A method and system for measuring temperature of a transmission line

Abstract

The present invention provides a transmission line temperature measurement method and system, comprising obtaining NTC resistor resistance data and dividing the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain multiple corresponding divided voltage values; calculating the multiple divided voltage values ​​using a preset calculation module to obtain multiple corresponding calculation results; fitting the multiple calculation results using a preset fitting module to obtain a corresponding voltage signal; and determining the corresponding temperature value based on the obtained voltage signal. Based on the straight line temperature-voltage relationship within the operating temperature range, the present invention further develops the design of temperature measurement and control circuits. This design can be completed without digital calibration, thereby simplifying instrument design and commissioning.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature measurement of transmission lines, and in particular to a temperature measurement method and system for transmission lines. Background Art

[0002] Insulators that operate with power for long periods of time are subject to not only internal overvoltage, operational overvoltage, electrical overvoltage, and long-term rated operating voltage, but are also constantly subjected to severe erosion from harsh weather conditions such as strong winds, haze, ice cover, snow cover, and heavy rainfall. Their insulation performance may be degraded or even reduced to zero, leading to flashover accidents and affecting the safety of the power system. Therefore, power companies need to regularly inspect insulators in operation. Temperature monitoring is an important indicator reflecting insulator performance. Existing temperature monitoring systems mostly use NTC resistors as monitoring sensors, but the resistance change of NTC resistors is not linearly related to temperature changes, which brings inconvenience to measurement.

[0003] Thermistors typically have a tolerance range that specifies the consistency between samples. Depending on the material used, this tolerance ranges from 1% to 10%. Due to their nonlinearity, temperature calibration and correction are difficult to perform. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for measuring temperature of a transmission line to solve the technical problem that existing methods cannot accurately calibrate and correct the temperature.

[0005] In one aspect, a method for measuring temperature of a transmission line is provided, comprising:

[0006] Obtaining NTC resistor resistance data, and dividing the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values;

[0007] Calculating the plurality of partial pressure values ​​respectively by a preset calculation module to obtain corresponding plurality of calculation results;

[0008] The plurality of calculation results are fitted and calculated by a preset fitting module to obtain corresponding voltage signals, and the corresponding temperature values ​​are determined according to the obtained voltage signals.

[0009] Preferably, dividing the acquired NTC resistor value data according to a preset resistance voltage division rule specifically includes:

[0010] The obtained NTC resistor resistance data is equally divided according to the preset number of resistance voltage division items to obtain the voltage division values ​​of multiple NTC resistors at the current temperature;

[0011] The voltage divider value of the NTC resistor at the current temperature and the NTC resistance value have the following linear correspondence:

[0012] V=k0*R t

[0013] Among them, V represents the voltage divider value of the NTC resistor at the current temperature, k0 represents the linear coefficient, and R t Indicates the NTC resistance at the current temperature.

[0014] Preferably, the calculation module specifically includes a plurality of sub-term multiplication modules, each of which corresponds to a voltage division value of an NTC resistor at a current temperature;

[0015] The sub-term multiplication module includes multiple multiplication modules, each of which is preset with a multiplication coefficient of a different proportion from that of other multiplication modules, so as to realize multiplication operations of different proportions and configure the sub-term multiplication modules of different orders.

[0016] Preferably, the calculation module is specifically used to determine the corresponding secondary multiplication module according to the multiplication operation of the ratio required to calculate the voltage division value when receiving the voltage division values ​​of multiple NTC resistors at the current temperature, and input the voltage division values ​​into the corresponding secondary multiplication module respectively.

[0017] Preferably, the secondary multiplication module is specifically configured to receive a voltage division value of the NTC resistor at a current temperature, and identify a multiplication coefficient to be calculated based on the voltage division value;

[0018] The corresponding multiplication module is selected according to the multiplication coefficient to be calculated, the voltage division value of the NTC resistor at the current temperature is calculated by the selected multiplication module, and the calculation result is output.

[0019] Preferably, the fitting module specifically includes:

[0020] an adding module, connected to the plurality of said secondary multiplication modules respectively, for performing an addition operation on the calculation results output by the plurality of said secondary multiplication modules to obtain a corresponding voltage signal;

[0021] The subtraction modules are respectively connected to the plurality of the sub-term multiplication modules and are used to perform subtraction operations on the calculation results output by the plurality of the sub-term multiplication modules to obtain corresponding voltage signals.

