Reference electrode calibration device, system and method

Abstract

The embodiment of the invention discloses a reference electrode calibration device, system and method. The device comprises a standard circuit which comprises a loop formed by grounding a standard reference electrode and a second polarized direct-current test piece; the main controller is connected with the polarization switch circuit and is used for controlling the working state of the polarization switch circuit so as to simultaneously control the on-off of paths between a power supply and a first polarization direct-current test piece and between the power supply and a second polarization direct-current test piece in the cathode protection system, and respectively acquiring voltage waveforms of the test reference electrode and the standard reference electrode; checking the potential of the test reference electrode; and the polarization switch circuit is respectively connected with the power supply, the first polarization direct-current test piece and the second polarization direct-current test piece. According to the embodiment of the invention, the respective voltage waveforms of the standard reference electrode and the test reference electrode under synchronous on-off of the access can be acquired, and the test reference electrode is verified based on the two voltage waveforms acquired by the same clock, so that the verification accuracy is improved.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the technical field of cathodic protection of oil pipelines, and in particular to a reference electrode calibration device, system, and method. Background Art

[0002] Reference electrodes are installed at the aviation fuel pipelines buried underground to test the cathodic protection potential of the pipelines to ensure pipeline safety. The pipelines at the apron may have large interference currents, irregular installation, large humidity fluctuations, and suspended soil settlement, which may cause certain errors in the potential collected by the buried reference electrodes. The accuracy of the reference electrodes needs to be checked regularly. Summary of the invention

[0003] Embodiments of the present disclosure provide a reference electrode calibration device, system, and method, which are intended to solve one or more of the above-mentioned problems and other potential problems.

[0004] According to a first aspect of the present disclosure, a reference electrode calibration device is provided for calibrating a test reference electrode in a cathodic protection system, wherein the test reference electrode in the cathodic protection system and a first polarized DC test strip form a loop, and the first polarized DC test strip is in contact with a pipeline protected by the cathodic protection system, and the device comprises: a standard circuit, comprising a loop formed by grounding a standard reference electrode and a second polarized DC test strip; a main controller, connected to a polarization switch circuit, for controlling the working state of the polarization switch circuit to simultaneously control the on-off of a path between a power supply and the first polarized DC test strip, and between the power supply and the second polarized DC test strip in the cathodic protection system, and respectively obtain voltage waveforms of the test reference electrode and the standard reference electrode to calibrate the potential of the test reference electrode; and a polarization switch circuit, respectively connected to the power supply, the first polarized DC test strip, and the second polarized DC test strip.

[0005] According to a second aspect of the present disclosure, there is provided a reference electrode calibration system, comprising: a pipeline, arranged underground; a cathodic protection system, comprising a test reference electrode and a first polarized DC test piece, for performing cathodic protection on the pipeline; and the reference electrode calibration device of the first aspect.

[0006] According to a third aspect of the present disclosure, a reference electrode calibration method is provided, which is applied to the main controller of the reference electrode calibration device of the first aspect, and the method includes: sending a control instruction to the polarization switch circuit, the control instruction is used to control the polarization switch circuit to switch the working state, so as to simultaneously disconnect the path in the polarization switch circuit. In addition, the method also includes respectively acquiring the voltage waveforms of the test reference electrode and the standard reference electrode, so as to calibrate the potential of the test reference electrode based on the voltage waveform of the standard reference electrode.

[0007] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein: Figure 1 A schematic diagram showing the structure of a reference electrode calibration device according to some embodiments of the present disclosure; Figure 2 A schematic diagram illustrating an example environment in which various embodiments of the present disclosure may be implemented; Figure 3 A schematic diagram showing comparison and display of voltage waveforms on a display according to some embodiments of the present disclosure; Figure 4 A schematic diagram showing the working principle of the polarization switch circuit of some embodiments of the present disclosure; Figure 5 A schematic diagram showing the circuit structure of a signal sampling circuit according to some embodiments of the present disclosure; Figure 6 A schematic diagram showing the circuit structure of a first power supply circuit of some embodiments of the present disclosure; Figure 7 A schematic diagram showing the circuit structure of a second power supply circuit of some embodiments of the present disclosure; Figure 8 A schematic block diagram showing a reference electrode calibration system according to some embodiments of the present disclosure; Fig. 9 A schematic diagram showing a flow chart of a reference electrode calibration method according to some embodiments of the present disclosure; Fig.10 An example process for reference electrode calibration of some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0009] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0010] The term "including" and its variations used in this document represent open inclusion, that is, "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one other embodiment". Terms such as "upper", "lower", "front", and "rear" indicating placement or positional relationships are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the principles of the present disclosure, and do not indicate or imply that the referred elements must have a specific orientation, be constructed or operate in a specific orientation, and therefore should not be understood as limitations on the present disclosure.

[0011] As mentioned above, the cathodic protection system is an important part of the oil and gas pipeline corrosion protection system. It can protect the pipeline from electrochemical corrosion in the environment under the condition of partial failure of the pipeline anti-corrosion layer. In order to determine the effectiveness of pipeline cathodic protection, a test reference electrode will be set up to use the test reference electrode as a potential sampling point to determine the polarization potential. However, due to the presence of large interference currents, irregular installation, large humidity fluctuations, and soil settlement and suspension on site, the potential data provided by the test reference electrode may be erroneous, so it is also necessary to regularly determine the accuracy of the test reference electrode.

