Internal heating early warning method and system for GIS device isolation switch

Abstract

An internal heating early warning method and system for a GIS device isolation switch. The heating early warning method comprises: acquiring an internal gas temperature, an original absolute pressure, and an ambient temperature of at least one GIS device isolation switch, and a three-phase load current of the isolation switch (S11); on the basis of the original absolute pressure, the ambient temperature, the gas temperature, and the three-phase load current, calculating a plurality of characteristic quantities of the pressure, wherein the plurality of characteristic quantities comprise a month-on-month growth quantity, a month-on-month growth rate, a year-on-year growth quantity, a year-on-year growth rate, an interphase difference quantity, an interphase difference rate, a growth quantity compared with an adjacent gas chamber, and a growth rate compared with the adjacent gas chamber (S21); making a severe heating anomaly determination, comprising: if an anomaly condition is satisfied, sending an early warning signal for a severe heating defect (S31); determining the correlation between the original absolute pressure and the ambient temperature, if the original absolute pressure is correlated to the ambient temperature, calculating the ambient compensation pressure after the ambient temperature is compensated, and using the ambient compensation pressure to recalculate the plurality of characteristic quantities of the pressure, and if the original absolute pressure is not correlated to the ambient temperature, determining the correlation between the pressure and the three-phase load current, and if the pressure is not correlated to the three-phase load current, making a general heating anomaly determination (S41); and making a general heating anomaly determination, comprising: if an anomaly condition is satisfied, sending an early warning signal for a general heating defect (S51).

Description

Internal heating warning method and system for GIS equipment isolation switch

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 26, 2023, with application number 202310758684.0. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power system equipment status monitoring, for example, to a method and system for early warning of internal heating of an isolating switch of a gas insulated switchgear (GIS) device. Background Art

[0003] Metal-enclosed gas-insulated switchgear (GIS) devices are increasingly used in power systems due to their compact structure, small footprint, high reliability, and strong environmental adaptability. The safe operation of GIS equipment is crucial to the stability of power systems. However, internal overheating caused by defects in components such as disconnector contacts is a significant factor affecting the safe operation of GIS equipment. Failure to promptly detect and address internal overheating can lead to disconnector failure, seriously impacting the normal operation of the power system. Therefore, developing a method and system that can accurately monitor internal overheating in GIS disconnectors in real time is of great practical value.

[0004] Chinese patent CN102508074A discloses a method for monitoring internal overheating faults in metal-enclosed gas-insulated switchgear. This method collects the sulfur hexafluoride (SF6) gas pressure and ambient temperature within each gas chamber. However, when the contacts heat up, a complex temperature field forms within the disconnector, resulting in a complex temperature distribution. Therefore, this method, using a fitting formula to infer the temperature, results in large errors and is not practical.

[0005] Chinese patent CN105203161B discloses a method, device, and system for online monitoring of the internal temperature of SF6 high-voltage electrical equipment. This method directly calculates the temperature using the Betty-Bridgeman equation of state, an empirical equation that describes the relationship between molar volume V, pressure p, and temperature T when a gas system is in equilibrium. However, when an internal heating fault occurs, the dynamic process is very complex, making it difficult to accurately describe using this equation.

[0006] Summary of the Invention

[0007] The present application provides a method and system for early warning of internal heating of an isolation switch of a GIS device, thereby improving the accuracy of the early warning.

[0008] This application provides a method for early warning of internal heating of an isolation switch of a GIS device, comprising:

[0009] Obtain the original absolute pressure, internal gas temperature, ambient temperature, and three-phase load current of at least one GIS device disconnector in the substation;

[0010] Based on the original absolute pressure, ambient temperature, internal gas temperature, and three-phase load current, multiple characteristic quantities of the pressure of each GIS equipment disconnect switch are calculated, including: month-on-month increase and month-on-month growth rate, year-on-year increase and year-on-year growth rate, phase difference and phase difference rate, and increase and growth rate compared to adjacent gas chambers.

[0011] Performing a severe heating abnormality judgment, including: when the value of at least one characteristic quantity among the month-on-month growth amount and month-on-month growth rate, year-on-year growth amount and year-on-year growth rate, phase-to-phase difference amount and phase-to-phase difference rate, growth amount compared to adjacent air chambers and growth rate compared to adjacent air chambers exceeds a preset severe heating threshold, a heating warning is issued, and a warning signal is issued indicating a severe heating defect in the air chamber of the GIS equipment isolation switch;

[0012] Time correlation judgment includes: calculating the time correlation between the original absolute pressure and the ambient temperature of each GIS equipment disconnect switch, and calculating the time correlation between the pressure and the three-phase load current of each GIS equipment disconnect switch, obtaining the time correlation calculation results, and performing correlation judgment based on the time correlation calculation results; when the original absolute pressure and the ambient temperature have a time correlation, calculating the environmental compensation pressure after compensating for the ambient temperature, and using the environmental compensation pressure to recalculate multiple characteristic quantities of the pressure of each GIS equipment disconnect switch; when the original absolute pressure and the ambient temperature do not have a time correlation and the pressure and the three-phase load current do not have a time correlation, performing a general heating abnormality judgment;

[0013] General heating abnormality judgment includes issuing a heating warning when the value of at least one characteristic quantity is greater than the preset general heating threshold but does not reach the preset severe heating threshold, and sending a warning signal to monitor the presence of a general heating defect inside the gas chamber of the GIS equipment isolation switch.

