A monitoring and diagnosis device and method for electrical safety failure of lifting machinery equipment

Abstract

The present invention discloses a monitoring and diagnosis device and method for electrical safety faults of lifting machinery and equipment, and belongs to the technical field of monitoring faults of lifting machinery and equipment. The monitoring and diagnosis method for electrical safety faults of lifting machinery and equipment includes: an electrical component fault early warning method, a limit switch fault monitoring and diagnosis identification method, and a motor fault monitoring and diagnosis identification method; the electrical component fault early warning method is implemented through the electrical component standard technical parameters and usage data recording module and the first early warning module; the limit switch fault monitoring and diagnosis identification method is implemented through the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module, and the limit switch fault monitoring and diagnosis module; the motor fault monitoring and diagnosis identification method is implemented through the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module, and the motor fault monitoring and diagnosis module.

Description

Technical Field

[0001] The present invention relates to the technical field of lifting machinery and equipment, and in particular to a monitoring and diagnosing device and method for electrical safety faults of lifting machinery and equipment. Background Art

[0002] Lifting machinery and equipment plays a vital role in industrial production and engineering construction. Usually, lifting machinery and equipment work under the action of electricity. Therefore, electrical failures are inevitable during the operation of lifting machinery. This not only has a serious impact on the normal operation of the crane, but also poses certain safety hazards that threaten the lives of operators.

[0003] The current diagnostic identification method for electrical safety faults in lifting machinery equipment uses machine learning methods or expert system evaluation methods based on the working data of the lifting machinery equipment. It can only diagnose and identify that an electrical safety fault has occurred or the results of the diagnostic identification have certain errors, and the specific location of the fault and the cause of the fault cannot be further determined. Summary of the invention

[0004] In order to better solve the above technical problems, the present invention is proposed. The embodiment of the present invention provides a monitoring and diagnosis device and method for electrical safety faults of lifting machinery equipment.

[0005] According to one aspect of the present invention, a monitoring and diagnostic device for electrical safety faults of lifting machinery is provided, the device comprising:

[0006] The electrical component standard technical parameters and usage data recording module is used to establish a database based on the acquired standard technical parameters and usage data of the electrical components of the lifting machinery equipment. The electrical component standard technical parameters include rated voltage, rated current, rated power, rated speed, and maximum allowable working temperature. The electrical component usage data includes working time, maximum working current and voltage, maximum speed, maximum working temperature, component status, fault cause, and maintenance or replacement record.

[0007] A first warning module is used to send warning information to the PLC control system of the lifting machinery equipment, wherein the warning information is obtained by evaluating the expert evaluation system based on the usage database and the standard technical parameter database of the electrical components;

[0008] A real-time data acquisition module is used to acquire real-time operation data of the lifting machinery and equipment, wherein the real-time operation data of the lifting machinery and equipment includes the position of the working mechanism, the closing and opening status of the limit switch, and the action command instruction data;

[0009] Limit switch fault monitoring and diagnosis module, used to monitor the working status of the limit switch and identify and diagnose limit switch faults;

[0010] Motor fault monitoring and diagnosis module, used to monitor the working status of the motor and identify and diagnose motor or motor circuit faults;

[0011] The fault output module is used to output the fault information identified and diagnosed by the limit switch fault monitoring and diagnosis module and the motor fault monitoring and diagnosis module.

[0012] In the above-mentioned monitoring and diagnostic device for electrical safety faults of lifting machinery and equipment, the electrical component standard technical parameters and usage data recording module includes: a data storage unit, used to store standard technical parameters and usage data of electrical components; a sensor data acquisition unit, used to obtain the voltage, current, speed and temperature of the electrical components during operation according to sensors installed in the main circuit, control circuit and protection circuit; obtain the ambient temperature; a data cache unit, used to store the data obtained by the sensor data acquisition unit; a data update unit, used to update the maximum working current voltage, maximum speed and maximum working temperature in the electrical component usage data according to the data obtained by the sensor data acquisition unit.

[0013] In the above-mentioned monitoring and diagnosing device for electrical safety faults of lifting machinery, the fault output module includes: a fault output unit for outputting fault information for identification and diagnosis; and a fault writing unit for writing electrical component fault information into the data storage unit.

[0014] According to another aspect of the present invention, a monitoring and diagnosis method for electrical safety faults of lifting machinery equipment is provided, including: an electrical component fault early warning method, a limit switch fault monitoring and diagnosis identification method and a motor fault monitoring and diagnosis identification method; the electrical component fault early warning method is implemented through the electrical component standard technical parameters and usage data recording module and the first early warning module; the limit switch fault monitoring and diagnosis identification method is implemented through the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module and the limit switch fault monitoring and diagnosis module; the motor fault monitoring and diagnosis identification method is implemented through the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module and the motor fault monitoring and diagnosis module.

