阅读说明：本技术 一种电缆绝缘运行温度在线监测装置 (Cable insulation operating temperature on-line monitoring device ) 是由 张静 张川 罗传仙 赵欣宇 蔡玉汝 刘熙 程林 于 2020-06-29 设计创作，主要内容包括：本发明涉及一种电缆绝缘运行温度在线监测装置。所述装置包括：电源,用于提供工作所需工频交流电；信号源模块,用于发出一定幅值、频率的脉冲信号。传感模块,用于接收信号源模块发出的脉冲信号。同步模块,用于同步信号源模块与传感模块的时间。信号处理模块,用于接收反射信号、并将信号进行A/D转换,输出数字信号。传输模块,用于传输脉冲信号。通信模块,用于将信号源模块发出的脉冲信号与信号处理模块输出的数字信号传送到数据分析载体。数据分析载体,用于提取数字信号,通过关系函数,获得电缆运行温度信息。本发明通过监测脉冲信号在电缆中的传输速度得到电缆绝缘运行温度,避免了现有装置直接测量电缆外表面温度受环境温度干扰的影响,提高了测量的准确性,安装方便,现场适用性强。(The invention relates to an on-line monitoring device for the insulation operating temperature of a cable. The device comprises: the power supply is used for providing power frequency alternating current required by work; and the signal source module is used for sending out pulse signals with certain amplitude and frequency. And the sensing module is used for receiving the pulse signal sent by the signal source module. And the synchronization module is used for synchronizing the time of the signal source module and the time of the sensing module. And the signal processing module is used for receiving the reflected signal, carrying out A/D conversion on the signal and outputting a digital signal. And the transmission module is used for transmitting the pulse signal. And the communication module is used for transmitting the pulse signals sent by the signal source module and the digital signals output by the signal processing module to the data analysis carrier. And the data analysis carrier is used for extracting the digital signals and obtaining the running temperature information of the cable through the relation function. According to the invention, the insulated operating temperature of the cable is obtained by monitoring the transmission speed of the pulse signal in the cable, so that the influence of the interference of the ambient temperature on the direct measurement of the temperature of the outer surface of the cable by the conventional device is avoided, the measurement accuracy is improved, the installation is convenient, and the field applicability is strong.)

1. The utility model provides a cable insulation operating temperature on-line monitoring device which characterized in that, monitoring devices includes:

power supply: the power frequency alternating current circuit is used for providing power frequency alternating current required by work and providing working voltage for the signal source module and the signal processing module;

a signal source module: the pulse signal is used for emitting a pulse signal with certain amplitude and frequency;

the sensing module: the pulse signal receiving module is used for receiving a pulse signal sent by the signal source module;

a synchronization module: the time synchronization module is used for synchronizing the time of the signal source module and the time of the sensing module;

the signal processing module: the digital signal processing circuit is used for receiving the reflected signal, carrying out A/D conversion on the signal and outputting a digital signal;

a transmission module: is used for transmitting pulse signals, is connected with the signal source module or the sensing module and the signal processing module,

a communication module: the data analysis carrier is used for transmitting the pulse signals sent by the signal source module and the digital signals output by the signal processing module to the data analysis carrier;

data analysis vehicle: the system is used for extracting the digital signals and obtaining the running temperature information of the cable through the relation function.

2. The cable insulation operation temperature online monitoring device according to claim 1, wherein the sensing module adopts a high-frequency current sensor or a capacitance sensor; the synchronization module adopts a GPS module; the transmission module adopts communication cables or optical fibers.

3. The cable insulation operation temperature on-line monitoring device according to claim 2, wherein the transmission module uses an optical fiber as a signal transmission medium, the monitoring device is equipped with a photoelectric conversion module for converting the pulse signal received by the sensing module into an optical signal, and when the signal is sent out, the photoelectric conversion module is connected with the signal source module and the signal processing module; when the photoelectric conversion module is used for receiving signals, the photoelectric conversion module is connected with the sensing module and the signal processing module.

4. The cable insulation operating temperature on-line monitoring device of claim 1, wherein the communication module adopts 4G or 5G communication network communication.

5. Using any of claims 1-4The cable insulation operation temperature on-line monitoring device comprises the following detection methods: by using the correlation between the propagation speed of the pulse signal in the cable insulation and the insulation temperature, knowing that the cable line length L is constant, the transmission speed v is inversely proportional to the transmission time T, and if the insulation material is constant, T is at the reference temperature₀At a time, a transmission speed v_T0Knowing the transmission time t_T0The following can be obtained:

t_T0＝L÷v_T0(1)

the temperature of the insulating layer rises and the temperature T is high when the cable runs_xWith a reference temperature T₀The relationship between the transmission speed and the transmission time is as follows:

v_T0*t_T0＝v_Tx*t_Tx(2)

by acquiring the pulse signal sent by the signal source module and the time for the sensing module to receive the pulse signal, the high-temperature T can be obtained_xTime of flight t_Tx. From formula (2):

v_Tx＝v_T0*t_T0/t_Tx(3)

v obtained by the formula (3)_TxFinally, the corresponding relation between the propagation speed and the temperature is utilized to obtain the operating temperature T of the cable insulation layer_x。

