Device and method for lifting pressure sensor of cooling system of high-voltage direct-current converter valve

Abstract

The invention relates to the technical field of high-voltage direct-current transmission equipment monitoring, and discloses a high-voltage direct-current converter valve cooling system pressure sensor lifting device and method.The method includes the steps that a gradient stress ring and an electric field shielding cover are arranged, and the fringe effect is restrained from the physical level; after field installation, pre-pressurizing processing is carried out to optimize a pressure conduction path, and a two-step data compensation algorithm is adopted: an original digital signal is corrected by using a nonlinear edge effect compensation model established based on a maximum deviation feature point; a precise pressure value is calculated through a linear basic relation model, a compensation coefficient self-adaptive updating mechanism is further included, through periodic field calibration, coefficients of an edge effect compensation model are only pertinently updated when the measurement deviation exceeds the limit, and therefore precise compensation is conducted on long-term drift on the premise that the basic characteristics of the sensor are not changed. According to the invention, physical suppression is combined with an adaptive algorithm, so that the full-period service measurement repeatability and environmental adaptability of the sensor are improved.

Description

Technical Field

[0001] This invention relates to the field of monitoring technology for high-voltage direct current (HVDC) transmission equipment, specifically to a method for improving the repeatability of pressure sensors in HVDC converter valve cooling systems. Background Technology

[0002] As the core converter component of the high-voltage direct current transmission system, the losses during operation of the high-voltage direct current converter valve will be converted into a large amount of heat. If it cannot be dissipated in time through the cooling system, it will directly lead to excessive temperature rise of the converter valve device, causing failures such as insulation aging and reduced flow capacity. The pressure parameters of the cooling system (such as circulation pipeline pressure and cooling medium filling pressure) are key indicators reflecting the system's operating status and are directly related to the circulation efficiency of the cooling medium and the system's sealing reliability. Therefore, pressure sensors are required for real-time and accurate monitoring.

[0003] However, the operating environment of high-voltage DC converter valve cooling systems is characterized by frequent pressure fluctuations, large changes in medium flow rate, and strong electromagnetic interference. Existing pressure sensors generally suffer from insufficient repeatability during long-term operation. Analysis reveals that one of the core contributing factors is the edge effect of the sensor's sensitive elements (such as piezoresistive chips and capacitive diaphragms). When pressure is applied to the sensitive element, the stress or electric field distribution at the element's edge is distorted, leading to differences in the output signal of the sensitive element under the same pressure input. Specifically, during cyclic pressure loading (e.g., repeated loading from 0.5 to 2.5 MPa), the output value deviation of multiple sensor measurements exceeds ±1.5%FS. After long-term operation, the cumulative effect of the edge effect leads to fatigue and aging of the sensitive element, further exacerbating repeatability degradation. Frequent calibration and maintenance are required, increasing operation and maintenance costs and potentially causing unnecessary losses such as downtime for cooling system repairs due to misjudgments of pressure anomalies caused by poor measurement repeatability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for improving the repeatability of pressure sensors in high-voltage DC converter valve cooling systems, solving the problem of insufficient repeatability of existing pressure sensors in high-voltage DC converter valve cooling systems due to edge effects.

[0005] To achieve the above objectives, the first aspect of the present invention provides a device for improving the repeatability of a pressure sensor in a high-voltage DC converter valve cooling system based on edge effect suppression, comprising a pressure transmission module, an edge effect suppression module, a signal acquisition module, and a data processing module connected in sequence.

[0006] The pressure transmission module includes a pressure interface, a buffer chamber, and a transmission rod; the pressure interface is used to connect to the cooling system pipeline; the buffer chamber is provided with a honeycomb flow stabilization structure; one end of the transmission rod extends into the buffer chamber, and the other end is connected to the edge effect suppression module;

[0007] The edge effect suppression module includes a sensitive element mounting base, a gradient stress ring, and an electric field shield. The sensitive element mounting base has a groove in the middle for fixing the pressure sensor sensitive element. The gradient stress ring is sleeved on the edge of the sensitive element, and its inner side has an arc-shaped protrusion with a thickness that gradually increases from the center to the edge. The electric field shield wraps around the outside of the sensitive element and is grounded.