[0015] In the above-mentioned monitoring and diagnosis method of electrical safety faults of lifting machinery and equipment, the method of monitoring and diagnosing limit switch faults includes: S1, obtaining the "limit state" information, action command instruction data, position of the working mechanism and motor current of the limit switch; S2, when the "limit state" of the limit switch changes from "closed" to "open", judging the motor current at this time, if the motor current is greater than zero, entering S3 to perform limit switch circuit fault diagnosis and identification, otherwise entering S4 to perform limit switch false trigger fault diagnosis and identification; S3, limit switch circuit fault diagnosis and identification; S4, limit switch false trigger fault diagnosis and identification; the "limit state" is the working state data of the limit switch, and when the "limit state" is "open", the motor circuit is cut off to prevent the working mechanism from continuing to move and overtravel.

[0016] In the above-mentioned method for monitoring and diagnosing limit switch faults, in S3, the limit switch circuit fault diagnosis and identification specifically includes the following steps: S31, obtaining the limit switch circuit current; S32, if the limit switch circuit current is greater than the first current threshold, diagnosing that a short circuit fault has occurred in the limit switch circuit; otherwise, diagnosing that the order of the wires connected from the limit switch to the controller is disordered.

[0017] In the above-mentioned method for monitoring and diagnosing limit switch faults, in S4, the limit switch false triggering fault diagnosis and identification specifically includes the following steps: S41, obtaining the movement direction of the working mechanism according to the action command instruction data, and obtaining the extreme position of the movement of the working mechanism according to the movement direction of the working mechanism; S42, judging whether the working mechanism reaches the extreme position when the limit switch is triggered according to the current position of the working mechanism, if the judgment result is no, diagnosing that the limit switch has a false triggering fault; otherwise, the limit switch false triggering fault diagnosis and identification ends; the extreme position of the working mechanism is the position of the working mechanism when the above-mentioned limit switch is triggered.

[0018] In the above-mentioned monitoring and diagnosis method of electrical safety faults of lifting machinery and equipment, the method of motor fault monitoring and diagnosis and identification includes: S1, obtaining the working voltage, working current, motor temperature, motor speed, and ambient temperature of the motor, drawing the motor temperature rise change curve according to the motor temperature and the ambient temperature, and judging whether the motor is loaded. If the judgment result is true, enter S3, otherwise enter S2; S2, when the motor is no-loaded, if the motor current is greater than the second current threshold, diagnose that the motor has a large no-load current fault, and enter the fault cause identification; S3, when the motor is loaded, if the third current threshold ≤ motor current < fourth current threshold, calculate the theoretical temperature rise of the motor according to the motor thermal balance differential equation, if the motor temperature rise is greater than the theoretical temperature rise of the motor and the motor speed decreases, diagnose that the motor has an overload fault, and enter the fault cause diagnosis and identification.

[0019] In the above-mentioned method for motor fault monitoring and diagnosis and identification, in S2, the identification of the cause of the motor's high no-load current fault specifically includes the following steps: S21, judging whether the motor voltage is greater than the first voltage threshold, if the judgment result is true, the fault cause is that the motor voltage is too high, and the process goes to S24, otherwise, the process goes to S22; S22, if the motor speed drops significantly and the motor temperature rise curve shows a non-smooth temperature rise, the fault cause is that the motor is stuck, and the process goes to S24, otherwise, the process goes to S23; S23, outputting possible causes of the fault, the possible causes of the fault include: drying up of grease in the bearing, excessive air gap between the stator and rotor, insufficient number of stator winding turns or incorrect wiring; S24, the identification of the cause of the motor's high no-load current fault ends.

[0020] In the above-mentioned method for motor fault monitoring and diagnosis and identification, in S3, the cause of the motor overload fault is identified, which specifically includes the following steps: S31, calculating the motor load. If the motor load exceeds the rated load of the motor, the cause of the fault is that the motor load is too heavy, and enter S34, otherwise enter S32; S32, obtaining the motor voltage. If the motor voltage is less than or equal to the second voltage threshold, the cause of the fault is that the motor voltage is low, and enter S34, otherwise enter S33; S33, judging whether the motor has exceeded the working time according to the motor working time, if the judgment result is true, the cause of the fault is that the motor has been running continuously for too long; S34, the diagnosis and identification of the cause of the motor overload fault is completed.

[0021] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0022] The present invention predicts the state of the electrical components of the lifting machinery and equipment through the electrical component fault early warning method, discovers potential faults, and generates early warning information to ensure electrical safety; identifies the fault information of the limit switch and the motor through the limit switch fault monitoring and diagnosis identification method and the motor fault monitoring and diagnosis identification method, and continues to identify the cause of the fault, directly outputs the determined fault cause, and outputs the possible cause after the fault cause is eliminated for the fault cause that requires manual judgment, which is convenient for maintenance personnel to inspect and repair. The monitoring and diagnosis device and method of electrical safety faults of lifting machinery and equipment of the present invention can discover potential faults of electrical safety, and can timely discover specific faults and fault causes when the lifting machinery is running, thereby improving the efficiency and accuracy of fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention.