[0014] The characteristic quantities of the pressure include month-on-month growth amount and month-on-month growth rate, year-on-year growth amount and year-on-year growth rate;

[0015] The formula for calculating the month-on-month increase in pressure is: ΔP1=P now -P ring ;

[0016] The formula for calculating the month-on-month growth rate of pressure is: ΔP 1ratio =(P now -Pring ) / T;

[0017] Among them, P now To monitor the pressure of the gas chamber during the current time period, P ring It is the pressure of the previous time period or several previous time periods; the time period T is set to any value between 1 minute and 30 minutes.

[0018] The formula for calculating the year-on-year increase in pressure is: ΔP2=P now -P last ;

[0019] The formula for calculating the year-on-year growth rate of pressure is: ΔP2 ratio =(P now -P last ) / T;

[0020] Among them, P last It is the pressure corresponding to the time of day when the three-phase load current and the ambient temperature in the most recent monitoring data are closest or relatively close to the current operating conditions; the most recent time is any value between 1 day and 1 month.

[0021] The characteristic quantities of the pressure also include the inter-phase difference quantity and the inter-phase difference rate, the growth quantity compared with the adjacent air chamber and the growth rate compared with the adjacent air chamber.

[0022] The calculation formula of the phase difference of pressure is: ΔP3=P now -(P m +P n ) / 2;

[0023] The calculation formula of the phase difference rate of pressure is: ΔP 3ratio =ΔP3 / T;

[0024] Among them, (P m +P n ) / 2 is the average pressure of the other two-phase gas chambers of the GIS equipment disconnector except the gas chamber of the current calculated characteristic quantity in the current time period.

[0025] The calculation formula for the pressure increase compared to the adjacent air chamber is: ΔP4=P now -P ring -(P′ now -P′ ring );

[0026] The formula for calculating the pressure growth rate relative to the adjacent air chamber is: ΔP 4ratio =ΔP4 / T;

[0027] Among them, P′ now is the absolute pressure of adjacent air chambers at the same interval in the current time period, P′ring The same interval, adjacent air chamber is in the same ring Absolute pressure for the same time period.

[0028] The calculation formula of the time correlation is:

[0029] Where X and Y are the time series data of the two parameters whose temporal correlation is to be calculated, and N is the length of the time series. N is usually set to a range of 5 to 10.

[0030] The performing time correlation judgment according to the time correlation calculation result includes:

[0031] Determine whether the calculation result of any time correlation is less than the preset threshold of time correlation. When the calculation result is less than the preset threshold of time correlation, it indicates that the two parameters corresponding to the calculated time correlation are not correlated. When the calculation result is greater than or equal to the preset threshold of time correlation, it indicates that the two parameters corresponding to the calculated time correlation are correlated.

[0032] This application also provides a GIS equipment isolation switch internal heating early warning system, including:

[0033] The sensor module is configured to collect the original absolute pressure, gas temperature, and ambient temperature inside the disconnector of at least one GIS device in the substation, and transmit the original absolute pressure, gas temperature, and ambient temperature to a data acquisition host via wireless or wired communication;

[0034] An external access module is configured to obtain the three-phase load current of the isolating switch and transmit the three-phase load current to a data acquisition host through an interface;

[0035] The data acquisition host includes a power supply module, a data acquisition module, and a data communication module. The power supply module is configured to provide power to the data acquisition host to ensure normal operation of the module; the data acquisition module is configured to collect data transmitted by the sensor module and the external access module; and the data communication module is configured to realize data transmission between the data acquisition host and the sensor module and the monitoring server.

[0036] The monitoring server includes a database, a host management unit, a data processing unit, an alarm management unit, and a display interface. The database is configured to store relevant data; the host management unit is configured to manage the data acquisition host; the alarm management unit is configured to perform alarm management based on the processing results of the data processing unit; the display interface is configured to display system settings, monitoring information, alarm signals, and other content on the screen to achieve human-computer interaction; the data processing unit is configured to analyze and process the data collected by the data acquisition host to determine whether an early warning is required, including: obtaining the original absolute pressure, gas temperature, ambient temperature, and three-phase load current of the isolating switch of at least one GIS device in the substation; calculating multiple characteristic quantities of the pressure of each GIS device isolating switch based on the original absolute pressure, ambient temperature, gas temperature, and three-phase load current; performing severe heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than a preset severe heating threshold, performing a heating early warning, and issuing an early warning signal to monitor the presence of severe heating defects in the gas chamber of the GIS device isolating switch; when Time correlation judgment includes: calculating the time correlation between the original absolute pressure and the ambient temperature of each GIS equipment disconnect switch, and calculating the time correlation between the pressure and the three-phase load current of each GIS equipment disconnect switch, obtaining the time correlation calculation result, and performing correlation judgment based on the time correlation calculation result; when the original absolute pressure and the ambient temperature have time correlation, calculating the environmental compensation pressure after compensating for the ambient temperature, and using the environmental compensation pressure to recalculate multiple characteristic quantities of the pressure of each GIS equipment disconnect switch; when the original absolute pressure and the ambient temperature do not have time correlation, and the pressure and the three-phase load current do not have time correlation, performing general heating abnormality judgment; general heating abnormality judgment includes: when the value of at least one characteristic quantity is greater than the preset general heating threshold but does not reach the preset severe heating threshold, performing a heating warning, and issuing a warning signal to monitor the presence of a general heating defect inside the gas chamber of the GIS equipment disconnect switch.