[0012] Some existing technologies need to dig the test reference electrode out of the ground for testing, which is time-consuming and laborious, and the position of the test reference electrode after digging is not fixed, resulting in changes in the potential of the test reference electrode and large measurement errors. Other existing technologies directly collect the potential of the test reference electrode through equipment such as test piles and intelligent collectors set on the ground. Although there is no need to dig out the test reference electrode, it is necessary to carry out complex wiring and debugging of multiple scattered detection equipment, and the process is complicated and the detection is inefficient. In either case, it is necessary to carry a calibrated standard reference electrode to the calibration environment, test the power-off voltage between the standard reference electrode and the pipeline protected by the cathodic protection system, and between the test reference electrode and the pipeline, and calculate the difference between the power-off voltages. When the potential of the test reference electrode does not change, the calculated difference should be a fixed value that can be preset and determined by the test. By determining whether the difference matches the fixed value, it can be reversely judged whether the potential of the test reference electrode is normal. Among them, since the test reference electrode is part of the cathodic protection system, it can be always connected to the intelligent collector installed on site under normal conditions, so the power-off voltage of the test reference electrode can be directly obtained through the intelligent collector. The standard reference electrode is not part of the normal setting in the cathodic protection system, so it is generally necessary to manually measure the power-off voltage through instruments such as multimeters. This verification method causes the test reference electrode and the standard reference electrode to be powered off separately, and it is impossible to truly power off at the same time. In addition, the different methods of collecting voltage data may also cause differences in the data reading time, making it impossible to accurately compare the voltages of the two reference electrodes at the same time during calibration, and the verification error is large.

[0013] In view of this, an embodiment of the present disclosure proposes a reference electrode calibration device. In an embodiment of the present disclosure, the device may include a standard circuit, a main controller, and a polarization switch circuit. Among them, the standard circuit may be composed of a standard reference electrode and a second polarization DC test strip, both of which may be grounded to form a loop through an electrolyte medium such as soil and concrete. The main controller may be connected to the polarization switch circuit to generate instructions to control the polarization switch circuit, so that the polarization switch circuit synchronously switches the on and off of the path between the power supply and the first polarization DC test strip in the cathodic protection system, and between the power supply and the second polarization DC test strip. In addition, the polarization switch circuit may also be connected to the power supply, the first polarization DC test strip, and the second polarization DC test strip.

[0014] Through this structure, the polarization switch circuit can, under the control of the main controller, simultaneously cut off the power to the circuit of the test reference electrode and the circuit of the standard reference electrode, and obtain the voltage data of the test reference electrode and the standard reference electrode through the main controller, so that the obtained voltage waveform is consistent in the clock. In addition, by forming a potential monitoring circuit in the calibration environment (the environment where the test reference electrode is located) with the second polarized DC test strip and the standard reference electrode, the potential reference points of the two reference electrodes in the same calibration environment can be different (the potential reference point of the test reference electrode is the first polarized DC test strip, and the potential reference point of the standard reference electrode is the second polarized DC test strip). Combined with the adjustment of the physical distance between the standard reference electrode and the second polarized DC test strip, the physical distances of the two reference electrodes relative to their respective reference points can be made consistent, thereby making the voltage data obtained when the potential of the test reference point is normal the same. The traditional calibration using the same reference point (i.e., the pipeline in the cathodic protection system, i.e., the first polarized DC test piece in contact with the pipeline) eliminates the need to measure and calculate the ideal voltage difference between the two reference electrodes in advance because the voltage data obtained are different due to the different physical distances of the two reference electrodes relative to the reference point. In this way, the accuracy of the test reference electrode can be directly verified by comparing the voltage waveforms to determine whether there is a difference between the voltage waveforms. The calibration process is simpler and the calibration results are more accurate.

[0015] Figure 1 FIG. 1 shows a schematic diagram of the structure of a reference electrode calibration device 100 according to some embodiments of the present disclosure. Figure 1 As shown, the device 100 is used to verify the test reference electrode in the cathodic protection system 104. The test reference electrode in the cathodic protection system 104 and the first polarized DC test strip form a loop. The first polarized DC test strip is in contact with the pipeline protected by the cathodic protection system 104. The device 100 includes a standard circuit 101, and the standard circuit 101 includes a loop formed by grounding the standard reference electrode and the second polarized DC test strip. Among them, the standard reference electrode is a reference electrode for providing a stable and known electrode potential. As an example, the potential of the standard reference electrode can be determined in advance in a laboratory with a known environment by testing the potential of the standard reference electrode relative to the standard hydrogen electrode under specific conditions. The loop can be formed by directly inserting the standard reference electrode and the second polarized DC test strip into the electrolyte medium at the site after arriving at the calibration site, or by inserting the standard reference electrode and the second polarized DC test strip into the electrolyte medium that is previously collected or manufactured and is the same as the calibration site. The latter can be placed in the environment of the calibration site as a whole when the calibration begins. The distance between the standard reference electrode and the second polarized DC test piece can be determined according to the distance between the test reference electrode and the pipeline at the calibration site to avoid different electrolyte resistances in the potential monitoring loop due to different distances, which in turn causes changes in the potential difference and increases the difficulty of calibration.

