Card relay verification circuit, system and method

Abstract

The invention discloses a card relay verification circuit, system and method, and relates to the technical field of relay verification, synchronous verification of multiple groups of relays is realized through the parallel design of card relay backboards, an adjustable power supply is integrated, a voltage / current transmitter collects contact action signals, coil loop voltage and current and contact loop parameters in real time, and the verification of the multiple groups of relays is realized. The method comprises the following steps of: calculating pull-in voltage, release voltage, contact resistance and coil resistance, constructing a weight model by adopting a Min-Max normalization processing and analytic hierarchy process, calculating residual reliability parameters through linear weighting, and adaptively correcting a judgment threshold in combination with a dynamic sample database. According to the method, the problems of low verification efficiency, strong subjective dependence, technical parameter deficiency and insufficient hidden danger pre-judgment of a traditional method are solved, multi-channel parallel detection, accurate quantitative evaluation and standardized preventive maintenance are realized, and the operation stability of the distributed control system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of relay calibration, and particularly to a calibration circuit, system and method for a card relay. Background Art

[0002] With the wide application of distributed control systems in the power industry, the on-site stability requirements for distributed control systems have been improved. The reliability and stability of the card relays widely used in distributed control systems play an important role in the safe and stable operation of distributed control systems. Therefore, there is a high-frequency calibration requirement for the card relays of distributed control systems.

[0003] During the major overhaul of the unit and the overhaul of important systems, it is necessary to calibrate all or main interlock protection signal relays, and timely replace the card relays with poor reliability, function attenuation and non-compliant relevant technical parameters, so as to ensure the safe and reliable operation of equipment and systems.

[0004] At present, most relay calibrations adopt observation methods, empirical methods, or are more inclined to portable operations. Less attention is paid to systematic calibration platforms and actual performance parameters. It is necessary to disassemble and assemble relays one by one, with cumbersome operations. Multi-group parallel calibration cannot be achieved. The relay status depends on manual experience judgment. Existing portable devices only detect the on / off function, ignoring key parameters such as contact resistance, pull-in / release voltage, and coil resistance. It is impossible to comprehensively evaluate the performance attenuation of relays, lack a reliability model based on dynamic data, and it is difficult to timely detect relays with critical parameter overlimits, which may lead to potential failure risks of distributed control systems. Summary of the Invention

[0005] Therefore, the technical problems to be solved by the present invention are as follows: The traditional calibration method has low efficiency, strong subjective dependence, lack of technical parameters, and insufficient hidden danger prediction.

[0006] The above technical problems are solved by the following technical solutions:

[0007] The present invention provides a calibration circuit for a card relay, which includes a relay calibration module and a parameter detection module.

[0008] In a preferred embodiment of the calibration circuit for a card relay of the present invention: The relay calibration module includes a plurality of relays, a first adjustable power supply and a second adjustable power supply. The relays are connected in parallel. The two ends of the relay coils are connected in parallel to the second adjustable power supply to form a coil loop. The two ends of the relay contacts are connected in parallel to the first adjustable power supply to form a contact loop; and,

[0009] The parameter detection module, connected to the relay calibration module, includes a voltage transmitter, connected in parallel across both ends of the second adjustable power supply, for collecting the coil circuit voltage and converting it into a first standard signal, and also includes a first current transmitter, connected in series in the coil circuit, for collecting the coil circuit current and converting it into a second standard signal; it further includes a second current transmitter, connected in series in the contact circuit, for collecting the contact circuit current and converting it into a third standard signal.

[0010] In a preferred embodiment of the card relay calibration circuit of the present invention: The relay calibration module further includes a power switch and a fixed resistor, and the power switch and the fixed resistor are connected in series in the contact circuit.

[0011] In a preferred embodiment of the card relay calibration circuit of the present invention: The relay is installed on the card relay backplane, and the card relay backplane is the SP board of the G2R type relay, with 16 relay slots, and 16 of the said relays can be installed.

[0012] In a preferred embodiment of the card relay calibration circuit of the present invention: The relay is installed on the card relay backplane, and the card relay backplane is the SP board of the KUEP type relay, with 12 relay slots, and 12 of the said relays can be installed.

