Low-power-consumption gas density relay and online self-checking method thereof

Abstract

According to the low-power-consumption gas density relay and the on-line self-checking method thereof provided by the invention, the stepped simulation contact group is arranged in the gas density relay body, and the temperature difference generated between the gas density relay body and the electrical equipment gas chamber due to the sudden change of environment temperature or the difference of thermal inertia is utilized; and a density detection element in the gas density relay body is driven to generate mechanical displacement, and at least one simulation contact in the stepped simulation contact group is triggered to act, so that on-line self-checking is realized under the condition that an additional power supply is not needed. Wherein the action triggering density value of each simulation contact is set above the alarm threshold value, so that false alarm is effectively avoided. According to the invention, a false alarm industry pain point caused by temperature difference is converted into a technical advantage, and long-term maintenance-free online self-checking can be realized without laying a power supply cable.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, and in particular to a low-power gas density relay and its online self-calibration method. Background Technology

[0002] Sulfur hexafluoride (SF6) gas is widely used as an insulating medium in high-voltage electrical equipment (such as circuit breakers, gas-insulated switchgear, and transformers) in the power industry due to its excellent insulation and arc-quenching properties. Since the 1950s, SF6 gas has gradually become the standard insulating gas in high-voltage switchgear. Its high chemical stability, excellent thermal conductivity, and ability to rapidly decompose and reform under the influence of an electric arc make it an irreplaceable insulating and arc-quenching medium in power systems.

[0003] The density of SF6 gas in high-voltage electrical equipment directly affects the insulation and arc-extinguishing performance of the equipment, thus impacting the power supply safety of the power system. Therefore, a gas density relay (referred to as a "density relay") is needed to monitor the SF6 gas density within the electrical equipment in real time, and trigger the protection action of the secondary circuit via contact signals when the density is abnormal. This secondary circuit is a power system secondary circuit independent of the density relay, deployed in the control cabinet of the substation electrical equipment, and is used to receive contact signals from the density relay and execute corresponding protection commands (such as alarms or interlocks).

[0004] Since the reliability of density relays directly affects the safe operation of SF6 electrical equipment, power grid operation regulations stipulate that density relays must be calibrated periodically before equipment commissioning and during the operating cycle. Traditional calibration methods are offline, requiring the density relay to be disassembled and connected to a standard pressure source to simulate density changes. This type of operation not only requires a power outage, consuming significant manpower and resources, but also leads to power outages and economic losses, and can no longer meet the continuous power supply requirements of smart grids.

[0005] To address this, existing technologies have proposed online self-verification schemes. For example, Chinese Patent Application No. CN202010359601.7 (publication date: July 24, 2020) discloses a gas density relay with simulation verification function and its simulation verification method. By using a pressure regulating mechanism or heating the temperature compensation element (such as a bimetallic strip or temperature compensation gas chamber gas) inside the density relay, the rise and fall of gas density is simulated, thereby triggering the simulation contact action without interrupting the operation of electrical equipment, and completing the simulation self-verification.

[0006] However, existing online self-calibration designs still have the following drawbacks: their voltage regulation / heating mechanisms require continuous external power supply, leading to high energy consumption; they rely on wired power supply for long-term operation; and in substation applications, new cabling needs to be laid (especially in older substations where wiring space is limited). Using battery power presents several problems: 1) large battery pack size increases production costs; 2) finding ideal installation points at substation sites increases construction difficulty; 3) battery life is limited by power consumption, supporting only a limited operating time and number of self-calibrations; 4) large batteries are detrimental to environmental protection and carbon neutrality goals; 5) construction time and costs increase accordingly. Furthermore, when using wired power, the simultaneous online self-calibration of numerous density relays in the substation poses a challenge to power capacity, potentially failing to meet simultaneous operation requirements. In addition, temperature differences often arise between density relays and electrical equipment chambers due to sudden changes in ambient temperature or differences in thermal inertia, which can lead to false alarms or lockout signals in secondary circuits. These problems make it difficult for existing technologies to achieve truly low-power, maintenance-free, long-term stable online self-calibration. Summary of the Invention

[0007] Under operating conditions, a temperature difference exists between the gas chamber of the electrical equipment and the installation location of the density relay. The temperature compensation effect of the density relay actually depends on the accuracy of the temperature value T at its installation location. When the temperature T1 of the electrical equipment's gas chamber is not equal to the temperature T2 of the density relay, an error will occur. When there is no gas leakage in the electrical equipment, and the temperature T1 of the electrical equipment's gas chamber is lower than the temperature T2 of the density relay, the internal temperature compensation element of the density relay will overcompensate, causing the mechanical indication value and the measured density value to be lower than expected. As the temperature difference increases, it will lead to a significant deviation in the density display value; if the temperature difference continues to increase, it will further cause alarm or interlocking contacts to malfunction, sending incorrect signals to the secondary circuit. In some areas with large temperature differences (such as Xinjiang), this false alarm problem caused by temperature difference poses a significant challenge to the application of density relays, becoming a common pain point in the industry.

[0008] This invention transforms the aforementioned temperature difference problem into a technological advantage. By utilizing this temperature difference and leveraging the motion characteristics of simulated contacts, it achieves online self-calibration without the need for external power supply.

[0009] This invention provides a low-power gas density relay and its online self-calibration method. By setting a stepped simulated contact group inside the gas density relay body, and using the gas density difference generated by the temperature difference between the gas density relay body and the gas chamber of the electrical equipment, at least one simulated contact in the stepped simulated contact group is triggered to operate, so as to achieve low-power online self-calibration and thus achieve the purpose of long-term maintenance-free operation.

[0010] To achieve the above objectives, this invention provides two technical solutions: Solution 1 and Solution 2. Solution 1 (including the first, second, and third aspects below) utilizes the ambient temperature difference between the gas density relay body and the gas chamber of the electrical equipment, and sets up a stepped simulated contact group to naturally drive the simulated contacts, achieving passive, powerless, and low-power online self-calibration, thus achieving long-term maintenance-free operation. When the natural temperature difference is insufficient, a micro-drive mechanism (such as a temperature regulation mechanism) can be used to actively generate gas density changes for calibration. Solution 2 (including the fourth, fifth, and sixth aspects below) uses a micro-drive mechanism and a stepped simulated contact group to controllably drive the simulated contacts, achieving active, low-power online self-calibration, thus achieving long-term maintenance-free operation.

[0011] In this invention, the ambient temperature difference includes, but is not limited to, differences in thermal inertia, diurnal temperature differences, or temperature differences caused by seasonal changes; the action trigger density value of each simulated contact in the stepped simulated contact group is higher than the action value of the alarm contact, so as to avoid false triggering of the protection signal.

[0012] In this invention, the nominal density value P 20E This refers to the rated density of SF6 gas at 20℃ under standard conditions (101.325 kPa), expressed in MPa.