[0016] The device 100 includes a main controller 102, which is connected to a polarization switch circuit 103 and is used to control the working state of the polarization switch circuit 103 to simultaneously control the on-off of the path between the power supply and the first polarization DC test strip in the cathode protection system 104, and between the power supply and the second polarization DC test strip, and respectively obtain the voltage waveforms of the test reference electrode and the standard reference electrode to verify the potential of the test reference electrode. The main controller 102 can directly collect voltage signals according to different specific selected models, or collect voltage signals by connecting a signal sampling circuit, wherein the signal sampling circuit may include an amplifier for amplifying signals and an AD converter for analog-to-digital conversion. The voltage signal collected from the test reference electrode may be the potential difference between the potential of the test reference electrode and the potential of the second polarization DC test strip, and the voltage signal collected from the standard reference electrode may be the potential difference between the potential of the standard reference electrode and the potential of the first polarization DC test strip. When the distance between the standard reference electrode and the second polarized DC test piece and the distance between the test reference electrode and the pipeline are the same, if there is no abnormality in the test reference electrode, the detected voltage signal should be the same. In this way, the potential of the test reference electrode can be verified to be accurate by comparing whether the voltage waveform of the test reference electrode matches the voltage waveform of the standard reference electrode. The voltage waveform comparison method can be, for example, manual observation and comparison of the voltage waveform directly after displaying the waveform graph, or it can be through the mathematical operation function of the oscilloscope, through sliding window averaging, fast Fourier transform algorithm, etc., to quickly calculate the average difference between the voltage waveforms or the difference of the specified node position, and determine whether the difference exceeds the acceptable threshold by manual experience or comparison with the preset value, so as to verify whether the potential of the test reference electrode is accurate.

[0017] The device 100 includes a polarization switch circuit 103, which is connected to a power supply, a first polarization DC test strip, and a second polarization DC test strip, respectively. Two switch channels for synchronously controlling the on-off state can be set in the polarization switch circuit 103 through a polarization switch, and each switch channel controls the on-off of an independent circuit, so as to achieve the synchronous disconnection of the path between the power supply and the first polarization DC test strip, and between the power supply and the second polarization DC test strip, so that the main controller 102 can synchronously obtain the power-off voltage of the test reference electrode and the standard reference electrode. The types of polarization switches include but are not limited to semiconductor switches, solid-state relays, photoelectric switches, and magnetic switches. Taking solid-state relays as an example, the relay of the polarization switch can be directly connected to the main controller 102, or it can be connected to the main controller 102 through a Darlington transistor array, so as to realize the switching of the on-off state of the switch channel in the polarization switch by controlling the relay.

[0018] Figure 2Schematic diagram 200 of an example environment in which various embodiments of the present disclosure may be implemented is shown. Figure 2 As shown, the environment 200 includes a standard reference electrode 201, a second polarized DC test strip 202, a test box 203, a cathodic protection system and a pipeline 212. The standard reference electrode 201 and the second polarized DC test strip 202 can be at least partially inserted into the ground 207 to form a potential monitoring loop through electrolytes such as soil and concrete. The cathodic protection system can include a power supply 208, an anode bed 209, a first polarized DC test strip 210 and a test reference electrode 211. The power supply 208 is used to provide current to the cathodic protection system to maintain the set protection potential. For example, it can be a constant potential instrument, a rectifier, etc. The power supply 208 can be installed in a place that is easy to monitor and maintain, such as a ground station building, a control room close to the protected pipeline, etc., or it can be directly buried in an underground protection box. The anode bed 209 can be connected to the power supply 208 through a cable 206, so that the current starts from the power supply 208, flows into the surrounding electrolyte medium through the anode bed 209, and then enters the protected pipeline 212. The test reference electrode 211 is arranged near the pipeline 212 to form another potential monitoring loop. The first polarized DC test strip 210 is also arranged in contact with the pipeline 212 to provide a potential collection point. A main controller, a polarization switch circuit and a display can be arranged in the check box 203. Through wires and the terminals on the panel of the check box 203, the polarization switch circuit can be connected to the standard reference electrode 201, the second polarized DC test strip 202, the power supply 208, the first polarized DC test strip 210 and the test reference electrode 211 respectively, so that the polarization switch circuit can simultaneously connect or disconnect the path between the power supply 208 and the first polarized DC test strip 210, and between the power supply 208 and the second polarized DC test strip 202. The main controller can obtain the voltages of the standard reference electrode and the test reference electrode respectively by direct acquisition or acquisition by a signal sampling circuit, and display the voltage waveforms on the display. The test reference electrode 211 and the first polarized DC test strip 210 can be provided with connection points on the ground 207 by setting a test pile 204 or directly connecting through a cable 206, so that the test reference electrode 211 and the first polarized DC test strip 210 do not need to be dug out from the ground during the verification process. Taking the setting of the test pile 204 as an example, the power supply 208, the first polarized DC test strip 210 and the test reference electrode 211 can all be connected to the wiring board 205 on the test pile 204 after passing through the inside of the test pile 204 through the cable 206, so that the calibration box 203 can be connected to the cathode protection system through the wiring of the wiring board 205. In this way, the polarization switch circuit can simultaneously cut off the power supply to the loop of the test reference electrode and the loop of the standard reference electrode, so that the acquisition clock of the voltage waveform obtained by the main controller is consistent, and the accuracy of the test reference electrode can be directly verified by comparing the voltage waveform, the verification process is simpler, and the verification result is more accurate.

