Methods and apparatus for testing valve characteristic parameters

Abstract

This invention proposes a method for detecting valve characteristic parameters of a valve actuator. The method includes: resetting the push rod to its top end position; driving the push rod to push the valve stem, and detecting the DC bus current value in real time; when a first sudden change in the DC bus current value is detected and continues for more than a first preset time, recording the first position value of the push rod when the DC bus current value begins to experience the first sudden change; continuing to drive the push rod to push the valve stem and detecting the DC bus current value in real time; when a second sudden change in the DC bus current value is detected and continues for more than a second preset time, recording the second position value of the push rod when the DC bus current value begins to experience the second sudden change; and calculating the stroke length of the valve based on the first position value and the second position value.

Description

Technical Field

[0001] This invention relates primarily to the field of valve controllers, and more particularly to a method and apparatus for detecting valve characteristic parameters of valve actuators. Background Technology

[0002] Valves are widely used in heating, ventilation, and air conditioning (HVAC) systems. Valve actuators control flow by adjusting the valve's position. Different valves have different dimensions, stroke lengths, sealing types, and dead zone lengths. Currently, valves are controlled by dedicated valve controllers, eliminating the need to monitor valve characteristics (stroke length, dead zone length, etc.). Control systems for different types of valves, and even those with different characteristics, are incompatible. Some manufacturers attempt to improve the versatility of valve actuators by incorporating mechanical methods such as baffles, but these methods still have significant limitations. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method and apparatus for detecting valve characteristic parameters, thereby improving the versatility of valve actuators.

[0004] To achieve the above objectives, this invention proposes a method for detecting valve characteristic parameters of a valve actuator. The valve characteristic parameters include the valve's stroke length. The valve actuator drives the valve and includes a push rod driven by a motor. The push rod is adapted to push the valve stem. The motor is connected to a current detector adapted to detect the DC bus current flowing into the motor. The detection method includes: resetting the push rod to its top end position; driving the push rod to push the valve stem, and detecting the DC bus current value in real time; when a first sudden change in the DC bus current value is detected and continues for more than a first preset time, recording a first position value of the push rod when the DC bus current value begins the first sudden change; continuing to drive the push rod to push the valve stem and detecting the DC bus current value in real time; when a second sudden change in the DC bus current value is detected and continues for more than a second preset time, recording a second position value of the push rod when the DC bus current value begins the second sudden change; and calculating the valve's stroke length based on the first position value and the second position value. Therefore, by using a current detector to detect the DC bus current of the motor in real time and determining the characteristic parameters of the valve based on the DC bus current value curve, the valve actuator can be made universally applicable to different types of valves.

[0005] Preferably, the valve characteristic parameters further include dead zone length, and the detection method further includes: continuing to drive the push rod to drive the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches a preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value. Therefore, the dead zone length of the valve can also be determined based on the DC bus current value curve, achieving the versatility of the valve actuator in different types of valves.

[0006] Preferably, the valve actuator further includes a position sensor for detecting the position of the motor's drive shaft. The detection method includes: the position sensor detecting the position value of the motor's drive shaft and converting the drive shaft position value into the position value of the push rod. Therefore, the position value of the push rod can be obtained from the motor's drive shaft position value, reducing structural complexity.

[0007] Preferably, the detection method includes: real-time detection of the DC bus current value and calculation of the average rate of change of the DC bus current value; when the instantaneous rate of change is greater than the average rate of change, determining that the DC bus current value has experienced the first abrupt change and / or the second abrupt change. This achieves the detection of abrupt changes in the DC bus current value.

[0008] Preferably, the detection method includes: repeating the detection method multiple times, and determining the detection result as the characteristic parameter of the valve when the detection results of the multiple detection methods are consistent. Therefore, by using multiple tests, the accuracy of the detection results can be improved.

[0009] This invention also proposes a device for detecting valve characteristic parameters of a valve actuator, the valve characteristic parameters including the stroke length of the valve, the valve actuator for driving the valve, the valve actuator including a push rod driven by a motor, the push rod being adapted to push the valve stem, the motor being connected to a current detector, the current detector being adapted to detect the DC bus current flowing into the motor, the detection device including: a reset module for resetting the push rod to the top end position; a first recording module for driving the push rod to push the valve stem, detecting the DC bus current value in real time, and recording the first position value of the push rod when the DC bus current value begins to change for a first time after a first sudden change is detected and lasts for a first preset time; a second recording module for continuing to drive the push rod to push the valve stem and detecting the DC bus current value in real time, and recording the second position value of the push rod when the DC bus current value begins to change for a second time after a second sudden change is detected and lasts for a second preset time; and a calculation module for calculating the stroke length of the valve based on the first position value and the second position value.

