disclosure can not be limited in this regard.

[0044] In S12, the processor obtains a first number of times that the temperature difference value is higher than a temperature difference value threshold within the first preset time period, in a case where the change trend indicates that the temperature difference value continues to increase.

[0045] In S13, the processor determines that the motor temperature satisfies the temperature warning condition in a case where the first number of times is greater than a first number of times threshold. The first number of times threshold can be 10 or 20, or other values.

[0046] The temperature difference value represents the difference between the motor temperature and a preset upper temperature threshold. The preset upper temperature threshold is the temperature range corresponding to the normal operation of the motor. When the motor temperature is the actual bearing temperature, the preset upper temperature threshold is the bearing temperature range corresponding to the normal operation of the motor. When the motor temperature is the actual winding temperature, the preset upper temperature threshold is the winding temperature range corresponding to the normal operation of the motor.

[0047] In this way, the embodiments of the present disclosure obtain the change trend of the temperature difference value within the first preset time period. If the change trend indicates that the temperature difference value of the motor temperature gradually increases, the first number of times that the temperature difference value is higher than the temperature difference value threshold within the first preset time period is obtained. If the first number of times is greater than the first number of times threshold, it is determined that the abnormal accumulation number is high, and it is determined that the motor temperature satisfies the temperature warning condition. At the same time, it can be accurately predicted that the motor will fail in subsequent operation, and a warning operation is needed. In this way, the embodiments of the present disclosure can determine whether the motor temperature satisfies the temperature warning condition according to the deviation between the winding temperature and the preset upper temperature threshold of the winding temperature range and whether the abnormal accumulation number reaches the set first number of times threshold, realize real-time fault monitoring of the motor, and ensure that the motor can operate reliably and stably.

[0048] As an example, the determining that the motor temperature satisfies the temperature warning condition comprises: simultaneously satisfying two conditions, the first condition is: obtaining a change trend of a temperature difference value of the actual bearing temperature in a first preset time period; in a case where the change trend indicates that the temperature difference value of the actual bearing temperature continuously increases, obtaining a third number of times that the temperature difference value of the actual bearing temperature is higher than a temperature difference value threshold in the first preset time period; the third number of times is greater than a first number of times threshold. The second condition is: obtaining a change trend of a temperature difference value of the actual winding temperature in the first preset time period; in a case where the change trend indicates that the temperature difference value of the actual winding temperature continuously increases, obtaining a fourth number of times that the temperature difference value of the actual winding is higher than the temperature difference value threshold in the first preset time period; the fourth number of times is greater than the first number of times threshold.

[0049] Optionally, the processor determines that the motor temperature does not satisfy the temperature warning condition in a case where the first number of times is less than or equal to the first number of times threshold. In this way, if the first number of times is less than or equal to the first number of times threshold, it indicates that the winding temperature or the bearing temperature of the motor occasionally appears abnormally, which can be caused by fluctuations in the unit load or fluctuations in the power grid, and at this time, no warning is needed. The unit represents the entire air conditioner.

[0050] Optionally, the processor adjusts the motor operation according to the motor warning strategy, comprising:

[0051] The processor adjusts the current rotating speed to operate within a preset rotating speed range to reduce the winding heat and reduce the winding temperature; and / or,

[0052] The processor adjusts the unit load to reduce the winding temperature and the bearing temperature.

[0053] In this way, when the motor temperature satisfies the temperature warning condition, the disclosed embodiment determines the motor warning strategy, and then adjusts the current rotating speed of the motor to operate within a preset rotating speed range, so as to reduce the winding heat and reduce the winding temperature. At the same time, the disclosed embodiment can also adjust the unit load, so as to reduce the winding temperature and the bearing temperature, to avoid the unit rotating speed being too high to cause the motor to stop during operation or to avoid the motor continuously operating in a low-efficiency rotating speed range to cause serious heating, even to avoid the situation of bearing seizure or winding burning, and to ensure the reliability and safety of the motor operation.

[0054] In combination with Figure 3 The disclosed embodiment also provides a fault self-diagnosis method for a motor, comprising:

[0055] S21, the processor obtains an actual motor temperature, the actual motor temperature comprising an actual bearing temperature and an actual winding temperature.

[0056] S22, the processor determines a motor warning strategy in a case where the motor temperature satisfies a temperature warning condition.

