Method and device for eliminating slight stalling of pump

Abstract

The invention discloses a method and device for eliminating slight stalling of a pump, and belongs to the technical field of motor control. In the pump operation process, the flux linkage change rate of a motor in the pump is obtained, and locked-rotor judgment is conducted on the pump based on the flux linkage change rate; on the basis of the obtained locked-rotor judgment result, according to the locked-rotor state of the pump, selecting to enter a blockage clearing mode; after the pump enters the blockage clearing mode, a pump motor is controlled to operate under the first-level torque condition, the flux linkage change rate of the motor is obtained, and the locked-rotor degree grade of the pump is judged based on the obtained flux linkage change rate; the first-stage torque is larger than the torque of normal starting of the pump; and according to different locked-rotor degree grades and preset corresponding blockage clearing rules, the pump is controlled to execute blockage clearing operation. The capacity of the motor can be brought into full play, the pump can automatically eliminate some slight locked-rotor faults when encountering the slight locked-rotor faults, and the shutdown maintenance frequency is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of motor control, and in particular to a method and device for eliminating minor pump stalling. Background Art

[0002] A pump is a machine that transports liquid or pressurizes liquid. A canned pump is a type of pump, in which the motor of a canned pump is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic conversion. The motor of a canned pump generates a large amount of heat energy during operation.

[0003] During the operation of the canned motor pump, some impurities will inevitably be precipitated in the fluid medium it transports. In the long-term operation, these impurities will easily cause the impeller to get stuck, making the canned motor unable to be used normally. There is also the possibility of the motor burning out due to continuous stalling. In this regard, motors controlled by FOC (field oriented control) generally have stall detection and protection functions, which allow the motor to stop in time when a stall fault is detected to prevent the motor from overheating.

[0004] At present, some manufacturers have launched products that can rotate the impeller by twisting a screw directly connected to the impeller from the outside to eliminate the blocking of the shielded pump. However, this method requires the user to disassemble the drive box or some other components, which is cumbersome and time-consuming.

[0005] At present, regardless of whether the shielded pump is only slightly blocked, the entire system generally needs to be shut down for maintenance. For some systems where the shielded pump is installed in a remote location, it is difficult to shut down for maintenance. Especially for some large systems, frequent shutdowns for maintenance will cause customer complaints and unnecessary cost increases, which is unacceptable. Some manufacturers also provide the function of clearing fault codes for shielded pumps, but this only eliminates the fault by clearing the fault code and tries to make the shielded pump run again in the blocked state. If the problem is not solved, it needs to be shut down again. Therefore, it is only a temporary solution and cannot fundamentally solve the problem.

[0006] Regarding the problem of eliminating pump jams, after searching, patent number CN110080998A discloses a method, device and storage medium for eliminating jams in automotive electronic water pumps. The patent obtains the current current flowing through the motor in the water pump; controls the motor to rotate in the opposite direction when the current current is greater than the current threshold; when the duration of the motor's reverse rotation reaches a first preset duration, controls the motor to rotate forward at a first speed to allow the motor to enter a normal operating state. The patent hopes to automatically eliminate the jam by rotating the motor in the opposite direction to remove impurities stuck in the impeller in the pipeline. However, the solution involved in the patent allows the pump to rotate in the opposite direction in the case of severe jams, which will cause the pump to operate under high current conditions, and there is a risk of damaging the motor.

[0007] Patent No. CN116771690A discloses a method and related device for eliminating the stall of an electronic water pump. During the operation of the water pump, the actual speed of the water pump in the first direction is collected, and based on the actual speed, the water pump is detected for stalling, and the first direction is the current rotation direction; if the obtained detection result indicates that the current operation state of the water pump is stalled, the water pump is controlled to perform the unblocking operation according to the preset number of unblocking times. Each unblocking operation controls the water pump to rotate forward or reverse for a preset time according to the predicted speed, and the predicted speed is greater than the actual speed. The patent determines whether the water pump is in a stalled state by obtaining the speed of the water pump. The severity of the stall can be judged to a certain extent according to the speed. If the speed is too low, it can be determined that the stall is serious and the pump is directly shut down and waits for manual maintenance, which can avoid the risk of damage caused by the operation of the water pump under high current conditions. However, most existing pumps do not collect the running speed of the pump in real time by installing sensors, but collect parameters such as the running current value of the motor and obtain the speed by calculation. In this case, the speed obtained by calculation is inaccurate, resulting in poor effect of clearing the stall fault. Summary of the invention