[0037] The characteristic quantities of the pressure include month-on-month growth amount and month-on-month growth rate, year-on-year growth amount and year-on-year growth rate;

[0038] The formula for calculating the month-on-month increase in pressure is: ΔP1=P now -P ring ;

[0039] The formula for calculating the month-on-month growth rate of pressure is: ΔP 1ratio =(P now -P ring ) / T;

[0040] Among them, P now is the pressure of the current time period, P ringIt is the pressure of the previous time period or the previous few time periods; T is the time period T is set to any value between 1 minute and 30 minutes.

[0041] The formula for calculating the year-on-year increase in pressure is: ΔP2=P now -P last ;

[0042] The formula for calculating the year-on-year growth rate of pressure is: ΔP2 ratio =(P now -P last ) / T;

[0043] Among them, P last It is the pressure corresponding to the time of day when the three-phase load current and the ambient temperature in the most recent monitoring data are closest or relatively close to the current operating conditions; the most recent time is any value between 1 day and 1 month.

[0044] The characteristic quantities of the pressure also include the inter-phase difference quantity and the inter-phase difference rate, the growth quantity compared with the adjacent air chamber and the growth rate compared with the adjacent air chamber.

[0045] The calculation formula of the phase difference of pressure is: ΔP3=P now -(P m +P n ) / 2;

[0046] The calculation formula of the phase difference rate of pressure is: ΔP 3ratio =ΔP3 / T;

[0047] Among them, (P m +P n ) / 2 is the average pressure of the other two-phase gas chambers of the GIS equipment disconnector except the gas chamber of the current calculated characteristic quantity in the current time period.

[0048] The calculation formula for the pressure increase compared to the adjacent air chamber is: ΔP4=P now -P ring -( P ' now -P′ ring );

[0049] The formula for calculating the pressure growth rate relative to the adjacent air chamber is: ΔP 4ratio =ΔP4 / T;

[0050] Among them, P′ now is the pressure of adjacent air chambers at the same interval in the current time period, P′ ring The same interval, adjacent air chamber is in the same ring Same time period of pressure.

[0051] The calculation formula of the time correlation is:

[0052] Among them, X and Y are the time series data of the two parameters whose time correlation is to be calculated, and N is the length of the time series.

[0053] The data processing unit is configured to perform time correlation determination according to the following method, including:

[0054] Determine whether the calculation result of any time correlation is less than the preset threshold of time correlation. When the calculation result is less than the preset threshold of time correlation, it indicates that the two parameters corresponding to the calculated time correlation are not correlated. When the calculation result is greater than or equal to the preset threshold of time correlation, it indicates that the two parameters corresponding to the calculated time correlation are correlated.

[0055] The sensor module includes a pressure sensor with a built-in temperature sensor for collecting the original absolute pressure and internal gas temperature, and an external temperature sensor for collecting the ambient temperature; wherein the pressure sensor is installed on a three-way valve connected to the interior of the gas chamber, and the temperature sensor for collecting the ambient temperature is installed outside the GIS equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is a schematic diagram of the structure of an internal heating warning system for an isolation switch of a GIS device provided in an embodiment of the present application;

[0057] FIG2A is a flow chart of a method for early warning of internal heating of an isolation switch of a GIS device provided in an embodiment of the present application;

[0058] FIG2B is a flow chart of another method for early warning of internal heating of an isolation switch of a GIS device provided in an embodiment of the present application;

[0059] FIG2C is a flow chart of another method for early warning of internal heating of an isolation switch of a GIS device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] The present application is described below with reference to the accompanying drawings and specific embodiments.

[0061] This application monitors the original absolute pressure of the insulating gas inside the GIS equipment disconnect switch, the internal gas temperature, the external ambient temperature and the three-phase load current of the disconnect switch in real time, and determines whether the disconnect switch is overheated through comprehensive analysis of multiple parameters.

[0062] This embodiment provides a GIS equipment disconnect switch internal heating early warning system based on multi-parameter comprehensive analysis, as shown in FIG1 , including:

[0063] (1) A sensor module is configured to collect the original absolute pressure, gas temperature, and ambient temperature inside the isolation switch, and transmit the original absolute pressure, gas temperature, and ambient temperature to a data acquisition host via wireless or wired communication.

[0064] In this embodiment, a three-way valve is connected in parallel to the density meter of the GIS device, and a sensor module is installed on the three-way valve. The sensor module is provided with a pressure sensor and two temperature sensors. One temperature sensor is located inside the air chamber near the three-way valve and is configured to monitor the gas temperature inside the air chamber. The other temperature sensor extends out of the sensor module body and is located outside the GIS device and is configured to monitor the ambient temperature.

[0065] (2) An external access module is configured to obtain the three-phase load current of the isolating switch and transmit the three-phase load current to a data acquisition host through an interface.