[0008] The signal acquisition module includes a signal conditioning circuit and an A / D converter, which are used to process and convert the electrical signal output by the sensitive element to obtain the original digital signal.

[0009] The data processing module includes a microprocessor and a storage unit; the microprocessor has a built-in edge effect compensation algorithm program for performing data compensation and output.

[0010] The gradient stress ring is made of elastic alloy steel, and the thickness of the arc-shaped protrusion gradually changes from the center to the edge in the range of 0.3mm-1.5mm.

[0011] The electric field shield is made of copper with a thickness of 0.2mm-0.5mm, and its inner wall is nickel-plated.

[0012] A second aspect of the present invention provides a method for improving the repeatability of a pressure sensor in a high-voltage DC converter valve cooling system. This method, based on the aforementioned device, includes the following steps:

[0013] Step 1: Calibration and Compensation Parameter Acquisition: Connect the device to a standard pressure source and repeatedly measure at multiple pressure calibration points to obtain the standard pressure value and the device's original digital signal. Based on the standard pressure value and the original digital signal, fit and establish a basic relationship model and an edge effect compensation model respectively, and store the compensation coefficients of the basic relationship model and the edge effect compensation model.

[0014] Step 2, On-site installation and pressure transmission optimization: Connect the device to the cooling system pipeline through the pressure interface, and pre-pressurize the buffer chamber inside the device to eliminate contact gaps;

[0015] Step 3: Real-time suppression of edge effects and signal acquisition: The edge effects of the pressure sensor are physically suppressed in real time, and the signal acquisition module acquires and converts the electrical signal output by the sensitive element to obtain the original digital signal.

[0016] Step 4: Data Compensation and Output: The data processing module calls the compensation coefficient, first compensates the original digital signal through the edge effect compensation model to obtain the compensated signal, and then substitutes the compensated signal into the basic relationship model to calculate and output the accurate pressure value.

[0017] Step 1: Acquisition of Calibration and Compensation Parameters

[0018] Connect the device to a standard pressure source and perform repeated measurements at multiple pressure calibration points covering the sensor's range. Each pressure calibration point should be measured at least 10 times. Record the standard pressure value and the multiple raw digital signals output by the device at each calibration point. Based on the collected data, establish a basic relationship model and an edge effect compensation model. First, calculate the average value of the raw digital signals measured multiple times at each pressure calibration point. Based on the standard pressure values ​​and the corresponding average raw digital signals at all calibration points, fit the basic relationship model using the least squares method.

[0019] ;

[0020] in, The pressure value calculated for the model. The output digital signal of the sensor, Basic gain coefficient, It is the base offset coefficient.

[0021] Secondly, to establish an edge effect compensation model, the maximum deviation value of the original digital signal measured multiple times at each pressure calibration point was calculated, and the three pressure calibration points with the largest maximum deviation values ​​were selected as edge effect feature points. Based on the measurement data of the edge effect feature points, a polynomial fitting method was used to establish an edge effect compensation model to describe the relationship between the original digital signal and its nonlinear deviation. This model will convert the original digital signal... Compensation is the signal after compensation. The specific form is as follows:

[0022] ;

[0023] in, The coefficients of the quadratic term in the edge effect compensation model are... The coefficient of the first term is the compensation coefficient obtained, i.e. , , and The data is stored in the storage unit of the data processing module.

[0024] Step 2: On-site installation and pressure transmission optimization

[0025] The device is connected to the circulation pipeline of the high-voltage DC converter valve cooling system through its pressure interface. The buffer chamber inside the device is pre-pressurized by filling the buffer chamber with a pressure of 40%-60% of the rated pressure of the cooling system and maintaining it for 8-12 minutes before depressurizing to eliminate the contact gap between the transmission rod and the sensitive element.

