Fault detection system based on servo valve control module

Abstract

The utility model relates to the technical field of servo valves, and particularly discloses a fault detection system based on a servo valve control module, the fault detection system comprises a displacement detection assembly and a control module, the displacement detection assembly comprises a working module and a diagnosis module, the working module is used for generating working voltage according to the displacement of a detected piece, and the diagnosis module is used for diagnosing the detected piece. The diagnosis module is in communication connection with the working module, the diagnosis module is used for detecting the insulativity between the working module and the ground, and the diagnosis module has an insulation cut-off state and a non-insulation conduction state. The displacement detection assembly is in communication connection with the control module. The control module is used for receiving the working voltage and state information of the diagnosis module. The control module can determine whether the working voltage detected by the corresponding working module is adopted or not according to the state information of the diagnosis module, the situation that the control module conducts wrong adjustment on the opening and closing amplitude of the valve of the servo valve according to the fault working voltage is reduced, and then valve control fluctuation of the servo valve is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of servo valves, and in particular to a fault detection system based on a servo valve control module. Background Art

[0002] Distributed control systems (DCS) have been widely used in automation control fields such as electricity, petroleum, chemical industry, steel, papermaking, cement, desulfurization, dust removal, and water treatment. It is a multi-level computer system composed of process control level and process monitoring level with communication network as the link. It integrates 4C technologies such as computer (Computer), communication (Communication), display (CRT) and control (Control). Its basic idea is decentralized control, centralized operation, hierarchical management, flexible configuration and convenient configuration.

[0003] In the related art, the servo valve control module in the DCS system often uses a displacement sensor (LVDT, Linear Variable Displacement Transducer) as feedback, thereby calculating the actual opening of the valve, and adjusting and calculating the output current value through proportional integral differential control, so as to control the switching amplitude of the servo valve to achieve the correct opening required by the system. In order to avoid the risk brought by the failure of the displacement sensor, the servo valve control module often adopts a redundant mechanism to improve reliability, that is, connecting two displacement sensor feedbacks for comparison and selection to avoid the situation where one displacement sensor fails and the output is completely lost.

[0004] The principle of the displacement sensor is that the coil skeleton is fixedly installed on the frame, and there is a freely movable rod-mounted iron core inside the coil. The iron core is connected to the valve. When the valve is opened, the iron core moves with it, thereby changing the magnetic field and the voltage value on the corresponding joint will also change. In actual production, the insulation performance between the iron core and the coil skeleton often deteriorates or even directly short-circuits due to reasons such as installation tilt, rod deformation, and environmental corrosion, causing data interference or even violent fluctuations in the displacement sensor, making it difficult to predict the law of its changing value. When the displacement sensor is selected for redundancy, a faulty displacement sensor is likely to be selected, causing valve control fluctuations. Utility Model Content

[0005] The utility model aims to provide a displacement detection component and a servo valve control system to solve the problem in the related art that the displacement sensor is prone to wear failure and inaccurate detection data may cause valve control fluctuation.

[0006] To achieve this purpose, the utility model provides a fault detection system based on a servo valve control module, comprising:

[0007] A displacement detection component, comprising a working module and a diagnostic module, wherein the working module is used to generate a working voltage according to the displacement of the detected component, the diagnostic module is communicatively connected with the working module, the diagnostic module is used to detect the insulation between the working module and the ground, and the diagnostic module has an insulation cutoff state and a non-insulation conduction state;

[0008] A control module, wherein the displacement detection component is communicatively connected to the control module, and the control module is used to receive the operating voltage and the status information of the diagnosis module.

[0009] Optionally, the diagnostic module includes: a rectifier bridge, the rectifier bridge has a first contact and a second contact, the first contact is used to connect to the working module, and the second contact is used to ground.

[0010] Optionally, the diagnosis module includes: a transistor, the base of the transistor is connected to the positive electrode of the rectifier bridge, and the emitter of the transistor is connected to the negative electrode of the rectifier bridge.

[0011] Optionally, the diagnosis module includes: an optocoupler, the optocoupler is connected between the first contact and the collector of the transistor, and the optocoupler is used to generate a disconnection signal.