6. The method for detecting the cable insulation operation temperature on-line monitoring device according to claim 5, wherein the method comprises the following steps: the correspondence of the propagation speed to the temperature includes:

for oil impregnated paper insulated power cables:

V_TX＝V_T0×(1.0318-0.00125T_X) (4)

for cross-linked polyethylene (XLPE) insulated power cables:

Technical Field

The invention relates to the technical field of electrician detection, in particular to an on-line monitoring device for the insulation operation temperature of a cable.

Background

Along with the rapid development of social economy, the power consumption demand is larger and larger, and when line faults occur and needs to be repaired or emergency power supply and the like, the problem of transmission bottleneck of an underground cable transmission line occurs. The construction of new lines is difficult due to the restriction of factors such as long period, limited capital and newly-built line planning space, environmental protection and the like. Therefore, from the perspective of sustainable development and energy conservation and emission reduction, in order to solve the contradiction between the power supply capacity requirement and the difficulty of building a new line, it becomes a feasible scheme to explore the potential of the existing power grid and dynamically increase the transmission capacity of the transmission line.

The decisive factor for restricting the transmission capacity of the cable is the maximum allowable working temperature of the cable insulation material for a long time, namely the core temperature of the cable, so that the core temperature value cannot exceed the long-term tolerance temperature of the insulation material (the XLPE is 90 ℃) to ensure the service life of the cable. Once the core temperature exceeds the limit value, the aging of the cable is accelerated, and even the cable is possibly thermally broken down due to local overheating, so that a cable accident is caused. The existing method for measuring the running temperature of the cable mainly adopts optical fiber or grating sensors which are arranged along the length direction of the cable to measure the temperature of the outer surface of the cable, establishes an equivalent circuit from the outer surface of the cable to a conductor and calculates the actual temperature of an inner conductor during the running of the cable.

Disclosure of Invention

The invention aims to provide the cable insulation operation temperature on-line monitoring device which can measure the operation temperature of the whole cable only by being arranged on the grounding wires at the two ends of the operation line cable, and the test result is not interfered by the ambient temperature, so as to overcome the defects of the prior art.

The technical scheme adopted by the invention for realizing the purpose is as follows:

an on-line monitoring device for the insulation operating temperature of a cable comprises:

power supply: the power frequency alternating current power supply device is used for providing power frequency alternating current required by work and providing working voltage for the signal source module and the signal processing module.

A signal source module: used for sending out pulse signals with certain amplitude and frequency.

The sensing module: for receiving the pulse signal from the signal source module, typically, a high-frequency current sensor may be used, and a capacitive sensor may also be used.

A synchronization module: for synchronizing the time of the signal source module and the time of the sensing module, a GPS module may be typically used.

The signal processing module: used for receiving the reflected signal, performing A/D conversion on the signal and outputting a digital signal.

A transmission module: the pulse signal transmission device is used for transmitting pulse signals and connecting a signal source module or a sensing module with a signal processing module, and the transmission module adopts a communication cable or an optical fiber. When the optical fiber is used as a signal transmission medium, the device needs to be provided with a photoelectric conversion module for converting the pulse signal received by the sensing module into an optical signal. Typically, when the photoelectric conversion module is used for sending signals, the photoelectric conversion module is connected with the signal source module and the signal processing module; when the photoelectric conversion module is used for receiving signals, the photoelectric conversion module is connected with the sensing module and the signal processing module.

A communication module: the data analysis carrier is used for transmitting the pulse signals sent by the signal source module and the digital signals output by the signal processing module to the data analysis carrier. And 4G or 5G communication networks are adopted for communication.

Data analysis vehicle: the system is used for extracting the digital signals and obtaining the running temperature information of the cable through the relation function.

The temperature measurement principle of the invention is as follows: the correlation between the propagation speed of the pulse signal in the cable insulation and the insulation temperature is used. Given that the cable run length L is constant, the transmission speed v is inversely proportional to the transmission time t. If the insulating material is constant, T is at the reference temperature₀Time of flight, time of flight t_T0 can be measured, the transmission speedDegree v_T0Can be obtained.

v_T0＝L÷t_T0(1)

The temperature of the insulating layer rises and the temperature T is high when the cable runs_xWith a reference temperature T₀The relationship between the transmission speed and the transmission time is as follows:

v_T0×t_T0＝v_Tx×t_Tx(2)

by acquiring the pulse signal sent by the signal source module and the time for the sensing module to receive the pulse signal, the high-temperature T can be obtained_xTime of flight t_Tx. From formula (2):

v_Tx＝v_T0×t_T0÷t_Tx(3)

v obtained by the formula (3)_TxThe temperature T of the cable insulation layer can be obtained by utilizing the corresponding relation between the propagation speed and the temperature_x。