[0010] Preferably, the valve characteristic parameters further include dead zone length, and the detection device further includes: continuing to drive the push rod to push the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches the preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value.

[0011] Preferably, the valve actuator further includes a position sensor for detecting the position of the motor drive shaft, and the detection device includes: the position sensor detecting the position value of the motor drive shaft and converting the drive shaft position value into the position value of the push rod.

[0012] Preferably, the detection device includes: real-time detection of the DC bus current value and calculation of the average rate of change of the DC bus current value; when the instantaneous rate of change is greater than the average rate of change, determining that the DC bus current value has experienced the first abrupt change and / or the second abrupt change.

[0013] Preferably, the detection device includes: repeatedly performing the function of the detection device multiple times, and determining the detection result as the characteristic parameter of the valve when the detection results of the multiple detection devices are consistent.

[0014] The present invention also proposes a valve actuator having the detection device as described above.

[0015] The present invention also proposes an electronic device including a processor, a memory and instructions stored in the memory, wherein the instructions, when executed by the processor, implement the method described above.

[0016] The present invention also proposes a computer-readable storage medium having computer instructions stored thereon, which, when executed, perform the methods described above. Attached Figure Description

[0017] The following figures are intended only to illustrate and explain the invention and do not limit the scope of the invention.

[0018] Figure 1 This is a flowchart of a detection method according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a valve actuator and a valve according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the DC bus current value according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of a detection device according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of an electronic device according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures

[0024] 100 Detection Method

[0025] Steps 110-140

[0026] 210 Valve Actuator

[0027] 211 Power Supply

[0028] 212 Current Detector

[0029] 213 motor

[0030] 214 Position Sensor

[0031] 215 Processing Units

[0032] 216 Transmission Mechanism

[0033] 217 putter

[0034] 220 valve

[0035] 221 Valve stem

[0036] D Valve closing direction

[0037] P1 First Position

[0038] P2 Second Position

[0039] 400 Detection Module

[0040] 410 Reset Module

[0041] 420 First Record Module

[0042] 430 Second Record Module

[0043] 440 Calculation Module

[0044] 500 electronic devices

[0045] 510 processor

[0046] 520 memory Detailed Implementation

[0047] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0048] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the invention is not limited to the specific embodiments disclosed below.

[0049] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0050] Figure 2 This is a schematic diagram of a valve actuator 210 and a valve 220 according to an embodiment of the present invention. The valve actuator 210 is used to drive the valve 220. The valve 220 can be a normally open valve, which is normally open by default, i.e., fully open. The valve 220 is partially opened or closed under the drive of the valve actuator 210. The valve 220 can also be a normally closed valve, which is normally closed by default, i.e., closed. The valve 220 is partially opened or fully opened under the drive of the valve actuator 210. For simplicity, a normally open valve will be used as an example below.

[0051] The valve actuator 210 includes a power supply 211, a current detector 212, a motor 213, a position sensor 214, a processing unit 215, a speed change mechanism 216, and a push rod 217. The power supply 211 powers the motor 213. The current detector 212 is located in the circuit between the power supply 211 and the motor 213, and is adapted to detect the DC link current flowing into the motor 213. The motor 213 can be an integrated motor, meaning the actuator and motor are integrated together, which reduces the size and cost of the motor 213. The position sensor 214 is connected to the motor 213 and the processing unit 215, and is adapted to detect the position of the drive shaft of the motor 213 and send the drive shaft position to the processing unit 215. The processing unit 215 is connected to the current detector 212 and the position sensor 214 to receive and process the data sent by the current detector 212 and the position sensor 214. The motor 213, the speed change mechanism 216, and the push rod 217 are sequentially connected, allowing the push rod 217 to move under the drive of the motor 213. The push rod 217 is adapted to push the valve stem 221 of the valve 220.

