CN114518534A - Control method and controller - Google Patents

Abstract

The invention provides a control method and a controller, wherein the method comprises a fault detection step, the fault detection step can detect motor faults, and the fault detection step comprises the following steps: receiving a detection signal, and performing first-type fault judgment and/or second-type fault judgment at least according to the detection signal; the first type of fault judgment comprises the following steps: the method comprises the steps that after a control controller applies electric energy to any one group of two-phase coils in three-phase coils of a motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs; the second type of fault judgment comprises the following steps: after the controller is controlled to drive the motor at a preset frequency, a second parameter is obtained, and the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs; and prompting the corresponding fault according to the fault type. The method can automatically detect the fault and prompt the fault type.

Description

Control method and controller

Technical Field

The invention relates to the technical field of motors, in particular to a control method and a controller with a fault detection function.

Background

Various faults may occur in the use of household appliances such as air conditioners, refrigerators, washing machines, and the like. When a fault occurs, the control system of the electric appliance stops the operation of the motor and controls the indicator light to flash so as to remind maintenance personnel to check the fault of the system, thereby achieving the purpose of protecting the motor and the whole electric appliance system. However, as a core component of the system, there are many most common faults of the motor, including short circuit, open circuit, etc., and for a maintenance person, it is necessary to first determine the fault type of the motor, so as to perform more accurate maintenance.

Disclosure of Invention

In view of this, the present invention provides a control method and a controller, which can accurately and quickly determine a fault.

In order to achieve the purpose, the invention provides the following technical scheme:

a control method comprising a fault detection step capable of detecting a motor fault, the fault detection step comprising:

receiving a detection signal, and performing first fault judgment and/or second fault judgment at least according to the detection signal:

the first type fault judgment comprises the following steps:

the method comprises the steps that after a control controller applies electric energy to any one group of two-phase coils in three-phase coils of a motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs;

the second type of fault judgment comprises the following steps:

after the controller is controlled to drive the motor at a preset frequency, a second parameter is obtained, and the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs;

and prompting the corresponding fault according to the fault type.

The control method provided by the invention comprises a fault detection step, wherein the fault detection step can execute a first type fault judgment step and/or a second type fault judgment step of the motor according to the detection signal, so that whether the motor is in open circuit and/or short circuit and/locked rotor fault or not is detected, and the corresponding fault type is prompted, so that related personnel can learn the fault type.

A controller comprising a fault detection system capable of detecting a motor fault, the fault detection system comprising:

a signal receiving unit: the device can receive a detection signal and trigger a first type fault judgment unit and/or a second type fault judgment unit to work at least according to the detection signal:

the first-type fault judging unit: the method comprises the steps that after a controller can be controlled to apply electric energy to any one group of two-phase coils in three-phase coils of the motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs;

the second type fault judgment unit: the controller can be controlled to drive the motor at a preset frequency, and then a second parameter is obtained, wherein the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs;

a fault prompting unit: and corresponding faults can be prompted according to the fault types. .

The controller provided by the invention comprises a fault detection system, wherein the fault detection system comprises a signal receiving unit, a first type fault judgment unit and/or a second type fault judgment unit, and can detect whether the motor has an open circuit and/or a short circuit and/or a locked rotor fault and carry out corresponding prompt.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of a method for fault detection according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method for fault detection according to another embodiment of the present invention;

fig. 3 is a schematic structural diagram of a fault detection system according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a fault detection system according to another embodiment of the present invention;

fig. 5 is a schematic structural diagram of a controller according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, so that the above is the core idea of the present invention, and the above objects, features and advantages of the present invention can be more clearly understood. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The motor is used as a core component of systems such as an air conditioner, a washing machine, a refrigerator and the like, the most common faults include short circuit, open circuit and the like, and for maintenance personnel, the fault type of the motor needs to be judged firstly, and then the motor can be maintained more accurately. At present, the inventors found that: when the fault of the motor or the electric control device is determined through multimeter measurement, the measurement is troublesome, the household appliance comprising the motor needs to be disassembled, the electric control device needs to be taken out for confirmation, and the requirement on technical experience is high; when the LED lamp flickers to prompt a fault or the liquid crystal display displays a corresponding fault, the time consumption is long due to the fact that the household appliance needs to be started, certain risks exist for the reliability of the product, and the risk of damaging the motor also exists.