[0066] (3) Data acquisition host

[0067] The data acquisition host includes a power module, a data acquisition module, and a data communication module. The power module provides power to the data acquisition host to ensure normal operation. The data acquisition module is configured to collect data transmitted by the sensor module and external access module, while the data communication module is configured to facilitate data transmission between the data acquisition host, the sensor module, and the monitoring server.

[0068] This embodiment connects data from pressure and temperature sensors to a data acquisition host via wireless or wired communication. This allows for real-time and accurate acquisition of the gas temperature and raw absolute pressure inside the GIS equipment, as well as the external ambient temperature. The data acquisition host also receives the three-phase load current of the GIS equipment's isolating switch. This data is used as a key indicator for fault warnings and can help determine whether the isolating switch is overheating.

[0069] In this embodiment, the time interval for collecting the gas temperature, original absolute pressure, ambient temperature, and three-phase load current inside the gas chamber is any value between 1 minute and 30 minutes.

[0070] (4) A monitoring server, comprising a database, a host management unit, a data processing unit, an alarm management unit, and a display interface. The database is configured to store relevant data, the host management unit is configured to manage the data acquisition host, the data processing unit is configured to process data collected by the data acquisition host and determine whether an early warning is required, the alarm management unit is configured to manage alarms based on the results of the data processing unit, and the display interface is configured to display system settings, monitoring information, alarm signals, and other content on the screen to achieve human-computer interaction.

[0071] In this embodiment, the data acquisition host is connected to the monitoring server through wireless or wired communication, so that the collected data can be sent to the monitoring server in real time for processing and analysis.

[0072] The monitoring server is responsible for data processing and analysis. It processes and comprehensively analyzes the collected data, including month-over-month and year-over-year trends, interphase differences, and differences between adjacent chambers. It also uses time correlation to identify overheating defects and issue early warnings. If the disconnector is deemed to be overheating, an alarm signal is issued.

[0073] Based on the above system, this embodiment also provides a method for early warning of internal heating of a GIS equipment disconnect switch based on multi-parameter comprehensive analysis, as shown in FIG2A , including the following steps:

[0074] S1. Obtain the gas temperature, original absolute pressure, ambient temperature inside the disconnectors of multiple GIS devices, and the three-phase load current of the disconnectors.

[0075] S2. Calculate multiple characteristic quantities of the pressure of each GIS device isolation switch based on the monitoring data. The pressure includes the original absolute pressure and the environmental compensation pressure. The characteristic quantities of pressure include:

[0076] 1) The month-on-month increase and growth rate of pressure in the same gas chamber in chronological order;

[0077] 2) Year-on-year increase in pressure and year-on-year rate under previous similar conditions in the same gas chamber;

[0078] Among them, the approximate condition refers to a condition that is relatively close to the current monitoring time point, the monitored ambient temperature and the three-phase load current. For example, the current monitoring time point is 10:00 on February 2, 2024. If the ambient temperature and three-phase load current monitored at 10:00 on February 1, 2024 are consistent with the ambient temperature and three-phase load current monitored at the current monitoring time point, then 10:00 on February 1, 2024 can be used as the approximate condition. If there is no time point at which the monitored data is consistent with the currently monitored data, then the time point at which the monitored data is approximate to the currently monitored data can be used as the approximate condition.

[0079] 3) The inter-phase difference and inter-phase difference rate of the pressure of different phase gas chambers of three-phase split GIS disconnector;

[0080] 4) The rate of increase of the pressure of the warning target air chamber compared with the air chambers at the same interval and adjacent to it, that is, the increase amount compared with the adjacent air chamber and the growth rate compared with the adjacent air chamber.

[0081] The characteristic quantities of the pressure include month-on-month growth amount and month-on-month growth rate, year-on-year growth amount and year-on-year growth rate;

[0082] The formula for calculating the month-on-month increase in pressure is: ΔP1=P now -P ring ;

[0083] The formula for calculating the month-on-month growth rate of pressure is: ΔP 1ratio =(P now -P ring ) / T;

[0084] Among them, P now is the pressure of the current time period, P ring The time period T is generally set to any value between 1 minute and 30 minutes. In one embodiment, the time period is set to 1 minute.

[0085] The formula for calculating the year-on-year increase in pressure is: ΔP2=P now -P last ;

[0086] The formula for calculating the year-on-year growth rate of pressure is: ΔP2 ratio =(P now -P last ) / T;

[0087] Among them, P last is the pressure corresponding to the time when the three-phase load current and the ambient temperature in the most recent monitoring data are closest or relatively close to the current operating conditions; in one embodiment, P last The pressure of the monitoring period is that the deviation between the most recent three-phase load current within two weeks and the current three-phase load current is within 10%, the deviation between the ambient temperature and the current ambient temperature is within 10%, and the time difference is within 1 hour.

[0088] The characteristic quantities of the pressure also include the inter-phase difference quantity and the inter-phase difference rate, the growth quantity compared with the adjacent air chamber and the growth rate compared with the adjacent air chamber.

[0089] The calculation formula of the phase difference of pressure is: ΔP3=P now -(P m +P n ) / 2;

[0090] The calculation formula of the phase difference rate of pressure is: ΔP 3ratio =ΔP3 / T;

[0091] Among them, (P m +P n ) / 2 is the average pressure of the other two-phase gas chambers of the GIS equipment disconnector except the gas chamber of the current calculated characteristic quantity in the current time period.