[0026] Step 3: Real-time suppression of edge effects and signal acquisition

[0027] During operation of the cooling system, the medium pressure is stabilized through the buffer chamber and then transmitted to the sensitive element via the conduction rod. A gradient stress ring applies preload to the edge of the sensitive element, ensuring uniform pressure load distribution on its surface and suppressing the stress edge effect. Simultaneously, a grounded electric field shield protects against electromagnetic interference from equipment such as the converter valve, suppressing the electric field edge effect. The signal acquisition module amplifies and filters the electrical signal output from the sensitive element and converts it into a raw digital signal via an A / D converter. Then, it is transmitted to the data processing module.

[0028] Step 4: Data Compensation and Output

[0029] The data processing module receives the raw digital signal. Then, the compensation coefficient in the storage unit is called to perform the following calculations:

[0030] First, the original digital signal is processed using an edge effect compensation model. Compensation is performed to obtain the compensated signal. .

[0031] Then, the compensated signal Substituting into the basic relationship model, the precise pressure value is calculated. .

[0032] Finally, the calculated precise pressure value is transmitted via the CAN bus. The main control unit transmits data to the cooling system.

[0033] Step 5: Adaptive Update of Compensation Coefficients

[0034] Every set period (e.g., 45-90 days), the device is calibrated in the field using a portable standard pressure calibrator. Calibration is performed at the three edge effect characteristic points identified in step one. At each characteristic point, the deviation between the device's output precise pressure value and the standard pressure value is calculated. If the deviation at any characteristic point exceeds a preset threshold (e.g., ±0.3% to ±0.5% of the sensor's full scale), an update procedure is triggered. The update procedure, based on the new in-field calibration data, recalculates the compensation coefficients of the edge effect compensation model. and And replace the old coefficients in the storage unit with new coefficients. In this process, the coefficients of the underlying relational model... and It remains unchanged.

[0035] This invention provides a method for improving the repeatability of pressure sensors in a high-voltage DC converter valve cooling system. It offers the following advantages:

[0036] 1. This invention improves the quality of the original signal by physically suppressing the sensitive element before signal acquisition. This method applies a gradient preload to the edge of the sensitive element and forms an electric field shield around it, actively homogenizing the pressure load and isolating external electromagnetic interference. This preprocessing step, performed before measurement, directly reduces signal source noise and inconsistencies caused by stress concentration and electric field distortion, providing a more stable and less discrete original signal foundation for all subsequent calculation steps, thereby directly improving measurement repeatability.

[0037] 2. This invention employs an innovative two-step data compensation method that separates and processes errors from different sources, achieving precise error correction. The method first performs an edge effect compensation step to specifically correct deviations caused by the inherent nonlinearity of the sensor, and then performs a basic relational model solution step. This step-by-step processing approach, which corrects nonlinearity first and then solves linearity, avoids the problems of overfitting or undercompensation that exist in traditional single compensation models, making the algorithm logic clearer and the compensation target more specific, thereby significantly improving the accuracy of the final output pressure value.

[0038] 3. This invention also includes an adaptive update method for compensation coefficients, which can efficiently and accurately compensate for performance drift of sensors caused by long-term service. This method periodically triggers a simplified on-site calibration process. Once the measurement deviation exceeds a preset threshold, it only refits and updates the edge effect compensation model coefficients most closely related to performance drift, while keeping the basic relationship model unchanged. This targeted update strategy avoids the complex work of completely recalibrating the entire system, greatly simplifies the long-term maintenance process of the sensor, and significantly improves its measurement stability and reliability throughout its entire lifecycle. Attached Figure Description

[0039] Figure 1 This is a flowchart of the method of the present invention;

[0040] Figure 2 This is a schematic diagram of the pressure sensor repeatability enhancement device of the present invention;

[0041] Figure 3 This is a schematic diagram of the edge effect suppression module of the present invention.

[0042] Among them, 10 is the pressure transmission module; 20 is the edge effect suppression module; 30 is the signal acquisition module; and 40 is the data processing module. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example:

[0045] Please see the appendix Figure 2 This invention provides a pressure sensor enhancement device for a high-voltage DC converter valve cooling system, comprising a pressure transmission module 10, an edge effect suppression module 20, a signal acquisition module 30, and a data processing module 40 connected in sequence.