[0008] 1. Technical problem to be solved by the invention

[0009] The present application provides a method and device for eliminating minor pump jams. The present application fully utilizes the motor's capabilities by adjusting the motor torque, and cooperates with adjusting the rotation direction of the pump impeller to enable the pump to break free from some relatively minor jams, allowing the pump to eliminate some minor jams by itself when encountering them, thereby reducing the number of shutdowns for maintenance.

[0010] 2. Technical solution

[0011] In order to achieve the above objectives, the technical solution provided by this application is:

[0012] A method for eliminating minor pump jam in the present application comprises:

[0013] During the operation of the pump, a flux change rate of a motor in the pump is obtained, and a pump stall determination is performed based on the flux change rate;

[0014] Based on the obtained blocking judgment result, according to the blocking state of the pump, choose to enter the blocking clearing mode;

[0015] After entering the blockage clearing mode, the pump motor is controlled to operate under the first-level torque condition, and the flux change rate of the motor is obtained, and the blocking degree level of the pump is judged based on the obtained flux change rate; the first-level torque is greater than the torque of the pump normal start-up;

[0016] According to different blocking degree levels and preset corresponding blocking clearing rules, the pump is controlled to perform a blocking clearing operation;

[0017] The blockage clearing rules are set for the torque, rotation direction and rotation time of the pump at different blocking levels.

[0018] Furthermore, during the stable operation of the pump, the magnetic flux change rate of the motor is obtained in real time. If the obtained magnetic flux change rate is less than the first set ratio of the magnetic flux change rate corresponding to the minimum operating speed under normal operation of the pump, it is determined that the pump is in a slight stall state and enters the clearing mode.

[0019] Furthermore, if the obtained flux change rate is less than the second set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and the second set ratio is less than the first set ratio, it is determined that the pump is in a serious stall state and is shut down for maintenance.

[0020] Furthermore, if it is determined that the pump is in a slight jam state, the pump is controlled to stop running for a first preset period of time, and then restarted to enter the jam clearing mode. When restarting, the motor torque is increased to the first-level torque condition and the magnetic flux change rate of the motor is obtained in real time.

[0021] Furthermore, the rules for judging the degree of stall of the pump are as follows:

[0022] If the obtained flux change rate is less than the third set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and is greater than the fourth set ratio, it is determined that the pump is in a first-level stall state;

[0023] If the obtained flux change rate is less than or equal to the fourth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and is greater than the fifth set ratio, it is determined that the pump is in a secondary stall state;

[0024] If the acquired flux change rate is less than or equal to a fifth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, it is determined that the pump is in a third-level stall state.

[0025] Furthermore, after determining the blocking degree level of the pump, the pump is controlled to stop running for a second preset time period, and the pump is restarted and controlled to perform a clearing operation according to a preset clearing rule.

[0026] Furthermore, if it is determined that the pump is in a first-level jam state, the motor is controlled to drive the impeller to rotate from the first-level torque to perform a cycle of unblocking operation; during the unblocking operation, it is determined in real time whether the motor has been successfully started; if the start-up fails, it progresses to the second-level torque to drive the impeller to rotate, and continues to perform a cycle of unblocking operation; until the motor starts successfully or reaches the third-level torque and still fails to restart and finally shuts down.

[0027] Furthermore, if it is determined that the pump is in a secondary stall state, the motor is controlled to drive the impeller to rotate starting from the third level torque; and in the event that the motor fails to start, the impeller is driven to rotate at a higher level torque until the motor starts successfully or reaches the fifth level torque and still fails to restart and finally shuts down.

