Multi-channel analog quantity calibration method and system of configuration relay protection test equipment

Abstract

The present application relates to the field of relay protection test, and relates to a kind of multi-channel analog calibration method and system of configuration relay protection test equipment, the method in which includes: host computer and the communication connection of analog quantity output control unit of configuration relay protection test equipment is established;Host computer obtains the analog quantity setting value of each channel of analog quantity output control unit at different output gear and corresponding analog quantity measured value;Host computer calculates and obtains the analog calibration coefficient of each channel, and it is packaged as calibration message and sent to analog quantity output control unit;Analog quantity output control unit carries out analysis and check to message, and after check passes, analog calibration coefficient is stored;Analog quantity output control unit reads the analog calibration coefficient stored and corrects analog output value when carrying out analog output. The method of the present application can effectively improve the calibration efficiency of analog quantity of configuration relay protection test equipment.

Description

Technical Field

[0001] This invention relates to the field of relay protection testing. More specifically, this invention relates to a multi-channel analog calibration method and system for configuring relay protection testing equipment. Background Technology

[0002] In the field of power system relay protection and automation, configuration relay protection test equipment is widely used to simulate power system faults to detect the operating behavior of relay protection devices. These devices are typically equipped with multi-channel analog output (voltage, current) functions. Due to the discreteness of components in the manufacturing process, changes in ambient temperature, and the aging of electronic components, there is often an error between the actual value and the set value of the analog output channels. Therefore, it is necessary to calibrate each channel periodically.

[0003] However, existing analog calibration technologies for configuration relay protection testing equipment have the following main problems, making it difficult for them to meet the requirements of multi-channel operation, high efficiency, and ease of maintenance:

[0004] 1. The calibration process relies on manual intervention, resulting in low efficiency and poor consistency: Traditional calibration methods typically require operators to measure the output values ​​of each channel individually, manually record the data, and calculate calibration parameters, or manually adjust potentiometers in the hardware circuit to correct errors. For configured equipment with a large number of output channels, this manual operation is not only repetitive and time-consuming, but also prone to unstable calibration accuracy due to human reading or calculation errors.

[0005] 2. Strong coupling between calibration data and host computer software, resulting in poor device portability: Some existing automated calibration schemes store the calculated calibration coefficients as configuration files in the host computer control software directory. This method makes the calibration data dependent on a specific control computer or software environment. Once the control computer is changed, the software is reinstalled, or the configuration file is lost, the device must be recalibrated. Furthermore, this method does not support "parameters following the board," meaning that when internal boards are replaced or moved to another system, the new host computer cannot automatically obtain the calibration characteristics of that board, increasing the complexity of system integration and maintenance.

[0006] 3. Firmware-based calibration lacks flexibility and online updates are difficult. Another existing technology is to directly embed the calibration coefficients as constants in the FPGA's logic program (Bitstream) or read-only memory (ROM). Although this method is free from the constraints of host computer configuration files, its drawback is that the calibration coefficients are deeply bound to the FPGA firmware. Whenever calibration parameters need to be adjusted, the FPGA project must be recompiled and the entire firmware version burned. It is impossible to quickly and independently update the calibration parameters of specific channels through the communication interface during device operation, resulting in extremely high maintenance costs.

[0007] In summary, the existing analog calibration technology for configuration relay protection testing equipment suffers from problems such as low efficiency, poor equipment portability, poor flexibility, and high maintenance costs. Summary of the Invention

[0008] To address the problems of low efficiency, poor equipment portability, poor flexibility, and high maintenance costs in the analog calibration technology of existing configuration relay protection test equipment, this invention provides solutions in the following aspects.

[0009] In a first aspect, the present invention provides a multi-channel analog quantity calibration method for a configuration relay protection test equipment, comprising:

[0010] The host computer establishes a communication connection with the analog output control unit of the configured relay protection test equipment via an Ethernet interface;

[0011] The host computer acquires the analog quantity set values ​​of each channel of the analog quantity output control unit at different output levels, as well as the actual analog quantity measured by the measuring instrument.

[0012] The host computer calculates the analog calibration coefficient of each channel based on the analog quantity set value and the analog quantity measured value, and encapsulates the analog quantity calibration coefficient into a calibration message and sends it to the analog quantity output control unit.