[0024] Figure 1 The figure shows a schematic diagram of a monitoring and diagnosing device for electrical safety faults of lifting machinery equipment provided according to an embodiment of the present invention;

[0025] Figure 2 A flowchart of a method for monitoring and diagnosing a limit switch fault according to an embodiment of the present invention is shown;

[0026] Figure 3 The figure shows a flow chart of a method for motor fault monitoring and diagnosis identification according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and the present invention is not limited to the exemplary embodiments described here.

[0028] Please refer to Figure 1 The monitoring and diagnostic device for electrical safety failure of the lifting machinery equipment comprises:

[0029] The electrical component standard technical parameters and usage data recording module is used to establish a database based on the acquired standard technical parameters and usage data of the electrical components of the lifting machinery equipment. The standard technical parameters of the electrical components include rated voltage, rated current, rated power, rated speed, and maximum allowable working temperature. The electrical component usage data includes working time, maximum working current and voltage, maximum speed, maximum working temperature, component status, cause of failure, and repair or replacement record.

[0030] The main electrical components of lifting machinery and equipment include motors, which are used to drive the working mechanisms of the crane, such as the movement of the trolley, car, main hook and auxiliary hook. Taking a 20 / 5t bridge crane as an example, the trolley is driven by two motors, and the trolley, auxiliary hook and main hook are driven by one motor respectively. Limit switches are installed on the trolley, car, auxiliary hook and main hook to control the extreme position of movement to ensure the safe operation of the lifting machinery and equipment; the trolley motor, car motor and auxiliary hook motor are controlled by a cam controller, and the main hook motor is controlled by a master controller; the main circuit and the control circuits of each motor are equipped with overcurrent relays and fuses for overcurrent and short-circuit protection;

[0031] The module for recording standard technical parameters and usage data of electrical components collects corresponding standard technical parameters according to the working characteristics of each electrical component. For example, the standard technical parameters of limit switches include rated voltage and rated current; the standard technical parameters of motors include rated voltage, rated current, rated power, rated speed, and maximum allowable working temperature; the standard technical parameters of overcurrent relays include rated current and current setting value, etc. A database of standard technical parameters of electrical components is established based on the collected standard technical parameters of electrical components; the usage data of electrical components counts different data according to different electrical components, such as the continuous working time, total working time, maximum and minimum current and voltage during working, maximum speed during working, and maximum temperature of the motor. It also includes the component status and the faults that occurred during equipment maintenance and the causes of the faults, the maintenance records and replacement records corresponding to the causes of the faults. If the replacement is for a different model of accessories, the standard technical parameter database needs to be updated, and a usage database is established based on the usage data of electrical components;

[0032] Optional, electrical component standard technical parameters and usage data recording module, including:

[0033] A sensor data acquisition unit is used to acquire the voltage, current, speed and temperature of the electrical components when they are working according to the sensors installed in the main circuit, the control circuit and the protection circuit; and to acquire the ambient temperature;

[0034] The sensors include current sensors, voltage sensors, and temperature sensors. The optional current sensor can use a Hall current sensor or a current transformer to measure the current data of the motor or the limit switch. The voltage sensor can use a Hall voltage sensor to measure the voltage data of the motor or the limit switch. The temperature sensor is used to measure the temperature of the motor and the external environment temperature. The Hall element speed measurement method can be used to measure the speed of the motor. The sensor can also be used to measure the current, voltage, and temperature data of components such as controllers, contactors, relays, and fuses.

[0035] A data cache unit, used to store the data acquired by the sensor data acquisition unit;

[0036] The real-time data of the temperature, voltage, current, speed, etc. of the electrical components acquired by the sensor data acquisition unit are stored in the data cache unit for use by other units and modules;

[0037] A data updating unit, used for updating the maximum working current and voltage, the maximum speed, and the maximum working temperature in the usage data of the electrical component according to the data acquired by the sensor data acquiring unit;

[0038] The data updating unit obtains the real-time current, voltage, temperature, speed and other data of the electrical components from the sensor data acquiring unit, obtains the larger voltage, current and other data through comparison, stores them temporarily, and updates the maximum working current voltage, maximum speed and maximum working temperature in the use data of the electrical components when the lifting machinery stops running;

[0039] A data storage unit for storing standard technical parameters and usage data of electrical components;

[0040] The data storage unit establishes a standard technical parameter database for data storage based on the collected standard technical parameters of each electrical component, and establishes a corresponding electrical component usage database for storing the usage data of the electrical components; the data storage unit supports manual writing of data, including an input terminal for manual operation, which can be used to input the component status, component faults found, fault causes, and fault handling during equipment maintenance, wherein the fault handling includes the repair or replacement of components;

[0041] A first warning module is used to send warning information to the PLC control system of the lifting machinery equipment, wherein the warning information is obtained by evaluating the expert evaluation system based on the usage database and the standard technical parameter database of the electrical components;

