An SF6 gas online pressure monitoring system with trend alarm function

Abstract

The present invention discloses an SF6 gas online pressure monitoring system with a trend alarm function. The system adopts a distributed structure, including an interval layer, a station control layer and a monitoring center layer. The interval layer and the station control layer are connected by a communication device one signal, and the station control layer and the monitoring center layer are connected by a communication device two signal; the interval layer includes a data collector and an SF6 pressure sensor for collecting pressure data of the SF6 gas chamber, and the data collector is used to convert the pressure data into a digital signal and send it up; the station control layer includes an in-station monitoring host for obtaining data uploaded by the data collector and uploading the obtained data to the monitoring center layer; the monitoring center layer includes a monitoring center host for obtaining data uploaded by the station control layer, and viewing the real-time data of SF6 gas pressure at any terminal of the monitoring center layer. The present invention can monitor the SF6 gas chamber pressure data online in real time and accurately, and has functions such as trend alarm, data statistical analysis, and report management.

Description

Technical Field

[0001] The invention relates to a pressure monitoring system, in particular to an SF6 gas online pressure monitoring system with a trend alarm function. Background Art

[0002] SF6 gas has been widely used in power systems for its excellent insulation and arc extinguishing performance, and has become almost the only insulation and arc extinguishing medium used in medium-voltage, high-voltage and ultra-high-voltage switches. Therefore, the accuracy and timeliness of the pressure data monitoring of the SF6 gas chamber directly affects the safe operation of the equipment.

[0003] At present, most of the SF6 gas density relays in GIS substations do not have remote transmission function, and mainly rely on regular recording by operation and maintenance personnel to monitor the SF6 gas pressure in the GIS gas chamber. This mode causes the following problems:

[0004] 1) Faults caused by regular transcription are not discovered in time;

[0005] 2) It is impossible to obtain the trend of chamber pressure changes, discover potential faults at an early stage, and take timely countermeasures when the fault expands;

[0006] 3) When a leak is found in the air chamber, the frequency of transcription needs to be greatly increased, even every hour;

[0007] 4) Manual transcription can no longer meet work needs.

[0008] Therefore, it is necessary to provide a SF6 gas online pressure monitoring system with more comprehensive functions.

[0009] The invention patent with publication number CN104701821B discloses a SF6 circuit breaker monitoring system, including a DC power supply, a first intermediate relay, a second intermediate relay, an SF6 density controller and a microcomputer protection and measurement control device. When the SF6 density controller detects that the SF6 gas pressure value in the monitored SF6 circuit breaker is lower than the pressure alarm setting value, the first group of normally open contacts of the SF6 density controller is closed, the coil of the first intermediate relay is energized, the normally open contacts of the first intermediate relay are closed, and the microcomputer protection and measurement control device outputs a low pressure alarm signal; when the SF6 density controller detects that the SF6 gas pressure value in the monitored SF6 circuit breaker is lower than the pressure lock action setting value, the second group of normally open contacts of the SF6 density controller is closed, the coil of the second intermediate relay is energized, the normally open contacts of the second intermediate relay are closed, and the microcomputer protection and measurement control device outputs a low pressure lock signal. This invention can only detect the SF6 gas pressure value in the SF6 circuit breaker, and does not have an alarm function.

[0010] The utility model patent with the authorization announcement number CN207488257U discloses an online monitoring system for SF6 gas in a substation, which is used to solve the problem of online monitoring of SF6 gas in a substation. It includes a main control module, a monitoring module, an automatic matching air conditioning control module, an indoor dehumidification module, a fan control module, a remote monitoring background, and a real-time monitoring module for mobile devices. The utility model can realize unattended operation of substations and GIS switch rooms, improve management efficiency, and improve the maintenance system. The monitoring center is centered on the database, which can not only monitor the environment and equipment operation status of substations and switch rooms in real time, but also conduct statistics and analysis based on previous environment and equipment operation data to provide managers with decision-making basis. However, the utility model can only perform online monitoring of SF6 gas in a single substation, and does not have a trend alarm function. Summary of the invention

[0011] In view of this, the purpose of the present invention is to address the deficiencies in the prior art and provide an SF6 gas online pressure monitoring system with a trend alarm function, which can monitor the SF6 gas chamber pressure data online in real time and accurately, and has functions such as trend alarm, data statistical analysis, and report management.