[0013] The analog output control unit receives the calibration message, parses and verifies the message, and stores the analog calibration coefficient in its non-volatile memory after the verification is successful.

[0014] When the analog output control unit outputs an analog signal, it reads the stored analog calibration coefficients to correct the analog output value, so as to output a calibrated analog signal.

[0015] Preferably, the calculation of the analog calibration coefficients for each channel includes: for the nth channel, calculating the scaling factor using the least squares method. and offset coefficient The calculation formula is as follows:

[0016]

[0017] In the formula, This represents the scaling factor for the nth channel. This represents the offset coefficient of the nth channel, where n is the channel index and M is the number of measurement points. This represents the analog quantity setpoint for the i-th measurement point in the n-th channel. This represents the average of the analog setting values ​​for all test points in the nth channel. This represents the measured analog value of the i-th measurement point in the n-th channel. This represents the average of the measured values ​​of the analog quantities at all test points in the nth channel.

[0018] Preferably, the analog output control unit corrects the analog output value by: calculating the corrected analog output value, wherein the calculation expression is:

[0019] ;

[0020] In the formula, This represents the corrected analog output value for the nth channel. This represents the original expected analog output value of the nth channel.

[0021] Preferably, the analog output control unit stores the analog calibration coefficients in the onboard non-volatile memory, including:

[0022] The verified analog calibration coefficients are written into the first random access memory inside the analog output control unit and simultaneously written into the electrically erasable programmable read-only memory (EEPROM) outside the analog output control unit. The storage space in the EEPROM is divided according to the calibration coefficient table address and includes a board identification area, a channel address area, a coefficient value area, and a verification information area.

[0023] Preferably, the method further includes: the analog output control unit performs a coefficient loading step when it is powered on, including: after the analog output control unit is powered on, it checks whether the internal first random access memory RAM0 is empty; if RAM0 is empty, the analog output control unit reads the historically stored analog calibration coefficients from the external electrically erasable programmable read-only memory EEPROM; the analog output control unit verifies the read historical analog calibration coefficients, and if the verification is successful, it writes them into the internal second random access memory RAM1 for the packet assembly unit to call, and sends them to the analog calibration module.

[0024] Preferably, the coefficient loading step further includes exception handling logic: if the calibration coefficient read by the analog output control unit from the external electrically erasable programmable read-only memory (EEPROM) fails to be verified, the analog output control unit does not update the calibration coefficient and adopts the default calibration coefficient, which is: the proportional coefficient is 1 and the offset coefficient is 0.

[0025] Preferably, the method further includes a calibration coefficient recall step, comprising:

[0026] The host computer sends a coefficient recall command to the analog output control unit;

[0027] After receiving the recall command, the analog output control unit reads the currently used analog calibration coefficients from the internal random access memory and packages them to send to the host computer.

[0028] The host computer receives and parses the analog calibration coefficients and displays them on the human-computer interaction interface.

[0029] Preferably, the calibration message includes a checksum, and the steps for the analog output control unit to parse and verify the message include: the analog output control unit parses the device identifier and board number in the calibration message; the analog output control unit compares whether the parsed device identifier and board number are consistent with its own hardware information, and verifies the integrity of the message data according to the checksum; the analog output control unit only performs the storage operation of the calibration coefficient when the device identifier matches, the board number matches, and the data integrity verification passes.

[0030] In a second aspect, the present invention provides an automated calibration system for configuration relay protection testing equipment, comprising:

[0031] The host computer is communicatively connected to the analog output control unit of the configuration relay protection test equipment. It is used to obtain the analog set values ​​of each channel of the analog output control unit under different output levels and the measured values ​​of the analog quantities obtained by the measuring instruments; then it calculates the analog calibration coefficient of each channel and encapsulates the analog calibration coefficient into a calibration message and sends it to the analog output control unit.

[0032] The analog output control unit of the configured relay protection test equipment is used to receive the calibration message, parse and verify the message, and store the analog calibration coefficient in its non-volatile memory and external EEPROM memory after the verification is passed; it is also used to read the stored analog calibration coefficient from its non-volatile memory or external EEPROM memory to correct the analog output value when performing analog output, so as to output the calibrated analog signal.