[0046] The pressure transmission module 10 includes a pressure interface, a buffer chamber, and a transmission rod; the pressure interface is used to connect to the cooling system pipeline; the buffer chamber is provided with a honeycomb-shaped flow stabilizer; one end of the transmission rod extends into the buffer chamber, and the other end is connected to the edge effect suppression module;

[0047] The edge effect suppression module 20 includes a sensitive element mounting base, a gradient stress ring, and an electric field shield. The sensitive element mounting base has a groove in the middle for fixing the pressure sensor sensitive element. The gradient stress ring is sleeved on the edge of the sensitive element, and its inner side has an arc-shaped protrusion with a thickness that gradually increases from the center to the edge. The electric field shield wraps around the outside of the sensitive element and is grounded.

[0048] The signal acquisition module 30 includes a signal conditioning circuit and an A / D converter, which are used to process and convert the electrical signal output by the sensitive element to obtain the original digital signal.

[0049] The data processing module 40 includes a microprocessor and a storage unit; the microprocessor has a built-in edge effect compensation algorithm program for performing data compensation and output.

[0050] Please see the appendix Figure 1 - Appendix Figure 3 This invention provides a method for improving the pressure sensor in a high-voltage DC converter valve cooling system, comprising the following steps:

[0051] Step S100, namely, obtaining device calibration and compensation parameters.

[0052] This is mainly used to establish the correspondence between pressure values ​​and sensor output signals before the device is put into operation, and to identify and quantify the nonlinear deviation caused by edge effects, ultimately obtaining the basic relationship model coefficients and edge effect compensation model coefficients for subsequent real-time compensation. This step specifically includes the following operations:

[0053] The repeatability enhancement device for the pressure sensor to be calibrated, including a pressure transmission module 10, an edge effect suppression module 20, a signal acquisition module 30, and a data processing module 40, is connected to a standard pressure source with an accuracy of ±0.02%FS. During the calibration process, the pressure calibration range is set to 0% to 100% of the sensor's range, for example, 0MPa-3MPa. Within the pressure calibration range, discrete pressure calibration points are applied sequentially starting from the zero pressure with a step size of 0.2MPa. The number of pressure calibration points is no less than 6, for example, 0MPa, 0.2MPa, 0.4MPa up to 3.0MPa.

[0054] At each standard pressure point Below (of which) (Indicates the sequence number of the pressure calibration point), after stabilizing and holding the pressure, the signal acquisition module 30 continuously performs... Number of measurements At least 10 times, for example, set to 10 times, the signal acquisition module 30 amplifies, filters, and performs analog-to-digital conversion on the electrical signal output by the sensitive element, and then converts the original digital signal obtained from each measurement. (in The measurement sequence number (indicating the number of measurements taken at that pressure calibration point) is transmitted to the data processing module 40 and recorded and stored.

[0055] After completing data acquisition for all pressure calibration points, the data processing module 40 processes the acquired data to fit and establish a basic relationship model and an edge effect compensation model. First, for each pressure calibration point... Calculate its The average value of the raw digital signal obtained from the measurements :

[0056] ;

[0057] in, In the first The pressure calibration point The original digital signal of the measurement; The number of times to repeat the measurement for each pressure calibration point.

[0058] Next, the data processing module 40 is based on the standard pressure values ​​of all pressure calibration points. The corresponding average value of the original digital signal The paired data were fitted using the least squares method to establish the following basic relationship model:

[0059] ;

[0060] in, This represents the pressure value calculated using this model; This represents the output digital signal of the sensor, which in this model takes the value after edge effect compensation. Indicates the base gain coefficient; This represents the basic offset coefficient, which is a basic relationship model that describes the correspondence between pressure and sensor output signal under ideal linear conditions.