[0013] In a first aspect, the present invention provides a low-power gas density relay, comprising:

[0014] The gas density relay body is installed outside or inside the gas chamber of electrical equipment to detect the gas density in the gas chamber of electrical equipment;

[0015] A gas density sensor is used to monitor one or more parameters of the gas density, pressure, and temperature in the gas chamber and / or gas density relay body of electrical equipment.

[0016] A stepped simulated contact group, disposed within the gas density relay body, includes at least two simulated contacts. These simulated contacts are discretely arranged along the mechanical displacement direction of the density detection element within the gas density relay body. Each simulated contact has a different trigger position distributed along the mechanical displacement direction, and each trigger position corresponds to an action trigger density value. The action trigger density value is within the rated density value P. 20E The gas density relay body has discrete distributions above and / or below the gas density relay body, and the minimum trigger density value is greater than the alarm contact action value of the gas density relay body.

[0017] The intelligent control unit, connected to the gas density detection sensor and each simulated contact, is configured to: acquire pressure and temperature values, and / or acquire gas density values; and detect the signal action value and / or signal return value of the triggered simulated contact.

[0018] In a preferred embodiment, the discretely distributed action trigger density value and the nominal density value P 20E Together they form an ordered sequence S, in which the difference between any two adjacent terms in the ordered sequence S is the same or different, forming a step-like deviation characteristic.

[0019] In a preferred embodiment, the triggering method of the simulated contact and the alarm / lock contact is: micro switch contact, magnetic-assisted electrical contact, or reed switch contact.

[0020] In a preferred embodiment, the action trigger density value of the stepped simulated contact group satisfies:

[0021] In the stepped simulated contact group, at least one simulated contact has an action trigger density value greater than the rated density value P. 20E , and / or

[0022] At least one simulated contact has an action trigger density value less than the rated density value P. 20E And it is greater than the alarm contact action value of the gas density relay body.

[0023] In a more preferred embodiment, the action trigger density value in the stepped simulated contact group is greater than the rated density value P. 20E The number of simulated contacts is greater than the action trigger density value but less than the rated density value P. 20E The number of simulated contacts.

[0024] In a preferred embodiment, the density detection element includes a pressure-sensing element or a temperature compensation element; wherein the pressure-sensing element includes a bellows or a Baden tube, and the temperature compensation element includes a bimetallic strip or a compensation chamber gas.

[0025] Specifically, the pressure-sensing element has any of the following structures:

[0026] (a) Single bellows structure:

[0027] The inner cavity of the bellows is connected to the gas chamber of the electrical equipment, and the outer cavity is connected to the temperature compensation gas chamber (referred to as the "compensation gas chamber," which is filled with standard compensation gas) of the gas density relay body; or

[0028] The outer cavity of the bellows is connected to the gas chamber of the electrical equipment, and the inner cavity is filled with standard compensating gas to form a temperature compensation gas chamber.

[0029] (b) Double-corrugated pipe structure:

[0030] It includes a first bellows and a second bellows that are mechanically coupled. The inner cavity of the first bellows is connected to the gas chamber of the electrical equipment, and the inner cavity of the second bellows is filled with a standard compensating gas to form a temperature compensating gas chamber.

[0031] (c) Baden tube structure:

[0032] The input end of the Baden tube is connected to the gas chamber of the electrical equipment, and the output end is connected to the temperature compensation gas chamber or temperature compensation plate (bimetallic strip) of the gas density relay body.

[0033] In a preferred embodiment, the intelligent control unit is configured to activate the online self-verification function under at least one of the following triggering conditions:

[0034] (a) An edge interruption of the simulation signal generated in response to the actuation of at least one of the simulation contacts in the stepped simulation contact group;

[0035] (b) Response to remote command execution detection from the background monitoring system;

[0036] (c) Perform detection based on a preset periodic wake-up mechanism.

[0037] In a more preferred embodiment, the edge interruption includes a rising edge interruption or a falling edge interruption.

[0038] In a preferred embodiment, the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor; or,

[0039] The gas density detection sensor is a gas density transmitter composed of a pressure sensor and a temperature sensor; or...

[0040] The gas density detection sensor uses quartz tuning fork technology.

[0041] In a more preferred embodiment, the pressure sensor is installed in the gas path of the gas density relay body; the temperature sensor is installed inside or outside the gas path of the gas density relay body, or inside or outside the gas density relay body.

[0042] In a preferred embodiment, the gas density relay further includes a remote communication module connected to the intelligent control unit, used to send all or part of the following information to the background monitoring system or a remote terminal:

[0043] (a) Simulated contact verification value calculated by the intelligent control unit;

[0044] (b) Verification values ​​of alarm contacts or interlock contacts;

[0045] (c) Real-time temperature and pressure data collected by the gas density detection sensor;

[0046] (d) Operating status information of the gas density relay;

[0047] (e) Self-verification results and status information;

[0048] The remote communication module includes a wireless communication interface and / or a wired communication interface.

[0049] In a preferred embodiment, the gas density relay is powered by a battery pack or by a self-powered method.

[0050] Optionally, the gas density relay further includes a miniature drive mechanism, which is located inside or outside the gas density relay body and connected to the intelligent control unit;

[0051] The micro-drive mechanism is configured to change the gas density of the gas density relay body or the temperature of the temperature compensation element by at least one of (a) and (b) below, to simulate a change in gas density and trigger at least one of the simulated contacts in the stepped simulated contact group to generate a simulated signal:

[0052] (a) The gas pressure inside the gas density relay body is changed by a pressure regulating mechanism, the pressure regulating mechanism comprising:

[0053] The mechanical pressure regulating unit, selected from one of the following: piston drive mechanism, airbag deformation mechanism, or bellows telescopic mechanism, directly changes the gas pressure inside the gas density relay body through physical deformation or displacement; or

[0054] Thermodynamic pressure regulating mechanism, including cylinder temperature regulating mechanism, indirectly regulates gas pressure in gas density relay body by changing the temperature of gas in cylinder through heating or cooling device.

[0055] When pressure regulation is used, the gas density relay also includes an electrically controlled valve. The electrically controlled valve is located in the gas path between the gas density relay body and the gas chamber of the electrical equipment. It is used to isolate the gas path connection between the two when the pressure is regulated, and to reset the electrically controlled valve to restore the gas path connection between the two after the regulation is completed.

[0056] (b) The temperature of the temperature compensation element (such as the gas in the compensation chamber or the temperature compensation plate) of the gas density relay body is changed by a temperature adjustment mechanism, the temperature adjustment mechanism including a heating element or a cooling element.

[0057] In a second aspect, the present invention provides a low-power gas density monitoring device, the gas density monitoring device comprising a low-power gas density relay as described in any one of the first aspects.

[0058] Thirdly, the present invention provides an online self-calibration method for a low-power gas density relay, comprising:

[0059] The density difference between the gas chamber of the electrical equipment and the gas density relay body caused by the ambient temperature difference is used to drive the density detection element of the gas density relay body to produce mechanical displacement.

[0060] The mechanical displacement triggers the action of at least one of the simulated contacts in the stepped simulated contact group, generating a simulated signal.