[0013] The present invention also proposes a card relay calibration system, which includes a card relay calibration circuit and also includes a signal processing module.

[0014] In a preferred embodiment of the card relay calibration system of the present invention: The signal processing module, connected to the parameter detection module, includes a DI card, connected to the contacts of multiple said relays, for collecting the action digital signals of the contacts; it also includes an AI card, connected to the voltage transmitter, the first current transmitter and the second current transmitter, for receiving the first standard signal, the second standard signal and the third standard signal; it further includes a host computer, communicatively connected to the DI card and the AI card, for calculating the contact resistance, pull-in voltage, release voltage and coil resistance of each relay based on the digital signals, the standard signals and the reliability model, and generating remaining reliability parameters through normalization processing and weight assignment to determine the reliability of the relay.

[0015] In a preferred embodiment of the card relay calibration system of the present invention: The calculation of the reliability model includes, based on the normalized parameters of the contact resistance, the pull-in voltage, the release voltage and the coil resistance, constructing a weight vector through the analytic hierarchy process, and calculating the remaining reliability K value by using the linear weighted method;

[0016] The contact resistance is calculated as follows: RJ = VDD1 / ITj-R0;

[0017] The pull-in voltage is the voltage value collected by the voltage transmitter when the normally open contact of the relay is actuated;

[0018] The release voltage is the voltage value collected by the voltage transmitter when the normally open contact of the relay is restored;

[0019] The calculation formula of the coil resistance is: RX=VDD2 / ITi.

[0020] In a preferred embodiment of the card relay calibration system of the present invention, the normalization process includes setting normalization ranges for the contact resistance, the pull-in voltage, the release voltage, and the coil resistance, respectively, and using the Min-Max normalization equation: Xg = (X - Xmin) / (Xmax - Xmin).

[0021] Where X is the original parameter value, Xmax is the upper limit allowed, and Xmin is the lower limit allowed;

[0022] The normalized range includes:

[0023] The contact resistance range is set to [0.2Ω, 1Ω],

[0024] The pull-in voltage range is set to [20.4V, 26.4V].

[0025] The release voltage range is set to [2.4V, 12V],

[0026] The coil resistance range is set to [460Ω, 506Ω].

[0027] In a preferred embodiment of the card relay verification system of the present invention, constructing the weight vector in the hierarchical analysis method includes constructing a judgment matrix of contact resistance, pull-in voltage, release voltage, and coil resistance, and obtaining a weight vector W=[0.055, 0.118, 0.263, 0.564]^T by calculating the geometric mean of each parameter and normalizing the result.

[0028] The calculation formula of the residual reliability K value is: K=1-A·W, where A is a matrix composed of normalized parameters.

[0029] In a preferred embodiment of the card relay verification system of the present invention: the host computer is further used to fit the relay reliability distribution curve based on historical verification data, calculate the mean and standard deviation, and use the mean plus 1 times the standard deviation as the critical reliability;

[0030] In subsequent verification, the sample database is dynamically updated and the critical reliability parameters are corrected to improve the accuracy of the determination.

[0031] The present invention also provides a method for calibrating a card relay, which includes parameter calculation, parameter normalization, threshold elimination, weight assignment, reliability calculation, critical reliability determination, and dynamic update.

[0032] In a preferred embodiment of the method for calibrating a card relay according to the present invention: parameter calculation includes: collecting the contact circuit voltage, contact circuit current, coil circuit voltage, and coil circuit current, and calculating the contact resistance, pull-in voltage, release voltage, and coil resistance;

[0033] Parameter normalization includes: performing normalization processing on the contact resistance, pull-in voltage, release voltage, and coil resistance by using the Min-Max normalization equation to obtain the normalized parameter Xg;

[0034] Threshold elimination includes: if any normalized parameter Xg > 1 or Xg < 0, it is determined that the corresponding relay is unqualified;

[0035] Weight assignment includes: constructing a judgment matrix based on the analytic hierarchy process and calculating the weight vector W of each parameter;

[0036] Reliability calculation includes: calculating the remaining reliability K value according to the formula K = 1 - A·W;

[0037] Critical reliability determination includes: fitting a reliability distribution curve based on the historical sample database, calculating the mean μ and the standard deviation σ, using μ + σ as the critical reliability. If K > 1 - (μ + σ), it is determined that the relay is reliable, otherwise it is eliminated;

[0038] Dynamic update includes: adding the parameters of this calibration to the sample database, recalculating the mean and the standard deviation, and updating the critical reliability.

