A temperature sensing cable performance detection device and method based on temperature resistance characteristics

Abstract

The present invention discloses a device and method for detecting the performance of a temperature-sensitive cable based on temperature-resistance characteristics. The device mainly includes three parts: a main control system, a temperature control system, and a detection structure. The main control unit controls the temperature control system to heat the temperature around the temperature-sensitive cable to a target value. The detection structure monitors the temperature around the temperature-sensitive cable and the cable resistance. The temperature-resistance characteristic curve is fitted by the cable resistance at different temperatures. The curve deviation rate, the number of large deviation points, and the maximum change rate are used to quantitatively judge the performance of the temperature-sensitive cable. The present invention can set different cable heating methods according to different cable layout environments on site, conveniently evaluate the performance of the temperature-sensitive cable on site, and effectively prevent damaged or low-quality temperature-sensitive cables from being used on site.

Description

Technical Field

[0001] The invention relates to a temperature-sensitive cable performance detection device and method based on temperature-resistance characteristics, belonging to the technical field of transformer state detection. Background Art

[0002] Temperature sensing cables used in electrical equipment in substations have the problem of sending false alarm signals due to the lack of quantitative detection equipment suitable for on-site use. Summary of the invention

[0003] The purpose of the present invention is to provide a temperature-sensing cable performance detection device and method based on temperature-resistance characteristics, by heating the area around the temperature-sensing cable, monitoring the impedance changes of the temperature-sensing cable at different temperatures, drawing a temperature-resistance characteristic curve, and quantitatively detecting the performance of the temperature-sensing cable.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] The present invention provides a temperature-sensitive cable performance detection device based on temperature resistance characteristics, comprising: a main control system, a temperature control system and a detection structure;

[0006] The main control system is used to control the temperature control system to heat the temperature around the temperature-sensing cable to a target value, and to fit the temperature-resistance characteristic curve based on the temperature around the temperature-sensing cable and the cable resistance, and to evaluate the performance of the temperature-sensing cable;

[0007] The temperature control system is used to heat the temperature sensing cable;

[0008] The detection structure is used to monitor the ambient temperature of the temperature-sensing cable and the cable resistance;

[0009] The temperature control system is wrapped around the outside of the temperature sensing cable;

[0010] The detection structure is installed on the stabilization control system;

[0011] The temperature control system and the detection structure both communicate with the main control system wirelessly.

[0012] Furthermore, the main control system includes a main control unit, a communication module, a voltage and current monitoring module, a temperature resistance curve fitting module, an AD acquisition module and a photoelectric coupling module;

[0013] The communication module is used for communication between the main control system and the temperature control system, and between the main control system and the detection structure;

[0014] The voltage and current monitoring module is used to sample the voltage and current of the temperature sensing cable resistance measurement loop;

[0015] The AD acquisition module is used to convert the ambient temperature of the temperature sensing cable into an electrical signal that can be collected by the main control unit;

[0016] The temperature resistance curve fitting module is used to fit the temperature resistance characteristic curve according to the resistance and temperature of the temperature sensing cable;

[0017] The main control unit is used to control the temperature control system to heat the temperature sensing cable, and is used to calculate the resistance of the temperature sensing cable according to the voltage and current electrical signals, and is used to determine the performance of the temperature sensing cable according to the temperature resistance characteristic curve;

[0018] The photoelectric coupling module is used to isolate input and output signals.

[0019] Furthermore,

[0020] For the temperature sensing cable structure that cannot be disassembled on site, the temperature control system adopts a cylindrical silicone heating sheet;

[0021] For the detachable temperature-sensing cable structure, the temperature control system adopts a containment-type constant temperature bag.

[0022] Furthermore,

[0023] The detection structure includes a temperature sensor and a voltage and current sensor;

[0024] The temperature sensor is used to measure the temperature around the temperature sensing cable;

[0025] The voltage and current sensor is used to measure the voltage and current of the temperature sensing cable resistance measurement loop.

[0026] The present invention also provides a method for detecting the performance of a temperature-sensitive cable based on temperature resistance characteristics, comprising:

[0027] Control the temperature control system in sequence according to the step length to heat the temperature sensing cable to the target temperature;

[0028] The detection structure monitors the surrounding temperature and resistance of the temperature sensing cable at different target temperatures;

[0029] Fit the standard curve and measurement curve of the temperature resistance characteristic of the temperature sensing cable according to the resistance value of the temperature sensing cable at different target temperatures;

[0030] The performance of the temperature sensing cable is evaluated based on the standard curve of the temperature sensing cable's thermal resistance characteristics and the measurement curve.