The correspondence of the propagation speed to the temperature includes:

for oil impregnated paper insulated power cables:

V_TX＝V_T0×(1.0318-0.00125T_X) (4)

for cross-linked polyethylene (XLPE) insulated power cables:

the invention has the following beneficial effects:

the technical principle of the on-line monitoring of the cable insulation operation temperature is that the cable insulation operation temperature is obtained by monitoring the transmission speed of the pulse signal in the cable by utilizing the correlation between the propagation speed of the pulse signal in the cable insulation and the insulation temperature, so that the influence of the interference of the environment temperature on the direct measurement of the outer surface temperature of the cable by the conventional device is avoided, the measurement accuracy is improved, and meanwhile, the device is arranged at two ends of the cable, so that the on-site applicability is strong.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of the structure of the apparatus of the present invention;

fig. 2 is a schematic diagram of an embodiment of the present invention.

Fig. 3 is a flow chart of a method of operation of an embodiment of the present invention.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in fig. 1 to 3, the cable insulation operation temperature on-line monitoring device of the present invention includes:

and the power supply is used for providing power frequency alternating current required by work and providing working voltage for the signal source module and the signal processing module.

And the signal source module is used for sending out pulse signals with certain amplitude and frequency.

And the sensing module is used for receiving the pulse signal sent by the signal source module, and typically, a high-frequency current sensor can be adopted, and a capacitance sensor can also be adopted.

And the synchronization module is used for synchronizing the time of the signal source module and the time of the sensing module, and a GPS module can be adopted typically.

And the signal processing module is used for receiving the reflected signal, carrying out A/D conversion on the signal and outputting a digital signal.

And the transmission module is used for transmitting pulse signals and connecting the signal source module or the sensing module with the signal processing module. The transmission module adopts communication cables or optical fibers. When the optical fiber is used as a signal transmission medium, the device needs to be provided with a photoelectric conversion module for converting the pulse signal received by the sensing module into an optical signal. Typically, when the photoelectric conversion module is used for sending signals, the photoelectric conversion module is connected with the signal source module and the signal processing module; when the photoelectric conversion module is used for receiving signals, the photoelectric conversion module is connected with the sensing module and the signal processing module.

And the communication module is used for transmitting the pulse signals sent by the signal source module and the digital signals output by the signal processing module to the data analysis carrier. And 4G or 5G communication networks are adopted for communication.

And the data analysis carrier is used for extracting the digital signals and obtaining the running temperature information of the cable through the relation function.

The working method of one embodiment of the invention is as follows:

the power supply, the synchronization module, the sensing module, the transmission module, the signal processing module and the communication module are combined to form a detection pulse signal input unit, the signal source module is installed on a grounding wire at one end of a cable line, the power supply, the synchronization module, the sensing module, the transmission module, the signal processing module and the communication module are combined, the transmission module and the communication module are combined to form a detection pulse signal output unit, and the sensing module is installed on a grounding wire at the other end of the cable line.

When the device works, the power supply supplies power to the signal source module, the signal source module sends out pulse signals with preset width at regular intervals, and the transmission module, the signal processing module and the communication module send out the time t of the pulse signals₁Information such as pulse amplitude A, pulse width a and the like is sent to a data analysis carrier, a pulse signal is transmitted along a cable line with the length of L through a cable grounding wire, a sensing module detects the pulse signal reaching the other end of the cable line, and a transmission module, a signal processing module and a communication module receive the time t of the pulse signal₂Information such as pulse amplitude B, pulse width B and the like are sent to the data analysis carrier. Synchronization Module ensure t₁、t₂Are consistent. Data analysis carrier calculates the transmission time t of pulse in cable line_x＝t₂-t₁And obtaining a transmission speed v using the formula (1)_TxAnd obtaining the running temperature information of the cable by using a relation function of the temperature and the transmission speed.

The device records parameters of pulse amplitude A, pulse width a, pulse amplitude B and pulse width B for pulse pairing, and ensures that pulse signals sent out from one end of a cable line correspond to pulse signals received from the other end one by one. The corresponding method for sending out the pulse signal and receiving the pulse signal is as follows: the pulse amplitude A is larger than the pulse amplitude B, and the pulse width a is smaller than the pulse width B.

The working method of the device of the embodiment of the invention comprises the following steps:

1. the power supply is switched on, and the device is in a working state;

2. the synchronization module synchronizes time of the signal source module and the sensing module;

3. the signal source module sends out pulse signals, and the data analysis carrier records the time t for sending out the pulse signals₁；

4. The sensing module detects the pulse signal, and the data analysis carrier records the time t of sending the pulse signal₂；

5. Calculating the pulse signal transmission time t by the data analysis carrier_xVelocity v of transmission_Tx；

6. And obtaining the running temperature information of the cable by using a relation function of the temperature and the transmission speed.