[0022] Preferably, determining the corresponding temperature value according to the obtained voltage signal specifically includes:

[0023] Determining a linear correspondence between the voltage signal and the NTC resistance value based on a linear correspondence between a voltage division value of the NTC resistor at a current temperature and the NTC resistance value;

[0024] The temperature value corresponding to the voltage signal is determined according to the linear correspondence between the voltage signal and the NTC resistance and the fitting relationship between the temperature and the NTC resistance.

[0025] Preferably, the fitting relationship between the temperature and the NTC resistance is expressed by the following formula:

[0026]

[0027] Among them, T1 represents temperature, S represents constant term, k1 represents linear term coefficient, k2 represents quadratic term coefficient, k n represents the coefficient of the n-th order term, Indicates the resistance value at temperature T1 corresponding to the nth-order coefficient.

[0028] On the other hand, a transmission line temperature measurement system is also provided, which is used to implement the transmission line temperature measurement method, comprising:

[0029] The voltage division module is used to obtain the NTC resistor resistance data and divide the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values;

[0030] a calculation module, configured to calculate the plurality of divided voltage values ​​respectively to obtain corresponding plurality of calculation results;

[0031] The fitting module is used to perform fitting calculation on the multiple calculation results to obtain corresponding voltage signals, and determine corresponding temperature values ​​according to the obtained voltage signals.

[0032] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0033] The transmission line temperature measurement method and system provided by the present invention, based on the temperature-voltage relationship being a straight line within the operating temperature range, secondary development of the design of the temperature measurement and temperature control circuits can be completed without digital calibration processing, thereby simplifying the design and debugging of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0035] Figure 1 The figure is a schematic diagram of the main process of a method for measuring temperature of a transmission line in an embodiment of the present invention.

[0036] Figure 2 Schematic diagram of the fitting curve in an embodiment of the present invention.

[0037] Figure 3 Schematic diagram of a computing module in an embodiment of the present invention.

[0038] Figure 4 Schematic diagram of a fitting module in an embodiment of the present invention.

[0039] Figure 5 Schematic diagram of a fitting module in an embodiment of the present invention.

[0040] Figure 6 Schematic diagram of the connection between the calculation module and the fitting module in an embodiment of the present invention.

[0041] Figure 7 Schematic diagram of a temperature measurement system for a power transmission line according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0043] like Figure 1 FIG. 1 is a schematic diagram of an embodiment of a method for measuring temperature of a transmission line provided by the present invention. In this embodiment, the method includes the following steps:

[0044] The resistance data of the NTC resistor is obtained and divided according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values. That is, the voltage division of the NTC resistor at the current temperature is obtained by dividing the NTC resistor with a fixed resistor. The multiplication coefficient and the addition and subtraction modules in the circuit are then configured according to the fitting parameters to finally output a voltage signal that is proportional to the temperature.

[0045] In this embodiment, the obtained NTC resistor resistance data is divided equally according to a preset number of resistance voltage division items to obtain the voltage division values ​​of multiple NTC resistors at the current temperature;

[0046] The voltage divider value of the NTC resistor at the current temperature and the NTC resistance value have the following linear correspondence:

[0047] V=k0*R t

[0048] Among them, V represents the voltage divider value of the NTC resistor at the current temperature, k0 represents the linear coefficient, and R t Indicates the NTC resistance at the current temperature.

[0049] The relationship between the resistance and temperature of an NTC resistor is exponential. Normally, the relationship between the resistance and temperature cannot be intuitively obtained:

[0050]

[0051] The corresponding relationship between temperature and NTC resistance value can be obtained as follows:

[0052]

[0053] Where R is the NTC resistor's resistance at 25°C, B is the material constant of the NTC thermistor, and T2 is the Kelvin temperature corresponding to 25°C. For specific values, refer to the table below. This correspondence is used for linearization.