[0039] The beneficial effects of the present invention are as follows: realizing synchronous calibration of multiple relays through the backplane parallel design to improve efficiency; integrating sensors and acquisition modules to obtain parameters such as pull-in voltage, release voltage, contact resistance, and coil resistance in real time, eliminating the dependence on manual experience; adopting normalization processing and intelligent algorithm models to calculate the remaining reliability, accurately evaluating the performance degradation; dynamically updating the database to fit the reliability distribution curve, adaptively correcting the judgment threshold, and predicting potential hidden dangers; establishing a standardized parameter evaluation system to solve the problems of parameter missing and subjective misjudgment in traditional methods, and realizing preventive maintenance and efficient management of relays in distributed control systems. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention and do not limit the present invention.

[0041] Figure 1 Shows the circuit diagram for checking the card relay;

[0042] Figure 2 Shows the reliability distribution diagram of the relay;

[0043] Figure 3 Shows the processing flow chart of the card relay checking system;

[0044] Figure 4 Shows the relay reliability calculation process;

[0045] Figure 5 Shows the wiring diagram of the G2R type relay;

[0046] Figure 6 Shows the wiring diagram of the KUEP type relay;

[0047] Figure 7 Shows the card relay checking system diagram. Detailed implementation manners

[0048] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with the specific implementation manners and the accompanying drawings.

[0049] The terms used in the present invention are those general terms that are currently widely used in the art in consideration of the functions of the present invention, but these terms may vary according to the intentions of those of ordinary skill in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in this case, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but based on the meanings of the terms and the overall description of the present invention.

[0050] Referring to Figure 1 , this embodiment provides a card relay checking circuit, including a relay checking module 1 and a parameter detection module 2.

[0051] The relay checking module 1 is designed through the card relay backplane. The coil circuits of multiple relays KM are connected in parallel to the second adjustable power supply VDD2, and the contact circuits are connected in parallel to the first adjustable power supply VDD1, supporting the simultaneous checking of multiple groups of relays. For example, the G2R type can check 16 channels simultaneously, and the KUEP type can check 12 channels simultaneously, greatly improving the detection efficiency; by adjusting the output voltages of the contact circuit and the coil circuit, the action characteristics of the relay KM under different working conditions can be simulated, and key parameters such as the pull-in voltage and the release voltage can be tested; at the same time, a power switch S and a fixed resistor R0 are connected in series in the contact circuit to control the on / off of the circuit and limit the current, protecting the relay and the detection equipment.

[0052] The parameter detection module 2 is connected in parallel with the second adjustable power supply VDD2 through the voltage transmitter VT to collect the coil loop voltage in real time and convert it into a 4-20 mA standard signal. The current signal is measured by the first current transmitter ITi connected in series in the coil loop and converted into a 4-20 mA standard signal. The contact loop current is measured by the second current transmitter ITj connected in series in the contact loop and converted into a 4-20 mA standard signal. Combining the fixed resistor R0 in the contact loop and the parameters of the first adjustable power supply VDD1 provides the original data support for calculating the relay contact resistance RJ, coil resistance RX, pull-in voltage VX, and release voltage VS. At the same time, the current limiting resistor R0 protects the contact loop to avoid overcurrent damage to the relay.

[0053] Refer to Figure 5 , as an optional embodiment, this embodiment provides a wiring diagram of the G2R type relay, showing the connection method of the G2R type relay on the relay backplane of the card. It includes the wiring conditions of the coil loop and the contact loop. The SP board of the G2R type relay can install 16 relays KM, and multiple relays can be tested simultaneously through the parallel connection method, improving the detection efficiency.