[0042] The first early warning module reads the standard technical parameter information and the latest usage data of the electrical components from the electrical component standard technical parameter and usage data recording module, and then the expert evaluation system evaluates the data. If there is a potential electrical fault, the corresponding early warning information is generated and sent to the PLC control system of the lifting machinery equipment, so as to deal with the potential safety hazards in time to ensure the electrical safety of the lifting machinery equipment;

[0043] A real-time data acquisition module is used to acquire real-time operation data of the lifting machinery and equipment, wherein the real-time operation data of the lifting machinery and equipment includes the position of the working mechanism, the closing and opening status of the limit switch, and the action command instruction data;

[0044] The real-time data acquisition module obtains the action command instruction data of the lifting machinery equipment according to the action signal conversion circuit, and obtains the closed and open states of the limit switch according to the voltage analog signal conversion of the limit switch. The working mechanism includes a trolley, a car, a main hook, and an auxiliary hook, which are respectively used for horizontal, vertical, and rotational movements. The RTK device can be optionally used to obtain the position information of the working mechanism. When the limit switch changes from a "closed" state to an "open" state, the position of the working mechanism at this time is collected according to the RTK device. If the limit switch is in a normal working state at this time, the position of the working mechanism at this time is used as the limit position of the movement direction, and the limit position is stored in the usage database as one of the usage data of the limit switch.

[0045] Limit switch fault monitoring and diagnosis module, used to monitor the working status of the limit switch and identify and diagnose limit switch faults;

[0046] The limit switch fault monitoring and diagnosis module diagnoses and identifies the limit switch fault and the cause of the fault according to the standard technical parameters of the electrical components and the real-time data such as the voltage and current of the electrical components stored in the data cache unit of the data recording module and the action command instruction data, the position of the working mechanism, and the closed and open states of the limit switch acquired by the real-time data acquisition module;

[0047] Motor fault monitoring and diagnosis module, used to monitor the working status of the motor and identify and diagnose motor or motor circuit faults;

[0048] The motor fault monitoring and diagnosis module diagnoses and identifies motor faults and fault causes based on standard technical parameters of electrical components and real-time data such as temperature, voltage, current, and speed of electrical components stored in the data cache unit of the data recording module and action command instruction data, working mechanism position, and limit switch closing and opening status acquired by the real-time data acquisition module;

[0049] A fault output module, used to output the fault information identified and diagnosed by the limit switch fault monitoring and diagnosis module and the motor fault monitoring and diagnosis module;

[0050] The fault output module receives the fault information identified and diagnosed by the limit switch fault monitoring and diagnosis module and the motor fault monitoring and diagnosis module, and is used for outputting the diagnostic information, and is also used for automatically storing the fault information into the electrical component usage database;

[0051] Optional, fault output module, including:

[0052] A fault output unit, used for outputting fault information for identification and diagnosis;

[0053] The fault output unit outputs the fault information according to the received fault information identified and diagnosed by the limit switch fault monitoring and diagnosis module and the motor fault monitoring and diagnosis module, wherein the fault information includes the fault phenomenon and the cause or possible cause of the fault;

[0054] A fault writing unit, used for writing electrical component fault information into the data storage unit;

[0055] The fault writing unit writes the fault information received into the data storage unit of the standard technical parameters of the electrical components and the usage data recording module. If the cause of the fault requires manual detection, only the fault phenomenon is written, and the fault cause data is subsequently stored manually.

[0056] Based on the monitoring and diagnosing device for electrical safety faults of lifting machinery and equipment provided in the above-mentioned embodiments, the present invention also provides a monitoring and diagnosing method for electrical safety faults of lifting machinery and equipment, the method comprising: an electrical component fault early warning method, a limit switch fault monitoring and diagnosis identification method, and a motor fault monitoring and diagnosis identification method;

[0057] The electrical component failure early warning method is implemented by the electrical component standard technical parameters and usage data recording module and the first early warning module;

[0058] Specifically, the electrical component standard technical parameter and usage data recording module establishes a standard technical parameter database according to the collected standard technical parameters of the electrical components, and establishes a usage database according to the collected usage data. The first early warning module reads the standard technical parameter information and the latest usage data of the electrical components from the electrical component standard technical parameter and usage data recording module, and then the expert evaluation system evaluates the data. If there is a potential electrical fault, a corresponding early warning message is generated, and the early warning message is sent to the lifting machinery equipment PLC control system, so as to facilitate timely processing of potential safety hazards to ensure the electrical safety of the lifting machinery equipment.

[0059] The method for monitoring and diagnosing limit switch faults is implemented by means of a standard technical parameter and usage data recording module for electrical components, a real-time data acquisition module and a limit switch fault monitoring and diagnosing module;

[0060] The "limit state" is one of the working state data of the limit switch. When the "limit state" is "off", the controller cuts off the motor circuit to prevent the motor from continuing to drive the working mechanism to move in that direction to cause overtravel and thus cause a safety accident. When the "limit state" is "closed", the limit switch is connected to the control circuit to limit the movement of the working mechanism.