[0061] To quantify and compensate for the nonlinear deviation introduced by the edge effect, the data processing module 40 continues to build an edge effect compensation model. First, for each pressure calibration point... Calculate its The raw digital signal obtained from the measurement is relative to the average value. Maximum deviation :

[0062] ;

[0063] in, This reflects the dispersion of the sensor output signal at that pressure calibration point. Then, the data processing module 40 selects... The three pressure calibration points with the largest values ​​are used as edge effect feature points, which represent the areas where the edge effect has the most significant impact.

[0064] Subsequently, the data processing module 40, based on the measurement data of edge effect feature points, uses a polynomial fitting method to establish an edge effect compensation model. This model is used to process the original digital signal. Nonlinear compensation is performed to obtain the compensated signal. Its specific form is a quadratic polynomial model:

[0065] ;

[0066] in, This is the output signal after edge effect compensation; The raw, unprocessed digital signal; For the quadratic term coefficients of the edge effect compensation model; These are the coefficients of the first-order term in the edge effect compensation model. This model allows for targeted correction of output biases caused by edge effects.

[0067] Finally, the data processing module 40 will process the basic gain coefficients obtained through the above fitting process. Basic offset coefficient And the quadratic coefficients of the edge effect compensation model and coefficient of the first term The data is stored in the storage unit of the data processing module 40 as parameters for subsequent real-time data compensation.

[0068] In this embodiment, a quadratic polynomial model is used for the edge effect compensation model because it can describe the main nonlinear deviation with relatively low computational overhead. However, the invention is not limited to this. In other embodiments, depending on the complexity of the actual measured deviation curve, the edge effect compensation model can also employ a higher-order polynomial model, a piecewise linear interpolation model, or a model based on a radial basis function neural network. These models can also achieve nonlinear compensation of the original digital signal. Correspondingly, the number of edge effect feature points selected when building the model must also meet the minimum data point requirement for fitting the model.

[0069] Step S200, namely, on-site installation and pressure transmission optimization

[0070] The purpose is to correctly deploy the pressure sensor device on the cooling system piping of the high-voltage DC converter valve and optimize the pressure transmission path to ensure the accuracy of subsequent measurements. This step specifically includes the following operations:

[0071] First, the device is physically installed by connecting the pressure interface of the pressure sensor device to the flange of the circulation pipeline of the high-voltage DC converter valve cooling system and securing it with fasteners to ensure the sealing of the connection. During installation, it is necessary to ensure that the buffer chamber of the device and the cooling system pipeline are coaxially installed. This alignment method allows the cooling medium to enter the buffer chamber smoothly, reducing local turbulence caused by sudden changes in the flow path. At the same time, it is necessary to ensure that the transmission rod in the pressure transmission module 10 and the sensitive element in the edge effect suppression module 20 are in perpendicular contact. This is to ensure that when the medium pressure is transmitted to the sensitive element through the transmission rod, the force is perpendicular to the surface of the sensitive element, avoiding measurement errors caused by off-center loading or tangential force.

[0072] After the physical installation is completed, pressure transmission optimization is performed, which involves pre-pressurizing the buffer chamber. The process is as follows: a pressure medium is injected into the buffer chamber through the reserved interface, and the pressure in the buffer chamber is slowly increased to a set value between 40% and 60% of the rated working pressure of the cooling system. The pressure is maintained at this set value for 8-12 minutes. After the pressure holding is completed, the pressure in the buffer chamber is slowly released to zero.

[0073] The purpose of pre-pressurization is to eliminate the microscopic contact gap between the transmission rod and the sensing element. Due to machining and assembly tolerances, there is an initial gap between the end face of the transmission rod and the force-bearing surface of the sensing element. By applying preload pressure, the contact surfaces of the transmission rod and the sensing element can be made to fit completely together. The pressure holding process allows for microscopic creep and stress release of the materials between the contact surfaces, thereby achieving a stable contact state. This operation ensures that in subsequent actual work, the medium pressure can be applied to the sensing element instantly and without delay through the transmission rod, avoiding initial measurement nonlinearity caused by the gap closing process, and providing a stable physical basis for subsequent accurate measurements.

[0074] Step S300, namely, real-time suppression of edge effects and signal acquisition.

