Variable frequency water pump leakage detection method and system

Abstract

The application discloses a kind of variable frequency water pump leakage detection method and system, the method includes the following steps: collecting the voltage variation value of variable frequency water pump, current variation value and insulation resistance variation value;First safety threshold, second safety threshold and third safety threshold are set;Variable frequency water pump voltage variation value is whether greater than the first safety threshold, or the current variation value of variable frequency water pump is whether greater than the second safety threshold, if not, it indicates that variable frequency water pump normal operation;If yes, it indicates that variable frequency water pump failure, and whether the insulation resistance variation value of variable frequency water pump is less than the third safety threshold, if yes, it indicates that variable frequency water pump occurs leakage;If not, it indicates that variable frequency water pump does not occur leakage.The application solves the problem that in the traditional variable frequency water pump detection field, single dimension detection mode is often difficult to comprehensively and accurately detect the leakage of variable frequency water pump.

Description

Technical Field

[0001] This invention relates to the field of leakage current detection technology for variable frequency water pumps, specifically a method and system for detecting leakage current in variable frequency water pumps. Background Technology

[0002] In the traditional field of variable frequency water pump leakage detection, the focus is usually on collecting a single key operating parameter of the variable frequency water pump, such as voltage or current variation, as the main basis for determining whether leakage has occurred. However, since the operating status of a variable frequency water pump is affected by a variety of factors, this single-dimensional detection method is often insufficient to comprehensively and accurately detect leakage. For example, brief fluctuations in voltage or current may be caused by normal power grid disturbances or load adjustments, rather than leakage, which may lead to false alarms or missed alarms. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention proposes a method and system for detecting leakage current in variable frequency water pumps. The aim is to solve the problem that in the traditional field of variable frequency water pump testing, single-dimensional detection methods are often insufficient to comprehensively and accurately detect leakage current in variable frequency water pumps.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A method for detecting leakage current in a variable frequency water pump includes the following steps:

[0006] Step S1: Collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump;

[0007] Step S2: Set the first security threshold, the second security threshold, and the third security threshold;

[0008] Step S3: Determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it indicates that the variable frequency water pump is operating normally; if yes, it indicates that the variable frequency water pump has malfunctioned. Determine whether the insulation resistance change value of the variable frequency water pump is less than the third safety threshold. If yes, it indicates that the variable frequency water pump is leaking current; if no, it indicates that the variable frequency water pump is not leaking current.

[0009] Preferably, in step S3, the process of determining whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold, specifically includes the following sub-steps:

[0010] When a large voltage fluctuation and a relatively smooth current fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the voltage change value is greater than the first safety threshold. When a large current fluctuation and a relatively smooth voltage fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the current change value is greater than the second safety threshold. When both the voltage and current of the variable frequency water pump are relatively stable, the pump's normal operation is determined by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold.

[0011] Preferably, the method further includes the following steps: when it is determined that the variable frequency water pump is leaking current, the leakage protection mechanism is triggered and a leakage alarm signal is generated.

[0012] Preferably, the method further includes the following steps: when it is determined that the variable frequency water pump is operating normally or no leakage has occurred, the current voltage value, current value and insulation resistance value of the variable frequency water pump are recorded.

[0013] Preferably, the method further includes the following steps: when leakage current detection is required for several variable frequency water pumps, the several variable frequency water pumps are divided into different priority levels, and different detection times are set for each priority level of variable frequency water pump.

[0014] Another aspect of this application provides a variable frequency water pump leakage current detection system, the system comprising:

[0015] The data acquisition module is used to collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump.

[0016] The first setting module is used to set the first security threshold, the second security threshold, and the third security threshold;

[0017] The first judgment module is used to determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it means that the variable frequency water pump is operating normally; if so, it means that the variable frequency water pump has malfunctioned and the second judgment module is executed.

[0018] The second judgment module is used to determine whether the change value of the insulation resistance of the variable frequency water pump is less than the third safety threshold. If it is, it means that the variable frequency water pump has leaked electricity; if not, it means that the variable frequency water pump has not leaked electricity.

[0019] Preferably, the first determination module includes:

[0020] The first selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the voltage change value is greater than the first safety threshold when a large voltage fluctuation and a relatively smooth current fluctuation are detected.