[0061] The limit position of the working mechanism is the position of the working mechanism when the limit switch is triggered;

[0062] The working mechanism includes a trolley, a small trolley, a main hook and an auxiliary hook. The limit switch is installed on the working mechanism to limit the movement limit positions of the working mechanism in the horizontal, vertical and rotational directions. When the working mechanism moves to the limit position in a certain direction, the limit switch is triggered to change from "closed" to "open". At this time, the position of the working mechanism is the limit position of the working mechanism in this direction.

[0063] like Figure 2 As shown, the method for monitoring and diagnosing limit switch faults includes:

[0064] S1, obtain the "limit state" information of the limit switch, the action command instruction data, the position of the working mechanism and the motor current;

[0065] The action command instruction data is the input request data for commanding the lifting machinery to move in a certain direction, including the command data for the horizontal, vertical and rotational luffing directions. The "limit state" information of the limit switch is the working state data of the limit switch, including the "closed" and "open" states. The position of the working mechanism includes the position information of the trolley, the car, the main hook and the auxiliary hook. The motor for executing the corresponding instruction is obtained according to the action command instruction data. The working mechanism moving at this time is obtained according to the motor for executing the instruction. The limit switch in the working state at this time is obtained according to the action command instruction data and the mechanism moving at this time, the motor current for executing the instruction is obtained, the position of the working mechanism moving at this time is obtained, and the "limit state" information of the limit switch in the working state at this time is obtained;

[0066] S2. When the "limit state" of the limit switch changes from "closed" to "open", the motor current is determined. If the motor current is greater than zero, the process goes to S3 to perform limit switch circuit fault diagnosis and identification. Otherwise, the process goes to S4 to perform limit switch mis-triggering fault diagnosis and identification.

[0067] According to the change of the "limit state" information of the limit switch, when the "limit state" of the limit switch changes from "closed" to "open", it means that the moving working mechanism has reached the limit position in the moving direction of the action command instruction data and triggered the limit protection. Under normal circumstances, the controller connected in series with the limit switch cuts off the power supply of the motor to prevent the motor from continuing to drive the working mechanism to move in this direction and causing overtravel and then causing a safety accident; judge the current information of the motor at this time. If the motor current is greater than zero, it means that the "limit state" of the limit switch has changed, but the limit switch circuit is not powered off. At this time, the limit switch circuit fails and enters S3 to perform limit switch circuit fault diagnosis and identification; if the judgment result is that the motor current is equal to zero, enter S4 to perform limit switch false trigger fault diagnosis and identification;

[0068] S3, limit switch circuit fault diagnosis and identification;

[0069] Specifically, the limit switch circuit fault diagnosis and identification includes:

[0070] S31, obtaining the limit switch circuit current;

[0071] Acquiring current information of the limit switch circuit according to a current sensor installed in the limit switch circuit;

[0072] S32. If the current of the limit switch circuit is greater than the first current threshold, diagnose that a short circuit fault occurs in the limit switch circuit; otherwise, diagnose that the order of the wires connecting the limit switch to the controller is disordered.

[0073] Under normal circumstances, the limit switch is in the "off" state at this time, and the current of the circuit should be zero. The first current threshold can be determined according to the rated current of the limit switch. For example, the first current threshold can be 3 times the rated current of the limit switch. When the current of the limit switch circuit is greater than the first current threshold, it is diagnosed that a short circuit fault occurs in the limit switch circuit. If the current of the limit switch circuit is less than or equal to the first current threshold, the cause of the fault is that the order of the wires connecting the limit switch to the controller is disordered;

[0074] S4, limit switch mis-triggering fault diagnosis and identification;

[0075] Specifically, the limit switch may have a change in contact sensitivity due to the use environment during operation. Dust, moisture or other contaminants in the use environment may adhere to the contacts, affecting the normal contact of the contacts, thereby causing the switch to malfunction. Therefore, the limit switch may have a false triggering failure.

[0076] Limit switch false trigger fault diagnosis and identification, including:

[0077] S41, acquiring the movement direction of the working mechanism according to the action command instruction data, and acquiring the extreme position of the movement of the working mechanism according to the movement direction of the working mechanism;

[0078] According to the instruction data of the action command, the direction of motion pointed by the action command and the corresponding motor for executing the action command can be obtained, and the working mechanism of the motion can be obtained according to the motor for executing the action command. At this time, the working mechanism and the direction of motion of the motion can be obtained from the usage data of the limit switch of the corresponding limit protection, and the limit position that the working mechanism can move to in this direction can be obtained;

[0079] S42. Determine whether the working mechanism reaches the limit position when the limit switch is triggered according to the current position of the working mechanism. If the judgment result is no, diagnose that the limit switch has a false triggering fault; otherwise, the limit switch false triggering fault diagnosis and identification ends.