[0019] Figure 3 A schematic diagram 300 showing a comparison of voltage waveforms on a display in some embodiments of the present disclosure is shown. Figure 3 As shown, the main controller 102 can display the voltage waveforms of the two reference electrodes through the display. The voltage waveforms can be as shown in FIG. Figure 3 It can be displayed separately as shown, and can also be displayed in other ways such as different colors and / or line segment types in the same coordinate system. In addition to the waveform diagram, the display can also display the polarization current, current density, power-on voltage and power-off voltage corresponding to the circuits of the two reference electrodes. Among them, the polarization current can be obtained by the main controller or by the signal sampling circuit. The current density requires an additional AC polarization test piece to collect the AC voltage and then calculate it based on the AC voltage. The power-on voltage can be the voltage data within a certain period of time before the polarization switch circuit disconnects the path. Although the voltage data collected after the polarization switch circuit disconnects the path are all power-off voltages, the power-off voltage displayed on the display can generally be the power-off voltage data when the data tends to stabilize after a certain period of power failure, or it can be the latest collected power-off voltage data, etc. By observing and comparing the two voltage waveforms, the staff can verify the potential of the test reference electrode based on the voltage waveform of the standard reference electrode. If the numerical values ​​of the inflection points / nodes and / or the changing trends of the curves are basically consistent by comparing multiple inflection points or specified nodes on the curve, it is considered that the curves are basically overlapped. In this case, the potential of the test reference electrode can be considered accurate. If there is a clear difference between the voltage waveforms, it can be considered that the potential of the test reference electrode is inaccurate and needs to be replaced. In some other embodiments, the specific difference between the voltage waveforms can be quickly calculated by means of the mathematical operation function of the oscilloscope, sliding window averaging, fast Fourier transform algorithm, etc., and the waveform error is determined to exceed an acceptable threshold value based on the size between the difference and the preset value, thereby verifying whether the potential of the test reference electrode is accurate.

[0020] In some embodiments of the present disclosure, the polarization switch circuit may include a polarization switch having a first switch channel and a second switch channel, or two polarization switches having a first switch channel and a second switch channel, respectively. The first switch channel is used to switch on and off the path between the power supply and the first polarization DC test strip, and the second switch channel is used to switch on and off the path between the power supply and the second polarization DC test strip. Figure 4 A schematic diagram 400 showing the working principle of the polarization switch circuit of some embodiments of the present disclosure is shown. Figure 4As shown, the polarization switch circuit may include a dual-channel polarization switch K1, and the first switch channel of the dual-channel polarization switch K1 may be connected to the first terminal J1 to be connected to the first polarization DC test strip through the first terminal J1. The second switch channel may be connected to the third terminal J3 to be connected to the second polarization DC test strip through the third terminal J3. The dual-channel polarization switch K1 may synchronously switch the first switch channel and the second switch channel to a connected state or a disconnected state, thereby achieving synchronous power-off of the paths corresponding to the first polarization DC test strip and the second polarization DC test strip, so that the collection clock of the collected open-circuit voltage is the same. Among them, each terminal may be set separately or uniformly on a terminal panel. The terminal panel may be set on Figure 2 In the environment 200 shown, the second terminal J2 can be used to connect to the standard reference electrode, and the fourth terminal J4 can be used to connect to the test reference electrode. When sampling the voltage signal, the main controller or the signal sampling circuit can be connected to the terminal corresponding to the object to be detected, so that the corresponding sampling signal can be collected.

[0021] In some embodiments of the present disclosure, the device may further include a test circuit respectively connected to the polarization switch circuit and the first polarization DC test strip, and the test circuit may include multiple first test branches, each of which has a resistor with a different resistance value. The main controller may be connected to the test circuit through a single-pole multi-throw switch, or it may be connected to each first test branch through multiple switches, for selecting a branch from multiple first test branches to access the path between the polarization switch circuit and the first polarization DC test strip. The standard circuit may also include multiple second test branches, each of which has a resistor with a different resistance value. The main controller may be connected to the standard circuit through a single-pole multi-throw switch, or it may be connected to each second test branch through multiple switches, for selecting a branch from multiple second test branches to access the path between the polarization switch circuit and the second polarization DC test strip. To avoid the influence of the polarization environment, the switch is preferably a polarization switch. In order to determine the accuracy of the test reference electrode from multiple dimensions, the polarization current flowing to the first polarization DC test strip and the second polarization DC test strip can be collected. In order to make the collected current signal within a reasonable value range, different resistors with different resistance values ​​can be connected in series by selecting different first test branches / second test branches to adjust the current size. In order to facilitate direct observation and comparison of the collected current signal, the resistance values ​​of the resistors in the first test branch and the second test branch selected at the same time are the same.

[0022] As an example, Figure 4As shown, the test circuit can be provided with two first test branches, and the resistors set in the first test branches are R1 and R2 respectively. The standard circuit can be provided with two second test branches, and the resistors set in the second test branches are R3 and R4 respectively. By selecting different test branches, the resistance values ​​of the resistors on the path can be different, thereby changing the current on the path. In this way, the current size in the path can be adjusted to adjust the current according to the actual selected signal acquisition method and the data sampling range corresponding to the signal sampling method, so that the current size is within the data sampling range. For example, R1 and R3 are 10 ohm resistors, and R2 and R4 are 100 ohm resistors. When the first test branch with R1 resistor and the second test branch with R3 resistor are selected, a test adjustment can be made to the current size in the path. When the first test branch with R2 resistor and the second test branch with R4 resistor are selected, another test adjustment can be made to the current size in the path. Different test branches required for multiple current test ranges can be configured according to actual needs, and the resistance of each test branch is selected according to the current test range.