[0033] Preferably, the analog output control unit includes:

[0034] Ethernet controller, used for calibrating message transmission and reception;

[0035] The calibration coefficient parsing unit is used to unpack and verify the calibration coefficient message, and stores the successfully parsed analog calibration coefficients into the first random access memory of the analog output control unit.

[0036] The calibration coefficient read / write control unit is used to read the analog calibration coefficient from the first random access memory or the external EEPROM memory, store it in the second random access memory of the analog output control unit, and send it to the analog calibration module.

[0037] The analog quantity calibration module is used to calculate the corrected analog quantity output value based on the analog quantity calibration coefficient.

[0038] The calibration coefficient packet unit is used to obtain the current analog calibration coefficients from the second storage unit, packetize them, and send them to the host computer via the Ethernet transmission controller.

[0039] The beneficial effects of this invention are as follows: The method of this invention utilizes a host computer to automatically calculate and distribute coefficients, replacing traditional manual calculations or hardware potentiometer adjustments, significantly reducing calibration time and repetitive workload, and minimizing human error. Furthermore, the calibration coefficients are calculated by the host computer but stored in the slave computer (analog output control unit), achieving decoupling between calibration data and the host computer software environment. When the host computer software is updated or the computer is replaced, recalibration is unnecessary. Moreover, establishing a communication loop via Ethernet enables seamless data flow throughout the entire process from measurement and calculation to storage and execution, ensuring high-precision correction of multi-channel analog outputs. Attached Figure Description

[0040] Figure 1 This is a schematic flowchart illustrating a multi-channel analog calibration method for a configuration relay protection test device according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram illustrating the address division of each field of a calibration message according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram illustrating the structure of an automated calibration system for a configuration relay protection testing device according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram illustrating the function of calibration tool software according to an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram illustrating the structure of an analog output control unit according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram illustrating the read / write control flow of the calibration coefficient read / write control unit according to an embodiment of the present invention. Detailed Implementation

[0046] 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, not all, of the embodiments of the present invention. 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.

[0047] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0048] Example of a multi-channel analog calibration method for configured relay protection test equipment:

[0049] like Figure 1 As shown, the multi-channel analog quantity calibration method for the configuration relay protection test equipment of the present invention includes:

[0050] S101. The host computer establishes a communication connection with the analog output control unit of the configured relay protection test equipment through the Ethernet interface.

[0051] In this embodiment, the analog output control unit of the configured relay protection test equipment is an FPGA board.

[0052] S102. The host computer acquires the analog quantity set values ​​of each channel of the analog quantity output control unit at different output levels and the actual analog quantity measured by the measuring instrument.

[0053] In this embodiment, five sample values ​​can be evenly selected as analog quantity set values ​​within the analog quantity output range. For example, if the analog quantity output range of a certain voltage is -10V to 10V, five sample values ​​can be selected: -10V, 10V, -5V, 5V, and 0V. The test values ​​of the analog quantity under these five sample values ​​are measured, and the calibration coefficient is calculated based on the relationship between the sample values ​​and the test values.

[0054] S103. The host computer calculates the analog calibration coefficient of each channel and sends it to the analog output control unit. Specifically, the host computer calculates the analog calibration coefficient of each channel based on the analog set value and the actual measured value of the analog quantity, and encapsulates the analog calibration coefficient into a calibration message and sends it to the analog output control unit.

[0055] The calibration coefficients are assembled into a UDP message according to a custom message content format. The analog output control unit identifies the calibration coefficient message based on message characteristics, including device identifier, board number, and checksum. A UDP message refers to a complete data packet sent based on UDP (User Datagram Protocol).

[0056] In this embodiment, the calculation of the analog calibration coefficients for each channel includes: for the nth channel, calculating the scaling factor using the least squares method. and offset coefficient The calculation formula is as follows:

[0057]

[0058] In the formula, This represents the scaling factor for the nth channel. This represents the offset coefficient of the nth channel, where n is the channel index and M is the number of measurement points. This represents the analog quantity setpoint for the i-th measurement point in the n-th channel. This represents the average of the analog setting values ​​for all test points in the nth channel. This represents the measured analog value of the i-th measurement point in the n-th channel. This represents the average of the measured values ​​of the analog quantities at all test points in the nth channel.