[0080] The limit trigger of the limit switch refers to the state of the limit switch changing from "closed" to "open" when the moving working mechanism reaches the limit position. At this time, the working mechanism driven by the motor should be at the theoretical limit position. The current position of the moving working mechanism is obtained. If the current position of the working mechanism has not reached the theoretical limit position, the limit switch is diagnosed to have a false triggering fault. It is necessary to check the sensitivity of the limit switch contacts, adjust the contact strength and sensitivity, and reduce the probability of false triggering. Otherwise, when the limit is triggered, the working mechanism has reached the theoretical limit position, and no false triggering fault occurs, and the diagnosis is completed.

[0081] The motor fault monitoring and diagnosis identification method is implemented through an electrical component standard technical parameter and usage data recording module, a real-time data acquisition module and a motor fault monitoring and diagnosis module.

[0082] like Figure 3 As shown, the method for motor fault monitoring and diagnosis identification includes:

[0083] S1, obtain the working voltage, working current, motor temperature, motor speed, and ambient temperature of the motor, draw the motor temperature rise curve according to the motor temperature and ambient temperature, and judge whether the motor is loaded. If the judgment result is true, enter S3, otherwise enter S2;

[0084] According to the various sensors, the motor's working voltage, working current, motor temperature, motor speed and other data are obtained, and the temperature of the external environment is obtained. The motor temperature rise refers to the difference between the motor temperature and the ambient temperature. When the motor is working, the temperature of the motor rises due to energy loss and exceeds the temperature of the external environment. Its energy loss mainly includes copper loss and iron loss. When the motor current is constant, the stable temperature rise of the motor is proportional to the motor loss and proportional to the square of the motor current. Its temperature rise curve should be a smooth curve. The motor temperature rise is calculated according to the obtained motor temperature and ambient temperature, and the motor temperature rise curve is drawn. The motor load condition is judged. If the motor is in a no-load state, enter S2, otherwise enter S3.

[0085] S2: When the motor is unloaded, if the motor current is greater than the second current threshold, the motor is diagnosed to have a high unloaded current fault, and the fault cause identification is started;

[0086] The motor may fail under both load and no-load conditions. The present invention performs motor fault diagnosis and identification based on load and no-load conditions. When the motor is no-loaded, if the current is too large, the energy consumption inside the motor will increase, causing the motor to overheat. Long-term overheating will reduce the efficiency of the motor and even accelerate the aging of the insulation material, shorten the service life of the motor, and also cause energy waste. For three-phase asynchronous motors used in lifting machinery and equipment, the no-load current is generally between 1 / 3 and 1 / 2 of the rated current. The second current threshold can be determined according to the model of the motor and the rated current of the motor. If the no-load current of the motor is greater than the second current threshold, it means that the motor has a large no-load current fault, and the fault cause identification is performed, which specifically includes the following steps:

[0087] S21, judging whether the motor voltage is greater than the first voltage threshold, if the judgment result is true, the fault cause is that the motor voltage is too high, and entering S24, otherwise entering S22;

[0088] If the voltage of the motor is higher than the rated voltage of the motor, more current will be generated. Voltage fluctuations within a certain range are allowed, generally ranging from -5% to 10% of the rated voltage. Too high a voltage will cause excessive current when the motor is no-load. The first voltage threshold is determined based on the rated voltage of the motor and the allowable fluctuation range. If the motor voltage is greater than the first voltage threshold at this time, the cause of the fault is that the motor voltage is too high, and the motor no-load current fault cause identification is completed. Otherwise, enter S22 to identify other fault causes.

[0089] S22: If the motor speed drops significantly and the motor temperature rise curve shows a non-smooth rise, the fault is caused by motor jamming, and the process goes to S24; otherwise, the process goes to S23;

[0090] The change of the motor speed is determined according to the obtained motor speed. If the motor temperature rise curve shows a non-smooth rise, it means that the heat generated by the motor at this time increases abnormally. At this time, if the motor speed decreases significantly, the cause of the fault is that the motor is stuck, resulting in a decrease in the motor speed and an increase in the heat. The fault cause identification ends, otherwise it enters S23;

[0091] S23, output possible causes of the fault, the possible causes of the fault include: drying of the grease in the bearing, too large air gap between the stator and rotor, insufficient number of turns of the stator winding, or wrong wiring;

[0092] Other possible causes of the motor's high no-load current fault include: the grease in the bearing is dried up, the air gap between the stator and rotor is too large, the number of stator winding turns is insufficient, or the wiring is wrong. Manual inspection is required to determine the specific cause. At this time, the possible cause is output to facilitate the troubleshooting of the fault cause, and the fault cause diagnosis and identification is completed;

[0093] S24, the motor no-load current high fault cause identification is completed;

[0094] S3, when the motor is loaded, if the third current threshold ≤ motor current < fourth current threshold, the theoretical temperature rise of the motor is calculated according to the motor thermal balance differential equation. If the motor temperature rise is greater than the theoretical temperature rise of the motor and the motor speed decreases, the motor is diagnosed to have an overload fault, and the fault cause diagnosis and identification is started;