[0028] Furthermore, if it is determined that the pump is in a third-level stall state, the motor is controlled to drive the impeller to rotate starting from a fifth-level torque; three cycles of unblocking operations are preset under this torque until the motor starts successfully or fails to restart and finally stops.

[0029] Furthermore, a cycle of unblocking operation is performed in the following manner: first rotate along the first rotation direction for a third preset time, stop for a fourth preset time, and then rotate along the second rotation direction for a fifth preset time; the second rotation direction is the opposite direction of the first rotation direction.

[0030] Furthermore, after one cycle of the clearing operation is completed, the pump is controlled to stop running for a sixth preset time period, and then the pump is controlled to restart to perform the next cycle of the clearing operation.

[0031] Furthermore, during the unblocking process, three cycles of unblocking operations are performed by default. If no successful feedback is received after three cycles of unblocking operations, a fault message is reported; and under the torque conditions of the previous cycle, two more cycles of unblocking operations are attempted. If the unblocking is still unsuccessful, the machine is shut down and waits for maintenance.

[0032] A device for eliminating minor pump jams of the present application includes a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement the method for eliminating minor pump jams.

[0033] 3. Beneficial effects

[0034] Compared with the existing known technologies, the technical solution provided by this application has the following significant effects:

[0035] The present application provides a method for eliminating minor pump jams by detecting the rate of change of the motor flux and adaptively adjusting the starting torque to eliminate minor jams. The application makes full use of the characteristics of the pump field oriented control (FOC) motor that can freely adjust the motor direction and starting torque, thereby bringing into play the potential of the pump itself, improving the stability of the pump operation, and reducing the number of pump shutdowns for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of a pump system using the method for eliminating minor pump stalling provided by an embodiment of the present application;

[0037] Figure 2This is a flow chart of a method for eliminating minor pump stalling provided by an embodiment of the present application;

[0038] Figure 3 This is a flow chart for determining a slight stall or a severe stall provided by an embodiment of the present application;

[0039] Figure 4 This is a schematic diagram of determining the degree of stall provided by an embodiment of the present application;

[0040] Figure 5 is a relationship diagram of the five-level jam-clearing torque relative to the normal starting torque provided by an embodiment of the present application;

[0041] Figure 6 This is a flow chart of clearing blockage in a first-level blocking state provided by an embodiment of the present application;

[0042] Figure 7 This is a flow chart of clearing blockage in a secondary blocking state provided by an embodiment of the present application;

[0043] Figure 8 This is a flow chart of clearing blockage in a three-stage blocking state provided by an embodiment of the present application;

[0044] Fig. 9 is a flow chart of a method for eliminating minor pump stalling provided by another embodiment of the present application;

[0045] Fig.10 It is a schematic structural diagram of a device for eliminating minor pump jams provided by an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to further understand the content of the present application, the present application is described in detail with reference to the accompanying drawings and embodiments.

[0047] Example 1

[0048] Combination Figure 1 The pump system at least includes a driver and a pump body, the pump body includes a motor and an impeller, the driver is used to control the operation of the motor, and the motor drives the impeller to rotate to transport liquid or pressurize the liquid. The method for eliminating pump stalling in this embodiment is applicable to all motors controlled by programmable drivers, and is applicable to shielded pumps, mechanical pumps, etc. that require stall protection.

[0049] In this embodiment, the driver is used to obtain the current current flowing through the motor after the pump is powered on and runs stably, and calculate the motor's flux change rate based on the current value, and judge the pump is stalled based on the obtained flux change rate.

[0050] It is worth noting that the increase in flux change rate is manifested in an abnormal increase in magnetic flux, which is caused by the abnormally large current generated by the stall. Therefore, the flux change rate can be used to indirectly determine whether the motor has a stall fault. Since the flux change rate is calculated based on a fixed variable relationship and the collected current value, compared with the motor speed obtained through a relatively complex estimation algorithm, using the flux change rate to determine whether the motor has a stall fault has a higher accuracy.