[0023] In some embodiments of the present disclosure, Figure 4 As shown, the test circuit may also include a first switch K2, the first switch K2 is connected between the third terminal J3 corresponding to the first polarized DC test strip and each first test branch, and is used to select different branches to be connected to the first polarized DC test strip. The standard circuit also includes a second switch K3, the second switch K3 is connected between the first terminal J1 corresponding to the second polarized DC test strip and each second test branch, and is used to select different branches to be connected to the second polarized DC test strip. The first resistor R1 may have the same resistance value as the third resistor R3, and the second resistor R2 may have the same resistance value as the fourth resistor R4. At the same time, the first test branch corresponding to the first resistor R1 and the second test branch corresponding to the third resistor R3 have the same on-off state, and the first test branch corresponding to the second resistor R2 and the second test branch corresponding to the fourth resistor R4 have the same on-off state.

[0024] In some embodiments of the present disclosure, Figure 4As shown, the test circuit may also include a third switch K4, which is respectively connected to the first polarized DC test strip and the polarized AC test strip in the cathodic protection system, and the third switch K4 is also connected in series with the first switch K2, for selecting the path between the first polarized DC test strip and the first switch K2, or between the polarized AC test strip and the first switch K2, and the polarized AC test strip is in contact with the pipeline. The polarized AC test strip can be specifically connected to the third switch K4 through the fifth terminal J5. In addition to the voltage signal, the current density of the test reference electrode can also be determined to determine the accuracy of the test reference electrode from data in multiple dimensions. The current density can be calculated by the AC signal, so the switching between the first polarized DC test strip and the polarized AC test strip can be achieved by the third switch K4 to collect DC signals or AC signals according to needs.

[0025] In some embodiments of the present disclosure, the device may further include a signal sampling circuit, which is respectively connected to the standard circuit, the test circuit and the main controller, for respectively collecting the voltage signals of the test reference electrode and the standard reference electrode, and transmitting the voltage signals to the main controller. The signal sampling circuit may include at least one AD converter to collect voltage / current signals through the AD converter. The device may collect voltage signals and current signals at different positions respectively through multiple signal sampling circuits, or may collect voltage signals and current signals at different positions respectively through different branches of a signal sampling circuit. Depending on the different signal objects collected, the connection point of the signal sampling circuit may be different. For example, when collecting the voltage signal of the test reference electrode, the input end of the signal sampling circuit may be directly connected to the test reference electrode. When collecting the current signal of the test circuit, the input end of the signal sampling circuit may be connected to the input end of the second switch channel of the polarization switch circuit.

[0026] Figure 5 A circuit structure diagram 500 of a signal sampling circuit according to some embodiments of the present disclosure is shown. Figure 5As shown, the signal sampling circuit may include at least one amplifier branch and an AD converter U1, and the branch structures of each amplifier branch may be the same. For example, the amplifier branch may include a first amplifier U2, the input end of the first amplifier U2 is connected to the input end of the signal sampling circuit through a fifth resistor R5, the output end of the first amplifier U2 is connected to an input end of the AD converter U1 through a sixth resistor R6, and the ground end of the first amplifier U2 may be grounded in a verification environment, or may be connected differently according to different signal acquisition objects (for example, when collecting the voltage signal of the test reference electrode, it may be connected to the second polarized DC test piece). In addition, the first amplifier U2 may also be connected in parallel with a first capacitor C1 to filter the signal. The input end of the first amplifier U2 may also be connected to a first diode D1 and a second diode D2, respectively, the first diode D1 is connected to ground in the reverse direction, and the second diode D2 is connected to ground in the forward direction, so as to provide overvoltage protection for the first amplifier U2. The first amplifier U2 may also be connected in parallel with a fourth switch K5, and the fourth switch K5 is used to select a third test branch with a resistor of different resistance values, so as to adjust the amplification factor of the first amplifier U2 by changing the selected third test branch. In addition to being directly connected to the main controller, a digital isolator may be provided between the output of the AD converter U1 and the main controller to provide electrical isolation through the digital isolator to prevent damage to the device caused by high voltage differences.

[0027] In some embodiments of the present disclosure, the polarization switch circuit K1 is connected to a power supply and a first polarization DC test strip located underground in the cathodic protection system through a test pile placed on the ground, so that the power supply and the first polarization DC test strip can be wired through a terminal board set on the ground by the test pile without digging or moving.

[0028] Figure 6 A circuit structure diagram 600 of a first power supply circuit of some embodiments of the present disclosure is shown, such as Figure 6As shown, the device can also be provided with a first power supply circuit to supply power to the display and the main controller. The first power supply circuit can include a power supply E1, which can be a self-contained battery power supply or a power supply of a connected cathode protection system. The voltage of the power supply E1 can be input into the buck converter U4 after filtering by the third capacitor C3 (one end of the third capacitor C3 in the figure is connected to the input end of the buck converter U4, and the other end is grounded). The buck converter U4 can convert the voltage and output it, so that the output voltage can meet the power demand of other devices such as the display and the main controller. For devices with higher voltage requirements, the voltage output by the buck converter U4 can also be input into the linear regulator U5 to further convert the voltage into a more accurate stable output voltage for power supply. In actual use, different voltage values ​​can be connected to different devices according to specific power requirements. In addition, a fourth capacitor C4 (one end of the fourth capacitor C4 in the figure is connected to the input end of the first linear regulator U5, and the other end is grounded) and a fifth capacitor C5 (one end of the fifth capacitor C5 in the figure is connected to the output end of the linear regulator U5, and the other end is grounded) can be set in the first power supply circuit to filter the voltages output by the buck converter U4 and the first linear regulator U5, respectively. A first inductor L1 and a second inductor L2 can also be set between the output end of the buck converter U4 and the input end of the first linear regulator U5, and between the output end of the first linear regulator U5 and the +3V output voltage, respectively, to smooth the output current. The output end of the buck converter U4 and the input end of the first linear regulator U5 can also be grounded through a fifth diode D5 and a sixth diode D6, respectively, to prevent reverse voltage from damaging components.