[0021] The second selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the current change value is greater than the second safety threshold when a large current fluctuation and a relatively flat voltage fluctuation are detected.

[0022] The third selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold when the voltage and current of the variable frequency water pump are in a relatively stable state.

[0023] Preferably, it further includes a trigger module and a generation module. The trigger module is used to trigger the leakage protection mechanism task, and the generation module is used to generate a leakage alarm signal. When it is determined that the variable frequency water pump has a leakage, the trigger module and the generation module are executed.

[0024] Preferably, it also includes a recording module, which is used to record the voltage value, current value and insulation resistance value of the current variable frequency water pump; when it is determined that the variable frequency water pump is operating normally or no leakage has occurred, the recording module is executed.

[0025] Preferably, it further includes a division module and a second setting module. The division module is used to divide the variable frequency water pumps into different priority levels, and the second setting module is used to set different detection times for each priority level of variable frequency water pump. When leakage current detection is required for the variable frequency water pumps, the division module and the second setting module are executed.

[0026] The technical solutions provided in this application embodiment may include the following beneficial effects:

[0027] This solution first uses changes in the voltage and current of the variable frequency water pump to initially determine whether the pump is operating normally. Then, if an anomaly is detected, further checks are made by monitoring changes in the pump's insulation resistance to detect leakage. This reduces the randomness of fault diagnosis. This multi-dimensional approach to detecting leakage avoids the potential for false alarms or missed alarms that can occur when relying on a single parameter, thus improving the accuracy and comprehensiveness of leakage detection for variable frequency water pumps. Attached Figure Description

[0028] Figure 1 This is a flowchart of a method for detecting leakage current in a variable frequency water pump. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] A method for detecting leakage current in a variable frequency water pump includes the following steps:

[0031] Step S1: Collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump;

[0032] Step S2: Set the first security threshold, the second security threshold, and the third security threshold;

[0033] Step S3: Determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it indicates that the variable frequency water pump is operating normally; if yes, it indicates that the variable frequency water pump has malfunctioned. Determine whether the insulation resistance change value of the variable frequency water pump is less than the third safety threshold. If yes, it indicates that the variable frequency water pump is leaking current; if no, it indicates that the variable frequency water pump is not leaking current.

[0034] This solution includes a method for detecting leakage current in a variable frequency water pump, such as... Figure 1As shown, the first step is to collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump. In this embodiment, by installing voltage and current sensors at the power input terminal of the variable frequency water pump, the changes in voltage and current can be monitored in real time. An insulation resistance tester is used to detect the change in insulation resistance of the variable frequency water pump. The second step is to set a first safety threshold, a second safety threshold, and a third safety threshold. In this embodiment, by setting the first safety threshold, i.e., the safety threshold for the voltage change value of the variable frequency water pump, it can be ensured that the variable frequency water pump operates within the normal voltage range, avoiding unstable operation or malfunction due to voltage fluctuations. By setting the second safety threshold, i.e., the safety threshold for the current change value of the variable frequency water pump, it can be ensured that the variable frequency water pump operates within the normal current range, preventing damage to the motor of the variable frequency water pump due to overload or undercurrent. By setting a third safety threshold, namely the safety threshold for the change in insulation resistance of the variable frequency water pump, the insulation status of the pump can be understood more intuitively. If the change in insulation resistance is found to be less than the corresponding safety threshold, it indicates poor insulation performance and leakage. The third step is to determine whether the voltage change is greater than the first safety threshold or the current change is greater than the second safety threshold. If not, the pump is operating normally; if so, it indicates a malfunction. Then, the insulation resistance change is checked against the third safety threshold. If so, leakage is present; if not, no leakage is present. Specifically, voltage and current are the most direct reflections of motor operating status. By monitoring these parameters in real time, it is possible to quickly determine whether the pump is operating normally. For example, an abnormal increase in current may indicate overload, blockage, or internal motor fault, while voltage fluctuations may be related to power quality or inverter settings. This initial diagnosis can quickly pinpoint the problem area, providing direction for subsequent in-depth inspections. After initially determining the presence of an anomaly, testing the insulation resistance to confirm whether there is leakage is an efficient and accurate method. A decrease in insulation resistance is a direct indicator of equipment leakage; this test can quickly locate the leakage point, providing a clear target for maintenance work.

