Real-time intelligent monitoring system for 35kV outdoor cable intermediate joint based on Internet of Things

Abstract

The invention relates to the technical field of real-time intelligent monitoring of cable intermediate joints, and discloses a real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things. Comprising a fluorescent optical fiber temperature sensor installed above a cable intermediate joint, a partial discharge on-line monitoring sensor installed on a well wall of the cable intermediate joint, electrical equipment and an Internet of Things gateway containing a data acquisition unit, and the fluorescent optical fiber temperature sensor is electrically connected with a photoelectric conversion module and an analysis module. The cable intermediate joint well is installed outdoors, so that the water accumulation phenomenon exists. A photoelectric liquid level sensor is installed on a well wall of a cable intermediate joint to achieve measurement and monitoring of accumulated water, and the water level of the accumulated water is transmitted to a gateway of the internet of things through 4-20 mA; an infrared network camera is installed on a well wall of a cable intermediate joint, monitors real-time pictures of the intermediate joint in real time, is connected to a gateway of the internet of things through an RJ45 network port, and transmits real-time video data to the gateway of the internet of things.

Description

Technical Field

[0001] The present invention relates to the technical field of real-time intelligent monitoring of cable intermediate joints, and in particular to a real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things. Background Art

[0002] There are many 35kV outdoor cables in the wind farm, and the cable intermediate joints are widely distributed, far away, and the environment in the outdoor cable well is complex. The temperature of the cable joints is heated due to crimping, insulation degradation and other problems. The heat further accelerates the expansion of defects and eventually leads to accidents. Partial discharge of cables is a common fault in cable operation. Further development of partial discharge will cause insulation damage and cause accidents. Since the cable wells are distributed on both sides of the road and power cannot be provided, the current wind farm operation and maintenance personnel conduct on-site inspections every month. This method has great limitations, there are monitoring blind spots, and the hidden dangers of the cable intermediate joints cannot be discovered in time. In addition, the personnel need to open the cable well cover every time for inspection, which is time-consuming and laborious. Most of the time is spent on vehicle commuting. The road conditions in mountainous wind farms are poor and the traffic risks are relatively high.

[0003] To address the above issues, we provide a real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things. By adding temperature sensors, partial discharge online monitoring sensors, and cameras to monitor the online status of cable intermediate joints in real time, we continuously monitor key parameters such as cable joint temperature, insulation status, and partial discharge to prevent power system accidents caused by joint failures and ensure the stable operation of cable intermediate joints. Summary of the invention

[0004] The purpose of the present invention is to provide a real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a real-time intelligent monitoring system for a 35kV outdoor cable intermediate joint based on the Internet of Things, comprising a fluorescent fiber optic temperature sensor installed above the cable intermediate joint, a partial discharge online monitoring sensor installed on the wall of the cable intermediate joint well, electrical equipment, and an Internet of Things gateway containing a data acquisition unit, wherein the fluorescent fiber optic temperature sensor is electrically connected to a photoelectric conversion module and an analysis module respectively; the electrical equipment is signal-connected to the cable intermediate joint, the cable intermediate joint is signal-connected to an ultra-high frequency sensor, the partial discharge online monitoring sensor is electrically connected to an antenna sensor, and receives ultra-high frequency electromagnetic waves radiated during partial discharge through the antenna sensor.

[0006] Preferably, the fluorescent fiber optic temperature sensor measures the direct temperature of the measured intermediate joint in real time, and receives it through the photoelectric conversion module. The analysis module parses the optical signal containing temperature information transmitted back by the fluorescent optical fiber, and transmits the temperature signal to the Internet of Things gateway through the RS485 interface according to the ModbusRTU communication protocol.

[0007] Preferably, the electrical equipment is used to evaluate the local discharge situation of the intermediate joint by using the electromagnetic wave signal stimulated by its internal partial discharge current, and to receive the ultra-high frequency electromagnetic waves radiated during the local discharge process through the antenna sensor, thereby realizing the detection of local discharge. In the process of evaluating the local discharge situation of the intermediate joint, the ultra-high frequency sensor is used to monitor the electrical equipment.

[0008] Preferably, the system further comprises: a photoelectric liquid level sensor installed on the wall of the cable intermediate joint well, and an infrared network camera installed on the wall of the cable intermediate joint well.

[0009] Preferably, the photoelectric liquid level sensor is connected to the Internet of Things gateway via an electrical signal, and the infrared network camera is connected to the Internet of Things gateway via an RJ45 network port.

[0010] Preferably, the Internet of Things gateway is electrically connected to a monitoring center via a communication network, and the monitoring center is electrically connected to a user interface. Specifically, a data acquisition unit transmits collected data to the monitoring center. The Internet of Things gateway supports a cellular network, and transmits the collected data to the Internet of Things background through a telecommunications network through a built-in SIM card. The monitoring center processes and analyzes the collected data, determines the health status of the cable connector through a preset algorithm, and issues an alarm when an abnormality is found. On the other hand, the user interface is an operating interface of the system, allowing users to view real-time data, historical data and alarm records.