[0054] Refer to Figure 6 , as an optional embodiment, this embodiment provides a wiring diagram of the KUEP type relay, showing the wiring method of the KUEP type relay on the relay backplane of the card. Compared with the G2R type, the SP board of the KUEP type relay can install 12 relays. Similarly, the parallel design enables multiple relays to be calibrated synchronously, ensuring a more efficient detection process.

[0055] Refer to Figure 3 and Figure 7 , this embodiment provides a relay calibration system for the card, including the relay calibration circuit of Embodiment 1, and further including a signal processing module 3.

[0056] The relay calibration module 1 realizes the synchronous calibration of multiple groups of relays KM and the controllable test of key action parameters by connecting multiple relays KM in parallel.

[0057] The parameter detection module 2 uses voltage / current transmitters to collect the electrical signals of the coil and contact loops in real time and convert them into standard signals, providing a data basis for calculating parameters such as contact resistance and pull-in voltage.

[0058] The signal processing module 3 collects the action switch quantity signals of each relay contact through the DI card 31, and receives the 4-20mA standard signals of the coil loop voltage, coil current and contact loop current from the parameter detection module 2 through the AI card 32. After transmitting to the host computer 33, it calculates the contact resistance RJ, pull-in voltage VX, release voltage VS and coil resistance RX based on a preset algorithm; performs Min-Max normalization processing on the above parameters to eliminate the dimension difference, and performs linear weighted calculation of the remaining reliability value K in combination with the weight vector W allocated by the analytic hierarchy process, and dynamically updates the critical reliability threshold based on the reliability distribution curve fitted by the historical sample database, determines the reliability status of the relay KM, outputs the qualified or rejection result, and at the same time stores the verification data in the database to optimize the model determination accuracy.

[0059] As Figure 4 , as an optional embodiment, the calculation of the reliability model includes constructing a weight vector based on the normalized parameters of the contact resistance RJ, pull-in voltage VX, release voltage VS and coil resistance RX through the analytic hierarchy process, and calculating the remaining reliability value K by using the linear weighted method;

[0060] Among them, the calculation formula of the contact resistance RJ is: RJ = VDD1 / ITj - R0;

[0061] The pull-in voltage VX is the voltage value collected by the voltage transmitter VT when the normally open contact of the relay acts;

[0062] The release voltage VS is the voltage value collected by the voltage transmitter VT when the normally open contact of the relay recovers;

[0063] The calculation formula of the coil resistance RX is: RX = VDD2 / ITi.

[0064] The reliability model collects four core technical parameters of the contact resistance RJ, pull-in voltage VX, release voltage VS and coil resistance RX of the relay KM, performs normalization processing on each parameter by using the Min-Max standardization equation to eliminate the dimension difference, constructs a judgment matrix and allocates a weight vector in combination with the analytic hierarchy process, calculates the remaining reliability value by using the linear weighted formula, dynamically establishes a sample database to fit the reliability distribution curve and sets the critical reliability threshold, quantifies the performance attenuation of the relay into a unified index, eliminates the relay with over-limit parameters through the dynamic threshold, solves the problem of traditional verification relying on subjective experience, realizes objective and accurate reliability assessment, and at the same time optimizes the model adaptability through data accumulation, provides a decision-making basis for preventive maintenance, and ensures the long-term stable operation of the DCS system.

[0065] As an alternative embodiment, the normalization process includes, when using a KUEP type relay, setting normalization ranges for the contact resistance RJ, pull-in voltage VX, release voltage VS, and coil resistance RX respectively, and adopting the Min-Max normalization equation: Xg = (X - Xmin) / (Xmax - Xmin),

[0066] where X is the original parameter value, Xmax is the allowable upper limit value, and Xmin is the allowable lower limit value;

[0067] The normalization ranges include:

[0068] The range of the contact resistance RJ is set to [0.2Ω, 1Ω],

[0069] The range of the pull-in voltage VX is set to [20.4V, 26.4V],

[0070] The range of the release voltage VS is set to [2.4V, 12V],

[0071] The range of the coil resistance RX is set to [460Ω, 506Ω].

