Detection method and system for blocking protection of variable frequency water pump

Abstract

A variable frequency water pump blocking protection detection method and system comprises the following steps that the operation mode of a variable frequency water pump is confirmed, and the operation mode comprises a constant rotating speed mode and a constant flow mode; corresponding detection parameters are obtained based on the operation mode, whether blockage occurs or not is judged based on the data result of the detection parameters, and the detection parameters comprise current data. Whether the water pump is blocked or not is judged according to the detection parameters in the variable frequency water pump, and no extra detection equipment is needed. And the accuracy and the efficiency of blocking detection are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of water pump detection, and in particular to a detection method and system for blocking protection of a variable frequency water pump. Background Art

[0002] The swimming pool pump is an important part of the swimming pool water treatment system. Its main function is to circulate and filter the pool water. It can filter and purify the pool water through the filter and keep the pool water clear and clean. After long-term use of the swimming pool pump, dirt and impurities such as leaves, hair, sand, etc. will accumulate at the pump impeller. When these substances accumulate to a certain amount, they will block the pump impeller and cause the pump to get stuck.

[0003] When the water pump is blocked, the performance parameters such as the flow rate and head of the water pump will decrease, and it will not be able to meet the needs of swimming pool water circulation and filtration. Moreover, when the water pump is seriously blocked, the amount of water entering the water pump will be greatly reduced, and the water pump is equivalent to idling. If it is not discovered in time, it may cause damage to the water pump. In serious cases, it may cause electrical failures, fires and other safety hazards, posing a threat to personnel and property.

[0004] Usually, a flow detection sensor device needs to be installed at the outlet of the water pump to detect whether the flow meets the flow threshold to determine whether it is blocked. However, this method requires the purchase of additional sensor equipment, which increases the cost of detection. In addition, it is limited by the installation experience of workers. When the installation position is not suitable, it is difficult to accurately obtain the flow, and thus it is impossible to effectively and accurately determine whether a blockage occurs. Summary of the invention

[0005] In view of the above-mentioned defects, the purpose of the present invention is to provide a detection method and system for variable frequency water pump blockage protection, so as to realize the detection of channel blockage without borrowing external data.

[0006] To achieve this purpose, the present invention adopts the following technical solution: a detection method for frequency conversion water pump blocking protection, comprising the following steps:

[0007] Determine the operation mode of the variable frequency water pump, wherein the operation mode includes a constant speed mode and a constant flow mode;

[0008] Based on the operation mode, corresponding detection parameters are obtained, and whether a jam occurs is determined based on data results of the detection parameters, wherein the detection parameters include current data.

[0009] Preferably, when the operation mode of the water pump is the constant speed mode, the specific steps of determining whether a jam occurs based on the data results of the detection parameters are as follows:

[0010] Obtaining the current of the water pump motor as the first current;

[0011] Determining whether the magnitude of the first current is less than a first current threshold;

[0012] If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

[0013] Preferably, the first current threshold is determined as follows:

[0014] The constant speed data set by the user is acquired, and the corresponding first current threshold is determined based on the speed interval into which the constant speed data falls.

[0015] Preferably, when the operation mode of the water pump is the constant flow mode, the specific steps of determining whether a blockage occurs based on the data results of the detection parameters are as follows:

[0016] The current of the water pump motor is obtained based on resistance sampling;

[0017] The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current;

[0018] The current speed of the water pump motor is obtained through the two-phase currents Id and Iq;

[0019] Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

[0020] Preferably, the first speed threshold is determined as follows:

[0021] Based on the constant power set by the user, obtain the idling speed of the water pump motor under constant power;

[0022] The first speed threshold is obtained by subtracting the idling speed from the speed regulation threshold.

[0023] A detection system for variable frequency water pump blocking protection, using the detection method for variable frequency water pump blocking protection, comprising a mode acquisition module and a confirmation module;

[0024] The mode acquisition module is used to confirm the operation mode of the variable frequency water pump;

[0025] The confirmation module is used to obtain corresponding detection parameters based on the operation mode, and determine whether a jam occurs based on data results of the detection parameters.