[0051] Combination Figure 2 In this embodiment, based on the obtained jam judgment result, if it is determined that the pump is in a slight jam state, the jam clearing mode is entered, and if it is determined that the pump is in a serious jam state, the pump is shut down and waits for maintenance.

[0052] As mentioned above, the motor will generate a lot of heat energy during operation. If the motor runs in a serious stall state, there will be a risk of motor overheating and damage, and the motor output torque has a limit. Therefore, when the pump is in a serious stall state, it is not advisable to eliminate the stall fault by controlling the motor.

[0053] Specifically, this embodiment is set to obtain the flux change rate of the motor in real time during the stable operation of the pump. If the obtained flux change rate is less than the first set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, the pump is determined to be in a slight stall state, and then enters the clearing mode to control the motor to eliminate the stall fault. If the obtained flux change rate is less than the second set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, where the second set ratio is less than the first set ratio, the pump is determined to be in a serious stall state and shut down for maintenance.

[0054] The normal operation of the pump described here specifically refers to the condition where there is no stalling failure and the pump is operating normally. When the pump is operating normally, it has multiple operating modes such as constant pressure and constant current, and the speed can also be adjusted in multiple gears. Since the flux change rate increases with the increase of speed, if the real-time flux change rate is lower than the flux change rate corresponding to the minimum operating speed under normal operation of the pump, it can be concluded that the pump has a certain degree of stalling.

[0055] In view of this, combined with Figure 3 In this embodiment, when the flux change rate is set to be less than the first threshold, the pump is judged to be in a slightly blocked state, and when the flux change rate is less than the second threshold, the pump is judged to be in a severely blocked state. The selection criteria of the first threshold and the second threshold are a certain proportion of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, that is, the corresponding first set proportion and second set proportion.

[0056] In specific implementation, the first set ratio and the second set ratio can be set according to needs. This embodiment provides a suggested implementation method, such as:

[0057] After the pump is powered on and stabilized for 500ms, the motor flux change rate is obtained in real time. If the obtained flux change rate is less than 1 / 2 of the flux change rate corresponding to the minimum operating speed under normal operation (i.e., the first set ratio), it is judged that the current speed of the pump is abnormal, and the rotor is stuck, causing the pump to fail to operate normally. This fault is a minor stall fault, and the stall fault can be eliminated by starting the clearing mode and exerting the pump's own potential. If the obtained flux change rate is less than 1 / 10 of the flux change rate corresponding to the minimum operating speed under normal operation (i.e., the second set ratio), it is judged that there is a serious stall situation at this time, and it is not appropriate to eliminate the stall fault by controlling the motor itself, and the pump is controlled to stop running and wait for maintenance.

[0058] In the case of determining that it is a minor stall fault, the driver of this embodiment chooses to enter the clearing mode. After entering the clearing mode, the driver first controls the pump motor to operate under the first-level torque condition, and obtains the flux change rate of the motor, and judges the stall degree of the pump based on the obtained flux change rate. Different clearing rules are preset according to different stall degrees, and the pump is controlled to perform clearing operations scientifically according to the clearing rules.

[0059] The clearing rules are set at different levels of blocking, with the pump running at different torques, changing rotation directions and different rotation times. The clearing rules will be described in detail below.

[0060] It is worth noting that when the pump is in different gears, only the speed and power are different, and the starting torque is the same. In this embodiment, when entering the clearing mode, the torque is increased to a level 1 torque greater than the normal starting torque when the motor restarts, and the severity of the stall is continued to be determined. The severity of the stall is divided into one to three levels according to different flux change rates, which can be understood as further subdivided into mild, moderate, and severe stall states under a minor stall fault state. Performing different clearing operations in different stall states will help eliminate the fault as soon as possible, and the pump will adjust back to normal operation at the fastest speed.