[0031] Furthermore, the method of fitting the temperature-resistance characteristic standard curve and the measurement curve of the temperature-sensing cable according to the resistance of the temperature-sensing cable at different target temperatures includes:

[0032] The temperature resistance characteristic curve of the temperature sensing cable between the i-th measuring point and the i+1-th measuring point is expressed as:

[0033]

[0034] Where, fx(t) i It represents the temperature resistance characteristic measurement curve of the temperature sensing cable between the i-th measurement point and the i+1-th measurement point. One target temperature corresponds to one measurement point. R i is the measured resistance of the temperature sensing cable at the i-th measuring point, R i+1 is the measured resistance of the temperature sensing cable at the i+1th measuring point, t represents the target temperature value corresponding to the measuring point, T G is the temperature interval between adjacent measuring points, N G is the total number of measurement points in the entire temperature range;

[0035] The temperature resistance characteristic measurement curves of the temperature sensing cable between all measurement points and adjacent measurement points are calculated in sequence, that is, the temperature resistance characteristic measurement curves of the temperature sensing cable within the entire temperature range are obtained;

[0036] Similarly, the standard curve of the temperature resistance characteristic of the temperature sensing cable in the entire temperature range is calculated based on the standard resistance value of the temperature sensing cable at different target temperatures.

[0037] Furthermore, the temperature range is selected from 20°C to 120°C;

[0038] The total number of measurement points over the entire temperature range is calculated as:

[0039]

[0040] Furthermore, the performance of the temperature sensing cable is evaluated based on the temperature sensing cable temperature resistance characteristic standard curve and the measurement curve, including:

[0041] Calculate the deviation rate and curve deviation score of the temperature-sensing cable's temperature resistance curve, calculate the number of large deviation points of the temperature-sensing cable's temperature resistance curve, and calculate the maximum change rate of the temperature-sensing cable's temperature resistance curve;

[0042] A temperature sensing cable evaluation system is established based on the deviation rate of the temperature sensing cable's thermal resistance characteristic curve, the curve deviation score, the number of large deviation points and the maximum change rate. The temperature sensing cables are divided into three grades: Ⅰ, Ⅱ and Ⅲ according to their performance.

[0043] Furthermore, the calculation of the temperature resistance curve deviation rate and the curve deviation score of the temperature sensing cable includes:

[0044] The curve deviation rate is calculated as follows:

[0045]

[0046] Among them, e z Indicates the curve deviation rate, R Mt Indicates the actual resistance of the temperature sensing cable when the target temperature is t, obtained using a standard resistance measuring instrument, R TtIndicates the measured resistance of the temperature sensing cable when the target temperature is t, R Ct It indicates the standard resistance of the temperature sensing cable when the target temperature is t, and c indicates the amount of temperature change;

[0047] The curve deviation score is calculated as follows:

[0048] P=∑P t

[0049]

[0050]

[0051] Among them, P represents the total score of the curve deviation of the temperature sensing cable, P t Indicates the curve deviation score when the target temperature of the temperature sensing cable is t, c 1t 、c 2t It indicates the deviation score coefficient when the temperature of the temperature sensing cable is t, e t Indicates the resistance deviation rate when the temperature is t.

[0052] Furthermore, the calculation of the number of large deviation points of the temperature resistance curve of the temperature sensing cable includes:

[0053] When e t Greater than E max The corresponding measurement point is the large deviation point, and the number of large deviation points N and E are calculated. max Indicates the preset threshold value of resistance deviation rate.

[0054] Further, the calculation of the maximum change rate of the temperature resistance curve of the temperature sensing cable includes:

[0055] M max =max||R T(t+1) -R Tt |-|R C(t+1) -R Ct ||

[0056] Among them, M max Indicates the maximum rate of change between the standard curve of the temperature resistance characteristic of the temperature sensing cable and the measurement curve.