An embodiment of the present invention provides a control method for controlling motors of household appliances such as air conditioners, refrigerators, washing machines, and the like, the control method including a fault detection step, where the fault detection step is applied to detect a fault of the motor, as shown in fig. 1, and the fault detection step includes:

s101: receiving a detection signal, and performing first-class fault judgment and/or second-class fault judgment at least according to the detection signal;

s102: judging the first and/or second type of faults; specifically, the first-type fault judgment includes the following steps:

s103: and (3) fault prompting: and displaying the corresponding fault according to the fault type. The fault types comprise open-circuit faults, short-circuit faults and locked rotor faults, different prompts can be given according to different fault types, and different prompts can be given according to different fault type combinations; specifically, voice prompt, light or display screen prompt can be adopted, and the application does not limit the prompt. And corresponding prompt can be carried out, so that related personnel can know the fault type.

The first type fault judgment comprises the following steps:

the method comprises the steps that after a control controller applies electric energy to any one group of two-phase coils in three-phase coils of a motor, a first parameter is obtained, and the first parameter represents motor phase current; and comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs. When electric energy is applied to any group of two-phase coils of the motor, the corresponding two-phase coils can generate phase current corresponding to the electric energy, a first parameter can be obtained by sampling or calculating the phase current of the motor, and when the motor has no fault, the first parameter corresponds to the electric energy and is positioned near a certain value or in a certain range; when short-circuit fault occurs, the first parameter is larger than the value or the maximum value of the range; and when open circuit, the first parameter will be less than the value or the minimum value of the range; based on this, by comparing the first parameter with the current-related threshold, it can be determined whether an open circuit and/or short circuit fault has occurred in the motor.

The second type of fault judgment comprises the following steps:

after the controller is controlled to drive the motor at a preset frequency, a second parameter is obtained, and the second parameter represents the running frequency of the motor; and comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs. When the controller drives the motor at a preset frequency, if the motor has no locked-rotor fault, the motor can reach the preset frequency, and when the motor does not reach the preset frequency or does not reach the preset frequency within a certain set time, the locked-rotor of the motor can be judged.

In the embodiment provided by the present application, the fault detection step may be executed by an MCU (central processing unit), in this embodiment, the detection signal may be a fault detection trigger signal generated by the MCU, and after receiving the trigger detection signal, the first and/or second fault determination steps are executed; for example, the detection signal is generated and sent by an MCU of an AOC (application oriented control) of an upper computer, and the fault detection step is executed by an MOC (motor oriented control), in a specific embodiment, when a user needs to detect, the user can send a signal to be detected to the AOC, the AOC sends a detection signal to the MOC, and the MOC receives the detection signal, and then executes the first and/or second fault judgment steps to judge whether the motor has a fault; before starting the machine each time, the AOC sends a detection signal to the MOC, and then the MOC judges the first and/or second faults; only when no motor fault exists, the MOC can normally start the motor and control the motor; and the controller can also carry out standby self-checking, wherein the detection signal is a signal for representing the standby of the controller. The detection signal can also be realized by hardware, for example, by a key, the key is electrically connected to a data terminal of an MCU of the MOC, when the key works, a detection signal is generated and input to the MCU, and the MCU executes the first and/or second fault judgment steps according to the detection signal; specifically, a user or a maintenance person can operate the key, so that the motor fault judgment is realized, and the invariance caused by the fact that other testing equipment (such as a universal meter) needs to be used for detection is avoided. The fault detection step can be used for detecting the open circuit and/or short circuit of the motor, when the open circuit and/or short circuit fault needs to be detected at the same time, the short circuit fault is preferentially detected, and then the open circuit fault is detected; specifically, in another embodiment, the fault detection step includes a step of judging a first type of fault and a step of judging a second type of fault, wherein the first type of fault judgment includes a step of judging an open-circuit fault and a step of judging a short-circuit fault, so that the type of the motor fault can be accurately judged, and the motor fault is convenient to maintain.

Further, this application still provides an embodiment, not only can realize foretell motor fault detection, can also realize the power return circuit fault detection of controller, specifically, still include the following step in the fault detection step:

before the first type fault judgment and/or the second type fault judgment are carried out according to the detection signals, the third type fault judgment is carried out according to the detection signals,

the third type of fault judgment comprises the following steps:

controlling the controller to stand by to obtain a third parameter, wherein the third parameter represents the bus voltage of the controller; specifically, the controller is controlled to be in a standby state, and after the controller is powered on, the controller is temporarily not controlled to normally drive the motor, that is, the controller is controlled to be in a powered-on state but not in a loaded state. At this time, the bus voltage output by a PFC (power factor correction) circuit of the controller is within a certain voltage range, and if a power supply loop of the controller has a fault, the bus voltage deviates from the voltage range; this voltage range is related to the PFC circuit design and the input voltage.