[0011] The present invention provides a real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things. It has the following beneficial effects:

[0012] (1) The present invention realizes the detection of partial discharge by installing a partial discharge online monitoring sensor on the wall of the cable intermediate joint well and receiving the ultra-high frequency electromagnetic waves radiated during the partial discharge process through the antenna sensor. The insulation strength and breakdown field strength of the insulator of the power equipment are very high. When the local discharge occurs in a very small range, the breakdown process will be very fast, and a partial discharge pulse current with a very steep rising edge will be generated during the breakdown process. Its rise time is in the ns level, and it excites electromagnetic wave signals with a frequency of up to several GHz. The partial discharge situation of the intermediate joint is evaluated by using an ultra-high frequency sensor to monitor the electromagnetic wave signal excited by the partial discharge current inside the electrical equipment. The partial discharge signal is transmitted to the Internet of Things gateway through the RS485 interface according to the Modbus RTU communication protocol.

[0013] (2) The present invention uses the fact that the cable intermediate joint well is installed outdoors and there is water accumulation. A photoelectric liquid level sensor is installed on the wall of the cable intermediate joint well to measure and monitor the water accumulation, and the water level is transmitted to the Internet of Things gateway through 4 to 20mA; an infrared network camera is installed on the wall of the cable intermediate joint well to monitor the real-time picture of the intermediate joint in real time, and is connected to the Internet of Things gateway through the RJ45 network port to transmit the real-time video data to the Internet of Things gateway. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the real-time intelligent monitoring system of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] A preferred embodiment of the real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things provided by the present invention is as follows: Figure 1As shown: A real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things, including a fluorescent fiber optic temperature sensor installed above the cable intermediate joint, a partial discharge online monitoring sensor installed on the wall of the cable intermediate joint well, electrical equipment, and an Internet of Things gateway containing a data acquisition unit. The fluorescent fiber optic temperature sensor is electrically connected to a photoelectric conversion module and an analysis module respectively. The fluorescent fiber optic temperature sensor measures the direct temperature of the measured intermediate joint in real time and receives it through the photoelectric conversion module. The analysis module parses the optical signal containing temperature information sent back by the fluorescent optical fiber, and transmits the temperature signal to the Internet of Things gateway through the RS485 interface according to the Modbus RTU communication protocol;

[0019] The electrical equipment is connected to the cable intermediate joint signal, the cable intermediate joint signal is connected to an ultra-high frequency sensor, the partial discharge online monitoring sensor is electrically connected to an antenna sensor, and receives the ultra-high frequency electromagnetic waves radiated during the partial discharge process through the antenna sensor;

[0020] It is further obtained that the electrical equipment is used to evaluate the partial discharge condition of the intermediate joint by using the electromagnetic wave signal stimulated by the internal partial discharge current, and the ultra-high frequency electromagnetic wave radiated during the partial discharge process is received by the antenna sensor, thereby realizing the detection of partial discharge. In the process of evaluating the partial discharge condition of the intermediate joint, the ultra-high frequency sensor is used to monitor the electrical equipment;

[0021] By installing partial discharge online monitoring sensors on the wall of the cable intermediate joint well, these sensors can receive the ultra-high frequency electromagnetic waves radiated during the partial discharge process through the antenna. This process enables us to effectively detect the partial discharge phenomenon. The insulators of power equipment usually have high dielectric strength and breakdown field strength, which means that when the partial discharge occurs in a very small area, the breakdown process will be very rapid. In this process, a partial discharge pulse current with a very steep rising edge will be generated. The rise time of these pulse currents is usually at the nanosecond level and can excite electromagnetic wave signals with a frequency of up to several GHz. By using ultra-high frequency sensors to monitor the electromagnetic wave signals excited by the partial discharge current inside the electrical equipment, we can evaluate and analyze the partial discharge of the intermediate joint. Finally, according to the Modbus RTU communication protocol, the partial discharge signal is transmitted to the IoT gateway through the RS485 interface, thereby realizing remote monitoring and management of data.

[0022] It is further obtained that the system also includes: a photoelectric liquid level sensor installed on the wall of the cable intermediate joint well, and an infrared network camera installed on the wall of the cable intermediate joint well; the photoelectric liquid level sensor is connected to the Internet of Things gateway through an electrical signal, and the infrared network camera is connected to the Internet of Things gateway through an RJ45 network port;

[0023] The present invention proposes an effective solution to the problem of water accumulation in view of the actual situation that the cable intermediate joint well is installed outdoors. In order to achieve the measurement and monitoring of water accumulation, the present invention specially installs a photoelectric liquid level sensor on the wall of the cable intermediate joint well. This sensor can accurately detect the water level in the well and transmit the measurement data to the Internet of Things gateway through a standard 4 to 20 mA signal. In this way, managers can understand the water accumulation in the well in real time, so as to take corresponding measures in time to ensure the safe operation of the cable.