[0026] Preferably, the confirmation module includes a first submodule;

[0027] The first submodule is used to obtain the current of the water pump motor as the first current;

[0028] Determining whether the magnitude of the first current is less than a first current threshold;

[0029] If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

[0030] Preferably, the first submodule includes a first subunit;

[0031] The first subunit is used to obtain constant speed data set by a user, and determine a corresponding first current threshold based on a speed interval into which the constant speed data falls.

[0032] Preferably, the confirmation module includes a second submodule;

[0033] The second submodule is used for acquiring the current of the water pump motor based on resistance sampling;

[0034] The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current;

[0035] The current speed of the water pump motor is obtained through the two-phase currents Id and Iq;

[0036] Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

[0037] Preferably, the second submodule includes a second subunit;

[0038] The second subunit is used to obtain the maximum idling speed of the water pump motor under constant power based on the constant power set by the user;

[0039] The first speed threshold is obtained by subtracting the maximum idling speed from the speed regulation threshold.

[0040] One of the above technical solutions has the following advantages or beneficial effects: the present invention determines whether the pump is blocked by detecting parameters inside the variable frequency pump without using additional detection equipment, which greatly improves the accuracy and efficiency of blockage detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of an embodiment of the system of the present invention.

[0042] Figure 2 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] like Figures 1-2 As shown, a method for detecting the blocking protection of a variable frequency water pump comprises the following steps:

[0047] Determine the operation mode of the variable frequency water pump, wherein the operation mode includes a constant speed mode and a constant flow mode;

[0048] Based on the operation mode, corresponding detection parameters are obtained, and whether a jam occurs is determined based on data results of the detection parameters, wherein the detection parameters include current data.

[0049] In the present invention, the operation mode of the variable frequency water pump is first determined, because in different operation modes, the system will perform corresponding control based on its operation mode. At this time, due to different control methods, it can reflect different detection parameters of whether it is blocked. Therefore, before the detection, it is necessary to determine the operation mode of the variable frequency water pump. After the operation mode is determined, it is necessary to obtain its detection parameters. The detection parameters are the current data of the variable frequency water pump motor. The condition of the motor can be determined by the detection parameters. By combining the operation condition of the motor with the operation mode, it can be judged whether there is a jam.

[0050] The present invention determines whether the pump is blocked by detecting parameters inside the variable frequency pump without using additional detection equipment, thus greatly improving the accuracy and efficiency of blockage detection.

[0051] Preferably, when the operation mode of the water pump is the constant speed mode, the specific steps of determining whether a jam occurs based on the data results of the detection parameters are as follows:

[0052] Obtaining the current of the water pump motor as the first current;

[0053] Determining whether the magnitude of the first current is less than a first current threshold;

[0054] If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

[0055] When the water pump is in constant speed mode, the water pump motor will run at a fixed speed, so the speed of the water pump motor will remain unchanged regardless of whether a blockage occurs.

[0056] When a blockage occurs, the amount of water entering the water pump is greatly reduced or no water enters the water pump, which is equivalent to a reduction in the load on the motor. In order to maintain a stable speed, the power of the water pump motor will be reduced. Therefore, when a blockage occurs, the current will drop sharply, so that the speed can be kept constant. Therefore, by detecting whether the first current is less than a certain current value (first current threshold), it can be determined whether a blockage occurs.

[0057] Of course, in actual operation, electromagnetic influence may cause instantaneous fluctuations in the current value, which may cause the first current to be less than the first current threshold, but it will be restored to the original current value later. Therefore, in the present invention, the time threshold length restriction will be added. Only when the first current is less than the first current threshold for a long time that meets the time threshold length, it will be judged that a jam has occurred. At this time, it is necessary to notify the staff to handle it.

[0058] Preferably, the first current threshold is determined as follows:

[0059] The constant speed data set by the user is acquired, and the corresponding first current threshold is determined based on the speed interval into which the constant speed data falls.