Comparing the third parameter with a bus voltage related threshold value, and judging whether the bus voltage represented by the third parameter is in a standby working voltage range of the controller;

and if not, judging that the power supply loop of the controller has a fault.

Specifically, the judgment can be performed through the bus voltage obtained by sampling, for example, through resistance voltage division, the MCU directly detects the AD value of the bus voltage, where the AD value is the third parameter, and the third parameter corresponds to the bus voltage, and in this embodiment, the two are in a linear relationship; in one embodiment, if the input voltage of the controller and the device parameters in the PFC (Power Factor Correction) circuit are determined, the standby operating voltage range of the controller is fixed; and if the sampled bus voltage represented by the third parameter is out of the range, determining that a power supply circuit of the controller of the motor has a fault, and if the sampled bus voltage is in the range, determining that the power supply circuit of the controller of the motor has no fault.

In one embodiment, the fault detection method includes a first type fault judgment, a second type fault judgment and a third type fault judgment, where the first type fault judgment includes an open-circuit fault judgment and a short-circuit fault judgment, and preferably, each fault judgment sequence is as shown in fig. 2, and the power supply circuit fault judgment is performed first, then the short-circuit fault judgment is performed, then the open-circuit fault judgment is performed, and finally the locked rotor judgment is performed.

Further, in one embodiment, the control method not only includes the above fault detection step, but also includes a motor control step, and the motor control step can control the motor to normally operate. In this embodiment, whether a fault exists may be determined through the fault detection step, and a corresponding fault prompt may be performed. The control method provided by the embodiment not only has a motor operation control function, but also has a fault detection function, so that the motor is controlled to work after the motor is determined to have no fault, and the operation reliability of the motor is improved. By adding the fault detection step in the motor control method, the fault detection can be more intelligent, the system can conveniently carry out fault self-detection, and related personnel can conveniently acquire the fault type and facilitate subsequent maintenance.

Further, in one embodiment, applying electrical energy to any one of a set of two phase coils of a three phase coil of the motor includes applying a constant current. If three-phase coils of the motor comprise UVW three phases, two phases are used as a group of applied currents for conducting, in an actual embodiment, constant current conducting of any group of two-phase coils can be achieved by using a current closed-loop control principle, namely, constant currents are applied to UV, UW, VW, VU, WU and WV, and then three-phase currents of the motor are obtained through sampling or calculation so as to generate a first parameter; in this embodiment, comparing the first parameter with a current-related threshold, and determining whether a short-circuit fault occurs includes:

judging whether the first parameter corresponding to each group of two-phase coils exceeds a current protection threshold value, wherein the current protection threshold value represents the maximum current value of the motor;

if the first parameter corresponding to at least one group of two-phase coils exceeds the current protection threshold value, determining that the fault of the motor is a short-circuit fault; wherein the first parameter exceeds the current protection threshold, i.e. the phase current representing the motor is larger than the maximum current value of the motor, which may be set by the system, and is also a value representing that the motor has a short-circuit fault, such as 120% of the applied constant current.

Comparing the first parameter with a current-related threshold value, and judging whether an open-circuit fault occurs comprises the following steps:

judging whether the first parameter corresponding to each group of two-phase coils is in a first preset range, preferably, the first preset range represents 80-120% of the constant current;

and if not, judging that the fault of the motor is an open-circuit fault.

In this embodiment, if it is sequentially determined whether phase currents after the constant currents are conducted by the UV, UW, VW, VU, WU, and WV, that is, a first parameter exceeds a current protection threshold, if the first parameter corresponding to at least one set of two-phase coils exceeds the current protection threshold, it is determined that the fault of the motor is a short-circuit fault, and if the phase currents of the six sets of two-phase coils, that is, the first parameter does not exceed the current protection threshold, it is determined that the fault of the motor is not a short-circuit fault; further, the open-circuit fault is determined as follows:

judging whether a first parameter corresponding to each group of two-phase coils is in a first preset range, wherein the first preset range represents 80% -120% of the constant current;

if not, the fault of the motor is judged to be an open-circuit fault.