[0012] Optionally, the diagnostic module also includes: a voltage-dividing resistor, wherein the voltage-dividing resistor is arranged between the working module and the first contact, and / or the voltage-dividing resistor is arranged between the base and the emitter of the transistor, and / or the voltage-dividing resistor is arranged between the working module and the optocoupler.

[0013] Optionally, the displacement detection component further includes: a power supply, wherein the power supply is used to supply power to the working module and the diagnostic module, and the displacement detection component is arranged in a one-to-one correspondence with the working module and the diagnostic module.

[0014] Optionally, the working module includes: a driving unit, wherein the driving unit is used to output a sinusoidal voltage.

[0015] Optionally, the working module includes: a sampling unit connected to the driving unit, and the sampling unit is used to convert the sinusoidal voltage into a direct current voltage to form the working voltage.

[0016] Optionally, the displacement detection components are provided in multiple groups, the multiple groups of displacement detection components are all communicatively connected to the same control module, and the multiple groups of displacement detection components are connected in parallel with each other.

[0017] Optionally, the fault detection system further comprises a drive circuit, and the drive circuit is arranged between the control module and the servo valve.

[0018] The utility model provides a fault detection system based on a servo valve control module. The fault detection system can determine whether to use a working voltage detected by a corresponding working module through status information of a diagnostic module. When the diagnostic module is in an insulated cutoff state, the working voltage delivered by the working module can be selected by the control module. When the diagnostic module is in a non-insulated conduction state, the working voltage delivered by the working module is excluded from the selection range of the control module, thereby reducing the delivery of the faulty working voltage to the control module, thereby reducing the situation in which the control module incorrectly adjusts the opening and closing amplitude of the valve of the servo valve according to the faulty working voltage, thereby reducing the valve control fluctuation of the servo valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a fault detection system in an embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the structure of the diagnostic module in the embodiment of the utility model.

[0021] In the figure:

[0022] 1. Displacement detection component; 1a. First detection component; 1b. Second detection component;

[0023] 11. working module; 111. driving unit; 112. sampling unit;

[0024] 12. Diagnostic module; 121. Rectifier bridge; 1211. First contact; 1212. Second contact; 122. Transistor; 123. Optocoupler; 124. Voltage divider resistor;

[0025] 13. Power supply;

[0026] 2. Control module; 3. Detected part; 31. Displacement sensor; 31a. First displacement sensor; 31b. Second displacement sensor; 32. Servo valve; 4. Driving circuit. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0028] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0031] like Figure 1 to Figure 2 As shown, the embodiment of the utility model provides a fault detection system based on a servo valve control module, the fault detection system includes a displacement detection component 1 and a control module 2, the displacement detection component 1 includes a working module 11 and a diagnostic module 12, the working module 11 is used to generate a working voltage according to the displacement of the detected part 3, it should be noted here that the detected part 3 can be configured as a displacement sensor 31 or a servo valve 32, the action parts of the two move synchronously, the displacement distance fed back is the same, and one can be selected. The diagnostic module 12 is connected to the working module 11 in communication, and the diagnostic module 12 is used to detect the insulation between the working module 11 and the ground, and the diagnostic module 12 has an insulation cut-off state and a non-insulation conduction state. The displacement detection component 1 is connected to the control module 2 in communication, and the control module 2 is used to receive the working voltage and the status information of the diagnostic module 12, that is, the working module 11 can transmit the generated working voltage to the control module 2 to form the feedback of the position detection information, and the diagnostic module 12 can also transmit and feedback the status information of its own insulation cut-off state and non-insulation conduction state to the control module 2.

[0032] With such arrangement, the control module 2 of the present embodiment can determine whether to adopt the working voltage detected by the corresponding working module 11 through the status information of the diagnosis module 12. When the diagnosis module 12 is in the insulation cutoff state, it means that the iron core of the displacement sensor 31 and the coil skeleton are not in contact and are insulated, the wear degree of the displacement sensor 31 is within the normal range, the working voltage detected by the working module 11 is subject to little external environmental interference and data fluctuation, the detection result of the working voltage is accurate, and the working voltage delivered by the working module 11 can be selected by the control module 2, so that the control module 2 can accurately adjust the opening and closing amplitude of the valve of the servo valve 32 through the working voltage to reduce valve control fluctuations.