[0060] Since different powers (different currents) are required to maintain different rotation speeds, the first current thresholds corresponding to different constant rotation speeds are also different.

[0061] As shown in the following figure:

[0062]

[0063] By obtaining the constant speed data set by the user, the speed range can be determined, and then the corresponding first current threshold can be determined. For example, the constant speed set by the current user is 3300, which falls into the range of 3251-3300, so the first current threshold is 1.66A.

[0064] Preferably, when the operation mode of the water pump is the constant flow mode, the specific steps of determining whether a blockage occurs based on the data results of the detection parameters are as follows:

[0065] The current of the water pump motor is obtained based on resistance sampling;

[0066] The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current;

[0067] The current speed of the water pump motor is obtained through the two-phase currents Id and Iq;

[0068] Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

[0069] Because the power of the water pump is proportional to the flow rate under the same outlet pressure. Therefore, when the water pump is in constant flow mode, the power input to the water pump motor is constant. Therefore, it is impossible to directly determine whether a jam has occurred by the change in current at this time. For this reason, in the present invention, when the operation mode of the water pump is the constant flow mode, the current of the water pump motor is obtained based on resistance sampling; the two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current; the obtained two-phase currents Id and Iq are input into the observer, and the real-time speed of the water pump motor is estimated by the observer.

[0070] It is worth mentioning that the water pump motor of the present invention is a permanent magnet synchronous motor, and the control method adopted is based on sensorless FOC vector control.

[0071] Specifically, the observer is a data model constructed by the relationship between parameters such as speed, torque, current, etc. Compared with directly using the input current value to obtain the speed, the speed of the permanent magnet synchronous motor can be clearly fed back through the two-phase currents Id and Iq.

[0072] When jamming occurs, due to the load reduction, under a fixed power, the speed increases as the load decreases. Therefore, by comparing the estimated speed with the first speed threshold, it can be determined whether jamming occurs. Of course, in actual operation, there may be electromagnetic influences, causing the two-phase current Id and Iq values ​​to fluctuate instantaneously, thereby causing the speed to increase. Therefore, only when the speed is greater than the first speed threshold for a period of time that meets the time threshold length, it is determined that jamming occurs.

[0073] Preferably, the first speed threshold is determined as follows:

[0074] Based on the constant power set by the user, obtain the idling speed of the water pump motor under constant power;

[0075] The first speed threshold is obtained by subtracting the idling speed from the speed regulation threshold.

[0076] Since the flow rate will be greatly reduced when the pump is blocked, or even no water will enter the pump, the first speed threshold will be very close to the idling speed. In order to improve fault tolerance, the speed adjustment threshold of the corresponding gear will be subtracted from the idling speed to obtain the first speed threshold.

[0077] Different constant powers will correspond to different first speed thresholds. This setting can detect the jamming condition without causing an alarm at the level of different cross flow modes under normal operation.

[0078] A detection system for variable frequency water pump blocking protection, using the detection method for variable frequency water pump blocking protection, comprising a mode acquisition module and a confirmation module;

[0079] The mode acquisition module is used to confirm the operation mode of the variable frequency water pump;

[0080] The confirmation module is used to obtain corresponding detection parameters based on the operation mode, and determine whether a jam occurs based on data results of the detection parameters.

[0081] Preferably, the confirmation module includes a first submodule;

[0082] The first submodule is used to obtain the current of the water pump motor as the first current;

[0083] Determining whether the magnitude of the first current is less than a first current threshold;

[0084] If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

[0085] Preferably, the first submodule includes a first subunit;

[0086] The first subunit is used to obtain constant speed data set by a user, and determine a corresponding first current threshold based on a speed interval into which the constant speed data falls.