If the phase currents, namely the first parameters, are not within a first preset range representing the range of 80% -120% of the constant current, the fault of the motor is determined to be an open-circuit fault, and if the six groups of phase currents, namely the first parameters, are within the range of 80% -120% of the constant current, the fault of the motor is determined not to have the open-circuit fault.

In the embodiment of the present invention, a control system, such as an MCU (micro controller Unit), may detect an AD value of a voltage V at two ends of a sampling resistor Rs, and calculate a phase current, i.e., a first parameter I, according to a formula V + b I Rs, where coefficients a and b are obtained according to a hardware loop.

The control method provided by the embodiment of the application can control the motor to normally work and can also judge the fault of the motor, so that the control method can also be used for fault detection. Specifically, the fault detection may be performed before the motor operates normally, and the motor control step may be performed normally only when there is no fault. Or, in a certain time interval, when starting up, executing the fault detection step first and then executing the motor control step; the motor control step can be realized by a common motor control principle, such as SVPMW (Space Vector Pulse Width Modulation), and is not limited; of course, in the specific use process, the motor judgment can be performed only by using the fault detection step in the method, and if the fault is detected, the maintenance personnel can perform maintenance according to the specific fault type.

Further, in the second type of fault determining step, comparing the second parameter with a frequency-related threshold value, and determining whether a locked rotor fault occurs includes the steps of:

judging whether the second parameter reaches a target frequency value within preset time after the motor operates, wherein the target frequency value represents the preset frequency of the motor operation;

if not, the fault of the motor is judged to be a locked-rotor fault.

Specifically, the controller is controlled to control the motor to operate at a certain preset frequency, after the motor operates, the actual frequency of the motor can be obtained through direct sampling of a speed sensor in the motor or through calculation of a speed-sensorless specific algorithm, that is, a second parameter is obtained, the actual frequency within a preset time is judged, that is, the second parameter is obtained is judged, whether the second parameter reaches a target frequency value is judged, if not, the fault of the motor is determined to be a locked rotor fault, and if so, the fault of the motor is determined not to be a locked rotor fault. For example, if the target frequency value is 15Hz and the actual frequency value is 10Hz within a predetermined time of 10s, the motor fault is a locked-rotor.

In the embodiment of the present invention, a plurality of faults of the motor may be sequentially determined. Specifically, as shown in fig. 2, S201 may be entered first, whether the bus voltage represented by the third parameter is within the normal operating voltage range of the controller is determined, if not, the power supply circuit fault of the controller of the motor is determined, the corresponding fault name or code is displayed, and the determination process is ended, if yes, S202 is entered, whether the first parameter corresponding to each group of the two-phase coils exceeds the current protection threshold, if the first parameter corresponding to at least one group of the two-phase coils exceeds the current protection threshold, the fault of the motor is determined to be a short-circuit fault, the corresponding fault name or code is displayed, and the determination process is ended, if not, S203 is entered, whether the first parameter corresponding to each group of the two-phase coils is within a first preset range is determined, if not, the fault of the motor is determined to be an open-circuit fault, the corresponding fault name or code is displayed, and the determination process is ended, if yes, and S204, judging whether the second parameter reaches a target frequency value within preset time after the motor runs, if not, judging that the motor fault is a locked rotor fault, displaying a corresponding fault name or code and the like, ending the judging process, and if so, ending the process. Of course, the present invention does not limit the judgment order of the faults, and may be any number or combination of order faults.

The control method provided by the embodiment of the invention not only comprises a motor control step, but also comprises a fault detection step, wherein the fault detection step is used for automatically acquiring the parameters of the motor, and then judging the parameters simultaneously or sequentially by adopting different judgment conditions, wherein the judgment conditions correspond to the faults of the motor, so that the fault type of the motor can be accurately and quickly judged according to the judgment result.