[0059] By employing the least squares method to fit multiple measurement points (at different speeds), random errors (noise) in the measurement process can be effectively smoothed out. Compared to the simple two-point calibration method, it can more accurately reflect the linear characteristics of the channel, significantly improving the linearity and accuracy of the analog output. Statistical methods are used to calculate the proportional coefficient and offset coefficient, enabling adaptation to hardware channels with different aging levels or device differences.

[0060] S104. The analog output control unit receives the calibration message, parses and verifies the message, and stores the analog calibration coefficient in its non-volatile memory after the verification is passed.

[0061] S105. When performing analog output, the analog output control unit reads the stored analog calibration coefficients to correct the analog output value, so as to output the calibrated analog signal.

[0062] In this embodiment, the analog output control unit corrects the analog output value by: calculating the corrected analog output value, the calculation expression being:

[0063] ;

[0064] In the formula, This represents the corrected analog output value for the nth channel. This represents the original expected analog output value of the nth channel.

[0065] In this embodiment, the analog output control unit stores the analog calibration coefficients in its non-volatile memory by: writing the verified analog calibration coefficients into the first random access memory inside the analog output control unit, and simultaneously writing them into the electrically erasable programmable read-only memory (EEPROM) outside the analog output control unit; wherein, the storage space in the EEPROM is divided according to the calibration coefficient table address, including a board identification area, a channel address area, a coefficient value area, and a verification information area.

[0066] The synchronization mechanism between RAM and EEPROM leverages the non-volatile nature of EEPROM to ensure data is not lost even when power is off (permanent storage), while utilizing the high-speed read / write capabilities of RAM to meet real-time data retrieval requirements during runtime. Partitioned storage (board identifier, channel address, etc.) facilitates structured management of data from multiple channels and boards, preventing read / write errors.

[0067] The method in this embodiment utilizes a host computer to automatically calculate and distribute coefficients, replacing traditional manual calculations or hardware potentiometer adjustments. This significantly reduces calibration time and repetitive workload, and minimizes human error. Furthermore, the calibration coefficients are calculated by the host computer but stored in the slave computer (analog output control unit), decoupling the calibration data from the host computer software environment. Recalibration is unnecessary when the host computer software is updated or the computer is replaced. Moreover, a closed-loop communication system is established via Ethernet, enabling seamless data flow from measurement and calculation to storage and execution, ensuring high-precision correction of multi-channel analog outputs.

[0068] In one embodiment, the method further includes: the analog output control unit performs a coefficient loading step upon power-on, including: after power-on, the analog output control unit detects whether its internal first random access memory RAM0 is empty; if RAM0 is empty, the analog output control unit reads historically stored analog calibration coefficients from the external electrically erasable programmable read-only memory EEPROM; the analog output control unit verifies the read historical analog calibration coefficients, and if the verification is successful, writes them into its internal second random access memory RAM1 for use by the packet assembly unit and sends them to the analog calibration module.

[0069] Upon power-up, coefficients are automatically loaded from the EEPROM, achieving "parameter-board binding." When the board is moved to another device or system, it can maintain high-precision output directly without recalibration, greatly reducing system maintenance and integration costs. Using the method in this embodiment, the device can automatically restore to its optimal calibration state upon power-up without host computer intervention, enhancing the device's independent operation capability.

[0070] In one embodiment, the coefficient loading step further includes exception handling logic: if the calibration coefficient read by the analog output control unit from the external electrically erasable programmable read-only memory (EEPROM) fails to be verified, the analog output control unit does not update the calibration coefficient and adopts the default calibration coefficient, which is: the proportional coefficient is 1 and the offset coefficient is 0.

[0071] In this embodiment, a default coefficient rollback mechanism (proportion of 1, offset of 0) is designed to prevent uncontrollable erroneous voltage / current output by the device due to memory damage or data bit flipping, thereby protecting the relay protection device under test from damage by abnormally large signals.

[0072] In one embodiment, a calibration coefficient recall step is also included, comprising:

[0073] S201, The host computer sends a coefficient recall command to the analog output control unit;

[0074] S202. After receiving the recall command, the analog output control unit reads the currently used analog calibration coefficients from the internal random access memory and packages them to send to the host computer.