[0061] In response to the simulated signal, the intelligent control unit detects the signal action value and / or signal return value of the triggered simulated contact;

[0062] The stepped simulated contact group is located within the gas density relay body and includes at least two simulated contacts. These simulated contacts are discretely arranged along the mechanical displacement direction of the density detection element within the gas density relay body. Each simulated contact has a different trigger position distributed along the mechanical displacement direction, and each trigger position corresponds to an action trigger density value. The action trigger density value is within the rated density value P. 20E The gas density relay body has discrete distributions above and / or below the gas density relay body, and the minimum trigger density value is greater than the alarm contact action value of the gas density relay body.

[0063] In a preferred embodiment, the method further includes: after the intelligent control unit detects the signal action value and / or signal return value of the triggered simulated contact,

[0064] Based on the signal action value and / or signal return value of the triggered simulated contact, the real-time temperature value and real-time pressure value when the triggered simulated contact is activated, the factory calibration value of the triggered simulated contact, and the factory calibration value of the alarm contact and / or the lockout contact, the intelligent control unit calculates the verification value of the alarm contact and / or the lockout contact.

[0065] In a more preferred embodiment, the specific steps for the intelligent control unit to calculate the verification values ​​of the alarm contact and / or the interlock contact include:

[0066] Obtain the simulated contact signal action value P of the gas density relay at temperature T. TFZDZ According to the simulated contact signal action value P TFZDZ The simulated contact signal action value P of the gas density relay at room temperature 20FZCS , and obtain the compensation amount ΔP at temperature T;

[0067] Based on the compensation amount ΔP and the alarm contact action value P of the gas density relay at room temperature. 20BJDZCS and / or the locking contact actuation value P 20BSDZCS The alarm contact actuation pressure value P of the gas density relay at temperature T is obtained. TBJDZ and / or the locking contact actuation pressure value P TBSDZ ;

[0068] Based on the alarm contact's actuation pressure value P TBJDZ and / or the locking contact actuation pressure value P TBSDZ The alarm action value P of the gas density relay at temperature T is obtained by converting the temperature value T and the pressure-temperature characteristic relationship of the gas to be measured. 20BJDZT and / or locking action value P 20BSDZT ;

[0069] According to the alarm action value P 20BJDZT and / or locking action value P 20BSDZT The gas density relay body is calibrated;

[0070] Among them, P 20BJDZCS P is obtained in advance by testing the alarm contact action value of the gas density relay body at room temperature. 20BSDZCS To obtain the pre-tested latching contact action value of the gas density relay at room temperature, P 20FZCS The gas density relay is pre-tested using simulated contact signal actuation values ​​of the gas density relay body at room temperature; the pressure value P based on the alarm contact actuation is then obtained. TBJDZ and / or the locking contact actuation pressure value P TBSDZ The conversion of temperature value T and pressure-temperature characteristics of the gas under test includes calculations using the Bertie-Bridgeman equation.

[0071] In a more preferred embodiment, the method further includes: uploading the verification values ​​of the alarm contacts and / or interlock contacts calculated by the intelligent control unit, the real-time temperature and pressure data collected by the gas density detection sensor, the operating status information of the gas density relay, and the self-verification results to the background monitoring system or remote terminal via the remote communication module.

[0072] In a preferred embodiment, the triggering conditions for the intelligent control unit to activate the online self-verification function include at least one of the following:

[0073] (a) Detection is performed after the device is awakened from sleep mode by an edge interrupt of the simulated signal;

[0074] (b) Execute detection in response to remote commands issued by the background monitoring system;

[0075] (c) Perform detection after waking up according to the preset cycle.

[0076] In a more preferred embodiment, the method further includes: after generating the simulation signal and before the intelligent control unit detects the signal action value and / or signal return value of the triggered simulation contact, determining whether the current simulation signal is triggered by an effective temperature difference, including:

[0077] Determine whether the rate of temperature change of the gas inside the gas density relay body is greater than or equal to a first preset threshold; and / or

[0078] Determine whether the rate of change of gas pressure in the gas chamber of the electrical equipment is less than or equal to a second preset threshold.

[0079] If the conditions are met, then perform the check value calculation;

[0080] Otherwise, discard this verification.

[0081] After the simulation contacts are reset, exit the online self-calibration and put the intelligent control unit into sleep mode.

[0082] Optionally, the gas density relay further includes a miniature drive mechanism, which is located inside or outside the gas density relay body and connected to the intelligent control unit.

[0083] If no simulation signal triggered by natural temperature difference is detected within the set time period, the gas density change is simulated to trigger the simulation contact action in the following manner (a) or (b):

[0084] (a) When pressure regulation is used:

[0085] The electrically controlled valve is used to isolate the gas path between the gas density relay body and the gas chamber of the electrical equipment.

[0086] The gas pressure in the gas path of the gas density relay body is changed by the pressure regulating mechanism.

[0087] Changes in gas density trigger the action of the simulated contact, generating a simulated signal.

[0088] The intelligent control unit responds to the simulation signal and performs a verification value calculation;

[0089] After completing the verification, reset the solenoid valve and restore the gas connection between the gas density relay body and the gas chamber of the electrical equipment;

[0090] (b) When temperature regulation is used:

[0091] The temperature of the temperature compensation element of the gas density relay body is changed by the temperature regulation mechanism.

[0092] Temperature changes in the temperature compensation element trigger the simulation contact to actuate, generating a simulation signal.

[0093] The intelligent control unit responds to the simulation signal and performs a verification value calculation;

[0094] After the calibration is completed, the temperature control mechanism will stop working.

[0095] In the above context, "no simulation signal triggered by natural temperature difference was detected" means that the temperature difference between the gas density relay body and the electrical equipment's gas chamber caused by sudden changes in ambient temperature or differences in thermal inertia did not reach the threshold condition required to trigger the action of any simulation contact in the stepped simulation contact group. This indicates that the mechanical displacement of the density detection element caused by the natural temperature difference is insufficient to trigger any simulation contact action. In this case, the micro-drive mechanism actively operates to forcibly change the gas density or temperature compensation element temperature within the gas density relay body, driving the density detection element to generate sufficient mechanical displacement to trigger at least one simulation contact action and generate a simulation signal, thereby completing online self-calibration.

[0096] Fourthly, the present invention provides a low-power gas density relay, comprising:

[0097] The gas density relay body is installed outside or inside the gas chamber of electrical equipment to detect the gas density in the gas chamber of electrical equipment;

[0098] A gas density sensor is used to monitor one or more parameters of the gas density, pressure, and temperature in the gas chamber and / or gas density relay body of electrical equipment.

[0099] A miniature drive mechanism, located inside or outside the gas density relay body, is configured to simulate gas density changes by altering the gas density or temperature of the temperature compensation element within the gas density relay body.