[0057] S23, the processor adjusts the motor operation according to the motor warning strategy to adjust the actual motor temperature.

[0058] S24, the processor obtains an electric field parameter value of the motor in a case where the motor temperature does not satisfy the warning condition.

[0059] S25, the processor adjusts the motor operation according to the motor warning strategy in a case where the electric field parameter value satisfies an electric field warning condition.

[0060] By using the fault self-diagnosis method for the motor provided in the embodiments of the present disclosure, the embodiments of the present disclosure determine the motor warning strategy and adjust the operation of the motor according to the motor warning strategy when the motor temperature satisfies the temperature warning condition after obtaining the actual bearing temperature and the actual winding temperature, so as to accurately adjust the actual bearing temperature and the actual winding temperature. In a case where the motor temperature does not satisfy the warning condition, the electric field parameter value of the motor is obtained, and the motor operation is adjusted according to the motor warning strategy in a case where the electric field parameter value does not satisfy the electric field warning condition, so as to avoid the situation that the motor continuously runs at high speed due to the motor voltage and the motor current exceeding the limit value, and the motor is seriously heated, and even the winding is burned, thereby ensuring the reliability and safety of the motor operation.

[0061] Optionally, the processor determines that the electric field parameter value satisfies the electric field warning condition in the following manner:

[0062] The processor obtains a second number of times that the electric field difference value is higher than the electric field difference threshold value within a second preset time length.

[0063] The processor determines that the electric field parameter value satisfies the temperature warning condition in a case where the second number of times is greater than a second number of times threshold value.

[0064] The electric field difference value represents a difference between the electric field parameter value and a preset upper limit threshold value of the electric field, and the electric field parameter value includes the motor voltage or the motor current.

[0065] In this way, the second number of times that the electric field difference value is higher than the electric field difference value threshold in the second preset time period is obtained. If the second number of times is greater than a second number of times threshold, it is determined that the abnormal cumulative number of times of the voltage value or the current value reaches the set second number of times threshold. Although the motor temperature does not satisfy the early warning condition, the electric field parameter value satisfies the electric field early warning condition. At this time, if the operation of the motor is not timely warned and adjusted, it is extremely likely that the motor voltage or the motor current exceeds the limit value and the winding is burned. Therefore, the motor running winding temperature, bearing temperature, and motor voltage and motor current multiple parameters of the motor are cooperated to predict the abnormal situation or fault situation that may occur, and the running situation of the motor is accurately known, which is beneficial to realize the reliable and stable operation of the motor.

[0066] Optionally, in combination with Figure 4 As shown in the figure, the processor obtains the actual bearing temperature, comprising:

[0067] S31, the processor obtains the motor input power and the motor running efficiency.

[0068] S32, the processor obtains the motor heat generation according to the motor input power and the motor running efficiency.

[0069] S33, the processor obtains the actual bearing temperature rise value according to the motor heat generation and the bearing temperature model, and the bearing temperature model represents the correlation between the motor heat generation and the bearing temperature rise value.

[0070] In this step, the bearing temperature model is associated with the motor model and the motor running environment. The processor obtains the test environment temperature where the motor currently locates; the processor obtains a plurality of groups of data under the above test environment temperature, each group of data comprising the motor heat generation and the bearing temperature rise value; and the processor obtains the bearing temperature model under the test environment temperature by fitting a plurality of groups of data. The fitting method includes least square method and the like. It can be understood that the bearing temperature model of different test environment temperatures can be obtained by the above method.

[0071] On this basis, the processor obtains the current environment temperature and matches to obtain the bearing temperature model corresponding to the current environment. In this way, the actual bearing temperature rise value is obtained.

[0072] S34, the processor obtains the actual bearing temperature according to the current environment temperature and the actual bearing temperature rise value.

[0073] In this step, the processor obtains the actual bearing temperature according to the current environment temperature and the actual bearing temperature rise value, comprising: the processor adds the current environment temperature and the actual bearing temperature rise value to obtain the sum value, and takes the sum value as the actual bearing temperature.