Based on the control method, the embodiment of the present application further provides a controller, which can be applied to control motors of household appliances such as air conditioners, refrigerators, washing machines, and the like, and the controller includes a fault detection system, which can detect a fault of the motor, as shown in fig. 3, the fault detection system includes a signal receiving unit 10, a fault determination unit 11, and a fault prompt unit 12;

wherein, the signal receiving unit 10: the fault judging unit 11 can receive the detection signal and trigger the fault judging unit 11 to operate at least according to the detection signal, and the fault judging unit 11 further includes a first type fault judging unit 111 and/or a second type fault judging unit 112:

the first-type failure determination unit 111: the method comprises the steps that after a controller can be controlled to apply electric energy to any one group of two-phase coils in three-phase coils of the motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs;

the second-type failure determination unit 112: the controller can be controlled to drive the motor at a preset frequency, and then a second parameter is obtained, wherein the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs; in the embodiment, the second parameter can be obtained by directly sampling by a speed sensor in the motor or by calculating the actual frequency of the motor by a specific algorithm without the speed sensor.

Failure presentation unit 12: and corresponding faults can be prompted according to the fault types.

In the embodiments provided by the present application, the fault detection system may be partially or entirely integrated in an MCU (central processing unit), that is, the signal receiving unit 10, the fault determining unit 11, and the fault prompting unit 12 are fully or partially integrated in the MCU. It should be noted that the integration mainly includes integration of functional units defined by a software program, and may also include hardware components, that is, functions corresponding to the signal receiving unit 10, the fault determining unit 11, and the fault prompting unit 12 are mainly implemented by an MCU, for example, corresponding functions are executed by a program inside the MCU.

In this embodiment, the detection signal may be a detection signal generated by an MCU, and after the signal receiving unit 10 in the fault detection system receives the detection signal, the first-type fault determining unit 111 and/or the second-type fault determining unit 112 execute the first and/or second-type fault determining steps; for example, the fault detection trigger signal is generated and transmitted by an MCU of an Application Oriented Control (AOC) of an upper computer, and the fault detection system is integrated in an MOC (motor oriented control), for example, at least partially integrated in the MCU of the MOC.

In a specific embodiment, when a user needs to detect, the user may send a signal to be detected to the AOC, and the AOC sends a detection signal to the signal receiving unit 10 in the MOC, and after the signal receiving unit 10 receives the detection signal, the first-type fault determining unit 111 and/or the second-type fault determining unit work 112 first executes the first and/or second-type fault determining step to determine whether the motor has a fault; before starting the machine each time, after the AOC sends the detection signal to the MOC, the first-type fault judgment unit 111 and/or the second-type fault judgment unit work 112 performs the first-type and/or second-type fault judgment; only when no motor fault exists, the MOC can normally start the motor and control the motor; and the controller can also carry out standby self-checking, wherein the detection signal is a signal for representing the standby of the controller. The detection signal may also be implemented by hardware, for example, by a key, the key is electrically connected to a data terminal of an MCU of the MOC, the signal receiving unit 10 includes the data terminal of the MCU, when the key is operated, a detection signal is generated and input to the MCU, and the first type fault determining unit 111 and/or the second type fault determining unit 112 integrated in the MCU execute the first and/or second type fault determining steps according to the detection signal; specifically, a user or a maintenance person can operate the key, so that the motor fault judgment is realized, and the invariance caused by the fact that other testing equipment (such as a universal meter) needs to be used for detection is avoided. In a specific embodiment, for the convenience of the client, the corresponding fault type may be prompted by voice, or by light or a display screen, and the corresponding control information may be generated by the MCU and controls the corresponding voice, light or display, regardless of the voice prompt, or the light or the display screen. Similarly, the MCU may also generate corresponding prompt information, such as a fault code, and the corresponding staff may identify the fault type through the fault code. This is not limited in this application.

It should be noted that, in the embodiment of the present invention, if a fault occurs and a control system of a motor controls the motor to stop, a maintenance worker may send a detection signal to the control system, after the signal receiving unit 10 receives the detection signal, the fault determining unit operates to determine the fault, and then the fault prompting unit prompts the fault type.

Of course, the invention is not so limited and in other embodiments the controller further comprises a motor control system. The controller can detect the fault before the motor starts to operate, and the fault detection system sends an instruction to the motor control system after determining that the motor has no fault so as to enable the motor control system to start to work.

Further, in an embodiment, as shown in fig. 4, the failure determination unit 11 further includes a third type failure determination unit 113, and the signal receiving unit is further capable of receiving a detection signal and triggering the third type failure determination unit 113 to operate according to at least the detection signal:

the third-type failure determination unit 113: the controller can be controlled to work in a standby mode, and a third parameter is obtained and represents the bus voltage of the controller; comparing the third parameter with a bus voltage related threshold value, and judging whether the bus voltage represented by the third parameter is in a standby working voltage range of the controller; and if not, judging that the power supply loop of the controller has a fault.