[0100] A stepped simulated contact group, located within the gas density relay body, includes at least two simulated contacts. These contacts are discretely arranged along the mechanical displacement direction of the density detection element within the gas density relay body. They are used to trigger an action and generate a simulated signal when the gas density within the gas density relay body decreases to the action trigger density value of the simulated contact. Each simulated contact has a different trigger position distributed along the mechanical displacement direction, and each trigger position corresponds to an action trigger density value. The action trigger density value is within the rated density value P. 20E The gas density relay body has discrete distributions above and / or below the gas density relay body, and the minimum trigger density value is greater than the alarm contact action value of the gas density relay body.

[0101] The intelligent control unit is connected to the gas density detection sensor, each simulated contact, and the micro-drive mechanism, and is configured to: acquire pressure and temperature values, and / or acquire gas density values; detect the signal action values ​​and / or signal return values ​​of the simulated contacts in the stepped simulated contact group; and control the start and stop of the micro-drive mechanism to trigger the simulated contact actions.

[0102] In a preferred embodiment, the discretely distributed action trigger density value and the nominal density value P 20ETogether they form an ordered sequence S, in which the difference between any two adjacent terms in the ordered sequence S is the same or different, forming a step-like deviation characteristic.

[0103] In a preferred embodiment, the triggering method of the simulated contact and the alarm / lock contact is: micro switch contact, magnetic-assisted electrical contact, or reed switch contact.

[0104] In a preferred embodiment, the action trigger density value of the stepped simulated contact group satisfies:

[0105] In the stepped simulated contact group, at least one simulated contact has an action trigger density value greater than the rated density value P. 20E , and / or

[0106] At least one simulated contact has an action trigger density value less than the rated density value P. 20E And it is greater than the alarm contact action value of the gas density relay body.

[0107] In a more preferred embodiment, the action trigger density value in the stepped simulated contact group is greater than the rated density value P. 20E The number of simulated contacts is greater than the action trigger density value but less than the rated density value P. 20E The number of simulated contacts.

[0108] In a preferred embodiment, the density detection element includes a pressure-sensing element or a temperature compensation element; wherein the pressure-sensing element includes a bellows or a Baden tube, and the temperature compensation element includes a bimetallic strip or a compensation chamber gas.

[0109] Specifically, the pressure-sensing element has any of the following structures:

[0110] (a) Single bellows structure:

[0111] The inner cavity of the bellows is connected to the gas chamber of the electrical equipment, and the outer cavity is connected to the temperature compensation gas chamber (referred to as the "compensation gas chamber," which is filled with standard compensation gas) of the gas density relay body; or

[0112] The outer cavity of the bellows is connected to the gas chamber of the electrical equipment, and the inner cavity is filled with standard compensating gas to form a temperature compensation gas chamber.

[0113] (b) Double-corrugated pipe structure:

[0114] It includes a first bellows and a second bellows that are mechanically coupled. The inner cavity of the first bellows is connected to the gas chamber of the electrical equipment, and the inner cavity of the second bellows is filled with a standard compensating gas to form a temperature compensating gas chamber.

[0115] (c) Baden tube structure:

[0116] The input end of the Baden tube is connected to the gas chamber of the electrical equipment, and the output end is connected to the temperature compensation gas chamber or temperature compensation plate (bimetallic strip) of the gas density relay body.

[0117] In a preferred embodiment, the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor; or,

[0118] The gas density detection sensor is a gas density transmitter composed of a pressure sensor and a temperature sensor; or...

[0119] The gas density detection sensor uses quartz tuning fork technology.

[0120] In a more preferred embodiment, the pressure sensor is installed in the gas path of the gas density relay body; the temperature sensor is installed in or outside the gas path of the gas density relay body, or inside or outside the gas density relay body.

[0121] In a preferred embodiment, the gas density relay further includes a remote communication module connected to the intelligent control unit, used to send all or part of the following information to the background monitoring system or a remote terminal:

[0122] (a) Simulated contact verification value calculated by the intelligent control unit;

[0123] (b) Verification values ​​of alarm contacts or interlock contacts;

[0124] (c) Real-time temperature and pressure data collected by the gas density detection sensor;

[0125] (d) Operating status information of the gas density relay;

[0126] (e) Self-verification results and status information;

[0127] The remote communication module includes a wireless communication interface and / or a wired communication interface.

[0128] In a preferred embodiment, the gas density relay is powered by a battery pack or by a self-powered method.

[0129] In a preferred embodiment, the micro-drive mechanism is configured to change the gas density of the gas density relay body or the temperature of the temperature compensation element by at least one of (a) and (b) below, to simulate a change in gas density within the electrical equipment and trigger at least one of the simulated contacts in the stepped simulated contact group to generate a simulated signal:

[0130] (a) The gas pressure inside the gas density relay body is changed by a pressure regulating mechanism, the pressure regulating mechanism comprising:

[0131] The mechanical pressure regulating unit, selected from one of the following: piston drive mechanism, airbag deformation mechanism, or bellows telescopic mechanism, directly changes the gas pressure inside the gas density relay body through physical deformation or displacement; or

[0132] Thermodynamic pressure regulating mechanism, including cylinder temperature regulating mechanism, indirectly regulates gas pressure in gas density relay body by changing the temperature of gas in cylinder through heating or cooling device.

[0133] When pressure regulation is used, the gas density relay also includes an electrically controlled valve. The electrically controlled valve is located in the gas path between the gas density relay body and the gas chamber of the electrical equipment. It is used to isolate the gas path connection between the two when the pressure is regulated, and to reset the electrically controlled valve to restore the gas path connection between the two after the regulation is completed.

[0134] (b) The temperature of the temperature compensation element of the gas density relay body is changed by a temperature regulating mechanism, which includes a heating element or a cooling element.

[0135] Fifthly, the present invention provides a low-power gas density monitoring device, the gas density monitoring device comprising a low-power gas density relay as described in any one of the fourth aspects.

[0136] In a sixth aspect, the present invention provides an online self-calibration method for a low-power gas density relay, comprising:

[0137] The intelligent control unit initiates an online self-verification process based on preset conditions;

[0138] Controlled by the intelligent control unit, the micro-drive mechanism simulates gas density changes by adjusting the gas density inside the gas density relay body or the temperature of the temperature compensation element;

[0139] The simulated gas density change drives the density detection element of the gas density relay body to produce mechanical displacement, triggering at least one simulated contact in the stepped simulated contact group to act and generate a simulated signal.

[0140] In response to the simulated signal, the intelligent control unit detects the signal action value and / or signal return value of the triggered simulated contact;

[0141] The stepped simulated contact group is located within the gas density relay body and includes at least two simulated contacts. These simulated contacts are discretely arranged along the mechanical displacement direction of the density detection element within the gas density relay body. Each simulated contact has a different fixed trigger position distributed along the mechanical displacement direction, and each fixed trigger position corresponds to an action trigger density value. The action trigger density value is within the rated density value P. 20E The gas density relay body has discrete distributions above and / or below the gas density relay body, and the minimum trigger density value is greater than the alarm contact action value of the gas density relay body.