[0092] The calculation formula for the pressure increase compared to the adjacent air chamber is: ΔP4=P now -P ring -(P′ now - P′ ring );

[0093] The formula for calculating the pressure growth rate relative to the adjacent air chamber is: ΔP 4ratio =ΔP4 / T;

[0094] Among them, P′ now is the pressure of adjacent air chambers at the same interval in the current time period, P′ ring The same interval, adjacent air chamber is in the same ring Same time period of pressure.

[0095] S3. Determine a severe thermal anomaly. If the value of at least one characteristic metric, such as the month-on-month increase and growth rate, year-on-year increase and growth rate, phase-to-phase difference and difference rate, and increase and growth rate relative to adjacent air chambers, of the pressure of a GIS device disconnect switch exceeds a preset severe thermal anomaly threshold, a thermal anomaly warning is issued, signaling a severe thermal anomaly within the disconnect switch. In one embodiment, a severe thermal anomaly warning is issued when the values ​​of three or 50% or more of the characteristic metrics exceed the preset severe thermal anomaly threshold.

[0096] S4. Determine the correlation between the original absolute pressure and the ambient temperature. Calculate the time correlation between the original absolute pressure and the ambient temperature:

[0097] Where X and Y are the time series data of the two parameters whose temporal correlation is to be calculated, and N is the length of the time series. N is usually set to a range of 5 to 10.

[0098] For example, when calculating the time correlation between the original absolute pressure and the ambient temperature, X and Y represent the time series data of the original absolute pressure and the ambient temperature, respectively.

[0099] Determine whether the calculation result of any time correlation is less than the preset threshold of time correlation. If the calculation result is less than the preset threshold of time correlation, it indicates that the two parameters for calculating the time correlation are not correlated. If the calculation result is greater than or equal to the preset threshold of time correlation, it indicates that the two parameters for calculating the time correlation are correlated.

[0100] If the original absolute pressure and ambient temperature are time-correlated, the ambient temperature-compensated pressure is calculated using the Betty-Bridgeman equation or the ideal gas equation, and the ambient temperature-compensated pressure is used for subsequent calculations and judgments. In this embodiment, the average value of multiple adjacent ambient temperature sensors is used as the ambient temperature value.

[0101] If the original absolute pressure and the ambient temperature have no time correlation, the subsequent steps still use the original absolute pressure for calculation and judgment.

[0102] S5. Determine the correlation between pressure and three-phase load current. Calculate the time correlation between the original absolute pressure or environmental compensation pressure and the three-phase load current:

[0103] Wherein, X and Y are time series data of two parameters whose time correlation is to be calculated, and N is the length of the time series. In one embodiment, N is set to 5.

[0104] If the pressure and the three-phase load current have a time correlation, then the system directly enters S1 of the next cycle.

[0105] If the pressure and the three-phase load current have no time correlation, the process proceeds to step S6 for determining a general heating abnormality.

[0106] S6. Determine general heating anomalies inside the disconnector. If the original absolute pressure and ambient temperature in step S4 are time-correlated, recalculate multiple pressure characteristic quantities using the ambient-compensated pressure, including the month-on-month increase and growth rate, the year-on-year increase and rate, and the phase difference and rate. If the original absolute pressure and ambient temperature in step S4 are not time-correlated, no recalculation is performed.

[0107] If the value of at least one of the above-mentioned characteristic quantities is greater than the preset general fever threshold but does not reach the preset severe fever threshold, a general fever warning is issued, and a warning signal is issued indicating that a general fever defect exists within the monitoring chamber. If no characteristic quantity has a value greater than the preset general fever threshold, the judgment logic of the current cycle is exited and the next monitoring cycle S1 is entered. In this embodiment, a general fever warning is issued when the values ​​of two or 50% or more of the characteristic quantities are greater than the preset general fever threshold.

[0108] The present application also provides another embodiment, as shown in FIG2B . The present application provides a method for early warning of internal heating of an isolation switch of a GIS device, including:

[0109] S101. Obtain the gas temperature, original absolute pressure, ambient temperature, and three-phase load current of the isolating switches of multiple GIS devices.

[0110] S102. Calculate the time correlation between the original absolute pressure and the ambient temperature of each GIS device disconnect switch. If the original absolute pressure and ambient temperature are time-correlated, calculate the ambient temperature-compensated pressure using the Betty-Bridgeman equation or the ideal gas equation. The ambient temperature is calculated using the average value of data collected by multiple adjacent ambient temperature sensors. Subsequent steps utilize the ambient temperature-compensated pressure for calculation and judgment. If the original absolute pressure and ambient temperature are not time-correlated, subsequent steps continue to utilize the original absolute pressure for calculation and judgment.

[0111] S103. Calculate the time correlation between the original absolute pressure or the environmentally compensated pressure and the three-phase load current. If the pressure and the three-phase load current are time-correlated, proceed directly to S101 of the next cycle. If the pressure and the three-phase load current are not time-correlated, proceed to step S104 of determining an abnormal heating condition.