In an embodiment, optionally, the first type fault determining unit includes:

an applied power control module: the controller can be controlled to apply electric energy to any one group of two-phase coils in three-phase coils of the motor, and the electric energy is constant current;

a first obtaining module: after the electric energy is applied, a first parameter can be obtained, and the first parameter represents the phase current of the motor;

a first judgment module: whether the first parameter corresponding to each group of two-phase coils exceeds a current protection threshold value or not can be judged, and the current protection threshold value represents the maximum current value of the motor; if the first parameter corresponding to at least one group of two-phase coils exceeds the current protection threshold value, determining that the fault of the motor is a short-circuit fault;

a second judging module: whether the first parameter corresponding to each group of two-phase coils is within a first preset range can be judged, and the first preset range represents 80% -120% of the constant current; and if not, judging that the fault of the motor is an open-circuit fault.

In an embodiment, optionally, the second type of fault determining unit includes:

a frequency control module: the controller can be controlled to drive the motor at a preset frequency;

a second obtaining module: the method comprises the steps that a second parameter can be obtained after a controller is controlled to drive a motor at a preset frequency, and the second parameter represents the running frequency of the motor;

a third judging module: whether the second parameter reaches a target frequency value within a preset time after the motor operates can be judged, and the target frequency value represents a preset frequency of the motor operation; and if not, judging that the fault of the motor is a locked rotor fault.

In the above embodiment, optionally, the controller further includes a detection key, and the detection key is connected to the signal receiving unit and sends a detection signal to the signal receiving unit. Related personnel, such as maintenance personnel, can start the fault detection system through this detection button, and when the signal receiving unit of fault detection system received the detection signal that detection button sent, the fault judgement unit began to carry out fault diagnosis, and fault suggestion unit carries out the fault suggestion afterwards to realize one key detection function, make things convenient for related personnel to carry out fault diagnosis or maintenance.

As shown in fig. 5, the controller 3 provided in at least one of the above embodiments includes not only the motor control system 2, but also the fault detection system 1, and the controller 3 has not only a motor operation control function, but also a fault detection function, and can accurately and quickly determine whether the motor has a fault according to the determination result, and if the motor has no fault, the motor control system 2 is restarted to perform motor control; if the fault exists, the fault detection system judges the fault type so that relevant personnel can process the fault. It should be noted that the motor control system 2 and the fault detection system 1 represent a motor control function and a fault detection function of the controller 3, and may specifically include an MCU with a related program in hardware, that is, the motor control function and the fault detection function are mainly implemented by the MCU with the related program. The two devices do not represent independent hardware settings, that is, the motor control function of the motor control system 2 and the fault detection function of the fault detection system 1 may be implemented by the same MCU that simultaneously carries the motor control program and the fault detection program. Of course, the present invention may be realized by a MCU having a motor control program and another MCU having a failure detection program. This is not limited in this application. Furthermore, the parameters input into the MCU for motor control and fault detection are obtained by other hardware modules of the controller, such as an electrical parameter sampling unit, and the electrical parameter sampling unit, such as a current sampling unit, a voltage sampling unit, and a speed sampling unit, refers to the existing design, which is not limited in this application.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (11)

1. A control method characterized by comprising a fault detection step capable of detecting a motor fault, the fault detection step comprising:

receiving a detection signal, and performing first-class fault judgment and/or second-class fault judgment at least according to the detection signal;

the first type fault judgment comprises the following steps:

the method comprises the steps that after a control controller applies electric energy to any one group of two-phase coils in three-phase coils of a motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs;

the second type of fault judgment comprises the following steps:

after the controller is controlled to drive the motor at a preset frequency, a second parameter is obtained, and the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs;

and prompting the corresponding fault according to the fault type.

2. The control method according to claim 1, wherein the failure detection step further includes:

before the first type fault judgment and/or the second type fault judgment are carried out according to the detection signals, the third type fault judgment is carried out according to the detection signals,

the third type of fault judgment comprises the following steps:

controlling the controller to stand by to obtain a third parameter, wherein the third parameter represents the bus voltage of the controller;

comparing the third parameter with a bus voltage related threshold value, and judging whether the bus voltage represented by the third parameter is in a standby working voltage range of the controller;

if not, judging that the power supply loop of the controller has a fault.

3. The control method according to claim 1, characterized by further comprising a motor control step;

and if the fault does not exist, executing the motor control step and controlling the motor to normally operate.