[0012] In order to achieve the above object, the present invention adopts the following technical solutions:

[0013] An SF6 gas online pressure monitoring system with a trend alarm function, the system adopts a distributed structure, including an interval layer, a station control layer and a monitoring center layer, the interval layer and the station control layer are connected by a communication device one signal, and the station control layer and the monitoring center layer are connected by a communication device two signal;

[0014] The spacer layer includes a data collector and an SF6 pressure sensor installed on each SF6 gas chamber, the SF6 pressure sensor is used to collect pressure data of the SF6 gas chamber, and the data collector is used to convert the pressure data into a digital signal and send it up;

[0015] The station control layer includes an in-station monitoring host, which is used to obtain the data uploaded by the data collector and upload the obtained data to the monitoring center layer;

[0016] The monitoring center layer includes a monitoring center host, which is used to obtain the data uploaded by the station control layer. On any terminal in the monitoring center layer, open the browser, enter the corresponding IP, and then view the real-time data of the SF6 gas pressure of the corresponding IP.

[0017] The data collector receives the analog signal from the SF6 pressure sensor and converts the analog signal into a digital signal. The Modbus communication protocol is used to connect the data to the station control layer signal through a communication device.

[0018] The communication device 1 is used to send the pressure data collected by the data collector to the monitoring host in the station in a digital protocol.

[0019] The in-station monitoring host is arranged in the control room of the substation. The in-station monitoring host is installed with SF6 online pressure monitoring software. It receives pressure data from the data collector through communication equipment and provides a human-computer dialogue window to the user. It also serves as a host for data storage / analysis.

[0020] The communication device 2 is used to transmit the data published by the monitoring host in the station to the monitoring center host.

[0021] The in-station monitoring host is equipped with a system main program, which includes the following subprograms: real-time monitoring, data storage and analysis, low pressure routine alarm, low pressure trend alarm, report management, curve query, parameter setting, and personnel management.

[0022] The monitoring center layer can refer to various pressure data and receive alarm information in real time.

[0023] The communication device 1 is connected to the spacer layer and the station control layer by a network cable connection, an optical fiber connection, or a wireless network connection.

[0024] The communication device 2 is connected to the station control layer and the monitoring center layer by a network cable connection, an optical fiber connection, or a wireless network connection.

[0025] The beneficial effects of the present invention are:

[0026] The present invention aims at the current method of monitoring the pressure of SF6 gas chambers, which is mainly to remove the old density relay, install a density relay with a remote transmission function, and collect and monitor the data of the density relay in real time through a set of monitoring software, which has the disadvantages of high cost, low fault tolerance and inability to realize trend alarm. The present invention provides an SF6 gas online pressure monitoring system with trend alarm function. The system adopts a distributed structure, including an interval layer, a station control layer and a monitoring center layer. The interval layer and the station control layer are connected by a communication device one signal, and the station control layer and the monitoring center layer are connected by a communication device two signal; the interval layer includes a data collector and an SF6 pressure sensor installed on each SF6 gas chamber, the SF6 pressure sensor is used to collect the pressure data of the SF6 gas chamber, and the data collector is used to convert the pressure data into a digital signal and send it up; the station control layer includes an in-station monitoring host, which is used to obtain the data uploaded by the data collector, and upload the obtained data to the monitoring center layer; the monitoring center layer includes a monitoring center host, which is used to obtain the data uploaded by the station control layer. On any terminal of the monitoring center layer, a browser is opened and the corresponding IP is entered to view the real-time data of the SF6 gas pressure of the corresponding IP.

[0027] The main workflow and usage of this system are as follows:

[0028] After starting the system, the "SF6 pressure sensor" installed on the SF6 gas chamber converts the pressure signal into a resistance value and further processes it into a 4...20mA or 0-5V signal, and connects it to the "analog quantity collector" through a signal cable. Please refer to the attached working principle diagram of the "SF6 pressure sensor". Figure 6

[0029] The "analog quantity collector" collects the data from the "SF6 pressure sensor", converts it into a digital signal after internal calculation, and sends it to the "station control layer host" through the "communication device 1" in the form of modbus protocol.

[0030] After receiving the pressure signals of the SF6 gas chambers in the station from the "analog collector", the "station monitoring host" stores, analyzes and counts these data. It realizes functions such as real-time monitoring, parameter setting, low pressure alarm, trend alarm, curve viewing, report management, and Web publishing. For the system software function block diagram of the "station control layer host", please refer to the attached Figure 2 For the system software flow of the "station control layer host", please refer to the attached Figure 3 .

[0031] The "station monitoring host" not only monitors the SF6 gas chamber pressure data in the station, but also has the function of WEB publishing. When the "station monitoring host" is started, you can start the browser on other terminal devices in the network and output the specified IP address to view the SF6 pressure data in the station in real time. Therefore, as long as the browser is installed on the "monitoring center host", the real-time data in the substation can be viewed. The "monitoring center host" only has the function of viewing, and does not have the function of modifying parameters.