[0075] Its purpose is to suppress edge effects in real time through its physical structure during device operation and accurately convert pressure signals into digital signals to provide raw input for subsequent data compensation. This step specifically includes the following operations:

[0076] When the device is put into operation, the medium pressure from the cooling system pipeline of the high-voltage DC converter valve first enters the buffer chamber of the pressure transmission module 10. The honeycomb flow stabilization structure set inside the buffer chamber plays a role in rectifying and buffering the flowing cooling medium, weakening the turbulent pulsation in the medium flow, and forming a relatively stable pressure field. This stable pressure is vertically transmitted to the sensitive element in the edge effect suppression module 20 through the transmission rod.

[0077] When pressure is transmitted to the sensitive element, the edge effect suppression module 20 performs real-time physical suppression. First, a gradient stress ring, made of elastic alloy steel, is fitted onto the edge of the sensitive element. Through its inner arc-shaped protrusion structure with gradually increasing thickness from the center to the edge, a precisely designed non-uniform preload is applied to the edge area of ​​the sensitive element. When the sensitive element deforms under the pressure of the medium, the preload can compensate for the stress concentration caused by the fixed constraint of the element edge, making the stress distribution on the entire force-bearing surface of the sensitive element tend to be uniform, thereby suppressing the stress edge effect caused by stress distortion.

[0078] Meanwhile, the electric field shielding cover, which is wrapped around the sensitive element and grounded together with the device casing, uses the Faraday cage effect to shield the strong electromagnetic field generated by external high-voltage equipment such as converter valves. The external electrostatic field and time-varying electric field lines terminate on the outer surface of the grounded shielding cover, forming an equipotential region of electric field inside it. This prevents the external electromagnetic field from inducing interference charges or noise currents on the surface of the sensitive element, especially in its edge region, and suppresses the edge effect of the electric field.

[0079] While providing physical suppression, the signal acquisition module 30 acquires and digitizes the weak electrical signal output by the sensitive element. The physical deformation generated by the sensitive element under pressure is converted into a voltage or resistance change signal at the microvolt or millivolt level. This signal first enters the instrumentation amplifier in the signal conditioning circuit for differential-mode amplification, increasing its amplitude to the volt level to match the processing range of subsequent circuits. The amplified signal then passes through a low-pass filter to filter out high-frequency noise introduced by system mechanical vibration or residual electromagnetic interference.

[0080] The conditioned analog voltage signal is fed into an A / D converter, which converts the continuous analog voltage signal into discrete digital quantities at a set sampling frequency. The conversion accuracy is, for example, 16 bits or 24 bits, thus obtaining a high-resolution raw digital signal. The original digital signal The data is transmitted in real time to the data processing module 40 for subsequent data compensation and stress calculation.

[0081] S400, namely data compensation and output

[0082] Its purpose is to perform algorithmic compensation on the acquired raw digital signal to correct the nonlinear errors it contains, and finally calculate the accurate pressure value and output it to the main control system. This step is executed in real time by the data processing module 40, and specifically includes the following operations:

[0083] The microprocessor within the data processing module 40 receives the raw digital signals transmitted from the signal acquisition module 30 in real time. Upon receiving the signal, the microprocessor first retrieves the compensation coefficients (i.e., quadratic term coefficients) of the edge effect compensation model stored in step S100 from its internal storage unit. and coefficient of the first term .

[0084] The microprocessor receives the raw digital signal As input variables, they are substituted into the following edge effect compensation model for calculation to obtain the intermediate result after nonlinear compensation, i.e., the compensated signal. :

[0085] ;

[0086] This calculation process uses a quadratic polynomial function to calculate the deviation component introduced by edge effects in the original digital signal, and then subtracts this deviation component from the original signal to obtain the compensated signal with the main nonlinear error eliminated. .

[0087] Signal after compensation Then, the microprocessor retrieves the compensation coefficients of the basic relational model, i.e., the basic gain coefficients, from the memory unit. and basic offset coefficient .