[0095] When the motor is loaded, it needs more power. Motor overload means that the actual power used by the motor exceeds the rated power of the motor. It is an abnormal operating state. The motor allows overload within a certain time and range. If it is in an overload state for a long time, it will cause an increase in heat and abnormal temperature rise, which will then affect the insulation level of the motor and even cause damage to the motor. When the motor is overloaded, the current will exceed the rated current accordingly. The third current threshold is determined according to the overcurrent range allowed by the motor and the setting value of the overcurrent relay of the motor circuit. The third current threshold is less than the setting value of the overcurrent relay. For example, the third current threshold can be set to 1.5~2 times the rated current. Generally, if the current is greater than 3 times the rated current, it is considered that the circuit is short-circuited. The fourth current threshold should be less than or equal to 3 times the rated current. If the motor current satisfies: the third current threshold ≤ motor current < fourth current threshold, at this time the motor current exceeds the rated value, and the circuit is not short-circuited, the motor theoretical temperature rise is calculated according to the motor thermal balance differential equation. If the motor temperature rise is greater than the motor theoretical temperature rise and the motor speed decreases, the motor is diagnosed to have an overload fault, and the fault cause diagnosis and identification is entered, which specifically includes the following steps:

[0096] S31, calculate the motor load. If the motor load exceeds the rated load of the motor, the fault cause is that the motor load is too heavy, and enter S34; otherwise, enter S32;

[0097] The reason for the motor overload may be that the motor load exceeds the rated load of the motor. The motor load is calculated based on the load force and speed. If the motor load exceeds the rated load of the motor, the fault cause is that the motor load is too heavy, otherwise enter S32;

[0098] S32, obtaining the motor voltage. If the motor voltage is less than or equal to the second voltage threshold, the fault cause is low motor voltage, and the process goes to S34; otherwise, the process goes to S33;

[0099] Motor overload may be related to voltage. Voltage fluctuation within a certain range is allowed. Generally, the fluctuation range is -5% to 10% of the rated voltage. The second voltage threshold can be set to be less than 95% of the rated voltage. If the motor voltage is less than or equal to the second voltage threshold, the fault is caused by low motor voltage. Otherwise, enter S33.

[0100] S33, judging whether the motor has been running for an excessive period of time according to the motor's working time, if the judgment result is true, the fault cause is that the motor has been running continuously for too long;

[0101] When the motor is working continuously, if it is in a high load state for a long time, the temperature of the motor will rise, which may cause the aging and failure of the motor insulation material. The motor is judged whether it has been running for an excessive time based on the motor working time. If the judgment result is true, the cause of the fault is that the motor has been running for too long continuously. Otherwise, the possible cause is mechanical failure or insulation damage. Output the possible cause of the fault.

[0102] S34, the diagnosis and identification of the cause of the motor overload fault is completed.

[0103] The present invention predicts the status of the electrical components of the lifting machinery and equipment through the electrical component fault warning method, discovers potential faults, and generates warning information to ensure electrical safety; identifies the fault information of the limit switch and the motor through the limit switch fault monitoring and diagnosis identification method and the motor fault monitoring and diagnosis identification method, and continues to identify the cause of the fault, directly outputs the determined fault cause, and outputs the possible cause after the fault cause is eliminated for the fault cause that requires manual judgment, which is convenient for maintenance personnel to inspect and repair. The monitoring and diagnosis device and method for electrical safety faults of lifting machinery and equipment of the present invention can discover potential electrical safety faults, and can promptly discover specific faults and fault causes when the lifting machinery is in operation, thereby improving the efficiency and accuracy of fault detection.