[0074] In this way, the motor input power and the motor operation efficiency are obtained, the motor heat generation is obtained according to the motor input power and the motor operation efficiency, the actual bearing temperature rise value is obtained according to the motor heat generation and the bearing temperature model, and the actual bearing temperature is obtained according to the current environment temperature and the actual bearing temperature rise value. In this way, the bearing temperature sensor is not needed to detect the bearing temperature, the complexity of the motor hardware configuration is reduced, the influence of the abnormal detection or fault detection caused by the detection of the bearing temperature sensor is reduced, and the accuracy of the bearing temperature value calculation is improved.

[0075] Optionally, the processor obtains the motor heat generation according to the motor input power and the motor operation efficiency, and the obtaining includes:

[0076] The processor obtains the motor heat power P according to P t = P * (1-η). t .

[0077] The processor obtains the motor heat generation Q by multiplying the motor heat power P t and the cumulative running time t.

[0078] P represents the motor input power, η represents the motor operation efficiency, P t represents the motor heat power.

[0079] In this way, the motor heat power P t can be accurately calculated according to the motor operation efficiency and the motor input power during the motor operation, the motor heat generation Q is obtained by multiplying the motor heat power P t and the cumulative running time t, the accuracy of the motor heat generation calculation is improved, the accuracy of the actual bearing temperature calculation is improved, and the real-time performance and the accuracy of the motor abnormal situation or fault situation detection are improved.

[0080] Optionally, the processor obtains the actual winding temperature, and the obtaining includes:

[0081] The processor controls the motor to start under the test environment temperature, and obtains test parameter values when the motor normally operates after starting, the test parameter values including test voltages and test currents, a test winding temperature, a test bearing temperature, a test early warning voltage, and a test early warning current.

[0082] The processor constructs a relationship between a winding resistance value and a winding temperature by using a preset model to generate a winding resistance value temperature model under the test environment temperature and the test parameter.

[0083] The processor obtains the actual winding temperature according to the winding resistance value temperature model and an actual winding resistance value.

[0084] The preset model includes a finite element simulation model and a characteristic curve.

[0085] In this way, the rotor winding temperature sensor does not need to be added to detect the winding temperature value, and the complexity of the motor hardware configuration is reduced. The actual winding temperature is obtained by constructing a model, and the accuracy is higher than that of hardware detection.

[0086] In combination Figure 5 As shown in the drawings, the embodiment of the present disclosure provides a fault self-diagnosis device 70 for a motor, which includes a processor 700 and a memory 701. Optionally, the device 70 can also include a communication interface 702 and a bus 703. The processor 700, the communication interface 702, and the memory 701 can communicate with each other through the bus 703. The communication interface 702 can be used for information transmission. The processor 700 can call the logical instructions in the memory 701 to execute the fault self-diagnosis method for the motor in the above-mentioned embodiments.

[0087] In addition, the logical instructions in the memory 701 described above can be implemented in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium.

[0088] The memory 701 is a kind of computer readable storage medium, which can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 700 executes the program instructions / modules stored in the memory 701, thereby performing function applications and data processing, i.e. implementing the fault self-diagnosis method for the motor in the above-mentioned embodiments.

[0089] The memory 701 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required by a function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 701 can include a high-speed random access memory, and can also include a non-volatile memory.

[0090] In combination Figure 6As shown, the embodiment of the present disclosure provides an air conditioner 100, comprising: an air conditioner body, and the above-mentioned fault self-diagnosis device 70 for the motor. The fault self-diagnosis device 70 for the motor is installed on the air conditioner body. The installation relationship described herein is not limited to being placed inside the product body, but also includes installation connection with other components of the air conditioner 100, including but not limited to physical connection, electrical connection or signal transmission connection, etc. Those skilled in the art can understand that the fault self-diagnosis device 70 for the motor can be adapted to a feasible air conditioner body, thereby realizing other feasible embodiments.

[0091] The embodiment of the present disclosure provides a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are configured to execute the above-mentioned fault self-diagnosis method for the motor.

[0092] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes one or more instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, such as a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, etc. various media that can store program codes.

[0093] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0094] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0095] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to apparatuses, devices, etc.), can be implemented in other manners. For example, the described apparatus embodiments can be implemented only in a form of a logical function, and can be implemented by using a manner such as software (for example, application program) or the like. In some embodiments, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or indirect coupling or communication connection between different components can be implemented by using some interfaces, and a combination of indirect coupling and direct coupling can be used. The integrated display or functional division can be physical or logical, and can be any other form. Some or all of the units can be selected according to actual needs to implement the embodiments. In addition, the units in the embodiments disclosed herein can be integrated into one processing unit, or each unit can exist alone physically, or two or more units can be integrated into one unit.