[0112] S104. Calculate multiple characteristic quantities of the pressure of each GIS device disconnect switch based on the original absolute pressure or the environmentally compensated pressure. The characteristic quantities of pressure include month-on-month growth and month-on-month growth rate, year-on-year growth and year-on-year growth rate, inter-phase difference and inter-phase difference rate, and growth relative to adjacent air chambers and growth rate relative to adjacent air chambers.

[0113] S105. Determine abnormal heating inside the disconnector. If the value of at least one characteristic quantity in S104 is greater than the preset severe heating threshold, a warning signal for a severe heating defect is issued; if the value of at least one characteristic quantity in S104 is greater than the preset general heating threshold but does not reach the severe heating threshold, a warning signal for a general heating defect is issued. In this embodiment, when the values ​​of 50% or more of the characteristic quantities are greater than the preset general heating threshold, a general heating warning is issued, and when the values ​​of 50% or more of the characteristic quantities are greater than the preset severe heating threshold, a severe heating warning is issued.

[0114] In summary, referring to FIG2C , the fever warning method of the present application includes the following steps:

[0115] S11: Obtain the original absolute pressure, gas temperature, ambient temperature inside the disconnector of at least one GIS device in the substation, and the three-phase load current of the disconnector.

[0116] S21: Calculate multiple characteristic quantities of the pressure of each GIS equipment disconnect switch based on the original absolute pressure, ambient temperature, gas temperature, and three-phase load current.

[0117] S31: Performing a severe heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than a preset severe heating threshold, issuing a heating warning and sending a warning signal to monitor the presence of a severe heating defect inside the air chamber of the GIS equipment isolation switch.

[0118] S41: Time correlation judgment, including: calculating the time correlation between the original absolute pressure and the ambient temperature of each GIS device disconnect switch, and calculating the time correlation between the pressure and the three-phase load current of each GIS device disconnect switch, obtaining the time correlation calculation result, and performing correlation judgment based on the time correlation calculation result; when the original absolute pressure and the ambient temperature have time correlation, calculating the environmental compensation pressure after compensating for the ambient temperature, and using the environmental compensation pressure for subsequent judgments and calculations, and using the environmental compensation pressure to recalculate multiple characteristic quantities of the pressure of each GIS device disconnect switch; when the original absolute pressure and the ambient temperature do not have time correlation, and the pressure and the three-phase load current do not have time correlation, performing a general heating abnormality judgment.

[0119] S51: General heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than the preset general heating threshold but does not reach the preset severe heating threshold, a heating warning is issued, and a warning signal is issued to monitor the presence of a general heating defect inside the air chamber of the GIS equipment isolation switch.

[0120] This application has the following beneficial effects:

[0121] (1) This application has more accurate monitoring capabilities. By collecting multi-dimensional data, including the original absolute pressure of the insulating gas inside the disconnector, the gas temperature inside the gas chamber, the external ambient temperature, and the three-phase load current of the disconnector, and then performing a comprehensive analysis, it is possible to more accurately determine whether the disconnector is overheating.

[0122] (2) This application comprehensively analyzes multiple characteristic quantities, such as the month-on-month growth amount, the month-on-month growth rate, the year-on-year growth amount, the year-on-year growth rate, the phase difference amount and the phase difference rate, and adopts a method in which multiple characteristic quantities simultaneously meet the abnormal fever judgment threshold, which can effectively judge abnormal situations and reduce system false alarms.

[0123] (3) The present application can detect the relationship between the original absolute pressure and the ambient temperature, and the relationship between the pressure and the three-phase load current through time correlation calculation. At the same time, the ambient temperature adopts the average value of the data collected by multiple adjacent sensors, which can effectively avoid the impact of the jump of the ambient temperature data and the normal heating caused by the load current on the early warning system, and further improve the accuracy of the internal overheating warning of the isolating switch.

[0124] (4) The gas temperature and original absolute pressure inside the equipment monitored by this application can be used to calculate the gas density inside the gas chamber, which is equivalent to an electronic density meter and can replace the density meter in the relevant technology; this application can also be effectively combined with the electronic density meter to realize gas density monitoring and internal overheating warning at the same time, which has a strong promotion and application value.

[0125] (5) This application has higher real-time performance. By real-time monitoring of the internal data of the GIS equipment disconnector and real-time data transmission and processing with the online monitoring server, it is possible to promptly detect the internal overheating defect of the disconnector and generate corresponding early warning signals, so that the defect can be handled in time, avoiding potential equipment failure and power system instability.

[0126] (6) This application can use wireless communication technologies such as ZigBee / Wireless Fidelity (WIFI) to simplify the wiring and installation of equipment, and can also use wired transmission to improve the convenience and flexibility of the system.

[0127] (7) The data collected by this application is analyzed, processed and stored through the monitoring server, which can form historical data records and trend analysis, provide strong support for the operation and maintenance management and defect detection of power equipment, and improve the operation and maintenance efficiency and operational reliability of the equipment.