[0029] Figure 7 A circuit structure diagram 700 of a second power supply circuit of some embodiments of the present disclosure is shown, such as Figure 7As shown, the amplifier of the signal sampling circuit requires a higher power supply voltage and a negative voltage. The device can also be provided with a second power supply circuit to further convert the stable voltage converted by the first power supply circuit and output a voltage that meets the power supply requirements of the amplifier. The second power supply circuit can include a DC / DC converter U6, a second linear regulator U7 and a third linear regulator U8. The voltage output by the first power supply circuit is input to the DC / DC converter U6 after the current stabilization of the third inductor L3 and the filtering of the sixth capacitor C6. After the DC / DC converter U6 converts the voltage into a voltage that meets the requirements of the amplifier, the converted positive voltage and negative voltage can be converted into a more accurate stable output voltage through the second linear regulator U7 and the third linear regulator U8 respectively, and the amplifier of the signal sampling circuit is powered by the output voltage. In addition, the second power supply circuit can respectively set a seventh capacitor C7 and an eighth capacitor C8 grounded at the positive and negative input ends of the DC / DC converter U6 for filtering, and can also respectively set a ninth capacitor C9 and a tenth capacitor C10 grounded at the output ends of the second linear regulator U7 and the third linear regulator U8 for filtering, and can also respectively set a thirteenth resistor R13 and a fourteenth resistor R14 at the output ends of the second linear regulator U7 and the third linear regulator U8 as load resistors to ensure the normal operation of the regulator, and can also be between the positive output voltage of the second linear regulator U7, A fourth inductor L4 and a sixth inductor L6 are respectively arranged between the output end of the third linear regulator U8 and the negative output voltage to smooth the current. The GND pin of the DC / DC converter U6 is also grounded through the fifth inductor L5. One end of the fifth inductor L5 connected to the DC / DC converter U is also connected to the connection between the seventh capacitor C7 and the eighth capacitor C8 and the connection between the thirteenth resistor R13 and the fourteenth resistor R14. One end of the fifth inductor L5 connected to the ground is connected to the connection between the ninth capacitor C9 and the tenth capacitor C10 to isolate and reduce interference between different regulators.

[0030] Figure 8 A schematic block diagram of a reference electrode calibration system 800 according to some embodiments of the present disclosure is shown. Figure 8As shown, the system 800 may include a reference electrode calibration device 100, a cathode protection system 104, and a pipeline 212. The pipeline 212 is arranged underground, the cathode protection system 104 includes a first polarized DC test strip 210 and a test reference electrode 211, which are used to perform cathode protection on the pipeline 212, and the reference electrode calibration device 100 includes a main controller 102, a standard circuit 101, and a polarization switch circuit 103. Under the control of the main controller 102, the polarization switch circuit 103 can synchronously power off the second polarized DC test strip in the standard circuit 101 and the first polarized DC test strip 210 in the cathode protection system 104, so that the acquisition clock of the voltage waveform obtained by the main controller 102 is consistent, and the accuracy of the reference electrode can be directly verified by comparing the voltage waveform, the verification process is simpler, and the verification result is more accurate.

[0031] Fig. 9 The flowchart of the reference electrode calibration method 900 of some embodiments of the present disclosure is shown. The method 900 can be executed by a main controller, or by a terminal device connected to the main controller. The main controller can be set at Figure 2 The test box 203 in the environment 200 shown in the figure can also be set separately. Fig. 9 As shown, in box 902, method 900 can send a control instruction to the polarization switch circuit, and the control instruction is used to control the polarization switch circuit to switch the working state to simultaneously disconnect the path in the polarization switch circuit. In some embodiments, the execution of the control instruction in the polarization switch circuit can have a certain delay, so that the polarization switch circuit will switch the working state after a certain period of time after the control instruction is generated. As an example, the control instruction can include delay information, so that after the polarization switch circuit receives the control instruction, it will wait for the time corresponding to the delay information before switching the working state, and the main controller can start to obtain voltage data within a certain period of time after sending the control instruction. In some other embodiments, the control instruction may not include delay information, so that the polarization switch circuit can switch the working state after receiving the control instruction. In the above manner, the main controller can obtain a voltage signal that changes continuously within a certain period of time to construct a continuous voltage waveform, and the voltage waveform can include a power-on voltage before power failure, a power-off voltage that changes rapidly when the power is just off, and a power-off voltage that tends to stabilize after a period of power failure (see Figure 3 The waveform shown in the figure can be used to perform a more comprehensive comparison and verification of the voltage signals of the two reference electrodes.