[0061] Example 2

[0062] Combination Figure 4 In this embodiment, the pump stalling degree level determination rule is further determined, and the flux change rate is continued to be used as the determination basis in the rule. Specifically:

[0063] If the obtained flux change rate is less than the third set ratio of the flux change rate corresponding to the minimum operating speed under normal pump operation, and is greater than the fourth set ratio, it is determined that the pump is in a primary (i.e., mild) stall state;

[0064] If the obtained flux change rate is less than or equal to the fourth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and is greater than the fifth set ratio, it is determined that the pump is in a secondary (i.e., moderate) stall state;

[0065] If the acquired flux change rate is less than or equal to the fifth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, it is determined that the pump is in the third level (ie severe) stall state.

[0066] Similarly, in specific implementation, the third setting ratio, the fourth setting ratio, and the fifth setting ratio can be set according to needs. This embodiment provides a suggested implementation method, such as:

[0067] When the pump detects a stall fault, it will first shut down to prevent the motor from running for too long under abnormally high current conditions, causing the motor to overheat; after 8 seconds, it will clear the blockage and restart. When restarting, the motor torque will be increased to the first-level starting torque. Then the three-phase current of the motor will be collected to derive the motor flux change rate. When the flux change rate is less than 1 / 10 of the flux change rate corresponding to the minimum operating speed under normal operation (i.e., the fifth set ratio), the stall degree is determined to be a severe level of mild stall. When the flux change rate is less than or equal to 3 / 10 of the flux change rate corresponding to the minimum operating speed under normal operation (i.e., the fourth set ratio) and greater than 1 / 10, the stall degree is determined to be a moderate level of mild stall. When the flux change rate is less than 1 / 2 of the flux change rate corresponding to the minimum operating speed under normal operation (i.e., the third set ratio) and greater than 3 / 10, the stall degree is determined to be a mild level of mild stall.

[0068] Example 3

[0069] Combination Figure 5 - Figure 8 In this embodiment, different clearing rules are preset according to different blocking degree levels, and the pump is controlled to perform clearing operations scientifically according to the clearing rules.

[0070] First see Figure 5In this embodiment, a total of 5 levels of torque are set, and each level of torque increases a certain multiple relative to the normal starting torque of the pump. The multiples of each level of torque relative to the normal starting torque of the pump may be the same or different, and are determined according to needs during actual implementation. In this embodiment, each level of torque is set to increase by 0.2 times relative to the normal starting torque of the pump. That is, the first level torque is 1.2 times the normal starting torque, the second level torque is 1.4 times the normal starting torque, and so on. The fifth level torque is 2 times the normal starting torque. There is a limit to the output torque of the motor. In this embodiment, the maximum torque that can be adjusted in the clearing mode is set to 2 times the normal starting torque, which is relatively appropriate and can ensure that the motor runs in a relatively safe condition.

[0071] Figure 6 The figure shows the unblocking process performed by the pump in the first-level jam state, which is specifically: controlling the motor to drive the impeller to rotate from the first-level torque to perform a cycle of unblocking operation; during the unblocking operation, judging in real time whether the motor has been successfully started (successful motor start-up means that the motor has eliminated the jam fault and restored the normal starting speed); if the start-up fails, it progresses to the second-level torque to drive the impeller to rotate, and continues to perform a cycle of unblocking operation; until the motor starts successfully or reaches the third-level torque and still fails to restart and finally shuts down.

[0072] Due to the judgment of the degree of stalling in the previous stage, the driver believes that the pump is only slightly stalled in the first-level stalling state. In theory, slightly increasing the starting torque should be able to eliminate the stalling fault. Therefore, the driver controls the motor to perform the clearing operation from the first-level torque. If the clearing fails under the first-level torque condition, the driver allows the motor to progress to the second-level torque and continue to try to clear the blockage until the motor starts successfully or reaches the third-level torque and still fails to restart. If the clearing still fails under the third-level torque condition, it means that the stalling judgment in the previous stage may be wrong. At this time, it is not advisable to take the risk of continuing to eliminate the stalling fault by controlling the motor. The machine should be shut down and wait for maintenance.