[0075] S203. The host computer receives and parses the analog calibration coefficients and displays them on the human-machine interface.

[0076] The method in this embodiment supports uploading the coefficients that are currently running inside the hardware to the host computer, which makes it easier for technicians to check the calibration status, verify the correctness of the coefficient assembly and distribution process, and also facilitates the backup of the original parameters during equipment maintenance.

[0077] In one embodiment, the calibration message includes a checksum. The steps for the analog output control unit to parse and verify the message include: the analog output control unit parses the device identifier and board number in the calibration message; the analog output control unit compares the parsed device identifier and board number with its own hardware information to see if they are consistent, and verifies the integrity of the message data according to the checksum; the analog output control unit only performs the storage operation of the calibration coefficient when the device identifier matches, the board number matches, and the data integrity verification passes.

[0078] In this embodiment, the calibration message includes fields such as device identifier, board number, number of channels, coefficients for each channel, and checksum. The address division of each field is as follows: Figure 2 As shown.

[0079] In this embodiment, the check code is calculated using a byte-by-byte XOR method, that is, the result of XORing all bytes of the calibration coefficient is used as the check value.

[0080] By comparing device identifiers and board numbers, it is ensured that calibration coefficients will not be incorrectly written to other boards in systems with multiple boards, thus resolving the address conflict risk in multi-channel systems. Furthermore, a checksum mechanism is used to prevent data errors caused by Ethernet transmission interference, ensuring the absolute reliability of coefficients written to the EEPROM.

[0081] Example of an automated calibration system for configuration relay protection testing equipment:

[0082] This invention also provides an automated calibration system for configuration relay protection testing equipment. For example... Figure 3 As shown, the automated calibration system for the configuration relay protection test equipment includes:

[0083] The host computer is communicatively connected to the analog output control unit of the configuration relay protection test equipment. It is used to obtain the analog set values ​​of each channel of the analog output control unit under different output levels and the measured values ​​of the analog quantities obtained by the measuring instruments; then it calculates the analog calibration coefficient of each channel and encapsulates the analog calibration coefficient into a calibration message and sends it to the analog output control unit.

[0084] The analog output control unit of the configured relay protection test equipment is used to receive the calibration message, parse and verify the message, and store the analog calibration coefficient in its non-volatile memory and external EEPROM memory after the verification is passed; it is also used to read the stored analog calibration coefficient from its non-volatile memory or external EEPROM memory to correct the analog output value when performing analog output, so as to output the calibrated analog signal.

[0085] In this embodiment, the analog output control unit is an FPGA board. The host computer communicates with the FPGA board via Ethernet, and the FPGA board communicates with the external EEPROM memory via the IIC protocol.

[0086] The host computer includes a multi-channel analog quantity test result input module, a calibration coefficient download module, and a calibration coefficient recall module. The calibration coefficient download module is used to send calibration coefficients. When the calibration coefficients are ready, they are packaged and sent to the FPGA board via Ethernet through the calibration coefficient download function. The calibration coefficient recall module is used to receive and unpack the calibration coefficients. After the FPGA board receives the recall data packet command sent from Ethernet, it packages the current calibration coefficients and sends them to the calibration tool software via Ethernet for processing.

[0087] The host computer is equipped with calibration tool software, which is used to complete the functions of inputting multi-channel analog quantity test results, calculating calibration coefficients, downloading and recalling data.

[0088] The calibration tool software has the ability to manage multiple boards and multiple channels, supports batch import and export of calibration data, and has data verification and recording functions.

[0089] The human-computer interface of the calibration tool software consists of a measurement data filling area, a calibration coefficient calculation area, and a calibration coefficient configuration area. Its functional block diagram is shown below. Figure 4 As shown. The measurement data filling area is used for entering calibration coefficients. Operators fill in the measured analog values ​​corresponding to the set values ​​of each channel's analog quantity into the corresponding positions of the corresponding channels in the measurement data filling area. The number of channels is consistent with the number of analog quantities output by the FPGA. The calibration coefficient calculation area is used for displaying and confirming the calibration coefficients for each channel. If an unreasonable calculated calibration coefficient value is found for a certain channel, it should be remeasured and recalculated, or the calibration value for that channel should be manually modified. The calibration coefficient configuration area includes functions for calculating, downloading, and recalling calibration coefficients.