[0057] Furthermore, the temperature sensing cable evaluation system is established based on the deviation rate of the temperature resistance characteristic curve of the temperature sensing cable, the number of large deviation points and the maximum change rate, and the temperature sensing cable is divided into three grades according to performance: I, II and III, including:

[0058] Evaluation criteria for the performance of temperature sensing cables as Class I: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Less than 1, and no large deviation points;

[0059] The evaluation criteria for the performance of temperature sensing cables to be Class II are to meet any of the following conditions:

[0060] Condition 1: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Greater than 1, but no large deviation point exists;

[0061] Condition 2: Curve deviation rate e z Greater than 5 or 60≤P<80, and the maximum change rate M max Less than 1, and the number of large deviation points N is less than or equal to 10;

[0062] Evaluation criteria for the performance of temperature sensing cables at level III: curve deviation rate e z Greater than 5 or P<60, and the maximum change rate M max is greater than 1, and the number of large deviation points N is greater than 10.

[0063] The beneficial effects of the present invention are:

[0064] The present invention provides a device and method for detecting the performance of a temperature-sensitive cable based on the temperature-resistance characteristic. The temperature control system is controlled to heat the surrounding temperature of the temperature-sensitive cable to a target value. The temperature-resistance characteristic curve is fitted based on the surrounding temperature of the temperature-sensitive cable and the cable resistance. The performance of the temperature-sensitive cable is quantitatively determined by using the deviation rate (deviation score), the number of large deviation points and the maximum change rate of the temperature-resistance characteristic curve of the temperature-sensitive cable. The device has the following advantages: 1. The device can be applied to the quantitative detection of the temperature-resistance characteristic of the temperature-sensitive cable. 2. The device can determine the performance level of the temperature-sensitive cable, which can effectively prevent the damaged or low-quality temperature-sensitive cables from being used on site, and improve the reliability of the fire protection system of the substation. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a structural diagram of the temperature sensing cable detection device of the present invention.

[0066] Figure 2 It is a flow chart of temperature sensing cable detection of the present invention. DETAILED DESCRIPTION

[0067] The present invention is further described below. The following examples are only used to more clearly illustrate the technical solution of the present invention, and are not intended to limit the protection scope of the present invention.

[0068] The present invention provides a temperature sensing cable performance detection device based on temperature resistance characteristics, such as Figure 1 As shown, it includes three parts: main control system, temperature control system and detection structure.

[0069] The main control system communicates with the temperature control system wirelessly.

[0070] The main control system is used to control the temperature control system, heat the temperature around the temperature sensing cable to the target value, fit the temperature-resistance characteristic curve based on the temperature around the temperature sensing cable and the cable resistance, and evaluate the performance of the temperature sensing cable.

[0071] The temperature control system is used to heat the temperature sensing cable.

[0072] The detection structure is used to monitor the ambient temperature of the temperature-sensing cable and the cable resistance.

[0073] Specifically, the main control system mainly includes six parts: main control unit, communication module, voltage and current monitoring module, temperature resistance curve fitting module, AD acquisition module and photoelectric coupling module.

[0074] The communication module is used for communication between the main control system and the temperature control system, and between the main control system and the detection structure.

[0075] The voltage and current monitoring module is used to sample the voltage and current of the temperature sensing cable resistance measurement circuit;

[0076] The AD acquisition module is used to convert the temperature of the cylindrical silicone heating sheet or the containing constant temperature bag into an electrical signal that can be collected by the main control unit;

[0077] The temperature resistance curve fitting module is used to fit the temperature resistance characteristic curve according to the temperature sensing cable resistance and temperature;

[0078] The main control unit is used to calculate the resistance of the temperature sensing cable according to the voltage and current electrical signals, and to judge the performance of the temperature sensing cable according to the temperature resistance characteristic curve;

[0079] The photoelectric coupling module is used to isolate the input and output signals to achieve precise temperature control.

[0080] Specifically, for structures that cannot be disassembled on site, the temperature control system uses a cylindrical silicone heating sheet; for structures that can be easily disassembled, the temperature control system uses a containing constant temperature bag, which can hold all the temperature sensing cables at one time to achieve constant temperature heating of the temperature sensing cables.

[0081] Specifically, the detection structure is installed on the temperature control system. The detection structure uses a temperature sensor and a voltage and current sensor. The temperature is monitored by the temperature sensor, and the resistance is monitored by the voltage and current sensors.