[0073] Figure 7 The figure shows the clearing process of the pump in the secondary jam state, which is specifically: controlling the motor to drive the impeller to rotate from the third level torque; and in the event of a motor starting failure, progressing to a higher level torque to drive the impeller to rotate until the motor starts successfully or reaches the fifth level torque and still fails to restart and finally shuts down.

[0074] Based on the judgment of the degree of stalling in the previous stage, the driver believes that the pump is in the second-level stalling state and is slightly seriously stalled. At this time, if the torque is still slowly increased step by step from the first-level torque, it will not have a significant effect on eliminating the stalling. Instead, it may gradually compact the impurities, making it more difficult to eliminate the fault, and waste excess energy on useless attempts, which is not conducive to eliminating the fault as soon as possible, and may also increase user losses. Therefore, the driver controls the motor to directly perform the clearing operation from the third-level torque. If the clearing fails under the third-level torque condition, the driver allows the motor to progress to the fourth-level torque and continue to try to clear the blockage until the motor is successfully started or the restart fails after reaching the fifth-level torque. If the clearing still fails under the fifth-level torque condition, it means that the previous stage of the stalling judgment may be wrong. At this time, it is not advisable to continue to control the motor to eliminate the stalling fault by yourself. The machine should be shut down and wait for maintenance.

[0075] Figure 8 The figure shows the unblocking process performed by the pump in the third-level jam state, which is specifically: controlling the motor to drive the impeller to rotate starting from the fifth-level torque; performing three cycles of unblocking operations at this torque until the motor starts successfully or fails to restart and finally stops.

[0076] Based on the judgment of the jam degree in the previous stage, the driver believes that it is in the third level jam state and the pump is in a mild jam state. At this time, from the perspective of saving time and energy, the driver controls the motor to directly perform the jam clearing operation from the fifth level torque. At the same time, in view of the short time of a single jam clearing cycle, there is a possibility that the jam fault cannot be completely cleared. Therefore, the driver presets three cycles of jam clearing operations. If the restart still fails after the three cycles, it means that the jam judgment in the previous stage may be wrong. At this time, it is not advisable to take the risk of continuing to eliminate the jam fault by controlling the motor. The machine should be shut down and wait for maintenance.

[0077] Furthermore, in this embodiment, a cycle of unblocking operation is performed in the following manner: first rotate along the first rotation direction for a third preset time, stop for a fourth preset time, and then rotate along the second rotation direction for a fifth preset time; the second rotation direction is the opposite direction of the first rotation direction.

[0078] It is worth noting that the first rotation direction and the second rotation direction correspond to the forward and reverse rotation of the motor. In a cycle of clearing operation, in theory, the motor can be controlled to rotate forward or reverse first. Considering that the motor is expected to be adjusted back to the normal operation state as soon as possible after eliminating the blocking fault, and the motor rotates forward during normal operation, it is preferred to rotate in the reverse direction first and then in the forward direction.

[0079] On the other hand, the third preset duration, the fourth preset duration, and the fifth preset duration are merely references. In actual implementation, they can be set according to demand. Not only can the third preset duration, the fourth preset duration, and the fifth preset duration in a single cycle remain the same, but they can also remain different. The third preset duration, the fourth preset duration, and the fifth preset duration in different cycles can also remain the same or different. Those skilled in the art can also know that when performing a clearing operation under different degrees of congestion, the third preset duration, the fourth preset duration, and the fifth preset duration involved can still remain the same or different.

[0080] This embodiment further provides suggested implementation methods, such as: controlling the motor to rotate in the reverse direction for 1.5 seconds (i.e., the third preset time length), and then controlling the intermediate pump to stop running for 1 second (i.e., the fourth preset time length), and then rotating forward for 2 seconds (i.e., the fifth preset time length).

[0081] Example 4

[0082] Combination Fig. 9 In this embodiment, considering that stalling will generate abnormally large current, which will cause the motor to generate a large amount of heat energy, in the process of controlling the motor to eliminate the stalling fault by itself, great care must be taken to avoid overheating of the motor and causing damage to the motor.