[0054]

[0055]

[0056] According to the NTC resistance temperature correspondence table and the required measurement range of the sensor, a polynomial fitting is performed on the temperature data. The polynomial fitting relationship between temperature and NTC resistance is assumed to be: constant term S, first order coefficient k1, second order coefficient k2, third order coefficient k3, ... nth order coefficient kn,

[0057]

[0058] The least squares method is the most commonly used method to solve curve fitting problems. The sum of the squares of the distances between the observed value and the function set value is calculated. When the sum of the squares of the distances is minimized, the fitting curve is obtained, as shown in the following formula. The highest degree of the polynomial is reasonably selected according to the actual fitting accuracy required, such as Figure 2 shown.

[0059]

[0060] Furthermore, the plurality of voltage division values ​​are calculated respectively by a preset calculation module to obtain corresponding plurality of calculation results; that is, a polynomial multiplication processing module is established, and the principle of the multiplication circuit is as follows: Figure 3 As shown, it is composed of multiple transistors and resistors. By constructing different resistance and capacitance parameters, multiplication coefficients of different proportions are realized. According to the fitting coefficients, multiplication modules of different orders are configured.

[0061] In this embodiment, the calculation module specifically includes multiple sub-term multiplication modules, each of which corresponds to the voltage divider value of an NTC resistor at the current temperature; the sub-term multiplication module includes multiple multiplication modules, each of which has a preset multiplication coefficient with a different proportion from that of other multiplication modules, which is used to realize multiplication operations of different proportions and configure sub-term multiplication modules of different terms.

[0062] Specifically, the calculation module is specifically used to receive the voltage division values ​​of multiple NTC resistors at the current temperature, determine the corresponding secondary multiplication module according to the multiplication operation of the ratio required to calculate the voltage division value, and input the voltage division value into the corresponding secondary multiplication module respectively.

[0063] The secondary multiplication module is specifically used to receive the voltage division value of the NTC resistor at the current temperature, and identify the multiplication coefficient to be calculated based on the voltage division value; select the corresponding multiplication module according to the multiplication coefficient to be calculated, calculate the voltage division value of the NTC resistor at the current temperature through the selected multiplication module, and output the calculation result.

[0064] Furthermore, a pre-set fitting module performs a fitting calculation on the multiple calculation results to obtain a corresponding voltage signal, and then determines the corresponding temperature value based on the obtained voltage signal. In other words, the multiplication coefficient and addition and subtraction modules in the fitting parameter configuration circuit determine the temperature value proportional to the output voltage signal based on the output voltage signal.

[0065] In this embodiment, the fitting module specifically includes: an addition module, which is connected to the multiple sub-term multiplication modules respectively, and is used to perform addition operation on the calculation results output by the multiple sub-term multiplication modules to obtain the corresponding voltage signal, such as Figure 4 As shown; a subtraction module, respectively connected to a plurality of said sub-term multiplication modules, for performing a subtraction operation on the calculation results output by the plurality of said sub-term multiplication modules to obtain a corresponding voltage signal, such as Figure 5 shown.

[0066] Specifically, if Figure 6 As shown, determining the corresponding temperature value based on the obtained voltage signal specifically includes: determining the linear correspondence between the voltage signal and the NTC resistance value based on the linear correspondence between the voltage divider value of the NTC resistor at the current temperature and the NTC resistance value; and determining the corresponding temperature value based on the linear correspondence between the voltage signal and the NTC resistance value and the fitting relationship between the temperature and the NTC resistance. The fitting relationship between the temperature and the NTC resistance is expressed by the following formula:

[0067]

[0068] Among them, T1 represents temperature, S represents constant term, k1 represents linear term coefficient, k2 represents quadratic term coefficient, k n represents the coefficient of the n-th order term, Indicates the resistance value at temperature T1 corresponding to the nth-order coefficient.

[0069] like Figure 7 As shown, the present invention also provides a transmission line temperature measurement system for implementing the transmission line temperature measurement method, comprising:

[0070] The voltage division module is used to obtain the NTC resistor resistance data and divide the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values;

[0071] a calculation module, configured to calculate the plurality of divided voltage values ​​respectively to obtain corresponding plurality of calculation results;

[0072] The fitting module is used to perform fitting calculation on the multiple calculation results to obtain corresponding voltage signals, and determine corresponding temperature values ​​according to the obtained voltage signals.

[0073] It should be noted that the system described in the above embodiment corresponds to the method described in the above embodiment. Therefore, the parts of the system described in the above embodiment that are not described in detail can be obtained by referring to the contents of the method described in the above embodiment, and will not be repeated here.