[0082] The present invention also provides a method for detecting the performance of a temperature-sensitive cable based on the temperature resistance characteristic. Figure 2 As shown, including:

[0083] Heat the temperature sensing cable to the target value;

[0084] Real-time monitoring of the surrounding temperature and resistance of the temperature sensing cable through the detection structure;

[0085] Fit the temperature-resistance characteristic measurement curve of the temperature-sensing cable according to the resistance value of the temperature-sensing cable at different temperatures, and display it on the screen of the detection device;

[0086] The performance of the temperature sensing cable is evaluated based on the standard curve of the temperature sensing cable's thermal resistance characteristics and the measurement curve.

[0087] Specifically, the temperature sensing cable temperature resistance characteristic measurement curve fitting method is as follows:

[0088] Assume that the temperature interval of the measuring point of the temperature sensing cable performance detection device is T G , then the total number of measurement points N G It can represent:

[0089]

[0090] In the embodiment of the present invention, each target value corresponds to a measurement point, and the measurement range is 20°C to 120°C.

[0091] Assume that the measured resistance of the temperature sensing cable at the i-th measuring point is R i , the measured resistance of the temperature sensing cable at the i+1th measuring point is R i+1 , then the temperature resistance characteristic curve of the temperature sensing cable between the i-th measuring point and the i+1-th measuring point can be expressed as:

[0092]

[0093] Where fx(t) i It represents the temperature resistance characteristic measurement curve of the temperature sensing cable between the i-th measurement point and the i+1-th measurement point, and t represents the target temperature value corresponding to the measurement point.

[0094] The temperature resistance characteristic curves of the temperature sensing cable from all measuring points to adjacent measuring points are calculated in sequence, that is, the temperature resistance characteristic measurement curves of the temperature sensing cable within the entire temperature range are obtained.

[0095] Similarly, the standard curve of the temperature resistance characteristics of the temperature sensing cable can be obtained according to the standard resistance value of the temperature sensing cable at different temperatures.

[0096] Specifically, the performance of the temperature sensing cable is evaluated using the temperature sensing cable temperature resistance characteristic standard curve and measurement curve, including:

[0097] Step 1: Calculate the temperature resistance curve deviation rate and curve deviation score of the temperature sensing cable.

[0098] According to the standard curve of the temperature-sensing cable's temperature resistance characteristic and the measurement curve, the deviation rate of the two temperature resistance characteristic curves is first calculated as follows:

[0099] In the formula, e z Indicates the curve deviation rate, R MtIndicates the actual resistance of the temperature sensing cable when the target temperature is t, obtained using a standard resistance measuring instrument, R Tt It indicates the measured resistance of the temperature sensing cable when the target temperature is t, measured by this device, R Ct is the standard resistance of the temperature sensing cable at the target temperature t, which is obtained from the factory test results of the temperature sensing cable manufacturer, and c represents the amount of temperature change.

[0100] Calculate the deviation rate between the standard resistance value and the measured resistance value of the temperature sensing cable at a certain temperature. The expression is as follows:

[0101]

[0102] In the formula, e t Indicates the resistance deviation rate when the temperature is t.

[0103] The deviation score is defined when the temperature of the temperature sensing cable is t, and its calculation formula is as follows:

[0104]

[0105] In the formula, c 1t 、c 2t Indicates the deviation score coefficient when the temperature of the temperature sensing cable is t, P t Indicates the performance deviation score when the temperature of the temperature sensing cable is t. 1t and c 2t The value of c is set artificially. 1t The value can be 15% to 30%, c 2t The possible value is 30% to 45%.

[0106] The performance deviation scores at t at 20℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, and 120℃ are calculated respectively to obtain the total deviation score of the temperature sensing cable:

[0107] P=∑P t (6)

[0108] Wherein, P represents the total score of the curve deviation of the temperature sensing cable.

[0109] Step 2: Calculate the number of large deviation points of the temperature resistance curve of the temperature sensing cable.

[0110] Define when e t Greater than E max is the large deviation point, and the number of large deviation points N is calculated.

[0111] Among them, E max Indicates the preset threshold value of resistance deviation rate.

[0112] Step 3: Calculate the maximum rate of change of the temperature resistance curve of the temperature sensing cable.

[0113] According to the standard curve of the temperature-sensing cable's temperature-resistance characteristic and the measurement curve, calculate the maximum change value of the temperature-resistance characteristic curve with 1°C as the minimum unit. The calculation method is as follows:

[0114] M max =max||R T(t+1) -R Tt |-|R C(t+1) -R Ct || (7)

[0115] Where M max Indicates the maximum rate of change between the standard curve of the temperature resistance characteristic of the temperature sensing cable and the measurement curve.