[0087] Preferably, the confirmation module includes a second submodule;

[0088] The second submodule is used for acquiring the current of the water pump motor based on resistance sampling;

[0089] The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current;

[0090] The current speed of the water pump motor is obtained through the two-phase currents Id and Iq;

[0091] Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

[0092] Preferably, the second submodule includes a second subunit;

[0093] The second subunit is used to obtain the maximum idling speed of the water pump motor under constant power based on the constant power set by the user;

[0094] The first speed threshold is obtained by subtracting the maximum idling speed from the speed regulation threshold.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for detecting blocking protection of a variable frequency water pump, characterized in that: The steps include: Determine the operation mode of the variable frequency water pump, wherein the operation mode includes a constant speed mode and a constant flow mode; Based on the operation mode, corresponding detection parameters are obtained, and whether a jam occurs is determined based on data results of the detection parameters, wherein the detection parameters include current data.

2. A method for detecting blocking protection of a variable frequency water pump according to claim 1, characterized in that: When the water pump is in constant speed mode, the specific steps for determining whether a blockage occurs based on the data results of the detection parameters are as follows: Obtaining the current of the water pump motor as the first current; Determining whether the magnitude of the first current is less than a first current threshold; If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

3. A method for detecting blocking protection of a variable frequency water pump according to claim 2, characterized in that: The first current threshold is determined as follows: The constant speed data set by the user is acquired, and the corresponding first current threshold is determined based on the speed interval into which the constant speed data falls.

4. A method for detecting blocking protection of a variable frequency water pump according to claim 1, characterized in that: When the water pump is in constant flow mode, the specific steps for determining whether a blockage occurs based on the data results of the detection parameters are as follows: The current of the water pump motor is obtained based on resistance sampling; The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current; The current speed of the water pump motor is obtained through the two-phase currents Id and Iq; Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

5. A method for detecting blocking protection of a variable frequency water pump according to claim 4, characterized in that: The first speed threshold is determined as follows: Based on the constant power set by the user, obtain the idling speed of the water pump motor under constant power; The first speed threshold is obtained by subtracting the idling speed from the speed regulation threshold.

6. A detection system for variable frequency water pump blocking protection, using a detection method for variable frequency water pump blocking protection according to any one of claims 1 to 5, characterized in that: It includes a mode acquisition module and a confirmation module; The mode acquisition module is used to confirm the operation mode of the variable frequency water pump; The confirmation module is used to obtain corresponding detection parameters based on the operation mode, and determine whether a jam occurs based on data results of the detection parameters.

7. A detection system for frequency conversion water pump blocking protection according to claim 6, characterized in that: The confirmation module includes a first submodule; The first submodule is used to obtain the current of the water pump motor as the first current; Determining whether the magnitude of the first current is less than a first current threshold; If it is less than, the time during which the first current is less than the first current threshold is obtained. If the time length during which the first current is less than the first current threshold satisfies the time threshold length, it is determined that a jam has occurred.

8. A detection system for frequency conversion water pump blocking protection according to claim 7, characterized in that: The first submodule includes a first subunit; The first subunit is used to obtain constant speed data set by a user, and determine a corresponding first current threshold based on a speed interval into which the constant speed data falls.

9. A detection system for frequency conversion water pump blocking protection according to claim 6, characterized in that: The confirmation module includes a second submodule; The second submodule is used for acquiring the current of the water pump motor based on resistance sampling; The two-phase currents Id and Iq are obtained after CLARK transformation and PARK transformation of the current; The current speed of the water pump motor is obtained through the two-phase currents Id and Iq; Determine whether the rotation speed is greater than a first rotation speed threshold. If so, obtain the time during which the rotation speed is greater than the first rotation speed threshold. If the length of time during which the rotation speed is greater than the first rotation speed threshold satisfies the time threshold length, determine that a jam has occurred.

10. A detection system for frequency conversion water pump blocking protection according to claim 9, characterized in that: The second submodule includes a second subunit; The second subunit is used to obtain the maximum idling speed of the water pump motor under constant power based on the constant power set by the user; The first speed threshold is obtained by subtracting the maximum idling speed from the speed regulation threshold.

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