[0142] In a preferred embodiment, the method further includes: based on the signal action value and / or signal return value of the triggered simulated contact, the real-time temperature value and real-time pressure value when the triggered simulated contact is activated, the factory calibration value of the triggered simulated contact, and the factory calibration value of the alarm contact and / or the lockout contact, the intelligent control unit calculates the verification value of the alarm contact and / or the lockout contact.

[0143] In a more preferred embodiment, the specific steps for the intelligent control unit to calculate the verification values ​​of the alarm contact and / or the interlock contact include:

[0144] Obtain the simulated contact signal action value P of the gas density relay at temperature T. TFZDZ According to the simulated contact signal action value P TFZDZ The simulated contact signal action value P of the gas density relay at room temperature 20FZCS , and obtain the compensation amount ΔP at temperature T;

[0145] Based on the compensation amount ΔP and the alarm contact action value P of the gas density relay at room temperature. 20BJDZCS and / or the locking contact actuation value P 20BSDZCS The alarm contact actuation pressure value P of the gas density relay at temperature T is obtained. TBJDZ and / or the locking contact actuation pressure value P TBSDZ ;

[0146] Based on the alarm contact's actuation pressure value P TBJDZ and / or the locking contact actuation pressure value P TBSDZ The alarm action value P of the gas density relay at temperature T is obtained by converting the temperature value T and the pressure-temperature characteristic relationship of the gas to be measured. 20BJDZT and / or locking action value P 20BSDZT ;

[0147] According to the alarm action value P 20BJDZT and / or locking action value P 20BSDZT The gas density relay body is calibrated;

[0148] Among them, P 20BJDZCSP is obtained in advance by testing the alarm contact action value of the gas density relay body at room temperature. 20BSDZCS To obtain the pre-tested latching contact action value of the gas density relay at room temperature, P 20FZCS The gas density relay is pre-tested using simulated contact signal actuation values ​​of the gas density relay body at room temperature; the pressure value P based on the alarm contact actuation is then obtained. TBJDZ and / or the locking contact actuation pressure value P TBSDZ The conversion of temperature value T and pressure-temperature characteristics of the gas under test includes calculations using the Bertie-Bridgeman equation.

[0149] In a more preferred embodiment, the method further includes: uploading the verification values ​​of the alarm contacts and / or interlock contacts calculated by the intelligent control unit, the real-time temperature and pressure data collected by the gas density detection sensor, the operating status information of the gas density relay, and the self-verification results to the background monitoring system or remote terminal via the remote communication module.

[0150] In a preferred embodiment, the preset conditions for initiating the online self-verification process include at least one of the following:

[0151] (a) Responding to remote commands from the background monitoring system;

[0152] (b) Execute automatically according to a preset cycle;

[0153] (c) Automatically activate when gas density deviates from the set threshold range.

[0154] In a preferred embodiment, the micro-drive mechanism triggers the simulated contact action by simulating a change in gas density in one of the following (a) or (b) ways:

[0155] (a) When pressure regulation is used:

[0156] The electrically controlled valve is used to isolate the gas path between the gas density relay body and the gas chamber of the electrical equipment.

[0157] The gas pressure in the gas path of the gas density relay body is changed by the pressure regulating mechanism.

[0158] Changes in gas density trigger the action of the simulated contact, generating a simulated signal.

[0159] The intelligent control unit responds to the simulation signal and performs a verification value calculation;

[0160] After completing the verification, reset the solenoid valve and restore the gas connection between the gas density relay body and the gas chamber of the electrical equipment;

[0161] (b) When temperature regulation is used:

[0162] The temperature of the temperature compensation element of the gas density relay body is changed by the temperature regulation mechanism.

[0163] Temperature changes in the temperature compensation element trigger the simulation contact to actuate, generating a simulation signal.

[0164] The intelligent control unit responds to the simulation signal and performs a verification value calculation;

[0165] After the calibration is completed, the temperature control mechanism will stop working.

[0166] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0167] 1) Solution 1 provides a low-power gas density relay and its online self-calibration method. A stepped simulated contact group is set within the gas density relay body. Utilizing the temperature difference between the gas density relay body and the gas chamber of the electrical equipment caused by sudden changes in ambient temperature or differences in thermal inertia, the density detection element (such as a bellows) within the gas density relay body is driven to produce mechanical displacement, passively triggering at least one simulated contact in the stepped simulated contact group to actuate, thereby achieving online self-calibration without the need for an external power supply. This solution avoids false alarms by ensuring that the density values ​​triggered by the simulated contact actuation are all higher than the alarm threshold, solving the problem of false alarms / lockout contacts caused by temperature differences. It also eliminates the need for power cable laying, transforming an industry pain point into the advantages of passive, low-power, and long-term maintenance-free online self-calibration technology.

[0168] 2) Scheme 2 provides a low-power gas density relay and its online self-calibration method. A stepped simulated contact group is set within the gas density relay body, and at least one simulated contact in the stepped simulated contact group is driven to actuate by a micro-drive mechanism. The actuation is achieved by measuring the rated density value P. 20E Multiple simulated contacts are discretely distributed nearby, significantly reducing the spacing between the trigger density values ​​of each simulated contact. This allows the micro-drive mechanism to trigger calibration with minimal energy consumption by finely adjusting the air pressure or the temperature compensation component. This solution consumes far less power than existing technologies, requiring only battery power to meet long-term online self-calibration needs. No power cable is needed, achieving active, low-power, long-term maintenance-free online self-calibration. Attached Figure Description

[0169] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0170] Figure 1 This is a schematic diagram illustrating the principle of temperature difference generation between the gas density relay and the gas chamber of the electrical equipment.

[0171] Figure 2 This is a top view of the stepped simulated contact group installed in the gas density relay body of the present invention.

[0172] Figure 3 This is a schematic diagram of the self-calibrating relative cavity bellows structure used in this invention.

[0173] Figure 4 The diagram shows the module composition of the gas density relay as illustrated in Examples 1 and 2.

[0174] Figure 5 This is a schematic diagram of the online self-calibration process of the gas density relay shown in Example 1.

[0175] Figure 6 This is a schematic diagram of the online self-calibration process of the gas density relay shown in Example 2.

[0176] Figure 7 The diagrams shown in Examples 1 and 2 illustrate the structure of the gas density relay, in which the miniature drive mechanism employs a temperature regulation mechanism.

[0177] Figure 8 This is a schematic diagram of the module composition of the gas density relay shown in Example 3.

[0178] Figures 9(a)-9(b) This is a schematic diagram of the gas density relay shown in Example 3, in which the micro-drive mechanism adopts a pressure regulating mechanism.

[0179] Figure 10 This is a schematic diagram of the online self-calibration process of the gas density relay shown in Example 3.