[0096] The flowcharts and block diagrams in the drawings show the possible implementation architectures, functions and operations of the system, method and computer program product according to the embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment or a part of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions noted in the blocks can occur in an order different from that noted in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the drawings, the operations or steps corresponding to different blocks can also occur in an order different from that disclosed in the descriptions, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. Each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for self-diagnosis of a fault of an electric machine, characterized in that, The method comprises: obtaining an actual motor temperature, the actual motor temperature comprising an actual bearing temperature and an actual winding temperature; determining a motor warning strategy when the motor temperature meets a temperature warning condition; adjusting motor operation according to the motor warning strategy to adjust the actual motor temperature; wherein the actual bearing temperature is obtained by: obtaining motor input power and motor operation efficiency; obtaining motor heat generation according to the motor input power and the motor operation efficiency; obtaining an actual bearing temperature rise value according to the motor heat generation and a bearing temperature model, the bearing temperature model representing a correlation between the motor heat generation and the bearing temperature rise value; obtaining the actual bearing temperature according to the current environmental temperature and the actual bearing temperature rise value. The actual winding temperature is obtained by: controlling the motor to start under a test environmental temperature, and obtaining test parameter values when the motor normally operates after starting, the test parameter values comprising test voltage and test current, test winding temperature, test bearing temperature, test warning voltage, and test warning current; constructing a correlation between winding resistance and winding temperature to generate a winding resistance temperature model using a preset model under the test environmental temperature and the test parameter values; obtaining the actual winding temperature according to the winding resistance temperature model and the actual winding resistance.

2. The method of claim 1, wherein, The motor temperature meets the temperature warning condition in the following manner: obtaining a change trend of a temperature difference value within a first preset time period; obtaining a first number of times when the temperature difference value is higher than a temperature difference value threshold within the first preset time period when the change trend indicates that the temperature difference value continuously increases; determining that the motor temperature meets the temperature warning condition when the first number of times is greater than a first number of times threshold. The actual winding temperature is obtained by:

3. The method of claim 1, wherein, adjusting the current speed to make the speed operate within a preset speed range to reduce winding heat generation and reduce the winding temperature; and / or adjusting the unit load to reduce the winding temperature and the bearing temperature. The method further comprises:

4. The method according to any one of claims 1 to 3, characterized in that, obtaining motor electric field parameter values when the motor temperature does not meet the warning condition; adjusting motor operation according to the motor warning strategy when the electric field parameter values meet an electric field warning condition. The electric field parameter values meet the electric field warning condition in the following manner:

5. The method of claim 4, wherein, obtaining a second number of times when an electric field difference value is higher than an electric field difference value threshold within a second preset time period; determining that the electric field parameter values meet the temperature warning condition when the second number of times is greater than a second number of times threshold. The electric field difference value represents a difference between the electric field parameter values and a preset electric field upper limit threshold, and the electric field parameter values comprise motor voltage or motor current. The motor heat generation is obtained according to the motor input power and the motor operation efficiency by:

6. The method of claim 1, wherein, obtaining a bearing temperature model by: According to P t =P*(1-η), the motor heating power P t ; The motor heat power P t The motor heat power P is multiplied by the cumulative running time t to obtain the motor heat quantity Q. where P represents the input power of the motor, η represents the operating efficiency of the motor, and P t represents the heat generation power of the motor.

7. The method of claim 1, wherein, obtaining a test environmental temperature in which the motor currently operates; obtaining a plurality of sets of data under the test environmental temperature, each set of data comprising motor heat generation and bearing temperature rise value; obtaining the bearing temperature model under the test environmental temperature by fitting the plurality of sets of data. The processor is configured to execute the program instructions to perform the fault self-diagnosis method for the motor according to any one of claims 1 to 7 when the program instructions are executed.

8. A fault self-diagnosis device for an electric machine, comprising a processor and a memory storing program instructions, characterized in that, The air conditioner comprises:

9. An air conditioner characterized by comprising: an air conditioner body comprising a motor; ​ The self-diagnosis device for failure of the electric motor according to claim 8 is installed in the air conditioner body.

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