[0052] Valve 220 is used to enable, disable, or regulate the flow rate of fluid in a pipeline. The valve includes a push rod 221, which is adapted to move along the closing direction D. When the push rod 221 is at the top end position P1, the valve 220 is fully open. When the push rod 221 moves along the closing direction D to the bottom end position P2, the valve 220 is closed. The distance between the top end position P1 and the bottom end position P2 is the stroke length of the valve 220. For elastic materials, the push rod 221 can continue to move from the bottom end position P2 to the stop position P3 (not shown in the figure). The distance between the bottom end position P2 and the stop position P3 is the dead zone length of the valve 220. Different types of valves 220 typically have different stroke lengths and dead zone lengths. Valves of different types, or even with different characteristic parameters, cannot be used interchangeably. Embodiments of this invention, by detecting the stroke length and dead zone length of the valve, can achieve the universality of the valve controller for use with different types of valves.

[0053] This invention proposes a method 100 for detecting valve characteristic parameters of a valve actuator, wherein the valve characteristic parameters include the valve stroke length. Figure 1 This is a flowchart of a detection method 100 according to an embodiment of the present invention, as follows: Figure 1 As shown, the detection methods include:

[0054] Step 110: Reset the push rod to the top end position.

[0055] The push rod 217 may not be in the top end position at the initial moment. The push rod 217 is reset to the top end position. When the push rod 217 moves from the middle position to the top end position, the DC bus current detected by the current detector 212 will change abruptly. By detecting the change in DC bus current, it can be determined that the push rod 217 has reached the top end position. Figure 3 This is a schematic diagram of the DC bus current value according to an embodiment of the present invention. The horizontal axis represents time in milliseconds (ms), and the vertical axis represents the DC bus current value in milliamperes (mA). S1 is the DC bus current value curve, and S2 is the rate of change curve of the DC bus current value. Figure 3 As shown, when push rod 217 reaches the top end position P0, the DC bus current value curve S1 suddenly increases, which is also reflected in the DC bus current value change rate curve S2.

[0056] Step 120: Drive the push rod to push the valve stem and detect the DC bus current value in real time. When the DC bus current value is detected to have a first sudden change and lasts for more than a first preset time, record the first position value of the push rod when the DC bus current value begins to have a first sudden change.

[0057] The drive rod 217 moves in the closing direction D of the valve 220, and the DC bus current value is monitored in real time. Figure 3 As shown, when the DC bus current value experiences a first abrupt change and persists for more than a first preset time, the position corresponding to the push rod at the start of the first abrupt change in the DC bus current value is when the push rod 217 and valve stem 221 begin to engage, that is, when valve stem 221 is at its top end position, until the push rod 217 and valve stem 221 are fully engaged, and the first position value VP1 of the push rod at the start of the first abrupt change in the DC bus current value is recorded. In some embodiments, the position value of the drive shaft of the motor 213 can be detected by the position sensor 214, and the drive shaft position value can be converted into the first position value VP1 of the push rod 217. In some embodiments, the DC bus current value can be detected in real time and the average rate of change of the DC bus current value (e.g., the root mean square value) can be calculated. When the instantaneous rate of change is greater than the average rate of change, it can be determined that the DC bus current value has experienced a first abrupt change.

[0058] Step 130: Continue to drive the push rod to push the valve stem and detect the DC bus current value in real time. When the DC bus current value is detected to have a second sudden change and lasts for more than a second preset time, record the second position value of the push rod when the DC bus current value begins to have a second sudden change.

[0059] Continue driving push rod 217 to move in the closing direction D of valve 220, and monitor the DC bus current value in real time, such as... Figure 3 As shown, when the DC bus current value experiences a second sudden change and persists for more than a second preset time, the position corresponding to the push rod when the DC bus current value begins its second sudden change is the position where the valve stem 221 contacts the bottom end. The second position value VP2 of the push rod when the DC bus current value begins its second sudden change is recorded. In some embodiments, the position value of the motor drive shaft can be detected by a position sensor and converted into the position value of the push rod. In some embodiments, the position value of the motor drive shaft can be detected by a position sensor 214 and converted into the second position value VP2 of the push rod 217. In some embodiments, the DC bus current value can be detected in real time and the average rate of change (e.g., root mean square value) of the DC bus current value can be calculated. When the instantaneous rate of change is greater than the average rate of change, it can be determined that the DC bus current value has experienced a second sudden change.

[0060] Step 140: Calculate the valve stroke length based on the first position value and the second position value.

[0061] The first position value VP1 is the position where the push rod 217 begins to engage with the valve stem 221, that is, when the valve stem 221 is at the top end position. The second position value VP2 is the position where the valve stem 221 contacts the bottom end position. By subtracting the first position value VP1 from the second position value VP2, the stroke length of the valve can be calculated.