[0090] In one embodiment, such as Figure 5 As shown, the analog output control unit includes:

[0091] Ethernet controller, used for calibrating message transmission and reception;

[0092] The calibration coefficient parsing unit is used to unpack and verify the calibration message, and stores the successfully parsed analog calibration coefficients into the first random access memory of the analog output control unit.

[0093] The calibration coefficient read / write control unit is used to read the analog calibration coefficient from the first random access memory or external EEPROM, store it in the second random access memory of the analog output control unit, and send it to the analog calibration module.

[0094] The analog quantity calibration module is used to calculate the corrected analog quantity output value based on the analog quantity calibration coefficient.

[0095] The calibration coefficient packet unit is used to obtain the current analog calibration coefficients from the second storage unit, packetize them, and send them to the host computer via the Ethernet transmission controller.

[0096] In one embodiment, the read / write control process of the calibration coefficient read / write control unit is as follows: Figure 6 As shown, it includes:

[0097] (1) After the analog output control unit is powered on, the calibration coefficient read / write control unit first determines whether the first random access memory RAM0 inside the analog output control unit is empty. If the first random access memory RAM0 is not empty, the calibration coefficient read / write control unit reads the calibration coefficient from the first random access memory RAM0 first. If the first random access memory RAM0 is empty, the calibration coefficient read / write control unit determines whether the calibration coefficient has been obtained from the external EEPROM after power-on. If the calibration coefficient has been obtained, the status jumps to the calibration coefficient update end status and ends this round of read / write control. If the calibration coefficient has not been obtained, the calibration coefficient read / write control unit obtains the calibration coefficient from the external EEPROM.

[0098] (2) After obtaining the calibration coefficient, the calibration coefficient read and write control unit will verify the calibration coefficient. If the verification fails, the status will jump to the calibration coefficient update end status and end this round of read and write control. If the verification is successful, the calibration coefficient will be updated and the new calibration coefficient will be written to the second random access memory RAM1 for the calibration coefficient grouping unit to read and group.

[0099] (3) After the calibration coefficient is successfully updated, the status will jump to the calibration coefficient update end status, and the current round of read and write control will end. This process will be repeated.

[0100] While this specification has shown and described numerous embodiments of the invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of this invention.

Claims

1. A multi-channel analog quantity calibration method for a configuration relay protection test equipment, characterized in that, include: The host computer establishes a communication connection with the analog output control unit of the configured relay protection test equipment via an Ethernet interface; The host computer acquires the analog quantity set values ​​of each channel of the analog quantity output control unit at different output levels, as well as the actual analog quantity measured by the measuring instrument. The host computer calculates the analog calibration coefficient of each channel based on the analog quantity set value and the analog quantity measured value, and encapsulates the analog quantity calibration coefficient into a calibration message and sends it to the analog quantity output control unit. The calculated analog calibration coefficients for each channel include: for the nth channel, the scaling factor is calculated using the least squares method. and offset coefficient The calculation formula is as follows: In the formula, This represents the scaling factor for the nth channel. This represents the offset coefficient of the nth channel, where n is the channel index and M is the number of measurement points. This represents the analog quantity setpoint for the i-th measurement point in the n-th channel. This represents the average of the analog setting values ​​for all test points in the nth channel. This represents the measured analog value of the i-th measurement point in the n-th channel. This represents the mean of the measured analog values ​​of all test points in the nth channel. The analog output control unit receives the calibration message, parses and verifies the message, and stores the analog calibration coefficient in its non-volatile memory after the verification is successful. When the analog output control unit outputs an analog signal, it reads the stored analog calibration coefficients to correct the analog output value, so as to output a calibrated analog signal.

2. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in claim 1, characterized in that, The analog output control unit corrects the analog output value by: calculating the corrected analog output value, the calculation expression being: ； In the formula, This represents the corrected analog output value for the nth channel. This represents the original expected analog output value of the nth channel.

3. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in claim 1, characterized in that, The analog output control unit stores the analog calibration coefficients into the onboard non-volatile memory, including: The verified analog calibration coefficients are written into the first random access memory inside the analog output control unit and simultaneously written into the electrically erasable programmable read-only memory (EEPROM) outside the analog output control unit. The storage space in the EEPROM is divided according to the calibration coefficient table address and includes a board identification area, a channel address area, a coefficient value area, and a verification information area.

4. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in claim 3, characterized in that, The method further includes: the analog output control unit performs a coefficient loading step when it is powered on, including: after the analog output control unit is powered on, it checks whether the internal first random access memory RAM0 is empty; if RAM0 is empty, the analog output control unit reads the historically stored analog calibration coefficients from the external electrically erasable programmable read-only memory EEPROM; the analog output control unit verifies the read historical analog calibration coefficients, and if the verification is successful, it writes them into the internal second random access memory RAM1 for the packet assembly unit to call, and sends them to the analog calibration module.

5. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in claim 4, characterized in that, The coefficient loading step also includes exception handling logic: If the calibration coefficient read by the analog output control unit from the external electrically erasable programmable read-only memory (EEPROM) fails to be verified, the analog output control unit will not update the calibration coefficient and will use the default calibration coefficient, which is: the proportional coefficient is 1 and the offset coefficient is 0.

6. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in claim 1, characterized in that, It also includes a calibration coefficient recall step, including: The host computer sends a coefficient recall command to the analog output control unit; After receiving the recall command, the analog output control unit reads the currently used analog calibration coefficients from the internal random access memory and packages them to send to the host computer. The host computer receives and parses the analog calibration coefficients and displays them on the human-computer interaction interface.

7. The multi-channel analog quantity calibration method for the configuration relay protection test equipment as described in any one of claims 1 to 6, characterized in that, The calibration message contains a checksum. The steps for the analog output control unit to parse and verify the message include: the analog output control unit parses the device identifier and board number in the calibration message; the analog output control unit compares the parsed device identifier and board number with its own hardware information to see if they are consistent, and verifies the integrity of the message data according to the checksum; the analog output control unit only performs the storage operation of the calibration coefficient when the device identifier matches, the board number matches, and the data integrity verification passes.

8. An automated calibration system for configuration relay protection testing equipment, characterized in that, include: The host computer is communicatively connected to the analog output control unit of the configuration relay protection test equipment. It is used to obtain the analog set values ​​of each channel of the analog output control unit under different output levels and the measured values ​​of the analog quantities obtained by the measuring instruments; then it calculates the analog calibration coefficient of each channel and encapsulates the analog calibration coefficient into a calibration message and sends it to the analog output control unit. The calculation of the analog calibration coefficients for each channel includes: for the nth channel, calculating the scaling factor using the least squares method. and offset coefficient The calculation formula is as follows: In the formula, This represents the scaling factor for the nth channel. This represents the offset coefficient of the nth channel, where n is the channel index and M is the number of measurement points. This represents the analog quantity setpoint for the i-th measurement point in the n-th channel. This represents the average of the analog setting values ​​for all test points in the nth channel. This represents the measured analog value of the i-th measurement point in the n-th channel. This represents the mean of the measured analog values ​​of all test points in the nth channel. The analog output control unit of the configured relay protection test equipment is used to receive the calibration message, parse and verify the message, and store the analog calibration coefficient in its non-volatile memory and external EEPROM memory after the verification is passed; it is also used to read the stored analog calibration coefficient from its non-volatile memory or external EEPROM memory to correct the analog output value when performing analog output, so as to output the calibrated analog signal.

9. The automated calibration system for configuration relay protection testing equipment as described in claim 8, characterized in that, The analog output control unit includes: Ethernet controller, used for calibrating message transmission and reception; The calibration coefficient parsing unit is used to unpack and verify the calibration coefficient message, and stores the successfully parsed analog calibration coefficients into the first random access memory of the analog output control unit. The calibration coefficient read / write control unit is used to read the analog calibration coefficient from the first random access memory or the external EEPROM memory, store it in the second random access memory of the analog output control unit, and send it to the analog calibration module. The analog quantity calibration module is used to calculate the corrected analog quantity output value based on the analog quantity calibration coefficient. The calibration coefficient packet unit is used to obtain the current analog calibration coefficients from the second storage unit, packetize them, and send them to the host computer via the Ethernet transmission controller.

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