[0032] In box 904, method 900 can respectively obtain at least the voltage waveforms of the test reference electrode and the standard reference electrode when the path is switched from the on state to the off state, so as to verify the potential of the test reference electrode based on the voltage waveform of the standard reference electrode. In some embodiments, the voltage waveform can be verified by directly displaying the voltage waveform, and the staff can manually compare the two voltage waveforms and directly observe whether there is a significant difference between the two voltage waveforms, and judge whether the difference will affect the accuracy of the potential of the test reference electrode by experience. In some embodiments, the voltage waveform can be verified by automatically comparing the waveforms, and this process can be performed by Figure 2 The operation is performed on the panel of the verification box 203 in the environment 200 shown in the figure, so as to generate corresponding operation instructions and send them to the main controller, which is executed by the main controller, or the main controller sends the voltage waveform to the terminal connected to the main controller for communication, and the terminal performs automatic comparison. As an example, the comparison of the voltage waveform can use the average value measurement, correlation analysis, root mean square error, eigenvalue extraction and machine learning to calculate the average error value between the two voltage waveforms. Considering that in practical applications, a certain tolerance can be given to the potential change of the test reference electrode, a preset value can be set. When the average error value does not exceed the preset value, the potential of the test reference electrode is considered to be normal. After obtaining the complete voltage waveform or obtaining the verification result, the controller can generate a recovery instruction to control the polarization switch circuit to switch from the disconnected state back to the on state to ensure the normal operation of the cathode protection system. In addition, the voltage data in the voltage waveform obtained by the main controller, in addition to the voltage data during the process of switching the path from the on state to the off state, can also include the voltage data of the path within the first preset time length before disconnection and / or the voltage data of the path within the second preset time length after disconnection. In this way, the voltage waveform covers more comprehensive data, which can improve the accuracy of comparison and verification through the voltage waveform.

[0033] In the above method, instead of directly measuring the potential difference between the standard reference electrode and the test reference electrode, the voltage of the standard reference electrode (the potential difference between the standard reference electrode and the second polarized DC test piece) and the voltage of the test reference electrode (the potential difference between the test reference electrode and the first polarized DC test piece) are obtained respectively, so as to directly realize the potential calibration of the test reference electrode by comparing the two voltage waveforms, eliminating the process of calculating the ideal potential difference between the standard reference electrode and the test reference electrode in advance according to the type of reference electrode used and its characteristics in a specific electrolyte. In addition, the voltage waveform comparison method can reflect the changing trend of the voltage data at continuous time points, and can more comprehensively evaluate the potential accuracy of the test reference electrode compared to the traditional method of comparing the voltage data at several specific moments.

[0034] Fig.10An example process 1000 for reference electrode calibration of some embodiments of the present disclosure is shown. Fig.10 As shown, the main controller may include a control unit 1010, a comparison unit 1040 and a verification unit 1060. After the control unit 1010 generates a control instruction 1020, the control instruction 1020 is sent to the polarization switch circuit, and the polarization switch circuit can respond to the control instruction 1020 and switch the working state to synchronously disconnect the path between the power supply and the standard reference electrode, and between the power supply and the test reference electrode. The comparison unit 1040 can obtain the voltage signals of the standard reference electrode and the test reference electrode respectively, and generate different voltage waveforms 1030. The comparison unit 1040 can obtain the voltage difference 1050 by using average value measurement, correlation analysis, root mean square error, eigenvalue extraction and machine learning to calculate the difference of the voltage waveform 1030. After the voltage difference 1050 is input to the verification unit 1060, the verification unit 1060 compares the voltage difference 1050 with the preset value 1070, and can generate a verification result 1080. Among them, the specific value of the preset value 1070 can be set according to the accuracy requirements of the potential in the actual pipeline environment, combined with historical test data and manual experience. As an example, when the voltage difference 1050 is greater than the preset value 1070, the generated verification result 1080 is characterized as abnormal potential, and when the voltage difference 1050 is not greater than the preset value 1070, the generated verification result 1080 is characterized as normal potential. In some embodiments, the verification result 1080 can be a text message containing text content such as "normal potential" or "abnormal potential", displayed on a display or terminal. In some other embodiments, the verification result 1080 can also be different voice information converted from text, different sound information emitted by a buzzer, and photoelectric information of different colors and / or brightness emitted by devices such as diodes and light bulbs.

[0035] In some embodiments of the present disclosure, the process of verifying the potential 904 of the test reference electrode based on the voltage waveform of the standard reference electrode may include determining the potential verification result of the test reference electrode based on the voltage difference between the voltage waveform of the standard reference electrode and the voltage waveform of the test reference electrode, and a preset value. In some embodiments, the average error value between the two voltage waveforms can be calculated as the voltage difference between the voltage waveforms using methods such as average value measurement, correlation analysis, root mean square error, eigenvalue extraction, and machine learning. In other embodiments, only the difference between specific positions in the waveform (such as peaks, troughs, rising edges of waveforms, and falling edges of waveforms, etc.) can be calculated, and the average value of these differences can be used as the voltage difference between the voltage waveforms. Considering that in practical applications, the test reference electrode is difficult to calibrate at the test site, if the potential is inaccurate, the test reference electrode needs to be directly replaced, which is costly, so a certain tolerance can be provided for the potential change of the test reference electrode, that is, a preset value can be set, and when the average error value does not exceed the preset value, the potential of the test reference electrode is considered normal. Different potential verification results will be generated depending on whether the potential is normal or not.