[0128] In summary, the present application relates to a technical solution for determining whether the interior of a GIS disconnector is overheated by real-time monitoring of the original absolute pressure of the insulating gas inside the disconnector, the gas temperature inside the gas chamber, the external ambient temperature, and the three-phase load current of the disconnector; avoiding false alarms caused by changes in ambient temperature and load current by determining the correlation between the original absolute pressure and ambient temperature, and between pressure and three-phase load current; and determining whether the interior of a GIS disconnector is overheated by calculating characteristic quantities such as the month-on-month increase in pressure, the month-on-month growth rate, the year-on-year increase, the year-on-year growth rate, the phase-to-phase difference, and the phase-to-phase difference rate. The present application has significant advantages in terms of accuracy, real-time performance, reliability, and maintenance efficiency, providing a reliable monitoring and early warning method for the safe operation of the power system and possessing important practical application value.

Claims

1. A method for early warning of internal heating of a gas insulated switch GIS equipment isolating switch, comprising: Obtain the original absolute pressure, internal gas temperature, ambient temperature, and three-phase load current of at least one GIS equipment disconnector in the substation; Calculate multiple characteristic quantities of the pressure of each GIS equipment disconnect switch according to the original absolute pressure, ambient temperature, internal gas temperature and three-phase load current, wherein the multiple characteristic quantities of the pressure include month-on-month growth amount and month-on-month growth rate, year-on-year growth amount and year-on-year growth rate, phase difference amount and phase difference rate, and growth amount compared to adjacent air chambers and growth rate compared to adjacent air chambers; Performing severe heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than a preset severe heating threshold, performing a heating warning, and issuing a warning signal that a severe heating defect exists inside the air chamber of the isolation switch of the monitoring GIS equipment; The time correlation judgment includes: calculating the time correlation between the original absolute pressure of each GIS equipment isolating switch and the ambient temperature, and calculating the time correlation between the pressure of each GIS equipment isolating switch and the three-phase load current, obtaining the time correlation calculation result, and performing correlation judgment based on the time correlation calculation result; when the original absolute pressure and the ambient temperature have a time correlation, calculating the environmental compensation pressure after compensating for the ambient temperature, and using the environmental compensation pressure to recalculate multiple characteristic quantities of the pressure of each GIS equipment isolating switch; when the original absolute pressure and the ambient temperature do not have a time correlation, and the pressure and the three-phase load current do not have a time correlation, performing a general heating abnormality judgment; the general heating abnormality judgment includes: when the value of at least one characteristic quantity is greater than the preset general heating threshold but does not reach the preset severe heating threshold, a heating warning is issued, and a warning signal is issued to monitor the presence of a general heating defect inside the air chamber of the GIS equipment isolating switch.

2. The method according to claim 1, wherein: The characteristic quantities of the pressure include month-on-month increase and month-on-month growth rate, year-on-year increase and year-on-year growth rate, phase difference and phase difference rate, increase compared to adjacent air chambers and growth rate compared to adjacent air chambers; The formula for calculating the month-on-month increase in pressure is: ΔP1=P now -P ring ; The formula for calculating the month-on-month growth rate of pressure is: ΔP 1ratio =(P now -P ring ) / T; Among them, P now is the pressure of the current time period, P ring It is the pressure of the last time period or the last few time periods; the time period T is set to any value between 1 minute and 30 minutes; The formula for calculating the year-on-year increase in pressure is: ΔP2=P now -P last ; The formula for calculating the year-on-year growth rate of pressure is: ΔP 2ratio =(P now -P last ) / T; Among them, P last The three-phase load current and ambient temperature in the most recent monitoring data during the day. The pressure corresponding to the time when the current operating condition is closest or relatively close to the current operating condition; the most recent time is any value from 1 day to 1 month; The calculation formula of the phase difference of pressure is: ΔP3=P now -(P m +P n ) / 2; The formula for calculating the phase difference rate of pressure is: ΔP 3ratio =ΔP3 / T; Among them, (P m +P n ) / 2 is the average pressure of the other two-phase air chambers of the GIS equipment disconnector except the air chamber of the current calculated characteristic quantity in the current time period; The formula for calculating the pressure increase relative to the adjacent air chamber is: ΔP4 = P now -P ring -(P′ now -P′ ring ); The formula for calculating the pressure growth rate relative to the adjacent air chamber is: ΔP 4ratio =ΔP4 / T; Among them, P′ now is the pressure of the adjacent air chambers at the same interval in the current time period, P′ ring The same interval, adjacent air chamber is in the same ring Same time period of pressure.

3. The method according to claim 1, wherein: The calculation formula of the time correlation is: Among them, X and Y are the time series data of two parameters whose time correlation is to be calculated, and N is the length of the time series.

4. The method according to claim 1, wherein: The performing correlation judgment according to the time correlation calculation result includes: Determine whether the calculation result of any time correlation is less than the preset threshold of the time correlation. When the calculation result is less than the preset threshold of the time correlation, it indicates that the two parameters corresponding to the calculated time correlation are not correlated. When the calculation result is greater than or equal to the preset threshold of the time correlation, it indicates that the two parameters corresponding to the calculated time correlation are correlated.