[0180] Legend:

[0181] 1. Gas density relay body;

[0182] 101. Display mechanism;

[0183] 10101, Baden tube; 10102, bimetallic strip; 10103, pointer;

[0184] 10201, Bellows; 10202, Support frame; 10203, Alarm / lock contact; 10204, Guide rod; 10205, Fixing plate; 10206, Alarm / lock contact adjusting screw; 10207, Compensating air chamber; 103, Stepped simulated contact group; 1030, Simulated contact; 10301, Simulated contact adjusting screw;

[0185] 2. Pressure sensor; 3. Temperature sensor; 4. Electrically controlled valve;

[0186] 5. Miniature drive mechanism; 51. Pressure regulating mechanism; 52. Temperature regulating mechanism;

[0187] 7. Intelligent control unit; 701. Power supply; 702. Remote communication module;

[0188] 9. Multi-port connector; 11. Electrical equipment gas chamber; 12. Secondary circuit. Detailed Implementation

[0189] To make the above-mentioned objects, features, and advantages of the present invention clearer, the present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art and are exemplary only, not restrictive.

[0190] A gas density relay is a pressure detection device with temperature compensation, installed inside or outside the gas chamber of electrical equipment. Affected by changes in ambient temperature, light, or wind speed, the gas density relay body 1 and the electrical equipment gas chamber 11 differ in surface area, material properties, and volume. Furthermore, SF6 gas has poor thermal conductivity, and the electrical equipment gas chamber 11 is larger and contains more SF6 gas, while the gas density relay body 1 is smaller and contains less SF6 gas. This difference in heat absorption and dissipation efficiency leads to a temperature difference. Figure 1 As shown in the figure. Actual measurements show that in Xinjiang, the temperature difference between the two can reach 10–15℃.

[0191] In applications in this field, it is generally necessary to maintain, as far as possible, the temperature at the mounting location of the gas density relay body 1 and the temperature of the electrical equipment's gas chamber 11 (such as an arc-extinguishing chamber). A temperature difference between the two will introduce measurement deviations and, in severe cases, may cause false alarms.

[0192] In the substation operating environment, the gas density relay body 1 and the electrical equipment gas chamber 11 have asynchronous temperature responses due to the difference in thermal inertia: thermal inertia, as a physical property that resists temperature changes, depends on the specific heat capacity, mass and structure of the material; the gas density relay body 1 is small in size and has low thermal inertia, so its temperature response is fast; the electrical equipment gas chamber 11 is large in size and has high thermal inertia, so its temperature response is lagging; this difference leads to an instantaneous temperature difference between the two.

[0193] Based on the aforementioned temperature difference characteristics, this invention generates a gas density difference between the temperature compensation chamber of the gas density relay body 1 and the electrical equipment chamber 11. This gas density difference drives the density detection element (such as a bellows) to produce a mechanical displacement. The mechanical displacement triggers the action of the simulated contact, thereby achieving online self-calibration. This transforms the risk of false alarms caused by temperature difference into a technical advantage, eliminating the need for laying power cables and enabling passive online self-calibration and long-term maintenance-free operation of the gas density relay.

[0194] Example 1

[0195] like Figure 1 The diagram illustrates the principle behind the temperature difference between a low-power gas density relay and the gas chamber 11 of an electrical device. The temperature of the temperature compensation element (bimetallic strip or gas in the compensation chamber) in the gas density relay body 1, and the temperature of the gas inside the electrical device's gas chamber 11, are mainly affected by the following factors: direct solar radiation, thermal radiation and convection between the casing and the atmosphere, thermal conduction between the casing and the fixed connection mechanism, and thermal convection of the internal gas. Due to differences in surface radiation characteristics, dimensions and geometric characteristics, materials, internal working conditions, and spatial orientation between the gas density relay body 1 and the electrical device's gas chamber 11, their thermal inertia differs. This results in a discrepancy between the rate of temperature change of the temperature compensation element and the gas temperature measured by the pressure sensing element (bellows or Baden tube) in response to changes in the external ambient temperature, thus generating a temperature difference. According to the measurement principle of the gas density relay body 1, the temperature sensed by the temperature compensation element must match the gas temperature measured by the pressure sensing element to accurately reflect the density of the measured gas. Therefore, when the temperature sensed by the temperature compensation element is inconsistent with the actual gas temperature measured by the pressure sensing element, there will be a certain density deviation between the density value indicated by the gas density relay body 1 and the actual gas density value in the gas chamber 11 of the electrical equipment. The greater the temperature difference, the greater the density deviation. This deviation is not only reflected in the indication of the pointer 10103 of the display mechanism 101 of the gas density relay body 1 (e.g., Figure 7 When the deviation reaches a certain threshold, it will also trigger the alarm / lock contact 10203. This invention, a low-power gas density relay, is based on this density difference caused by changes in ambient temperature, and adds a stepped simulation contact group 103 (such as...). Figure 4 This completes the verification of the alarm / lock contact 10203 of the gas density relay body 1.

[0196] In a further optimization scheme, based on the rated density value of the gas density relay body 1 and the actual gas density value that may be filled into the gas chamber 11 of the electrical equipment, the number of simulated contacts of the stepped simulated contact group 103 is increased so that the contacts can be verified under small density difference conditions or when the density is finely adjusted by the micro drive mechanism 5 (pressure regulating mechanism 51 or temperature regulating mechanism 52).

[0197] This embodiment 1 provides a core implementation method of Scheme 1, which relies solely on the natural temperature difference between the gas density relay body 1 and the electrical equipment gas chamber 11 to drive the simulated contact action, thereby achieving completely passive online self-calibration.

[0198] It should be noted that the passive online self-calibration described in this embodiment refers to the passive driving link of the simulated contact action, that is, the simulated contact does not require an external power supply to drive it, but is driven only by the density difference generated by the temperature difference; the power supply of the intelligent control unit 7 can be a small battery or a self-powered module, without the need to lay a dedicated power cable.

[0199] Figures 2-4 , Figure 7 The diagram shows the structure of the low-power gas density relay in this embodiment. This gas density relay is used to monitor the density of sulfur hexafluoride (SF6) gas in the gas chamber 11 of high-voltage electrical equipment (such as circuit breakers and gas-insulated switchgear GIS) in real time, and can perform online self-calibration without interrupting power to the electrical equipment.

[0200] The gas density relay body 1 is connected to the gas chamber 11 of the electrical equipment through a gas pipeline, and includes a pressure detection element bellows 10201, a stepped simulation contact group 103, a pressure sensor 2, a temperature sensor 3, an alarm / lock contact 10203, an intelligent control unit 7, and a remote communication module 702.

[0201] The inner cavity of the bellows 10201 is connected to the electrical equipment gas chamber 11 to provide feedback on the gas density status in the electrical equipment gas chamber 11, and the outer cavity is connected to the compensation gas chamber 10207 (filled with standard compensation gas) of the gas density relay body 1.