[0072] The normalization process maps technical parameters with different dimensions such as the contact resistance RJ, pull-in voltage VX, release voltage VS, and coil resistance RX to a unified interval of 0 - 1 through the Min-Max normalization equation. Specifically, the formula Xg = (X - Xmin) / (Xmax - Xmin) is used, where X is the original parameter value, and Xmax and Xmin are the preset allowable parameter ranges. Its function is to eliminate the evaluation deviation caused by the dimensional differences between parameters, enable the weight distribution and reliability calculation of each parameter on the same scale, and at the same time identify out-of-limit abnormal data by setting reasonable parameter intervals. For example, when Xg > 1 or Xg < 0, it is directly excluded, providing standardized input for constructing the weight model by the analytic hierarchy process and linearly weighted calculating the remaining reliability, ensuring the objectivity and accuracy of the evaluation results. For example, the measured contact resistance of 300mΩ of the KUEP type relay is converted to 0.125 after normalization and directly participates in the reliability calculation to reflect the degree of contact aging.

[0073] As an alternative embodiment, the construction of the weight vector in the analytic hierarchy process includes constructing a judgment matrix for the contact resistance, pull-in voltage, release voltage, and coil resistance, and obtaining the weight vector W = [0.055, 0.118, 0.263, 0.564]^T by calculating the geometric mean of each parameter and normalizing the process;

[0074] The calculation formula for the remaining reliability K value is: K = 1 - A·W, where A is the matrix composed of normalized parameters.

[0075] The weight vector construction of the analytic hierarchy process constructs a judgment matrix by defining the relative importance relationship among the four parameters of contact resistance RJ, pull-in voltage VX, release voltage VS, and coil resistance RX, as shown in Table 1.

[0076] Table 1: Judgment Matrix

[0077] Contact resistance Pull-in voltage Release voltage Coil resistance Contact resistance 1 1 / 3 1 / 5 1 / 7 Pull-in voltage 3 1 1 / 3 1 / 5 Release voltage 5 3 1 1 / 3 Coil resistance 7 5 3 1

[0078] And calculate the geometric mean of each row of the matrix, where:

[0079] L1 = [1 * 1 / 3 * 1 / 5 * 1 / 7] 1 / 4 ≈0.312

[0080] L2 = [3 * 1 * 1 / 3 * 1 / 5] 1 / 4 ≈0.669

[0081] L3 = [5 * 3 * 1 * 1 / 3] 1 / 4 ≈1.495

[0082] L4 = [7 * 5 * 3 * 1] 1 / 4 ≈3.201

[0083] Sum_L = L1 + L2 + L3 + L4 = 5.677

[0084] Normalization processing

[0085] W1 = L1 / Sum_L ≈ 0.055

[0086] W2 = L2 / Sum_L ≈ 0.118

[0087] W3 = L3 / Sum_L ≈ 0.263

[0088] W4 = L4 / Sum_L ≈ 0.564

[0089] The corresponding weight vector is obtained as W = [0.055, 0.118, 0.263, 0.564]^T. Quantify the influence degree of each parameter on reliability. For example, the weight of the coil resistance 0.564 reflects its high sensitivity to the winding state. By using an objective mathematical method to replace the subjective experience in weight allocation, the deviation caused by human preference in traditional evaluation is solved, ensuring the scientificity and consistency of the remaining reliability model, accurately identifying high-reliability relays, and supporting preventive maintenance decisions.

[0090] As an alternative embodiment, the calculation formula for the remaining reliability K value is: K = 1 - A·W, where A is a matrix composed of normalized parameters.

[0091] The remaining reliability K value is the core index for quantifying the reliability status of the relay in the present invention. It integrates the multi-dimensional performance parameters of the relay into a single reliability value. By comparing it with the dynamically updated critical reliability threshold, it is determined whether the relay is qualified. For example, for the KUEP type relay, after normalizing the measured parameters, the matrix A = [0.125, 0.433, 0.792, 0.435]. Calculating gives K = 0.685 > 1 - 0.437 = 0.563, and it is determined to be of high reliability. At the same time, the system continuously incorporates the verification data into the sample library, corrects the threshold parameters, improves the adaptive ability of the model to the actual working conditions, and realizes accurate preventive maintenance decisions.