[0116] Step 4: Establish an evaluation system for temperature sensing cables.

[0117] The temperature sensing cable evaluation system is based on the deviation rate of the temperature resistance characteristic curve of the temperature sensing cable, and the number of large deviation points and the maximum change rate are used as auxiliary criteria. The temperature sensing cable is divided into three grades according to performance: I, II and III. The specific evaluation method is as follows:

[0118] 1. Evaluation criteria for the performance of temperature sensing cables at level I: curve deviation rate e z Less than 5 or deviation score greater than 80, the maximum change rate M max Less than 1, no major deviation point.

[0119] 2. The evaluation standard for the performance of temperature sensing cables to be Class II is to meet any of the following conditions:

[0120] Condition 1: Curve deviation rate e z Less than 5 or deviation score greater than 80, the maximum change rate M max Greater than 1, but there is no large deviation point.

[0121] Condition 2: Curve deviation rate e z Greater than 5 or the deviation score is less than 80 but greater than or equal to 60, the maximum change rate M max Less than 1, the number of large deviation points N is less than or equal to 10.

[0122] 3. Evaluation criteria for the performance of temperature sensing cables at level III: curve deviation rate e z Greater than 5 or deviation score less than 60, the maximum change rate M max is greater than 1, and the number of large deviation points N is greater than 10.

[0123] According to the evaluation standard for temperature sensing cables, the performance is defined as follows:

[0124] The performance of Class I temperature sensing cable is good and it is recommended to continue to use it.

[0125] If the performance of Class II temperature sensing cable is qualified, it can be used or replaced. If it needs to continue to be used, the corresponding parameters of the temperature sensing cable terminal box need to be adjusted according to the on-site conditions in order to sensitively monitor the over-temperature state.

[0126] The performance of Class III temperature sensing cables is unqualified and needs to be replaced in time to avoid false alarms or refusal to report fire.