[0035] In one embodiment, the voltage change value of the variable frequency water pump is 60V, the current change value is 90A, and the insulation resistance change value is 1 megohm. The first safety threshold is 50V, the second safety threshold is 80A, and the third safety threshold is 2 megohms. If the voltage or current change value of the variable frequency water pump is greater than its corresponding safety threshold in the first assessment, a fault can be determined. If the insulation resistance change value is less than its corresponding safety threshold in the second assessment, the fault can be determined to be leakage current, facilitating timely repair of the leakage fault by personnel.

[0036] This solution first uses changes in the voltage and current of the variable frequency water pump to initially determine whether the pump is operating normally. Then, if an anomaly is detected, further checks are made by monitoring changes in the pump's insulation resistance to detect leakage. This reduces the randomness of fault diagnosis. This multi-dimensional approach to detecting leakage avoids the potential for false alarms or missed alarms that can occur when relying on a single parameter, thus improving the accuracy and comprehensiveness of leakage detection for variable frequency water pumps.

[0037] Preferably, in step S3, the process of determining whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold, specifically includes the following sub-steps:

[0038] When a large voltage fluctuation and a relatively smooth current fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the voltage change value is greater than the first safety threshold. When a large current fluctuation and a relatively smooth voltage fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the current change value is greater than the second safety threshold. When both the voltage and current of the variable frequency water pump are relatively stable, the pump's normal operation is determined by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold.

[0039] In this embodiment, when a large voltage fluctuation and a relatively smooth current fluctuation are detected in the variable frequency water pump, the significant voltage change may directly affect the motor performance and operational stability of the variable frequency water pump. In contrast, the relatively smooth current fluctuation indicates that the load change of the variable frequency water pump motor is not significant, or at least the current change is not the primary issue. Therefore, the voltage change value can be prioritized to determine whether the variable frequency water pump is operating normally. When a large current fluctuation and a relatively smooth voltage fluctuation are detected in the variable frequency water pump, the significant current change signifies a significant change in the motor load or operating state, which may be due to an increased pump load, internal motor faults, etc. In contrast, the relatively smooth voltage fluctuation indicates that the voltage change is not the primary issue. Therefore, the current change value can be prioritized to determine whether the variable frequency water pump is operating normally. When both the voltage and current of the variable frequency water pump are relatively stable, it means that the pump's operating environment is good and the motor performance is stable. Therefore, either the current change value or the voltage change value can be monitored, and as long as the value is within a safe range, the pump is considered to be operating normally.

[0040] Preferably, the method further includes the following steps: when a leakage current is detected in the variable frequency water pump, the leakage current protection mechanism is triggered and a leakage current alarm signal is generated. In this embodiment, after a leakage current is detected in the variable frequency water pump, the power supply to the variable frequency water pump is immediately cut off, and a leakage current alarm signal is issued so that staff can take timely measures to prevent safety accidents, thereby enhancing the safety of the variable frequency water pump during use.

[0041] Preferably, when it is determined that the variable frequency water pump is operating normally or that no leakage has occurred, the current voltage, current, and insulation resistance values ​​of the variable frequency water pump are recorded. In this embodiment, after determining that the variable frequency water pump is operating normally or that no leakage has occurred, the current voltage, current, and insulation resistance values ​​of the variable frequency water pump are recorded as reference values ​​for subsequent testing, so as to carry out long-term performance monitoring and preventive maintenance.

[0042] Preferably, when leakage current detection is required for several variable frequency water pumps, the pumps are divided into different priority levels, and different detection times are set for each priority level. In this embodiment, during the process of dividing multiple variable frequency water pumps into different priority levels, the historical fault records of each pump are analyzed, and pumps that frequently fail or are known to have leakage potential are given higher priority levels. Dividing multiple pumps into different priority levels facilitates subsequent leakage current detection of the pumps according to their priority levels from high to low. Setting different detection times for each priority level ensures that high-priority pumps are processed first.