4. The control method according to any one of claims 1 to 3, wherein applying the electric power to any one of the sets of three-phase coils of the motor comprises applying a constant current to any one of the sets of three-phase coils of the motor;

comparing the first parameter with a current-related threshold value, and judging whether a short-circuit fault occurs comprises the following steps:

judging whether the first parameter corresponding to each group of two-phase coils exceeds a current protection threshold value, wherein the current protection threshold value represents the maximum current value of the motor;

if the first parameter corresponding to at least one group of two-phase coils exceeds the current protection threshold value, determining that the fault of the motor is a short-circuit fault;

comparing the first parameter with a current-related threshold value, and judging whether an open-circuit fault occurs comprises the following steps:

judging whether the first parameter corresponding to each group of two-phase coils is in a first preset range, wherein the first preset range represents 80-120% of the constant current;

and if not, judging that the fault of the motor is an open-circuit fault.

5. The control method according to claim 4, wherein comparing the second parameter with a frequency-dependent threshold value and determining whether a locked rotor fault occurs comprises the steps of:

judging whether the second parameter reaches a target frequency value within preset time after the motor operates, wherein the target frequency value represents the preset frequency of the motor;

and if not, judging that the fault of the motor is a locked rotor fault.

6. A controller comprising a fault detection system capable of detecting a motor fault, the fault detection system comprising:

a signal receiving unit: the device can receive a detection signal and trigger a first type fault judgment unit and/or a second type fault judgment unit to work at least according to the detection signal:

the first-type fault judging unit: the method comprises the steps that after a controller can be controlled to apply electric energy to any one group of two-phase coils in three-phase coils of the motor, a first parameter is obtained, and the first parameter represents motor phase current; comparing the first parameter with a current-related threshold value, and judging whether an open circuit and/or short circuit fault occurs;

the second type fault judgment unit: the controller can be controlled to drive the motor at a preset frequency, and then a second parameter is obtained, wherein the second parameter represents the running frequency of the motor; comparing the second parameter with a frequency-related threshold value, and judging whether a locked rotor fault occurs;

a fault prompting unit: and corresponding faults can be prompted according to the fault types.

7. The controller according to claim 6, wherein the signal receiving unit is further capable of receiving a detection signal and triggering a third type of failure determination unit to operate according to at least the detection signal:

the third type fault judgment unit: the controller can be controlled to be in standby state, and a third parameter is obtained, wherein the third parameter represents the bus voltage of the controller; comparing the third parameter with a bus voltage related threshold value, and judging whether the bus voltage represented by the third parameter is in a standby working voltage range of the controller; and if not, judging that the power supply loop of the controller has a fault.

8. The controller of claim 6, further comprising a motor control system;

when the fault detection system judges that no fault exists, the motor control system can start working and control the motor to normally operate.

9. The controller according to any one of claims 6 to 8,

the first type fault judgment unit comprises:

an applied power control module: the controller can be controlled to apply electric energy to any one group of two-phase coils in three-phase coils of the motor, and the electric energy is constant current;

a first obtaining module: after the electric energy is applied, a first parameter can be obtained, and the first parameter represents the phase current of the motor;

a first judgment module: whether the first parameter corresponding to each group of two-phase coils exceeds a current protection threshold value or not can be judged, and the current protection threshold value represents the maximum current value of the motor; if the first parameter corresponding to at least one group of two-phase coils exceeds the current protection threshold value, determining that the fault of the motor is a short-circuit fault;

a second judging module: whether the first parameter corresponding to each group of two-phase coils is within a first preset range can be judged, and the first preset range represents 80% -120% of the constant current; and if not, judging that the fault of the motor is an open-circuit fault.

10. The controller according to claim 9, wherein the second type of fault determining unit comprises:

a frequency control module: the controller can be controlled to drive the motor at a preset frequency;

a second obtaining module: the method comprises the steps that a second parameter can be obtained after a controller is controlled to drive a motor at a preset frequency, and the second parameter represents the running frequency of the motor;

a third judging module: whether the second parameter reaches a target frequency value within a preset time after the motor operates can be judged, and the target frequency value represents a preset frequency of the motor operation; and if not, judging that the fault of the motor is a locked rotor fault.

11. The controller according to claim 6, comprising a detection key connected to the signal receiving unit for sending a detection signal to the signal receiving unit.

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