[0074] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0075] The transmission line temperature measurement method and system provided by the present invention, based on the temperature-voltage relationship being a straight line within the operating temperature range, secondary development of the design of the temperature measurement and temperature control circuits can be completed without digital calibration processing, thereby simplifying the design and debugging of the instrument.

[0076] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for measuring temperature of a transmission line, characterized in that: include: Obtaining NTC resistor resistance data, and dividing the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values; Calculating the plurality of partial pressure values ​​respectively by a preset calculation module to obtain corresponding plurality of calculation results; The plurality of calculation results are fitted by a preset fitting module to obtain corresponding voltage signals, and the corresponding temperature values ​​are determined according to the obtained voltage signals; The step of dividing the obtained NTC resistor resistance data according to a preset resistance voltage division rule specifically includes: dividing the obtained NTC resistor resistance data equally according to a preset number of resistance voltage division items to obtain voltage division values ​​of multiple NTC resistors at the current temperature; Furthermore, the calculation module specifically includes a plurality of sub-term multiplication modules, each of which corresponds to a voltage division value of an NTC resistor at a current temperature; The sub-term multiplication module includes multiple multiplication modules, each of which is preset with a multiplication coefficient of a different proportion from that of other multiplication modules, so as to realize multiplication operations of different proportions and configure the sub-term multiplication modules of different orders.

2. The method according to claim 1, wherein There is a linear correspondence between the voltage divider value of the NTC resistor at the current temperature and the NTC resistance: V=k0*R t Among them, V represents the voltage divider value of the NTC resistor at the current temperature, k0 represents the linear coefficient, and R t Indicates the NTC resistance at the current temperature.

3. The method according to claim 2, wherein The calculation module is specifically used to determine the corresponding secondary multiplication module according to the multiplication operation of the ratio required to calculate the voltage division value when receiving the voltage division values ​​of multiple NTC resistors at the current temperature, and input the voltage division values ​​into the corresponding secondary multiplication module respectively.

4. The method according to claim 3, wherein The secondary multiplication module is specifically configured to receive a voltage division value of the NTC resistor at a current temperature and identify a multiplication coefficient to be calculated based on the voltage division value; The corresponding multiplication module is selected according to the multiplication coefficient to be calculated, the voltage division value of the NTC resistor at the current temperature is calculated by the selected multiplication module, and the calculation result is output.

5. The method according to claim 4, wherein The fitting module specifically includes: an adding module, connected to the plurality of said secondary multiplication modules respectively, for performing an addition operation on the calculation results output by the plurality of said secondary multiplication modules to obtain a corresponding voltage signal; The subtraction modules are respectively connected to the plurality of the sub-term multiplication modules and are used to perform subtraction operations on the calculation results output by the plurality of the sub-term multiplication modules to obtain corresponding voltage signals.

6. The method according to claim 5, wherein Determining the corresponding temperature value according to the obtained voltage signal specifically includes: Determining a linear correspondence between the voltage signal and the NTC resistance value based on a linear correspondence between a voltage division value of the NTC resistor at a current temperature and the NTC resistance value; The temperature value corresponding to the voltage signal is determined according to the linear correspondence between the voltage signal and the NTC resistance and the fitting relationship between the temperature and the NTC resistance.

7. The method according to claim 6, wherein The fitting relationship between the temperature and the NTC resistance is expressed by the following formula: Among them, T1 represents temperature, S represents constant term, k1 represents linear term coefficient, k2 represents quadratic term coefficient, k n represents the coefficient of the n-th order term, Indicates the resistance value at temperature T1 corresponding to the nth-order coefficient.

8. A transmission line temperature measurement system, used to implement the method according to any one of claims 1 to 7, characterized in that: include, The voltage division module is used to obtain the NTC resistor resistance data and divide the obtained NTC resistor resistance data according to a preset resistance voltage division rule to obtain corresponding multiple voltage division values; a calculation module, configured to calculate the plurality of divided voltage values ​​respectively to obtain corresponding plurality of calculation results; The fitting module is used to perform fitting calculation on the multiple calculation results to obtain corresponding voltage signals, and determine corresponding temperature values ​​according to the obtained voltage signals.

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