[0043] Another aspect of this application provides a variable frequency water pump leakage current detection system, the system comprising:

[0044] The data acquisition module is used to collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump.

[0045] The first setting module is used to set the first security threshold, the second security threshold, and the third security threshold;

[0046] The first judgment module is used to determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it means that the variable frequency water pump is operating normally; if so, it means that the variable frequency water pump has malfunctioned and the second judgment module is executed.

[0047] The second judgment module is used to determine whether the change value of the insulation resistance of the variable frequency water pump is less than the third safety threshold. If it is, it means that the variable frequency water pump has leaked electricity; if not, it means that the variable frequency water pump has not leaked electricity.

[0048] This solution presents a variable frequency water pump leakage detection system. Through the coordinated operation of a data acquisition module, a first setting module, a first judgment module, and a second judgment module, it achieves leakage detection of the variable frequency water pump. This solution first uses changes in the pump's voltage and current to preliminarily determine if the pump is operating normally. Then, when an anomaly is detected, it further detects leakage by monitoring changes in the pump's insulation resistance. This reduces the blindness of fault diagnosis. This multi-dimensional approach to detecting leakage avoids the potential for false alarms or missed alarms caused by relying on a single parameter, thereby improving the accuracy and comprehensiveness of variable frequency water pump leakage detection.

[0049] Preferably, the first determination module includes:

[0050] The first selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the voltage change value is greater than the first safety threshold when a large voltage fluctuation and a relatively smooth current fluctuation are detected.

[0051] The second selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the current change value is greater than the second safety threshold when a large current fluctuation and a relatively flat voltage fluctuation are detected.

[0052] The third selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold when the voltage and current of the variable frequency water pump are in a relatively stable state.

[0053] In this embodiment, in the first selection submodule, significant voltage changes may directly affect the motor performance and operational stability of the variable frequency water pump. In contrast, relatively gentle current fluctuations indicate that the load change of the variable frequency water pump motor is not significant, or at least the current change is not the primary issue. Therefore, voltage change values ​​can be prioritized to determine whether the variable frequency water pump is operating normally. In the second selection submodule, significant current changes signify a significant change in the motor load or operating state. In contrast, relatively gentle voltage fluctuations indicate that voltage changes are not the primary issue. Therefore, current change values ​​can be prioritized to determine whether the variable frequency water pump is operating normally. In the third selection submodule, relatively stable voltage and current of the variable frequency water pump indicate a good operating environment and stable motor performance. Therefore, either current or voltage change values ​​can be monitored, and as long as the values ​​are within safe limits, the water pump is considered to be operating normally.

[0054] Preferably, the system further includes a triggering module and a generation module. The triggering module is used to trigger the leakage current protection mechanism, and the generation module is used to generate a leakage current alarm signal. When a leakage current is detected in the variable frequency water pump, the triggering module and the generation module are executed. In this embodiment, after a leakage current is detected in the variable frequency water pump, executing the triggering and generation modules allows staff to take timely measures to prevent safety accidents, thereby enhancing the safety of the variable frequency water pump during use.

[0055] Preferably, the system further includes a recording module, which records the current voltage, current, and insulation resistance values ​​of the variable frequency water pump. The recording module is executed when it is determined that the variable frequency water pump is operating normally or that no leakage has occurred. In this embodiment, after determining that the variable frequency water pump is operating normally or that no leakage has occurred, the recording module is executed to use the current voltage, current, and insulation resistance values ​​of the variable frequency water pump as reference values ​​for subsequent testing, in order to perform long-term performance monitoring and preventative maintenance.

[0056] Preferably, the system further includes a division module and a second setting module. The division module is used to divide the variable frequency pumps into different priority levels, and the second setting module is used to set different detection times for each priority level of the variable frequency pumps. When leakage current detection of the variable frequency pumps is required, the division module and the second setting module are executed. In this embodiment, executing the division module facilitates subsequent leakage current detection of the variable frequency pumps according to their priority levels from high to low. Executing the second setting module ensures that high-priority variable frequency pumps are processed first.