[0127] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A temperature sensing cable performance detection device based on temperature resistance characteristics, characterized in that: include: Main control system, temperature control system and detection structure; The main control system is used to control the temperature control system to heat the temperature around the temperature sensing cable to a target value, and to fit the standard curve and measurement curve of the temperature resistance characteristic of the temperature sensing cable according to the resistance of the temperature sensing cable at different target temperatures, and to evaluate the performance of the temperature sensing cable based on the standard curve and measurement curve of the temperature resistance characteristic of the temperature sensing cable; The method of fitting the standard curve of the temperature resistance characteristic of the temperature sensing cable and the measurement curve is as follows: The temperature resistance characteristic measurement curve of the temperature sensing cable between the i-th measurement point and the i+1-th measurement point is expressed as: Where, fx(t) i It represents the temperature resistance characteristic measurement curve of the temperature sensing cable between the i-th measurement point and the i+1-th measurement point. One target temperature corresponds to one measurement point. R i is the measured resistance of the temperature sensing cable at the i-th measuring point, R i+1 is the measured resistance of the temperature sensing cable at the i+1th measuring point, t represents the target temperature value corresponding to the measuring point, T G is the temperature interval between adjacent measuring points, N G is the total number of measuring points in the entire temperature range; the temperature resistance characteristic measurement curves of the temperature sensing cable from all measuring points to adjacent measuring points are calculated in sequence, that is, the temperature resistance characteristic measurement curves of the temperature sensing cable in the entire temperature range are obtained; Similarly, the standard curve of the temperature resistance characteristic of the temperature sensing cable in the entire temperature range is calculated based on the standard resistance value of the temperature sensing cable at different target temperatures; The evaluation method is: calculating the deviation rate and curve deviation score of the temperature-sensing cable temperature resistance characteristic curve, calculating the number of large deviation points of the temperature-sensing cable temperature resistance characteristic curve, and calculating the maximum change rate of the temperature-sensing cable temperature resistance characteristic curve; Among them, the calculation of the temperature sensing cable temperature resistance characteristic curve deviation rate and curve deviation score includes: The curve deviation rate is calculated as follows: Among them, e z Indicates the curve deviation rate, R Mt Indicates the actual resistance of the temperature sensing cable when the target temperature is t, obtained using a standard resistance measuring instrument, R Tt Indicates the measured resistance of the temperature sensing cable when the target temperature is t, R Ct It indicates the standard resistance of the temperature sensing cable when the target temperature is t, and c indicates the amount of temperature change; The curve deviation score is calculated as follows: P=∑P t ; Among them, P represents the curve deviation score of the temperature sensing cable, P t Indicates the curve deviation score when the target temperature of the temperature sensing cable is t, c 1t 、c 2t It indicates the deviation score coefficient when the temperature of the temperature sensing cable is t, e t Indicates the resistance deviation rate when the temperature is t; The calculation of the number of large deviation points of the temperature-sensing cable temperature resistance characteristic curve includes: When e t Greater than E max The corresponding measurement point is the large deviation point, and the number of large deviation points N and E are calculated. max Indicates the preset threshold value of resistance deviation rate; The calculation of the maximum rate of change of the temperature resistance characteristic curve of the temperature sensing cable includes: M max =max||R T(t+1) -R Tt |-|R C(t+1) -R Ct ||; Among them, M max Indicates the maximum rate of change between the standard curve of the temperature resistance characteristic of the temperature sensing cable and the measurement curve; Based on the deviation rate of the temperature-sensing cable's thermal resistance characteristic curve, the curve deviation score, the number of large deviation points and the maximum change rate, a temperature-sensing cable evaluation system was established, and the temperature-sensing cables were divided into three grades: I, II and III according to their performance. The evaluation criteria for the three levels Ⅰ, Ⅱ and Ⅲ are: Evaluation criteria for the performance of temperature sensing cables as Class I: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Less than 1, and no large deviation point; where P is the curve deviation score of the temperature sensing cable; The evaluation criteria for the performance of temperature sensing cables to be Class II are to meet any of the following conditions: Condition 1: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Greater than 1, but no large deviation point exists; Condition 2: Curve deviation rate e z Greater than 5 or 60≤P<80, and the maximum change rate M max Less than 1, and the number of large deviation points N is less than or equal to 10; Evaluation criteria for the performance of temperature sensing cables at level III: curve deviation rate e z Greater than 5 or P<60, and the maximum change rate M max is greater than 1, and the number of large deviation points N is greater than 10; The temperature control system is used to heat the temperature sensing cable; The detection structure is used to monitor the ambient temperature of the temperature-sensing cable and the cable resistance; The temperature control system is wrapped around the outside of the temperature sensing cable; The detection structure is installed on the temperature control system; The temperature control system and the detection structure both communicate with the main control system wirelessly.

2. A temperature sensing cable performance detection device based on temperature resistance characteristics according to claim 1, characterized in that: The main control system includes a main control unit, a communication module, a voltage and current monitoring module, a temperature resistance curve fitting module, an AD acquisition module and a photoelectric coupling module; the communication module is used for communication between the main control system and the temperature control system, and between the main control system and the detection structure; The voltage and current monitoring module is used to sample the voltage and current of the temperature sensing cable resistance measurement loop; The AD acquisition module is used to convert the ambient temperature of the temperature sensing cable into an electrical signal that can be collected by the main control unit; The temperature resistance curve fitting module is used to fit the temperature resistance characteristic curve according to the resistance and temperature of the temperature sensing cable; The main control unit is used to control the temperature control system to heat the temperature sensing cable, and is used to calculate the resistance of the temperature sensing cable according to the voltage and current electrical signals, and is used to determine the performance of the temperature sensing cable according to the temperature resistance characteristic curve; The photoelectric coupling module is used to isolate input and output signals.

3. A temperature sensing cable performance detection device based on temperature resistance characteristics according to claim 1, characterized in that: For the temperature sensing cable structure that cannot be disassembled on site, the temperature control system adopts a cylindrical silicone heating sheet; For the detachable temperature-sensing cable structure, the temperature control system adopts a containment-type constant temperature bag.

4. A temperature sensing cable performance detection device based on temperature resistance characteristics according to claim 1, characterized in that: The detection structure includes a temperature sensor, a voltage sensor and a current sensor; The temperature sensor is used to measure the temperature around the temperature sensing cable; The voltage sensor and the current sensor are used to measure the voltage and current of the temperature-sensitive cable resistance measurement loop.