[0032] In general, this system has the following advantages:

[0033] 1) Reduce transformation cost: The price of SF6 pressure sensor is much lower than that of remote density relay, so the transformation cost is lower;

[0034] 2) High reliability: After installing the pressure sensor, the same measuring point has two relatively independent monitoring instruments (SF6 density relay and pressure sensor). If any measuring device fails, it will not affect other devices, so it has higher reliability.

[0035] 3) Implementation of trend alarm function: By analyzing the historical data collected by the pressure sensor, the change rate can be set according to the time period. When the change rate exceeds the set value (but does not trigger the set pressure alarm value), the system sends a trend alarm signal, which can detect the hidden danger of air chamber leakage at an early stage.

[0036] 4) With Web publishing function, any terminal in the same network can query the SF6 gas chamber pressure data in the station through a browser (such as IE) by simply entering a specific IP address.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural block diagram of the present invention;

[0039] Figure 2 It is a functional block diagram of the main program of the system of the present invention;

[0040] Figure 3 It is a flow chart of the main program of the system of the present invention;

[0041] Figure 4 This is a schematic diagram of the SF6 pressure monitoring trend alarm in the present invention;

[0042] Figure 5 It is a structural diagram of the SF6 pressure sensor in the present invention;

[0043] Figure 6 It is the principle diagram of the SF6 pressure sensor in the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0045] See attached Figure 1-6 , an SF6 gas online pressure monitoring system with trend alarm function, the system adopts a distributed structure, including an interval layer, a station control layer and a monitoring center layer, the interval layer and the station control layer are connected by a communication device one signal, and the station control layer and the monitoring center layer are connected by a communication device two signal;

[0046] The spacer layer includes a data collector and an SF6 pressure sensor installed on each SF6 gas chamber, the SF6 pressure sensor is used to collect pressure data of the SF6 gas chamber, and the data collector is used to convert the pressure data into a digital signal and send it up;

[0047] The station control layer includes an in-station monitoring host, which is used to obtain the data uploaded by the data collector and upload the obtained data to the monitoring center layer;

[0048] The monitoring center layer includes a monitoring center host, which is used to obtain the data uploaded by the station control layer. On any terminal in the monitoring center layer, open the browser, enter the corresponding IP, and then view the real-time data of the SF6 gas pressure of the corresponding IP.

[0049] The data collector receives the analog signal from the SF6 pressure sensor and converts the analog signal into a digital signal. The Modbus communication protocol is used to connect the data to the station control layer signal through a communication device.

[0050] The communication device 1 is used to send the pressure data collected by the data collector to the monitoring host in the station in a digital protocol.

[0051] The in-station monitoring host is arranged in the control room of the substation. The in-station monitoring host is installed with SF6 online pressure monitoring software. It receives pressure data from the data collector through communication equipment and provides a human-computer dialogue window to the user. It also serves as a host for data storage / analysis.

[0052] The communication device 2 is used to transmit the data published by the monitoring host in the station to the monitoring center host.

[0053] like Figure 2 As shown, the in-station monitoring host has a built-in system main program, which includes the following sub-programs: real-time monitoring, data storage and analysis, low pressure routine alarm, low pressure trend alarm, report management, curve query, parameter setting, and personnel management.

[0054] The monitoring center layer can refer to various pressure data and receive alarm information in real time.

[0055] The communication device 1 is connected to the spacer layer and the station control layer by a network cable connection. Of course, an optical fiber connection or a wireless network connection can also be used.

[0056] The communication device 2 is connected to the station control layer and the monitoring center layer by a network cable connection. Of course, an optical fiber connection or a wireless network connection can also be used.

[0057] The main workflow and usage of this system are as follows:

[0058] After starting the system, the "SF6 pressure sensor" installed on the SF6 gas chamber converts the pressure signal into a resistance value and further processes it into a 4...20mA or 0-5V signal, and connects it to the "analog quantity collector" through a signal cable. Please refer to the attached working principle diagram of the "SF6 pressure sensor". Figure 6

[0059] The "analog quantity collector" collects the data from the "SF6 pressure sensor", converts it into a digital signal after internal calculation, and sends it to the "station control layer host" through the "communication device 1" in the form of modbus protocol.

[0060] After receiving the pressure signals of the SF6 gas chambers in the station from the "analog collector", the "station monitoring host" stores, analyzes and counts these data. It realizes functions such as real-time monitoring, parameter setting, low pressure alarm, trend alarm, curve viewing, report management, and Web publishing. For the system software function block diagram of the "station control layer host", please refer to the attached Figure 2 For the system software flow of the "station control layer host", please refer to the attached Figure 3 .

[0061] The "station monitoring host" not only monitors the SF6 gas chamber pressure data in the station, but also has the function of WEB publishing. When the "station monitoring host" is started, you can start the browser on other terminal devices in the network and output the specified IP address to view the SF6 pressure data in the station in real time. Therefore, as long as the browser is installed on the "monitoring center host", the real-time data in the substation can be viewed. The "monitoring center host" only has the function of viewing, and does not have the function of modifying parameters.