[0036] In some embodiments of the present disclosure, the main controller may periodically generate multiple control instructions, and perform a check after each control instruction is generated. Each check process may calculate the voltage difference between the voltage waveforms, and determine whether the voltage difference exceeds the preset value based on the comparison between the voltage difference and the preset value, and generate different check results based on different judgment results. In this way, the process of on-off control and voltage waveform acquisition may be repeated multiple times periodically to obtain multiple check results. As an example, assuming that each hour is a cycle, and the preset duration of collecting the voltage waveform is 10 minutes, the controller may generate a control instruction once an hour to control the polarization switch circuit to disconnect the path, and collect the voltage data within ten minutes after sending the control instruction, generate a voltage waveform for comparison, and obtain a check result. After the number of checks meets the preset number of times, or the cumulative check duration meets the preset total check duration, the same check results that occupy at least a preset proportion of the total number of check results are used as the final check results. In some other embodiments, the potential check results with the same check results in the last several potential check results may also be determined as the final check results according to the generation time sequence of the check results. Through the above method, the calibration result error caused by the unstable initial reading of the measuring equipment when the measurement and calibration is just started, and the inaccurate reading caused by the instantaneous disturbance of the local electric field when the standard reference electrode is inserted for the first time can be eliminated. The same majority of the calibration results among multiple calibration results are used as the final calibration result for judgment, thereby improving the accuracy of the calibration result.

[0037] Although several specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Certain features described in the context of separate embodiments may also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable sub-combination.

[0038] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

[0039] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A reference electrode calibration device (100) for calibrating a test reference electrode in a cathodic protection system (104), wherein the test reference electrode in the cathodic protection system (104) and a first polarized DC test strip form a loop, and the first polarized DC test strip is in contact with a pipeline protected by the cathodic protection system (104), characterized in that: The device (100) comprises: A standard circuit (101) includes a loop formed by a standard reference electrode and a grounded second polarized DC test piece; A main controller (102) is connected to the polarization switch circuit (103) and is used to control the working state of the polarization switch circuit (103) to simultaneously control the on / off of the path between the power supply in the cathode protection system (104) and the first polarization DC test strip, and between the power supply and the second polarization DC test strip, and to respectively obtain the voltage waveforms of the test reference electrode and the standard reference electrode to verify the potential of the test reference electrode; and The polarization switch circuit (103) is respectively connected to the power supply, the first polarization DC test strip, and the second polarization DC test strip.

2. The device (100) according to claim 1, characterized in that The polarization switch circuit (103) comprises a polarization switch having a first switch channel and a second switch channel, or two polarization switches having a first switch channel and a second switch channel respectively; the first switch channel is used to open and close the path between the power supply and the first polarization DC test strip; the second switch channel is used to open and close the path between the power supply and the second polarization DC test strip.

3. The device (100) according to claim 2, characterized in that Also included are test circuits respectively connected to the polarization switch circuit (103) and the first polarization DC test strip, the test circuit comprising a plurality of first test branches, each of the first test branches having a resistor with a different resistance value; the main controller is connected to the test circuit and is used to select one branch from the plurality of first test branches to connect to the path between the polarization switch circuit (103) and the first polarization DC test strip; and The standard circuit also includes a plurality of second test branches, each of which has a resistor with a different resistance value; the main controller (102) is connected to the standard circuit and is used to select one branch from the plurality of second test branches to connect to the path between the polarization switch circuit (103) and the second polarization DC test strip; the resistance values ​​of the selected first test branch and the selected second test branch are the same.

4. The device (100) according to claim 3, characterized in that The test circuit further includes a first switch, which is connected between the first polarized DC test strip and each of the first test branches and is used to select different branches to be connected to the first polarized DC test strip; and The standard circuit also includes a second switch, which is connected between the second polarized DC test strip and each of the second test branches and is used to select different branches to be connected to the second polarized DC test strip.

5. The device (100) according to claim 4, characterized in that The test circuit also includes a third switch, which is respectively connected to the first polarized DC test strip and the polarized AC test strip in the cathode protection system (104), and is also connected in series with the first switch to select a path between the first polarized DC test strip and the first switch, or between the polarized AC test strip and the first switch; the polarized AC test strip is in contact with the pipeline.

6. The device (100) according to claim 3, characterized in that Also includes: A signal sampling circuit is connected to the standard circuit, the test circuit and the main controller (102) respectively, and is used to respectively collect voltage signals of the test reference electrode and the standard reference electrode, and transmit the voltage signals to the main controller (102).

7. The device (100) according to claim 1, characterized in that The polarization switch circuit (103) is connected to the power supply and the first polarization DC test piece located underground in the cathode protection system (104) respectively through a test pile placed on the ground.

8. A reference electrode calibration system (800), characterized in that: include: A pipeline (212) is arranged underground; A cathodic protection system (104), comprising a test reference electrode and a first polarized DC test piece, for performing cathodic protection on the pipeline; and A reference electrode calibration device (100) according to any one of claims 1 to 7.

9. A reference electrode calibration method (900), applied to the main controller of the device (100) according to any one of claims 1 to 7, characterized in that: include: Sending (902) a control instruction to the polarization switch circuit, the control instruction being used to control the polarization switch circuit to switch a working state so as to simultaneously disconnect a path in the polarization switch circuit; as well as At least voltage waveforms of the test reference electrode and the standard reference electrode when the path is switched from the on state to the off state are respectively acquired (904) to verify the potential of the test reference electrode based on the voltage waveform of the standard reference electrode.

10. The method (900) according to claim 9, characterized in that Verifying the potential of the test reference electrode based on the voltage waveform of the standard reference electrode includes: Based on the voltage difference between the voltage waveform of the standard reference electrode and the voltage waveform of the test reference electrode, and a preset value, a potential calibration result of the test reference electrode is determined.

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