5. A method for detecting the performance of a temperature-sensitive cable based on temperature-resistance characteristics, characterized in that: include: Control the temperature control system in sequence according to the step length to heat the temperature sensing cable to the target temperature; The detection structure monitors the surrounding temperature and resistance of the temperature sensing cable at different target temperatures; Fitting the temperature-sensing cable temperature resistance characteristic standard curve and measurement curve according to the temperature-sensing cable resistance at different target temperatures, including: The temperature resistance characteristic curve of the temperature sensing cable between the i-th measuring point and the i+1-th measuring point is expressed as: Where, fx(t) i It represents the temperature resistance characteristic measurement curve of the temperature sensing cable between the i-th measurement point and the i+1-th measurement point. One target temperature corresponds to one measurement point. R i is the measured resistance of the temperature sensing cable at the i-th measuring point, R i+1 is the measured resistance of the temperature sensing cable at the i+1th measuring point, t represents the target temperature value corresponding to the measuring point, T G is the temperature interval between adjacent measuring points, N G is the total number of measuring points in the entire temperature range; the temperature resistance characteristic measurement curves of the temperature sensing cable from all measuring points to adjacent measuring points are calculated in sequence, that is, the temperature resistance characteristic measurement curves of the temperature sensing cable in the entire temperature range are obtained; Similarly, the standard curve of the temperature resistance characteristic of the temperature sensing cable in the entire temperature range is calculated based on the standard resistance value of the temperature sensing cable at different target temperatures; The performance of the temperature sensing cable is evaluated based on the standard curve and measurement curve of the temperature sensing cable's temperature resistance characteristics, including: Calculate the deviation rate and curve deviation score of the temperature-sensing cable's temperature resistance characteristic curve, where: The curve deviation rate is calculated as follows: Among them, e z Indicates the curve deviation rate, R Mt Indicates the actual resistance of the temperature sensing cable when the target temperature is t, obtained using a standard resistance measuring instrument, R Tt Indicates the measured resistance of the temperature sensing cable when the target temperature is t, R Ct It indicates the standard resistance of the temperature sensing cable when the target temperature is t, and c indicates the amount of temperature change; The curve deviation score is calculated as follows: P=∑P t ; Among them, P represents the curve deviation score of the temperature sensing cable, P t Indicates the curve deviation score when the target temperature of the temperature sensing cable is t, c 1t 、c 2t It indicates the deviation score coefficient when the temperature of the temperature sensing cable is t, e t Indicates the resistance deviation rate when the temperature is t; Calculate the number of large deviation points of the temperature-sensing cable's temperature resistance characteristic curve as follows: When e t Greater than E max The corresponding measurement point is the large deviation point, and the number of large deviation points N and E are calculated. max Indicates the preset threshold value of resistance deviation rate; Calculate the maximum rate of change of the temperature resistance characteristic curve of the temperature sensing cable as follows: M max =max||R T(t+1) -R Tt |-|R C(t+1) -R Ct ||; Among them, M max Indicates the maximum rate of change between the standard curve of the temperature resistance characteristic of the temperature sensing cable and the measurement curve; Based on the deviation rate of the temperature-sensing cable's thermal resistance characteristic curve, the curve deviation score, the number of large deviation points and the maximum change rate, a temperature-sensing cable evaluation system was established, and the temperature-sensing cables were divided into three grades: I, II and III according to their performance. The evaluation criteria for the three levels Ⅰ, Ⅱ and Ⅲ are: Evaluation criteria for the performance of temperature sensing cables as Class I: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Less than 1, and no large deviation point; where P is the curve deviation score of the temperature sensing cable; The evaluation criteria for the performance of temperature sensing cables to be Class II are to meet any of the following conditions: Condition 1: Curve deviation rate e z Less than 5 or P>80, and the maximum change rate M max Greater than 1, but no large deviation point exists; Condition 2: Curve deviation rate e z Greater than 5 or 60≤P<80, and the maximum change rate M max Less than 1, and the number of large deviation points N is less than or equal to 10; Evaluation criteria for the performance of temperature sensing cables at level III: curve deviation rate e z Greater than 5 or P<60, and the maximum change rate M max is greater than 1, and the number of large deviation points N is greater than 10.

6. A method for detecting the performance of a temperature-sensitive cable based on temperature-resistance characteristics according to claim 5, characterized in that: The temperature range is 20°C to 120°C; The total number of measurement points over the entire temperature range is calculated as:

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