[0062] In some embodiments, the valve characteristic parameters further include dead zone length, and the detection method further includes: continuing to drive the push rod to push the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches the preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value. According to the valve closing force requirement, when the output driving force reaches the preset output force, it indicates that the valve has been fully closed.

[0063] Specifically, the push rod 217 continues to move in the closing direction D of the valve 220, and the DC bus current value is monitored in real time, such as... Figure 3 As shown, when the output driving force reaches the preset output force, the position corresponding to the push rod is the stop position of the valve stem 221, and the third position value VP3 of the push rod is recorded. The third position value VP3 is the valve stem 221 reaching the stop position. By subtracting the second position value VP2 from the third position value VP3, the dead zone length of the valve can be calculated. In some embodiments, the position sensor detects the position value of the motor drive shaft and converts the drive shaft position value into the position value of the push rod. In some embodiments, the position sensor 214 can detect the position value of the motor 213 drive shaft and convert the drive shaft position value into the third position value VP3 of the push rod 217.

[0064] In some embodiments, the detection method includes repeating the detection method multiple times, and when the detection results of the multiple detection methods are consistent, determining the detection result as a characteristic parameter of the valve. This can improve the accuracy of the detection results.

[0065] The table below shows the test results using the detection method in the embodiments of the present invention. As can be seen, the detection method in the embodiments of the present invention is very accurate.

[0066]

[0067] The embodiments of the present invention propose a method for detecting valve characteristic parameters for valve actuators. The method uses a current detector to detect the DC bus current of the motor in real time, and determines the valve characteristic parameters based on the DC bus current value curve. This method enables the valve actuator to be used in different types of valves.

[0068] The present invention also proposes a device for detecting valve characteristic parameters of valve actuators. Figure 4 This is a schematic diagram of a detection device 400 according to an embodiment of the present invention, as shown below. Figure 4 As shown, the detection device 400 includes:

[0069] Reset module 410, reset push rod to the top end position;

[0070] The first recording module 420 drives the push rod to push the valve rod and detects the DC bus current value in real time. When the DC bus current value is detected to have a first sudden change and lasts for more than a first preset time, the first position value of the push rod is recorded when the DC bus current value begins to have a first sudden change.

[0071] The second recording module 430 continues to drive the push rod to push the valve rod and detect the DC bus current value in real time. When the DC bus current value is detected to have a second sudden change and lasts for more than a second preset time, the second position value of the push rod is recorded when the DC bus current value begins to have a second sudden change.

[0072] The calculation module 440 calculates the stroke length of the valve based on the first position value and the second position value.

[0073] In some embodiments, the valve characteristic parameters also include dead zone length, and the detection device further includes: continuing to drive the push rod to push the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches the preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value.

[0074] In some embodiments, the valve actuator further includes a position sensor for detecting the position of the motor drive shaft. The detection device includes: the position sensor detecting the position value of the motor drive shaft and converting the drive shaft position value into the position value of the push rod.

[0075] In some embodiments, the detection device includes: detecting the DC bus current value in real time and calculating the average rate of change of the DC bus current value; and determining that a first abrupt change and / or a second abrupt change has occurred in the DC bus current value when the instantaneous rate of change is greater than the average rate of change.

[0076] In some embodiments, the detection device includes: repeatedly performing the function of the detection device multiple times, and determining the detection result as a characteristic parameter of the valve when the detection results of the multiple detection devices are consistent.

[0077] The present invention also proposes a valve actuator having the detection device 400 as described above.

[0078] The present invention also proposes an electronic device 500. Figure 5 This is a schematic diagram of an electronic device 500 according to an embodiment of the present invention. Figure 5 As shown, the electronic device 500 includes a processor 510 and a memory 520. The memory 520 stores instructions, which, when executed by the processor 510, implement the method 100 described above.

[0079] The present invention also proposes a computer-readable storage medium having computer instructions stored thereon, which, when executed, perform the method 100 described above.

[0080] Some aspects of the methods and apparatus of this invention can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this invention may be embodied as computer products residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compact discs (CDs), digital multifunction discs (DVDs), etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0081] Flowcharts are used herein to illustrate the operations performed by the method according to embodiments of this application. It should be understood that the preceding operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from them.