[0083] Therefore, when the present embodiment determines that the pump is in a slightly blocked state and will subsequently enter the clearing mode, the pump is first controlled to stop running for a first preset time period and then restarted to enter the clearing mode.

[0084] After determining the blocking degree of the pump, the pump is also controlled to stop running for a second preset time, and then the pump is restarted and controlled to perform a clearing operation according to a preset clearing rule.

[0085] And after each cycle of the unblocking operation is completed, the pump is controlled to stop running for the sixth preset time, and then the pump is controlled to restart to perform the next cycle of unblocking operation. Taking the first-level jam state as an example, the motor is controlled to drive the impeller to rotate from the first-level torque to perform a cycle of unblocking operation; during the unblocking operation, it is determined in real time whether the motor is successfully started; if the entire cycle fails to start, the pump is controlled to stop running for the sixth preset time, and then the pump is controlled to restart, and automatically progresses to the second-level torque to drive the impeller to rotate, and continues to perform a cycle of unblocking operation.

[0086] The first preset time, the second preset time, and the sixth preset time are also determined according to the needs during the specific implementation. This embodiment further provides a suggested implementation method, such as: the first preset time, the second preset time, and the sixth preset time are all set to 8s, and the pump is controlled to stop running for 8s, which can basically prevent the motor from running for too long under the state of abnormally high current, causing the motor to overheat.

[0087] Example 5

[0088] Combination Fig. 9 This embodiment further defines that during the clearing process, three cycles of clearing operations are performed by default. If no successful start feedback is received after three cycles of clearing operations, the driver reports a fault message to remind manual handling. At the same time, the driver attempts to perform two cycles of clearing operations under the torque conditions of the previous cycle. If the clearing still fails, the driver stops and waits for maintenance.

[0089] This design can be understood as the driver giving the motor two more chances to clear the stall fault. If the stall still fails, it means that it is not feasible for the motor to clear the stall fault by itself, and the motor must be shut down for maintenance.

[0090] At the same time, this embodiment limits the handling of unexpected situations. When an abnormal parameter input is detected in the clearing mode, the pump returns to the jam fault detection stage and initializes all parameters generated and changed in this fault processing (including the jam judgment count variable, the forward and reverse flag bit and the current limit variable). This prevents the pump from operating in an abnormal state due to unexpected conditions, causing damage to the pump itself. For example: when the pump is eliminating the jam fault, it receives a shutdown command from the customer. The pump will immediately stop running and initialize the variables and parameters involved in the process of eliminating the jam fault. When the customer re-issues the running command, the pump will re-perform fault detection to prevent the fault from being eliminated during the shutdown period, but the pump still operates according to the original state, causing the pump to be out of control.

[0091] Example 6

[0092] Combination Fig.10 This embodiment provides a device for eliminating minor pump jams, which includes a driver, a motor, an impeller, an input device, and an output device. The input device may be a key or a touch screen, and the output device may be a display device such as a liquid crystal display. The driver includes a processor and a memory, wherein a program is stored in the memory, and the program is loaded and executed by the processor to implement the method for eliminating minor pump jams as described in embodiments 1-5.

[0093] The above is a schematic description of the present application and its implementation methods, which is not restrictive. The drawings show only one implementation method of the present application and are not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs methods and embodiments similar to the technical solution without creativity without departing from the inventive purpose of the present application, they should all fall within the protection scope of the present application.

Claims

1. A method for eliminating minor pump stalling, characterized in that: include: During the operation of the pump, a flux change rate of a motor in the pump is obtained, and a pump stall determination is performed based on the flux change rate; Based on the obtained blocking judgment result, according to the blocking state of the pump, choose to enter the blocking clearing mode; After entering the blockage clearing mode, the pump motor is controlled to operate under the first-level torque condition, and the flux change rate of the motor is obtained, and the blocking degree level of the pump is judged based on the obtained flux change rate; the first-level torque is greater than the torque of the pump normal start-up; According to different blocking degree levels and preset corresponding blocking clearing rules, the pump is controlled to perform a blocking clearing operation; The blockage clearing rules are set for the torque, rotation direction and rotation time of the pump at different blocking levels.