[0057] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0058] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for detecting leakage current in a variable frequency water pump, characterized in that: Includes the following steps: Step S1: Collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump; Step S2: Set the first security threshold, the second security threshold, and the third security threshold; Step S3: Determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it indicates that the variable frequency water pump is operating normally; if yes, it indicates that the variable frequency water pump has malfunctioned. Then determine whether the insulation resistance change value of the variable frequency water pump is less than the third safety threshold. If yes, it indicates that the variable frequency water pump is leaking current; if no, it indicates that the variable frequency water pump is not leaking current. In step S3, the process of determining whether the voltage change value of the variable frequency water pump is greater than the first safety threshold, or whether the current change value of the variable frequency water pump is greater than the second safety threshold, specifically includes the following sub-steps: When a large voltage fluctuation and a relatively smooth current fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the voltage change value is greater than the first safety threshold. When a large current fluctuation and a relatively smooth voltage fluctuation are detected in the variable frequency water pump, the pump's normal operation is determined by comparing whether the current change value is greater than the second safety threshold. When both the voltage and current of the variable frequency water pump are relatively stable, the pump's normal operation is determined by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold.

2. The method for detecting leakage current in a variable frequency water pump according to claim 1, characterized in that: It also includes the following steps: When a leakage current is detected in the variable frequency water pump, the leakage current protection mechanism is triggered and a leakage current alarm signal is generated.

3. The method for detecting leakage current in a variable frequency water pump according to claim 1, characterized in that: It also includes the following steps: When it is determined that the variable frequency water pump is operating normally or there is no leakage, the current voltage, current and insulation resistance values ​​of the variable frequency water pump are recorded.

4. The method for detecting leakage current in a variable frequency water pump according to claim 1, characterized in that: It also includes the following steps: When leakage current detection is required for several variable frequency water pumps, the pumps are divided into different priority levels, and different detection times are set for each priority level.

5. A variable frequency water pump leakage current detection system, using the variable frequency water pump leakage current detection method as described in any one of claims 1-4, characterized in that: The system includes: The data acquisition module is used to collect the voltage change value, current change value, and insulation resistance change value of the variable frequency water pump. The first setting module is used to set the first security threshold, the second security threshold, and the third security threshold; The first judgment module is used to determine whether the voltage change value of the variable frequency water pump is greater than the first safety threshold or whether the current change value of the variable frequency water pump is greater than the second safety threshold. If not, it means that the variable frequency water pump is operating normally; if so, it means that the variable frequency water pump has malfunctioned and the second judgment module is executed. The second judgment module is used to determine whether the change value of the insulation resistance of the variable frequency water pump is less than the third safety threshold. If it is, it means that the variable frequency water pump has leaked electricity; if not, it means that the variable frequency water pump has not leaked electricity.

6. The variable frequency water pump leakage detection system according to claim 5, characterized in that: The first judgment module includes: The first selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the voltage change value is greater than the first safety threshold when a large voltage fluctuation and a relatively smooth current fluctuation are detected. The second selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether the current change value is greater than the second safety threshold when a large current fluctuation and a relatively flat voltage fluctuation are detected. The third selection submodule is used to determine whether the variable frequency water pump is operating normally by comparing whether either the voltage change value or the current change value is greater than its corresponding safety threshold when the voltage and current of the variable frequency water pump are in a relatively stable state.

7. The variable frequency water pump leakage detection system according to claim 5, characterized in that: It also includes a triggering module and a generation module, wherein the triggering module is used to trigger the leakage current protection mechanism task, and the generation module is used to generate a leakage current alarm signal; When a leakage current is detected in the variable frequency water pump, the trigger module and the generation module are executed.

8. The variable frequency water pump leakage detection system according to claim 5, characterized in that: It also includes a recording module, which is used to record the voltage, current and insulation resistance values ​​of the current variable frequency water pump; When it is determined that the variable frequency water pump is operating normally or no leakage has occurred, the recording module is executed.

9. The variable frequency water pump leakage detection system according to claim 5, characterized in that: It also includes a division module and a second setting module. The division module is used to divide several variable frequency water pumps into different priority levels, and the second setting module is used to set different detection times for each priority level of variable frequency water pump. When leakage current detection is required for several variable frequency water pumps, the division module and the second setting module are executed.

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