[0092] As an alternative embodiment, a sample database is established for the relay KM after threshold rejection, its distribution curve is fitted, and its mean and standard deviation are calculated. The mean plus 1 standard deviation is used as the critical reliability, which serves as the standard for judging the reliability of the relay. At the same time, as the number of verifications increases, the sample parameters are dynamically updated, and its critical reliability is continuously corrected.

[0093] Reject the unreliable relays, and restore the instrument to its original state after the verification is completed. Repeating this process can perform a large number of relay verifications.

[0094] The critical reliability is the dynamic threshold for judging the reliability of the relay. The mean μ and standard deviation σ of the reliability K value are calculated through the historical sample database. μ + σ is used as the critical value. When the remaining reliability K of the measured relay > 1 - the critical value, it is regarded as reliable; otherwise, it is determined that it needs to be replaced. At the same time, the system continuously incorporates new verification data to update the sample library, recalculates the mean and standard deviation, adaptively adjusts the critical value, and improves the adaptive ability of the model to the actual working conditions; by statistical distribution, the relays with parameter offsets are rejected, avoiding the hidden danger that the parameters are temporarily qualified but approaching failure in the traditional method.

[0095] As Figure 2 shown in the reliability distribution diagram of the relay, the sample parameters are 500, the calculated reliability mean is 0.334, the standard deviation is 0.104, and the critical reliability is taken as 0.437. Comparing the remaining reliability 0.685 of the above-mentioned tested relay > 1 - 0.437, so this relay is regarded as having a relatively high remaining reliability.

[0096] Finally, it should be pointed out that the methods and devices described in detail above are only examples, and those skilled in the art can modify these examples in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A card relay calibration circuit, characterized in that: including, a relay calibration module (1), comprising a plurality of relays (KM), a first adjustable power supply (VDD1) and a second adjustable power supply (VDD2), wherein the relays (KM) are connected in parallel, and both ends of the coils of the relays (KM) are connected in parallel to the second adjustable power supply (VDD2) to form a coil circuit, and both ends of the contacts of the relays (KM) are connected in parallel to the first adjustable power supply (VDD1) to form a contact circuit; and, a parameter detection module (2), connected to the relay calibration module (1), comprising a voltage transmitter (VT), connected in parallel across the second adjustable power supply (VDD2), for collecting the coil circuit voltage and converting it into a first standard signal, and further comprising a first current transmitter (ITi), connected in series in the coil circuit, for collecting the coil circuit current and converting it into a second standard signal; and further comprising a second current transmitter (ITj), connected in series in the contact circuit, for collecting the contact circuit current and converting it into a third standard signal.

2. The card relay calibration circuit according to claim 1, wherein: the relay calibration module (1) further comprises a power switch (S) and a fixed resistor (R0), and the power switch (S) and the fixed resistor (R0) are connected in series in the contact circuit.

3. The card relay calibration circuit according to claim 1, wherein: the relay (KM) is installed on the backplane of the card relay, and the backplane of the card relay is the SP board of the G2R type relay, which has 16 relay slots and can install 16 relays (KM).

4. The card relay calibration circuit according to claim 1, wherein: the relay (KM) is installed on the backplane of the card relay, and the backplane of the card relay is the SP board of the KUEP type relay, which has 12 relay slots and can install 12 relays (KM).

5. A card relay calibration system, characterized in that: including the card relay calibration circuit according to claims 1 to 4, further comprising, a signal processing module (3), connected to the parameter detection module (2), comprising a DI card (31), connected to the contacts of a plurality of the relays (KM), for collecting the action switch quantity signals of the contacts; further comprising an AI card (32), connected to the voltage transmitter (VT), the first current transmitter (ITi) and the second current transmitter (ITj), for receiving the first standard signal, the second standard signal and the third standard signal; further comprising a host computer (33), communicatively connected to the DI card (31) and the AI card (32), for calculating the contact resistance (RJ), pull-in voltage (VX), release voltage (VS) and coil resistance (RX) of each relay based on the switch quantity signals, the standard signals and the reliability model, and generating remaining reliability parameters through normalization processing and weight assignment to determine the reliability of the relay.