5. A gas insulated switch GIS equipment disconnector internal heating early warning system, comprising: The sensor module is configured to collect the original absolute pressure, gas temperature, and ambient temperature inside the isolating switch of at least one GIS device in the substation, and transmit the original absolute pressure, gas temperature, and ambient temperature to a data acquisition host through wireless or wired communication; The external access module is configured to obtain the three-phase load current of the isolating switch and transmit the three-phase load current to the isolating switch through the interface. The phase load current is transmitted to the data acquisition host; The data acquisition host includes a power module, a data acquisition module and a data communication module; wherein the power module is configured to provide power to the data acquisition host to ensure normal operation of the module; the data acquisition module is configured to collect data transmitted by the sensor module and the external access module, and the data communication module is configured to realize data transmission between the data acquisition host and the sensor module and the monitoring server; The monitoring server includes a database, a host management unit, a data processing unit, an alarm management unit, and a display interface; wherein the database is configured to store relevant data; the host management unit is configured to manage the data acquisition host; the alarm management unit is configured to perform alarm management according to the processing results of the data processing unit; the display interface is configured to display system settings, monitoring information, alarm signals and other contents on the screen to realize human-computer interaction; the data processing unit is configured to perform data processing according to the data collected by the data acquisition host, and determine whether an early warning is required, including: obtaining the original absolute pressure, gas temperature, ambient temperature inside the isolating switch of at least one GIS device in the substation, and the three-phase load current of the isolating switch; calculating multiple characteristic quantities of the pressure of each GIS device isolating switch according to the original absolute pressure, ambient temperature, gas temperature and three-phase load current; and performing severe heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than a preset severe heating threshold, a heating early warning is issued, and a monitoring GIS device isolating switch is issued. A warning signal indicating that there is a serious heating defect inside the air chamber; time correlation judgment, including: calculating the time correlation between the original absolute pressure and the ambient temperature of each GIS equipment disconnect switch, and calculating the time correlation between the pressure and the three-phase load current of each GIS equipment disconnect switch, obtaining the time correlation calculation result, and performing correlation judgment based on the time correlation calculation result; when the original absolute pressure and the ambient temperature have a time correlation, calculating the environmental compensation pressure after compensating for the ambient temperature, and using the environmental compensation pressure to recalculate multiple characteristic quantities of the pressure of each GIS equipment disconnect switch; when the original absolute pressure and the ambient temperature do not have a time correlation, and the pressure and the three-phase load current do not have a time correlation, performing a general heating abnormality judgment; general heating abnormality judgment, including: when the value of at least one characteristic quantity is greater than the preset general heating threshold but does not reach the preset severe heating threshold, a heating warning is issued, and a warning signal for monitoring the existence of a general heating defect inside the air chamber of the GIS equipment disconnect switch is issued.

6. The system according to claim 5, wherein: The characteristic quantities of the pressure include month-on-month increase and month-on-month growth rate, year-on-year increase and year-on-year growth rate, phase difference and phase difference rate, increase compared to adjacent air chambers and growth rate compared to adjacent air chambers; The formula for calculating the month-on-month increase in pressure is: ΔP1=P now -P ring ; The formula for calculating the month-on-month growth rate of pressure is: ΔP 1ratio =(P now -P ring ) / T; Among them, P now is the pressure of the current time period, P ring It is the pressure of the last time period or the last few time periods; the time period T is set to any value between 1 minute and 30 minutes; The formula for calculating the year-on-year increase in pressure is: ΔP2=P now -P last ; The formula for calculating the year-on-year growth rate of pressure is: ΔP 2ratio =(P now -P last ) / T; Among them, P last It is the pressure corresponding to the time of the day when the three-phase load current and the ambient temperature in the most recent monitoring data are closest or relatively close to the current operating conditions; the most recent time is any value from 1 day to 1 month; The calculation formula of the phase difference of pressure is: ΔP3=P now -(P m +P n ) / 2; The formula for calculating the phase difference rate of pressure is: ΔP 3ratio =ΔP3 / T; Among them, (P m +P n ) / 2 is the average pressure of the other two-phase air chambers of the GIS equipment disconnector except the air chamber of the current calculated characteristic quantity in the current time period; The formula for calculating the pressure increase relative to the adjacent air chamber is: ΔP4 = P now -P ring -(P′ now -P′ ring ); The formula for calculating the pressure growth rate relative to the adjacent air chamber is: ΔP 4ratio =ΔP4 / T; Among them, P′ now is the pressure of the adjacent air chambers at the same interval in the current time period, P′ ring The same interval, adjacent air chamber is in the same ring Same time period of pressure.

7. The system according to claim 5, wherein: The calculation formula of the time correlation is: Among them, X and Y are the time series data of two parameters whose time correlation is to be calculated, and N is the length of the time series.

8. The system according to claim 5, wherein: The data processing unit is configured to perform time correlation determination according to the following method: Determine whether the calculation result of any time correlation is less than the preset threshold of the time correlation. When the calculation result is less than the preset threshold of the time correlation, it indicates that the two parameters corresponding to the calculated time correlation are not correlated. When the calculation result is greater than or equal to the preset threshold of the time correlation, it indicates that the two parameters corresponding to the calculated time correlation are correlated.

9. The system according to claim 5, wherein: The sensor module includes a pressure sensor with a built-in temperature sensor for collecting internal gas temperature and original absolute pressure, and an external temperature sensor for collecting ambient temperature. The pressure sensor is installed on a three-way valve connected to the inside of the gas chamber.

10. The system according to claim 5, wherein: The time period for the data acquisition module to collect data is any value between 1 minute and 30 minutes.

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