[0024] In addition, in order to further improve the safety and reliability of the cable intermediate joint well, the present invention also installs an infrared network camera on the well wall. This camera can monitor the real-time picture of the cable intermediate joint in real time and connect to the Internet of Things gateway through the RJ45 network port. In this way, managers can view the real-time video data in the well at any time to ensure the normal operation of the cable intermediate joint. This real-time monitoring system not only improves the safety of the cable intermediate joint well, but also provides maintenance personnel with a convenient remote monitoring method, greatly improving work efficiency.

[0025] It is further obtained that the Internet of Things gateway is electrically connected to the monitoring center through the communication network, and the monitoring center is electrically connected to the user interface. Specifically, the data acquisition unit transmits the collected data to the monitoring center. The Internet of Things gateway supports the cellular network. Through the built-in SIM card, the collected data is transmitted to the Internet of Things background through the telecommunications network. The monitoring center processes and analyzes the collected data, determines the health status of the cable connector through a preset algorithm, and issues an alarm when an abnormality is found. On the other hand, the user interface is the system operation interface, allowing users to view real-time data, historical data and alarm records.

[0026] The present invention adopts the Internet of Things gateway, which has the functions of edge data collection, calculation, active reporting, data reading and writing, linkage control, I0 collection and control, etc. The collection protocol includes the standard Modbus protocol and a variety of common PLC protocols; it supports Modbus RTU / ICP and OPC UA protocol conversion and other functions, and supports the rapid access of common platforms such as Human Cloud, Alibaba Cloud, AWS, Huawei Cloud, etc. The hardware integrates DI, D0, AI, and RS485 to meet the needs of industrial field control and collection, and can also realize linkage control according to various collection point data or status.

[0027] In summary, the present invention has a real-time monitoring effect: the operating status of the cable joint can be understood at any time, and abnormalities can be discovered in time; it has a preventive maintenance effect: by monitoring data, maintenance can be performed before a fault occurs, reducing sudden faults; it has an efficiency improvement effect: automated monitoring reduces the workload of manual inspections and improves operation and maintenance efficiency. It has a data support effect: it provides a large amount of operating data, supports more accurate status assessment and decision-making, and realizes continuous monitoring of key parameters such as temperature, insulation status, partial discharge, etc. of the cable joint, so as to prevent power system accidents caused by joint failures and ensure the purpose of stable operation of the cable intermediate joint.

[0028] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things, including a fluorescent optical fiber temperature sensor installed above the cable intermediate joint, a partial discharge online monitoring sensor installed on the wall of the cable intermediate joint well, electrical equipment, and an Internet of Things gateway containing a data acquisition unit, characterized in that: The fluorescent optical fiber temperature sensor is electrically connected to a photoelectric conversion module and an analysis module respectively; the electrical equipment is signal-connected to the intermediate joint of the cable, the intermediate joint of the cable is signal-connected to an ultra-high frequency sensor, and the partial discharge online monitoring sensor is electrically connected to an antenna sensor, and receives ultra-high frequency electromagnetic waves radiated during the partial discharge process through the antenna sensor.

2. The real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things according to claim 1 is characterized in that: The fluorescent fiber optic temperature sensor measures the direct temperature of the measured intermediate joint in real time, and receives it through the photoelectric conversion module. The analysis module analyzes the optical signal containing temperature information sent back by the fluorescent optical fiber, and transmits the temperature signal to the Internet of Things gateway through the RS485 interface according to the Modbus RTU communication protocol.

3. The real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things according to claim 1 is characterized in that: The electrical equipment is used to evaluate the partial discharge situation of the intermediate joint using the electromagnetic wave signal stimulated by its internal partial discharge current, and to receive the ultra-high frequency electromagnetic waves radiated during the partial discharge process through the antenna sensor, thereby realizing the detection of partial discharge. In the process of evaluating the partial discharge situation of the intermediate joint, the ultra-high frequency sensor is used to monitor the electrical equipment.

4. The real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things according to claim 1 is characterized in that: The system also includes: a photoelectric liquid level sensor installed on the wall of the cable intermediate joint well, and an infrared network camera installed on the wall of the cable intermediate joint well.

5. The real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things according to claim 4 is characterized in that: The photoelectric liquid level sensor is connected to the Internet of Things gateway via an electrical signal, and the infrared network camera is connected to the Internet of Things gateway via an RJ45 network port.

6. The real-time intelligent monitoring system for 35kV outdoor cable intermediate joints based on the Internet of Things according to claim 1 is characterized in that: The Internet of Things gateway is electrically connected to a monitoring center through a communication network, and the monitoring center is electrically connected to a user interface. Specifically, a data acquisition unit transmits the collected data to the monitoring center. The Internet of Things gateway supports a cellular network. Through a built-in SIM card, the collected data is transmitted to the Internet of Things background through a telecommunications network. The monitoring center processes and analyzes the collected data, determines the health status of the cable connector through a preset algorithm, and issues an alarm when an abnormality is found. On the other hand, the user interface is an operating interface of the system, allowing users to view real-time data, historical data and alarm records.

Images