6. The card relay calibration system according to claim 5, wherein: The calculation of the reliability model includes constructing a weight vector through the analytic hierarchy process based on the normalized parameters of the contact resistance (RJ), the pull-in voltage (VX), the release voltage (VS), and the coil resistance (RX), and calculating the remaining reliability K value using the linear weighted method; Among them, the calculation formula of the contact resistance (RJ) is: RJ = VDD1 / ITj - R0; The pull-in voltage (VX) is the voltage value collected by the voltage transmitter (VT) when the normally open contact of the relay acts; The release voltage (VS) is the voltage value collected by the voltage transmitter (VT) when the normally open contact of the relay recovers; The calculation formula of the coil resistance (RX) is: RX = VDD2 / ITi.

7. The card relay calibration system according to claim 6, characterized in that: The normalization process includes setting normalization ranges for the contact resistance (RJ), the pull-in voltage (VX), the release voltage (VS), and the coil resistance (RX) respectively, and using the Min-Max normalization equation: Xg = (X - Xmin) / (Xmax - Xmin), where X is the original parameter value, Xmax is the allowable upper limit value, and Xmin is the allowable lower limit value; The normalization ranges include: The range of the contact resistance (RJ) is set to [0.2Ω, 1Ω], The range of the pull-in voltage (VX) is set to [20.4V, 26.4V], The range of the release voltage (VS) is set to [2.4V, 12V], The range of the coil resistance (RX) is set to [460Ω, 506Ω].

8. The card relay calibration system according to claim 6, characterized in that: The construction of the weight vector in the analytic hierarchy process includes constructing a judgment matrix of the contact resistance, the pull-in voltage, the release voltage, and the coil resistance, and obtaining the weight vector W = [0.055, 0.118, 0.263, 0.564]^T by calculating the geometric mean of each parameter and normalizing it; The calculation formula of the remaining reliability K value is: K = 1 - A·W, where A is a matrix composed of normalized parameters.

9. The card relay calibration system according to claim 5, characterized in that: The upper computer (33) is further used to fit the relay reliability distribution curve according to the historical calibration data, calculate the mean value and the standard deviation, and use the mean value plus 1 times the standard deviation as the critical reliability; Dynamically update the sample database in subsequent calibrations and correct the critical reliability parameters to improve the determination accuracy.

10. A method for calibrating a card relay, characterized in that: The calibration method applicable to the card relay calibration system according to any one of claims 5 to 9 includes the following steps: S1. Parameter calculation: Collect the contact circuit voltage, the contact circuit current, the coil circuit voltage, and the coil circuit current, and calculate the contact resistance (RJ), the pull-in voltage (VX), the release voltage (VS), and the coil resistance (RX); S2. Parameter normalization: Perform normalization processing on the contact resistance (RJ), the pull-in voltage (VX), the release voltage (VS), and the coil resistance (RX) using the Min-Max normalization equation to obtain the normalized parameter Xg; S3. Threshold rejection: If any normalized parameter Xg > 1 or Xg < 0, it is determined that the corresponding relay is unqualified; S4. Weight assignment: Based on the analytic hierarchy process, construct a judgment matrix and calculate the weight vector W of each parameter; S5. Reliability calculation: Calculate the remaining reliability K value according to the formula K = 1 - A·W; S6. Critical reliability determination: Based on the historical sample database, fit the reliability distribution curve, calculate the mean μ and the standard deviation σ, and take μ + σ as the critical reliability. If K > 1 - (μ + σ), it is determined that the relay is reliable, otherwise it is rejected; S7. Dynamic update: Add the current verification parameters to the sample database, recalculate the mean and the standard deviation, and update the critical reliability.

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