[0082] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0083] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method (100) for detecting valve characteristic parameters of a valve actuator, wherein the valve characteristic parameters include the stroke length of the valve, the valve actuator is used to drive the valve, the valve actuator includes a push rod driven by a motor, the push rod being adapted to push the valve stem of the valve, the motor being connected to a current detector, the current detector being adapted to detect the DC bus current flowing into the motor, characterized in that, The detection method (100) includes: Reset the push rod to the top end position, wherein when the push rod reaches the top end position from the middle position, the current detector detects the sudden change in the DC bus current to determine that the push rod has reached the top end position (110). The push rod is driven to push the valve rod, the DC bus current value is detected in real time and the average rate of change of the DC bus current value is calculated. When the instantaneous rate of change is greater than the average rate of change, it is determined that the DC bus current value has a first sudden change. When the first sudden change lasts for more than a first preset time, the first position value (120) of the push rod when the DC bus current value begins the first sudden change is recorded. Continue to drive the push rod to push the valve rod and detect the DC bus current value in real time, and calculate the average rate of change of the DC bus current value. When the instantaneous rate of change is greater than the average rate of change, it is determined that the DC bus current value has a second sudden change. When the second sudden change lasts for more than a second preset time, the second position value (130) of the push rod when the DC bus current value begins the second sudden change is recorded. The stroke length of the valve is calculated based on the first position value and the second position value so that the valve actuator can be adapted to different types of valves (140).

2. The detection method (100) according to claim 1, characterized in that, The valve characteristic parameters also include dead zone length, and the detection method (100) further includes: continuing to drive the push rod to drive the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches the preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value.

3. The detection method (100) according to claim 1 or 2, characterized in that, The valve actuator also has a position sensor for detecting the position of the drive shaft of the motor. The detection method (100) includes: the position sensor detecting the position value of the drive shaft of the motor and converting the drive shaft position value into the position value of the push rod.

4. The detection method (100) according to claim 1 or 2, characterized in that, The detection method (100) includes: repeating the detection method (100) multiple times, and when the detection results of the multiple detection methods (100) are consistent, determining the detection result as the characteristic parameter of the valve.

5. A device (400) for detecting valve characteristic parameters of a valve actuator, the valve characteristic parameters including the stroke length of the valve, the valve actuator for driving the valve, the valve actuator including a push rod driven by a motor adapted to push the valve stem of the valve, the motor being connected to a current detector adapted to detect a DC bus current flowing into the motor, characterized in that, The detection device (400) includes: The reset module (410) resets the push rod to the top end position, wherein when the push rod reaches the top end position from the middle position, the current detector detects the sudden change in the DC bus current to determine that the push rod has reached the top end position; The first recording module (420) drives the push rod to push the valve rod, detects the DC bus current value in real time and calculates the average rate of change of the DC bus current value. When the instantaneous rate of change is greater than the average rate of change, it determines that the DC bus current value has a first sudden change. When the first sudden change lasts for more than a first preset time, it records the first position value of the push rod when the DC bus current value starts the first sudden change. The second recording module (430) continues to drive the push rod to push the valve rod and detect the DC bus current value in real time, and calculates the average rate of change of the DC bus current value. When the instantaneous rate of change is greater than the average rate of change, it determines that the DC bus current value has a second sudden change. When the second sudden change lasts for more than a second preset time, it records the second position value of the push rod when the DC bus current value begins the second sudden change. The calculation module (440) calculates the stroke length of the valve based on the first position value and the second position value, so that the valve actuator can be adapted to different types of valves.

6. The detection device (400) according to claim 5, characterized in that, The valve characteristic parameters also include dead zone length. The detection device (400) further includes: continuing to drive the push rod to push the valve stem and detecting the output driving force of the motor in real time; when the output driving force reaches the preset output force, recording the third position value of the push rod; and calculating the dead zone length of the valve based on the second position value and the third position value.

7. The detection device (400) according to claim 5 or 6, characterized in that, The valve actuator also has a position sensor for detecting the position of the drive shaft of the motor. The detection device (400) includes: the position sensor detecting the position value of the drive shaft of the motor and converting the drive shaft position value into the position value of the push rod.

8. The detection device (400) according to claim 5 or 6, characterized in that, The detection device (400) includes: repeatedly performing the function of the detection device (400) multiple times, and when the detection results of the multiple detection devices (400) are consistent, determining the detection result as the characteristic parameter of the valve.

9. A valve actuator, characterized in that, The valve actuator has a detection device as described in any one of claims 5-8.

10. An electronic device (500) comprising a processor (510), a memory (520) and instructions stored in the memory (520), wherein the instructions, when executed by the processor (510), implement the method as claimed in any one of claims 1-4.

11. A computer-readable storage medium having stored thereon computer instructions that, when executed, perform the method according to any one of claims 1-4.

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