[0033] When the diagnostic module 12 is in a non-insulated conductive state, it means that the iron core and the coil frame of the displacement sensor 31 will contact each other due to wear, resulting in a short circuit. The wear degree of the displacement sensor 31 exceeds the normal range. The working voltage detected by the working module 11 will be disturbed by the external environment to form a large data fluctuation, and the detection result of the working voltage is inaccurate. Therefore, the working voltage delivered by the working module 11 is excluded from the selection range of the control module 2, reducing the delivery of the faulty working voltage to the control module 2, thereby reducing the control module 2 from incorrectly adjusting the switching amplitude of the servo valve 32 according to the faulty working voltage, thereby reducing the valve control fluctuation of the servo valve 32, and solving the problem that the displacement sensor is prone to wear failure and inaccurate detection data will cause valve control fluctuations in the related technology.

[0034] like Figure 1 to Figure 2 As shown, in some embodiments, the diagnostic module 12 includes a rectifier bridge 121, and the rectifier bridge 121 has a first contact 1211 and a second contact 1212. The first contact 1211 is used to connect to the working module 11, and the second contact 1212 is used for grounding. Whether there is a voltage difference between the first contact 1211 and the second contact 1212 can reflect the insulation state of the working module 11. The model of the rectifier bridge 121 can be MB6S.

[0035] In some embodiments, the diagnostic module 12 includes a transistor 122, the base of the transistor 122 is connected to the positive electrode of the rectifier bridge 121, and the emitter of the transistor 122 is connected to the negative electrode of the rectifier bridge 121. The positive output current of the rectifier bridge 121 can flow through the base and emitter of the transistor 122 and then flow back to the negative electrode of the rectifier bridge 121. The model of the transistor 122 can be SST3904.

[0036] In some embodiments, the diagnosis module 12 includes an optocoupler 123 connected between the first contact 1211 and the collector of the transistor 122 . The optocoupler 123 is used to generate a disconnection signal. When the transistor 122 is powered, it can drive the optocoupler 123 to work.

[0037] In this embodiment, when the diagnosis module 12 is in an insulation cutoff state, that is, when the wear degree of the displacement sensor 31 is within a normal range, the first contact 1211 and the circuit components such as the working module 11 or the power supply 13 connected to the first contact 1211 are insulated from the ground, and the rectifier bridge 121 will not be turned on, and the transistor 122 will be in a cutoff state. Therefore, the optical coupler 123 will not be turned on, and the optical coupler 123 will generate a disconnection signal and transmit it to the control module 2. For example, the circuit at the optical coupler 123 is cut off, and the disconnection signal generated by the optical coupler 123 can be configured as an open circuit signal.

[0038] When the diagnostic module 12 is in a non-insulated conductive state, that is, when the wear degree of the displacement sensor 31 exceeds the normal range, a voltage difference is generated between the first contact 1211 and the circuit components such as the working module 11 or the power supply 13 connected to the first contact 1211. At this time, the rectifier bridge 121 is turned on, and the transistor 122 is electrically turned on, thereby driving the optical coupler 123 to work, and the optical coupler 123 generates a disconnection signal and transmits it to the control module 2. For example, the circuit at the optical coupler 123 is conductive, and the disconnection signal generated by the optical coupler 123 is configured as a low-level signal. The diagnostic module 12 can be connected and coordinated through the rectifier bridge 121, the transistor 122 and the optical coupler 123 to detect whether there is sufficient insulation between the line of the working module 11 and the ground, thereby generating corresponding switching information such as the disconnection signal, so as to diagnose whether there is a fault in the working module 11 and feed it back to the control module 2.

[0039] Among them, the control module 2 can be but is not limited to a controller, the working module 11 is used to generate a working voltage according to the displacement of the detected component 3, and the controller controls the valve opening of the servo valve 32 according to the working voltage, which is similar to the traditional technology and will not be repeated here.