2. A method for eliminating minor pump stalling according to claim 1, characterized in that: During stable operation of the pump, the motor's flux change rate is obtained in real time. If the obtained flux change rate is less than the first set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, the pump is determined to be in a slight stall state and enters the clearing mode.

3. A method for eliminating minor pump stalling according to claim 2, characterized in that: If the obtained flux change rate is less than the second set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and the second set ratio is less than the first set ratio, the pump is determined to be in a serious stall state and is shut down for maintenance.

4. A method for eliminating minor pump stalling according to claim 1, characterized in that: If the pump is judged to be in a slight jam state, the pump is controlled to stop running for the first preset time, and then restarted to enter the jam clearing mode. When restarting, the motor torque is increased to the first-level torque condition and the magnetic flux change rate of the motor is obtained in real time.

5. A method for eliminating minor pump stalling according to claim 1, characterized in that: The rules for judging the degree of stalling of the pump are as follows: If the obtained flux change rate is less than the third set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and is greater than the fourth set ratio, it is determined that the pump is in a first-level stall state; If the obtained flux change rate is less than or equal to the fourth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, and is greater than the fifth set ratio, it is determined that the pump is in a secondary stall state; If the acquired flux change rate is less than or equal to a fifth set ratio of the flux change rate corresponding to the minimum operating speed under normal operation of the pump, it is determined that the pump is in a third-level stall state.

6. A method for eliminating minor pump stalling according to claim 1, characterized in that: After determining the blocking degree level of the pump, the pump is controlled to stop running for a second preset time period, and the pump is restarted and controlled to perform a clearing operation according to a preset clearing rule.

7. A method for eliminating minor pump stalling according to any one of claims 1 to 6, characterized in that: If it is determined that the pump is in the first-level jam state, the motor is controlled to drive the impeller to rotate from the first-level torque to perform a cycle of unblocking operation; during the unblocking operation, it is determined in real time whether the motor is successfully started; if the startup fails, it progresses to the second-level torque to drive the impeller to rotate, and continues to perform a cycle of unblocking operation; until the motor starts successfully or reaches the third-level torque and still fails to restart and finally shuts down.

8. A method for eliminating minor pump stalling according to claim 7, characterized in that: If it is determined that the pump is in a secondary stall state, the motor is controlled to drive the impeller to rotate from the third level torque; and if the motor fails to start, it is progressively promoted to a higher level torque to drive the impeller to rotate until the motor starts successfully or reaches the fifth level torque and still fails to restart and finally shuts down.

9. A method for eliminating minor pump stalling according to claim 8, characterized in that: If it is determined that the pump is in the third-level stall state, the motor is controlled to drive the impeller to rotate starting from the fifth-level torque; three cycles of unblocking operations are preset under this torque until the motor is successfully started or the restart fails and finally stops.

10. A method for eliminating minor pump stalling according to claim 9, characterized in that: A cycle of unblocking operation is performed in the following manner: first rotate in the first rotation direction for the third preset time, stop for the fourth preset time, and then rotate in the second rotation direction for the fifth preset time; the second rotation direction is the opposite direction of the first rotation direction.

11. A method for eliminating minor pump stalling according to claim 9, characterized in that: After one cycle of the clearing operation is completed, the pump is controlled to stop running for a sixth preset time period, and then the pump is controlled to restart to perform the next cycle of the clearing operation.

12. A method for eliminating minor pump stalling according to claim 9, characterized in that: During the clearing process, three cycles of clearing operations are performed by default. If no successful feedback is received after three cycles of clearing operations, a fault message will be reported; and under the torque conditions of the previous cycle, two more cycles of clearing operations will be attempted. If the clearing is still unsuccessful, the machine will be shut down and wait for maintenance.

13. A device for eliminating minor pump stalling, characterized in that: It comprises a processor and a memory; the memory stores a program, and the program is loaded and executed by the processor to implement the method for eliminating slight pump jam as described in any one of claims 1 to 12.

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