[0104] The basic principles of the present invention are described above in conjunction with specific embodiments. It should be understood that the specific details disclosed above are only for illustration and ease of understanding, rather than limitation, and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A monitoring and diagnosis method for electrical safety failure of lifting machinery and equipment, using a monitoring and diagnosis device for electrical safety failure of lifting machinery and equipment, the device comprising: The electrical component standard technical parameters and usage data recording module is used to establish a database based on the acquired standard technical parameters and usage data of the electrical components of the lifting machinery equipment. The electrical component standard technical parameters include rated voltage, rated current, rated power, rated speed, and maximum allowable working temperature. The electrical component usage data includes working time, maximum working current and voltage, maximum speed, maximum working temperature, component status, fault cause, and maintenance or replacement record. The first warning module is used to send warning information to the PLC control system of the lifting machinery equipment, and the warning information is obtained by evaluating the expert evaluation system based on the usage database and standard technical parameter database of the electrical components; the real-time data acquisition module is used to obtain the real-time operation data of the lifting machinery equipment, and the real-time operation data of the lifting machinery equipment includes the position of the working mechanism, the closing and opening status of the limit switch, and the action command instruction data; the limit switch fault monitoring and diagnosis module is used to monitor the working status of the limit switch and identify and diagnose the limit switch fault; the motor fault monitoring and diagnosis module is used to monitor the working status of the motor and identify and diagnose the motor or motor circuit fault; A fault output module is used to output the fault information identified and diagnosed by the limit switch fault monitoring and diagnosis module and the motor fault monitoring and diagnosis module; it is characterized by comprising: an electrical component fault early warning method, a limit switch fault monitoring and diagnosis identification method and a motor fault monitoring and diagnosis identification method; the electrical component fault early warning method is implemented by the electrical component standard technical parameters and usage data recording module and the first early warning module; the limit switch fault monitoring and diagnosis identification method is implemented by the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module and the limit switch fault monitoring and diagnosis module; the motor fault monitoring and diagnosis identification method is implemented by the electrical component standard technical parameters and usage data recording module, the real-time data acquisition module and the motor fault monitoring and diagnosis module; The method for monitoring and diagnosing limit switch faults includes: S1, obtaining "limit state" information, action command instruction data, position of the working mechanism and motor current of the limit switch; S2, when the "limit state" of the limit switch changes from "closed" to "open", judging the motor current at this time, if the motor current is greater than zero, entering S3 to perform limit switch circuit fault diagnosis and identification, otherwise entering S4 to perform limit switch false trigger fault diagnosis and identification; S3, limit switch circuit fault diagnosis and identification; S4, limit switch false trigger fault diagnosis and identification; the "limit state" is the working state data of the limit switch, when the "limit state" is "open", the motor circuit is cut off to prevent the working mechanism from continuing to move and causing overtravel, in S3, limit switch circuit fault diagnosis and identification, specifically includes the following steps: S31, obtaining the current of the limit switch circuit; S32, if the current of the limit switch circuit is greater than the first current threshold, diagnosing that the limit switch circuit has a short circuit fault; otherwise, diagnosing that the order of the wires connected from the limit switch to the controller is disordered, in S4, the limit switch false trigger fault diagnosis and identification specifically includes the following steps: S41, obtaining the movement direction of the working mechanism according to the action command instruction data, and obtaining the limit position of the working mechanism movement according to the movement direction of the working mechanism; S42, judging whether the working mechanism reaches the limit position when the limit switch is triggered according to the current position of the working mechanism, if the judgment result is no, diagnosing that the limit switch has a false trigger fault; otherwise, the limit switch false trigger fault diagnosis and identification ends; the limit position of the working mechanism is the position of the working mechanism when the limit switch is triggered; The method for motor fault monitoring and diagnosis and identification includes: S1, obtaining the working voltage, working current, motor temperature, motor speed, and ambient temperature of the motor, drawing a motor temperature rise change curve according to the motor temperature and the ambient temperature, judging whether the motor is loaded, and if the judgment result is true, entering S3, otherwise entering S2; S2, when the motor is unloaded, if the motor current is greater than the second current threshold, diagnosing that the motor has a large no-load current fault, and entering fault cause identification; S3, when the motor is loaded, if the third current threshold ≤ motor current < fourth current threshold, calculating the theoretical temperature rise of the motor according to the motor thermal balance differential equation, if the motor temperature rise is greater than the theoretical temperature rise of the motor and the motor speed decreases, diagnosing that the motor has an overload fault Fault, enter the fault cause diagnosis and identification, in S2, the motor no-load current large fault cause identification, specifically includes the following steps: S21, determine whether the motor voltage is greater than the first voltage threshold, if the judgment result is true, the fault cause is that the motor voltage is too high, enter S24, otherwise enter S22; S22, if the motor speed is significantly reduced and the motor temperature rise curve shows a non-smooth temperature rise, the fault cause is that the motor is stuck, enter S24, otherwise enter S23; S23, output the possible causes of the fault, the possible causes of the fault include: the grease in the bearing is dried up, the air gap between the stator and the rotor is too large, the number of stator winding turns is insufficient or the wiring is wrong; S24, the motor no-load current large fault cause identification is completed.

2. The monitoring and diagnosis method for electrical safety failure of lifting machinery equipment according to claim 1, characterized in that: The electrical component standard technical parameter and usage data recording module includes: a data storage unit, which is used to store the electrical component standard technical parameters and usage data; a sensor data acquisition unit, which is used to acquire the voltage, current, speed and temperature of the electrical component when it is working according to the sensors installed in the main circuit, the control circuit and the protection circuit; and acquire the ambient temperature; a data cache unit, which is used to store the data acquired by the sensor data acquisition unit; and a data update unit, which is used to update the maximum working current voltage, maximum speed and maximum working temperature in the electrical component usage data according to the data acquired by the sensor data acquisition unit.

3. The monitoring and diagnosis method for electrical safety failure of lifting machinery equipment according to claim 2, characterized in that: The fault output module comprises: a fault output unit for outputting fault information for identification and diagnosis; and a fault writing unit for writing the fault information of the electrical component into the data storage unit.

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