[0088] The microprocessor will compensate the signal As input variables, they are substituted into the following basic relational model for linear transformation to calculate the final accurate pressure value. :

[0089] ;

[0090] This calculation process will use the compensated signal that has already undergone nonlinear correction. By using a linear function, the pressure is mapped and converted into its corresponding actual physical quantity, thus obtaining a precise pressure value. .

[0091] After calculating the precise pressure value Subsequently, the data processing module 40, through its integrated communication interface, such as the controller local area network bus interface, packages the pressure value data into a data frame according to a preset communication protocol and message format, and sends it to the main control unit of the high-voltage DC converter valve cooling system for system operation status monitoring and control. In addition, the data processing module 40 can also process the raw digital signal... Compensated signal and precise pressure values Along with the corresponding timestamp information, it is recorded in its local storage unit for subsequent analysis of device status or fault diagnosis.

[0092] S500, i.e., adaptive update of compensation coefficients.

[0093] To address the potential performance parameter drift of pressure sensor sensing elements due to long-term operation and ensure the device consistently provides highly repeatable pressure measurements throughout its service life, this step is achieved through periodic checks and on-demand updates, specifically including the following operations:

[0094] The data processing module 40 has a preset update cycle, for example, 45-90 days. When the update cycle is reached, the system triggers a periodic on-site calibration procedure. The operator uses a portable standard pressure calibrator and connects it to the pressure sensor device that is installed on the cooling system pipeline. This calibration is performed only on the three edge effect feature points determined during the offline calibration in step S100.

[0095] At each edge effect characteristic point, a portable standard pressure calibrator applies a known standard pressure value. The signal acquisition module 30 and data processing module 40 of the device acquire the raw digital signal in real time and calculate the precise pressure value according to the process of steps S300 and S400. The data processing module 40 records the standard pressure value at each feature point. and the precise pressure value output by the device .

[0096] Subsequently, the data processing module 40 calculates the precise pressure value output by the device at each edge effect feature point. Compared with standard pressure value absolute value of the deviation between The absolute value of the deviation is compared with the full scale of the sensor. If the absolute value of the deviation at any edge effect feature point exceeds the preset threshold, the measurement performance of the device is determined to have drifted significantly, and the compensation coefficient update procedure is triggered.

[0097] Once the update procedure is triggered, the data processing module 40 will utilize the raw digital signals obtained during this field calibration at the three edge effect feature points. and the corresponding standard pressure value Considering the coefficients of the basic relational model and The sensor remains relatively stable during long-term operation and does not change during this update process. The microprocessor first utilizes this fixed value. and Each standard pressure value The corresponding ideal compensation signal is derived by reverse calculation. Then, the microprocessor refits the edge effect compensation model according to the following relationship:

[0098] ;

[0099] By performing least squares fitting on new data from three edge effect feature points, a new set of quadratic term coefficients was recalculated and determined. and coefficient of the first term After the calculation is completed, the data processing module 40 will store the old edge effect compensation model coefficients in the storage unit. and The newly calculated coefficient values ​​are replaced, and this update operation ensures that the edge effect compensation model can adapt to long-term aging of sensor sensitive elements or environmental changes, thereby maintaining the measurement repeatability of the entire device.

[0100] In another embodiment, the adaptive update mechanism in step S500 can set two preset thresholds. The first threshold is a smaller value; when the deviation exceeds the first threshold but does not reach the second threshold, the operation of updating only the edge effect compensation model coefficients as described above is performed. The second threshold is a larger value; when the deviation exceeds the second threshold, it indicates that the sensor's fundamental linear characteristics may also have changed significantly. At this time, the system will trigger a complete field calibration procedure, not only refitting the edge effect compensation model but also refitting the fundamental relationship model, i.e., updating all four compensation coefficients.