[0040] like Figure 1 to Figure 2 As shown, in some embodiments, the diagnostic module 12 also includes a voltage-dividing resistor 124, which is arranged between the working module 11 and the first contact 1211, and / or, the voltage-dividing resistor 124 is arranged between the base and the emitter of the transistor 122, and / or, the voltage-dividing resistor 124 is arranged between the working module 11 and the optocoupler 123, and the voltage-dividing resistor 124 can be used to control current and adjust voltage, prevent excessive current and voltage from damaging circuit elements, and protect circuit elements.

[0041] like Figure 1 to Figure 2As shown, in some embodiments, the displacement detection component 1 also includes a power supply 13, and the power supply 13 is used to supply power to the working module 11 and the diagnostic module 12. The first contact 1211 can be directly connected to the power supply 13. The displacement detection component 1 is arranged in a one-to-one correspondence with the working module 11 and the diagnostic module 12, that is, an independent power supply 13 can be arranged in each displacement detection component 1 to reduce the interference of the voltage or current changes of the external environment or other circuit elements on the working state of the working module 11 and the diagnostic module 12 in the displacement detection component 1, so that the faulty displacement detection component 1 can be accurately located.

[0042] In this embodiment, the power supply 13 can use 15V, the resistance value of the voltage-dividing resistor 124 set between the first contact 1211 and the working module 11 or the power supply 13 can be selected as 10K ohms, the resistance value of the voltage-dividing resistor 124 set between the base and the emitter of the transistor 122 can be selected as 20K ohms, and the resistance value of the voltage-dividing resistor 124 set between the working module 11 or the power supply 13 and the optical coupler 123 can be selected as 1K ohms. It should be noted here that when there are multiple groups of displacement detection components 1, the power supplies 13 of the multiple groups of displacement detection components 1 can be powered by the same isolation power supply 13 after partition isolation, and the power supplies between the multiple groups of displacement detection components 1 do not affect each other. For example, the model of the isolation power supply 13 can be selected as WRA2415S-3WR2, the input voltage can be selected as 24V, and the output voltage can be ±15V, which can be used to drive the working module 11 to generate a sine wave output.

[0043] like Figure 1 to Figure 2 As shown, in some embodiments, the working module 11 includes a driving unit 111, which is used to output a sinusoidal voltage. The driving unit 111 can be set at the valve position of the servo valve 32. When the valve is opened, the iron core moves, and the magnetic field at the driving unit 111 changes, and its voltage value changes accordingly to form a sinusoidal voltage.

[0044] In some embodiments, the working module 11 includes a sampling unit 112, which is connected to the driving unit 111. The sampling unit 112 is used to convert the sinusoidal voltage into a DC voltage to form a working voltage, that is, the sampling unit 112 can convert the AC voltage into a DC voltage for easy reception by the control module 2.

[0045] In this embodiment, the sampling unit 112 may use a rectifier-integrator circuit, which can convert a sine wave into a DC voltage waveform with a voltage amplitude between 0V and 4V. The model of the rectifier-integrator circuit may be SGM8274.

[0046] like Figure 1 to Figure 2As shown, in some embodiments, the displacement detection components 1 may be provided with multiple groups, and the multiple groups of displacement detection components 1 are all connected to the same control module 2 in communication and in parallel. When the diagnostic modules 12 of one or more of the multiple groups of displacement detection components 1 are in a non-insulated conductive state, the operating voltage corresponding to the diagnostic modules 12 of another one or more of the groups in an insulated disconnected state can be selected by the control module 2.

[0047] See also Figure 1 , taking the case where two groups of displacement detection components 1 are provided as an example, the two groups of displacement detection components 1 can be respectively recorded as the first detection component 1a and the second detection component 1b. The first detection component 1a can be used as the electrical control part of the first displacement sensor 31a, and is used to feedback the relative displacement between the iron core and the coil of the first displacement sensor 31a, that is, the valve opening of the servo valve 32. The second detection component 1b can be used as the electrical control part of the second displacement sensor 31b, and is used to feedback the relative displacement between the iron core and the coil of the second displacement sensor 31b. When the wear degree of the first displacement sensor 31a exceeds the normal range, the diagnosis module 12 of the first detection component 1a is in a non-insulated conduction state, and the first detection component 1a fails. At this time, the control module 2 no longer selects the working voltage delivered by the first detection component 1a, but only selects the working voltage delivered by the second detection component 1b whose wear degree is within the normal range and has not failed, thereby avoiding the selection of inaccurate working voltage.