[0062] The trend alarm function can be realized on the "station monitoring host". The principle of the trend alarm is as follows Figure 4 As shown: the system sampling time axis is divided into according to the sampling period, the starting point is t0, the system sampling period is set to s, the trend alarm sampling period is set to s1, the system sampling value at t0 is V0, and the system trend alarm change rate is set to d. It can be seen that the end point of the first trend alarm sampling period is t0+s1, and the value at this moment is V(t0+s1); by analogy, the end point of the second trend alarm sampling period is t1+s1, and the value at this moment is V(t1+s1); the end point of the third trend alarm sampling period is t2+s1, and the value at this moment is V(t2+s1); the end point of the n+1 trend alarm sampling period is tn+s1, and the value at this moment is V(tn+s1). At this time, the change amount △V of the first and last time of the trend alarm period is calculated, and the corresponding change rate d can be obtained by comparing △V with the value Vn (n=0,1,…) of the first time of the alarm period. When the d value is greater than the custom value set by the system, the trend alarm signal can be activated.

[0063] In the system, the sampling period s, trend alarm sampling period s1, s1=n*s (n≥1), and trend alarm change rate constant d are all parameters that can be freely set.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. An SF6 gas online pressure monitoring system with trend alarm function, characterized in that: The system adopts a distributed structure, including an interval layer, a station control layer and a monitoring center layer. The interval layer and the station control layer are connected by a communication device 1 signal, and the station control layer and the monitoring center layer are connected by a communication device 2 signal. The spacer layer includes a data collector and an SF6 pressure sensor installed on each SF6 gas chamber, the SF6 pressure sensor is used to collect pressure data of the SF6 gas chamber, and the data collector is used to convert the pressure data into a digital signal and send it up; The station control layer includes an in-station monitoring host, which is used to obtain the data uploaded by the data collector and upload the obtained data to the monitoring center layer; The monitoring center layer includes a monitoring center host, which is used to obtain the data uploaded by the station control layer. On any terminal in the monitoring center layer, open the browser, enter the corresponding IP, and then view the real-time data of the SF6 gas pressure of the corresponding IP; The data collector receives the analog signal from the SF6 pressure sensor, converts the analog signal into a digital signal, and uses the Modbus communication protocol to connect with the station control layer signal through the communication device 1; The communication device 1 is used to send the pressure data collected by the data collector to the monitoring host in the station in a digital protocol; The station monitoring host is arranged in the substation control room, and the station monitoring host is installed with SF6 online pressure monitoring software, which receives pressure data from the data collector through the communication equipment, and provides a human-computer dialogue window to the user, and also serves as a host for data storage / analysis; The station monitoring host has a built-in system main program, which includes the following subprograms: real-time monitoring, data storage and analysis, low pressure routine alarm, low pressure trend alarm, report management, curve query, parameter setting, and personnel management; The specific operation of realizing trend alarm on the monitoring host in the station is as follows: divide the system sampling time axis into sampling periods, with the starting point as t0, the system sampling period as s, the trend alarm sampling period as s1, the system sampling value at time t0 as V0, and the trend alarm change rate of the system as d. It can be concluded that the end point of the first trend alarm sampling period is t0+s1, and the value at this moment is V(t0+s1); by analogy, the end point of the second trend alarm sampling period is t1+s1, and the value at this moment is V( t1+s1); the end point of the third trend alarm sampling period is t2+s1, and the value at this moment is V(t2+s1); the end point of the n+1th trend alarm sampling period is tn+s1, and the value at this moment is V(tn+s1). At this time, the change △V between the first and last time of the trend alarm period is calculated, and the corresponding change rate d can be obtained by comparing △V with the value Vn (n=0,1,…) of the first time of the alarm period. When the d value is greater than the custom value set by the system, the trend alarm signal can be activated.

2. The SF6 gas online pressure monitoring system with trend alarm function according to claim 1 is characterized in that: The communication device 2 is used to transmit the data published by the monitoring host in the station to the monitoring center host.

3. The SF6 gas online pressure monitoring system with trend alarm function according to claim 2 is characterized in that: The monitoring center layer can refer to various pressure data and receive alarm information in real time.

4. The SF6 gas online pressure monitoring system with trend alarm function according to claim 1 is characterized in that: The communication device 1 is connected to the spacer layer and the station control layer by a network cable connection, an optical fiber connection, or a wireless network connection.

5. The SF6 gas online pressure monitoring system with trend alarm function according to claim 4 is characterized in that: The communication device 2 is connected to the station control layer and the monitoring center layer by a network cable connection, an optical fiber connection, or a wireless network connection.

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