[0101] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pressure sensor lifting device for a high-voltage DC converter valve cooling system, characterized in that, It includes a pressure transmission module, an edge effect suppression module, a signal acquisition module, and a data processing module connected in sequence; The pressure transmission module includes a pressure interface, a buffer chamber, and a transmission rod; the pressure interface is used to connect to the cooling system pipeline; the buffer chamber is provided with a honeycomb flow stabilization structure; one end of the transmission rod extends into the buffer chamber, and the other end is connected to the edge effect suppression module; The edge effect suppression module includes a sensitive element mounting base, a gradient stress ring, and an electric field shield. The sensitive element mounting base has a groove in the middle for fixing the pressure sensor sensitive element. The gradient stress ring is sleeved on the edge of the sensitive element, and its inner side has an arc-shaped protrusion with a thickness that gradually increases from the center to the edge. The electric field shield wraps around the outside of the sensitive element and is grounded. The signal acquisition module includes a signal conditioning circuit and an A / D converter, which are used to process and convert the electrical signal output by the sensitive element to obtain the original digital signal. The data processing module includes a microprocessor and a storage unit; the microprocessor has a built-in edge effect compensation algorithm program for performing data compensation and output.

2. A method for lifting a pressure sensor in a high-voltage DC converter valve cooling system, as described in claim 1, characterized in that... Includes the following steps: Step 1: Calibration and Compensation Parameter Acquisition: Connect the device to a standard pressure source and repeatedly measure at multiple pressure calibration points to obtain the standard pressure value and the device's original digital signal. Based on the standard pressure value and the original digital signal, fit and establish a basic relationship model and an edge effect compensation model respectively, and store the compensation coefficients of the basic relationship model and the edge effect compensation model. Step 2, On-site installation and pressure transmission optimization: Connect the device to the cooling system pipeline through the pressure interface, and pre-pressurize the buffer chamber inside the device to eliminate contact gaps; Step 3: Real-time suppression of edge effects and signal acquisition: The edge effects of the pressure sensor are physically suppressed in real time, and the signal acquisition module acquires and converts the electrical signal output by the sensitive element to obtain the original digital signal. Step 4: Data Compensation and Output: The data processing module calls the compensation coefficient, first compensates the original digital signal through the edge effect compensation model to obtain the compensated signal, and then substitutes the compensated signal into the basic relationship model to calculate and output the accurate pressure value.

3. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 1, characterized in that, The method further includes: Compensation coefficient adaptive update: On-site calibration is performed at set intervals to determine whether the measurement deviation exceeds a preset threshold. If it does, the compensation coefficient of the edge effect compensation model is updated based on the new calibration data.

4. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 1, characterized in that, The process of establishing the edge effect compensation model in step one is as follows: The maximum deviation value of the original digital signal measured multiple times at each pressure calibration point is calculated. The three pressure calibration points with the largest maximum deviation values ​​are selected as edge effect feature points. Based on the measurement data of the edge effect feature points, the edge effect compensation model is obtained by polynomial fitting.

5. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The real-time physical suppression of edge effects in step three specifically involves: The gradient stress ring applies a preload to the edge of the sensitive element to ensure uniform distribution of the pressure load, while the grounded electric field shield blocks external electromagnetic interference.

6. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The data processing sequence for data compensation and output in step four is as follows: First, the original digital signal is nonlinearly compensated using the edge effect compensation model to correct the deviation introduced by the edge effect; Then, the compensated signal obtained through nonlinear compensation is substituted into the basic relationship model for linear transformation to calculate the precise pressure value.

7. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The adaptive update of the compensation coefficients in step five is specifically as follows: After the set period is reached, on-site calibration is performed at the edge effect feature point. If the deviation between the accurate pressure value output by the device and the standard pressure value exceeds the preset threshold, an update is triggered.

8. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The update of the compensation coefficients only applies to the refitting and updating of the compensation coefficients of the edge effect compensation model, while the coefficients of the basic relationship model remain unchanged during the adaptive update process.

9. The method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The set period is 45-90 days.

10. A method for improving the pressure sensor in a high-voltage DC converter valve cooling system according to claim 2, characterized in that, The pre-charge process in step two is specifically as follows: The buffer chamber is filled with a pressure of 40%-60% of the rated pressure of the cooling system and held for 8-12 minutes before being depressurized.

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