[0202] A stepped simulation contact group 103 is fixedly installed on the displacement output path of the bellows 10201, including at least two microswitch contacts as simulation contacts 1030. Simulation contact adjusting screws 10301 are discretely arranged along the mechanical displacement direction of the bellows 10201. These screws are used to trigger an action and generate a simulation signal when the gas density inside the gas density relay body 1 changes due to an ambient temperature difference between the gas density relay body 1 and the electrical equipment gas chamber 11, thereby driving the density detection element to generate mechanical displacement. The density detection element includes a pressure-sensing element (such as a bellows or Baden tube) or a temperature compensation element (such as a bimetallic strip or a gas compensation chamber gas). In this embodiment, the density detection element is the bellows 10201. The trigger density value for each simulation contact 1030 is preset and calibrated, all within the rated density value P. 20E Discrete distributions above and / or below (e.g., P) 20E -0.015MPa, P 20E +0.015MPa, P 20E+0.030MPa, P 20E +0.045MPa), and all action trigger density values ​​are higher than the action value of alarm / lock contact 10203 (e.g., P). 20E -0.05MPa). In actual conditions, the gas density filled into the electrical equipment gas chamber 11 is within the rated density value P. 20E The temperature is near (including a range slightly above or slightly below) the operating value of the alarm / lock contact 10203. Due to asynchronous temperature changes, when the temperature of the gas in the electrical equipment gas chamber 11 is lower than the temperature of the gas in the compensation gas chamber 10207 where the bellows 10201 of the gas density relay body 1 is located, the displacement output terminal of the bellows 10201 moves towards the alarm / lock contact 10203, triggering at least one simulated contact 1030 in the stepped simulated contact group 103 to operate. Conversely, the simulated contact group 103 is reset.

[0203] In this embodiment, the pressure sensor 2 is installed in the gas line of the gas density relay body 1, and the temperature sensor 3 is installed in the compensation gas chamber 10207.

[0204] like Figure 4 As shown, the intelligent control unit 7 is connected to the pressure sensor 2, the temperature sensor 3, and all the simulated contacts 1030 in the stepped simulated contact group 103, respectively, to collect data in real time and transmit the data to the background monitoring system through the remote communication module 702. In a further optimization scheme, the intelligent control unit 7 adopts a redundant design (such as including a first intelligent control unit and a second intelligent control unit) to improve system reliability and prevent failures such as program crashes.

[0205] Example 1 does not include a micro-drive mechanism 5 (pressure regulation mechanism 51 or temperature regulation mechanism 52), but uses natural temperature difference for self-calibration. Therefore, the power supply 701 can be a small battery pack or a self-powered module.

[0206] Combination Figure 5 As shown, this embodiment 1 also provides an online self-calibration method for a low-power gas density relay, the specific steps of which are as follows:

[0207] Step S11, Temperature Difference Drives Density Deviation: When the ambient temperature changes abruptly (such as increased or decreased sunlight, or changes in wind speed), the gas density relay body 1, due to its small size and low thermal inertia, responds to temperature faster than the electrical equipment gas chamber 11, which is larger and has higher thermal inertia, thus creating an instantaneous temperature difference Δt between the two (see principle). Figure 1 This temperature difference will cause a deviation between the gas density (pressure) in the compensation chamber 10207 inside the gas density relay body 1 and the actual gas density in the electrical equipment chamber 11.

[0208] Step S12, density deviation drives mechanical displacement: The density deviation acts on the density detection element (such as a bellows), overcomes the elastic force of the density detection element itself, and drives the bellows 10201 to generate an axial mechanical displacement ΔL.

[0209] Step S13: Trigger the action of the simulation contact 1030: The displacement ΔL of the bellows 10201 pushes the guide rod 10204. When the displacement reaches the preset trigger position of a simulation contact 1030 in the stepped simulation contact group 103, the micro switch of the simulation contact 1030 is activated (such as the normally open contact closing or the normally closed contact opening), generating a step-type simulation signal.

[0210] Step S14, Intelligent Control Unit 7 Response and Data Acquisition: Intelligent Control Unit 7 is normally in a low-power sleep state. The edge of the simulation signal (rising or falling edge) will trigger a hardware interrupt, waking up Intelligent Control Unit 7. Upon waking, Intelligent Control Unit 7 immediately records the following data:

[0211] The specific ID of the triggered simulation contact 1030.

[0212] At the instant the simulated contact 1030 actuates, the reading P of pressure sensor 2... TFZDZ .

[0213] The reading T of temperature sensor 3 at the instant the simulated contact 1030 actuates.

[0214] Step S15: Temperature Difference Validity Judgment: The intelligent control unit 7 calculates the rate of change of gas temperature inside the gas density relay body 1 (dT / dt) based on the most recent temperature readings (e.g., 3 or 5 times), and simultaneously calculates the rate of change of gas pressure in the electrical equipment gas chamber 11 (dP / dt) based on the data collected by the pressure sensor 2. If dT / dt ≥ threshold (e.g., 0.5℃ / s) and dP / dt ≤ threshold (e.g., 0.001MPa / s), then the current simulation signal is determined to be caused by an effective temperature difference, and a self-verification calculation is performed. Otherwise, the collected data is discarded.

[0215] Step S16, Check value calculation:

[0216] Obtain the simulated contact signal action value P of the gas density relay at temperature T. TFZDZ According to the simulated contact signal action value P TFZDZ The simulated contact signal action value P of the gas density relay at room temperature (20℃) 20FZCS The compensation amount ΔP at temperature T is calculated.

[0217] Based on the compensation amount ΔP and the alarm contact action value P of the gas density relay at room temperature. 20BJDZCS and / or the locking contact actuation value P 20BSDZCSThe alarm contact activation pressure value P of the gas density relay at temperature T is calculated. TBJDZ and / or the locking contact actuation pressure value P TBSDZ ;

[0218] Based on the alarm contact's actuation pressure value P TBJDZ and / or the locking contact actuation pressure value P TBSDZ The alarm action value P of the gas density relay at temperature T is obtained by converting the temperature value T and the pressure-temperature characteristic relationship of the gas to be measured. 20BJDZT and / or locking action value P 20BSDZT ;

[0219] According to the alarm action value P 20BJDZT and / or locking action value P 20BSDZT The gas density relay body 1 is calibrated;

[0220] Among them, P 20BJDZCS To obtain the alarm contact action value of the gas density relay in advance through the gas density relay body 1 at room temperature, P 20BSDZCS To obtain the pre-tested latching contact action value of the gas density relay body 1 at room temperature, P 20FZCS The gas density relay is pre-obtained by testing the simulated contact signal action value of the gas density relay body 1 at room temperature; the pressure value P based on the alarm contact action value is... TBJDZ and / or the locking contact actuation pressure value P TBSDZ The conversion of temperature value T and pressure-temperature characteristics of the gas under test includes calculations using the Bertie-Bridgeman equation.

[0221] Step S17, Data Reporting and Sleep Mode: The intelligent control unit 7 transmits the verification results (such as contact ID, P) through the remote communication module 702. TFZDZ T, P 20BJDZT The system uploads real-time monitoring data (including whether the device is in a qualified state) and equipment status information to the background monitoring system. After the upload is complete, the intelligent control unit 7 resets the relevant flags and re-enters low-power sleep mode, waiting for the next simulation signal interruption or periodic wake-up. When the temperature difference is eliminated, the displacement of the bellows 10201 automatically recovers, and the simulation contact 1030 resets synchronously.