[0048] In some embodiments, when the diagnostic modules 12 in multiple displacement detection components 1 are in a non-insulated conductive state, the detected component 3 that is communicated with the control module 2 is closed. That is, when multiple displacement detection components 1 fail, the control module 2 will take cutting measures to control the detected component 3 to be closed in order to carry out maintenance work and prevent the servo valve 32 from continuing to work in the fault position.

[0049] When the diagnostic modules 12 in multiple displacement detection components 1 are all in an insulated cut-off state, the maximum value of the multiple working voltages is configured as the input voltage value of the control module 2, that is, the control module 2 can control the valve opening of the servo valve 32 according to the maximum working voltage among the multiple working voltages to ensure that the servo valve 32 meets the usage requirements.

[0050] In some embodiments, the fault detection system also includes a drive circuit 4, which is arranged between the control module 2 and the servo valve 32. The control module 2 can control the valve action of the servo valve 32 through the drive circuit 4. The model of the drive circuit 4 of the servo valve 32 can be DAC7311, which can output a current of ±20mA.

[0051] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A fault detection system based on a servo valve control module, characterized in that: include: A displacement detection component (1) comprises a working module (11) and a diagnostic module (12), wherein the working module (11) is used to generate a working voltage according to the displacement of a detected component (3), the diagnostic module (12) is communicatively connected with the working module (11), the diagnostic module (12) is used to detect the insulation between the working module (11) and the ground, and the diagnostic module (12) has an insulation cutoff state and a non-insulation conduction state; A control module (2), the displacement detection component (1) being communicatively connected to the control module (2), the control module (2) being used to receive the operating voltage and status information of the diagnostic module (12).

2. The fault detection system according to claim 1, characterized in that: The diagnostic module (12) comprises: A rectifier bridge (121), the rectifier bridge (121) having a first contact (1211) and a second contact (1212), the first contact (1211) being used to be connected to the working module (11), and the second contact (1212) being used to be grounded.

3. The fault detection system according to claim 2, characterized in that: The diagnostic module (12) comprises: A transistor (122), wherein the base of the transistor (122) is connected to the positive electrode of the rectifier bridge (121), and the emitter of the transistor (122) is connected to the negative electrode of the rectifier bridge (121).

4. The fault detection system according to claim 3, characterized in that: The diagnostic module (12) comprises: An optical coupler (123), the optical coupler (123) being connected between the first contact (1211) and the collector of the transistor (122), the optical coupler (123) being used to generate a disconnection signal.

5. The fault detection system according to claim 4, characterized in that: The diagnostic module (12) further comprises: A voltage-dividing resistor (124), wherein the voltage-dividing resistor (124) is arranged between the working module (11) and the first contact (1211), and / or the voltage-dividing resistor (124) is arranged between the base and the emitter of the transistor (122), and / or the voltage-dividing resistor (124) is arranged between the working module (11) and the optical coupler (123).

6. The fault detection system according to claim 1, characterized in that: The displacement detection component (1) further comprises: A power supply (13), wherein the power supply (13) is used to supply power to the working module (11) and the diagnostic module (12), and the displacement detection component (1) is arranged in a one-to-one correspondence with the working module (11) and the diagnostic module (12).

7. The fault detection system according to claim 1, characterized in that: The working module (11) further comprises: A drive unit (111), wherein the drive unit (111) is used to output a sinusoidal voltage.

8. The fault detection system according to claim 7, characterized in that: The working module (11) further comprises: A sampling unit (112) is connected to the driving unit (111), wherein the sampling unit (112) is used to convert the sinusoidal voltage into a direct current voltage to form the working voltage.

9. The fault detection system according to claim 1, characterized in that: The displacement detection components (1) are provided in multiple groups, the multiple groups of displacement detection components (1) are all communicatively connected to the same control module (2), and the multiple groups of displacement detection components (1) are connected in parallel with each other.

10. The fault detection system according to any one of claims 1 to 9, characterized in that: The fault detection system further comprises a drive circuit (4), wherein the drive circuit (4) is arranged between the control module (2) and the servo valve (32).

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