[0222] This case will be illustrated with a specific set of data:

[0223] In practical implementation, the states of the stepped simulation contact group 103 and the alarm / lock contact 10203 can be designed to be normally open or normally closed. During the self-verification process, the action logic judgment of the contact state change is executed by the intelligent control unit 7. In this embodiment, the contact state is designed to be closed when it is below the action density value of the contact and open when it is above the action density value of the contact.

[0224] In this embodiment, the rated density value P of a low-power gas density relay is used. 20E =0.60MPa, leakage alarm contact action value P 20XLBJ =0.57MPa (optional), low-pressure alarm contact action value P 20DYBJ =0.55MPa, locking contact actuation value P 20BS =0.50MPa, simulation contact 1030 has the first simulation contact P 20FZ1 =0.585MPa, second simulation contact P 20FZ2 =0.615MPa, third simulation contact P 20FZ3 =0.63MPa, fourth simulation contact P 20FZ4 For example, with a pressure of 0.645 MPa, the actual density value P added to the gas chamber 11 of the electrical equipment by the user at the site is... 20SJ The pressure is 0.62 MPa. At this time, the leakage alarm contact P... 20XLBJ The low-voltage alarm contact P is in the off state. 20DYBJ When in the open state, the latching contact P is closed. 20BS In the disconnected state, the first simulated contact P 20FZ1 In the disconnected state, the second simulated contact P 20FZ2 In the off state, the third simulated contact P 20FZ3 In the closed state, the fourth simulated contact P 20FZ4 It is in a closed state.

[0225] For example, in Shanghai in July, at 8:00 AM, the temperature of the electrical equipment gas chamber 11 is 20℃. Assume the density P of the electrical equipment gas chamber 11 at that time... 20 The pressure was 0.61 MPa. By 9:30 AM, the temperature in the electrical equipment's gas chamber 11 had risen to 22°C, with a pressure of 0.6159 MPa and a corresponding density of P. 20 The pressure was 0.61 MPa; the temperature on the gas density relay side rose to 31℃, and the measured pressure was 0.6159 MPa, corresponding to a density P. 20The pressure was 0.5847 MPa. At this point, the simulated contact 1030, with a set value of 0.585 MPa, activated. The calculated temperature change rate on the gas density relay side was 0.122℃ / minute (within one and a half hours), while the pressure remained essentially unchanged. This temperature change rate, pressure change rate, and the characteristics of the simulated contact 1030 activation met the online self-check trigger conditions, and an online self-check calculation and analysis were then performed.

[0226] Taking the verification of the low-pressure alarm normal operation contact as an example, the first step is to calculate the low-pressure alarm pressure compensation difference ΔP, assuming the factory value P of the alarm contact. 20BJCS (0.5544MPa) and the factory operating value P of the simulation contact 1030 20XZ1CS The pressure difference (0.5854MPa) is 0.031MPa; the second step is to calculate the simulated pressure value P of the low-pressure alarm contact during its normal operation. BJ P BJ =0.6159-0.031, thus obtaining P BJ =0.5849MPa; Third step, simulate the pressure value P based on the normal operation of the low-pressure alarm contact. BJ Given (0.5849 MPa) and temperature T (31℃), calculate P. 20BJ =0.5553MPa. The positive pressure density P of the low-pressure alarm contact. 20BJ Its factory density P 20EBJ The deviation of (0.55MPa) is within the accuracy range of grade 1.0, and the verification conclusion is qualified.

[0227] This embodiment utilizes the temperature difference between the gas density relay body 1 and the electrical equipment gas chamber 11 caused by changes in ambient temperature, which is then converted into a pressure difference to drive the action of the simulated contacts 1030 in the stepped simulated contact group 103. This verifies the contact action value of the gas density relay body 1 without the need for an additional contact action driving device. This not only reduces the power consumption of the self-calibrating gas density relay but also reduces the energy consumption configuration requirements of the wired remote transmission system. It improves the system adaptability of the self-powered wireless remote transmission self-calibrating density relay and extends the battery life of the battery-powered wireless remote transmission self-calibrating density relay.

[0228] Example 2

[0229] This embodiment 2 provides another core implementation of scheme 1. When the natural temperature difference is insufficient, a micro-drive mechanism 5 (such as a temperature regulation mechanism 52 or a pressure regulation mechanism 51) can be used to actively generate gas density changes for online self-verification. This embodiment uses the temperature regulation mechanism 52 as the main example for illustration.

[0230] like Figure 3 , Figure 4 , Figure 7As shown, this embodiment inherits all the technical features of embodiment 1 in terms of structure. At the same time, a temperature adjustment mechanism 52 is added on the basis of the structure of embodiment 1. This mechanism is used to perform low-power active compensation to complete self-verification when the natural temperature difference is insufficient to trigger any simulation contact 1030.

[0231] The temperature regulation mechanism 52 is installed inside or outside the gas density relay body 1, connected to and controlled by the intelligent control unit 7. The temperature regulation mechanism 52 heats up and / or cools down the gas in the compensation chamber 10207 in the gas density relay body 1, thereby increasing or decreasing the pressure of the gas in the compensation chamber 10207. The pressure change drives the simulation contact 1030 in the stepped simulation contact group 103 to actuate, completing the self-calibration process.

[0232] The fixed end of the bellows 10201 is mounted on the support frame 10202, and the free end of the bellows 10201 is connected to the fixing plate 10205 through the guide rod 10204. The alarm / lock contact adjusting screw 10206 and the simulation contact adjusting screw 10301 are both fixed on the fixing plate 10205. The alarm / lock contact 10203 and the simulation contact 1030 are both fixedly mounted on the support frame 10202.

[0233] When the temperature regulating mechanism 52 heats the compensation chamber 10207, causing the gas inside to expand due to heat, the pressure inside the compensation chamber 10207 increases, pushing the free end of the bellows 10201 away from the fixed end. This movement drives the fixed plate 10205 to move synchronously via the guide rod 10204, thereby displacing the simulation contact adjusting screw 10301 fixed on the fixed plate 10205 towards the free end. When the displacement reaches the preset trigger position of the simulation contact 1030, the simulation contact 1030 activates, triggering the self-calibration process.

[0234] Combination Figure 6 As shown in Example 2, this embodiment provides another online self-calibration method for low-power gas density relays. The specific steps are as follows:

[0235] Step S21, Determine if the natural temperature difference is insufficient: The intelligent control unit 7 initiates the online self-verification process under the following two scenarios. If no simulation signal triggered by the natural temperature difference is detected within a preset time, it is determined that the natural temperature difference is insufficient to trigger the simulation contact 1030, and then the micro-drive mechanism 5 (temperature regulation mechanism 52 in this embodiment) is activated:

[0236] Scenario 1: Periodic wake-up check

[0237] The intelligent control unit 7 wakes up from low-power sleep mode at a preset cycle (e.g., once a day), collects real-time data from pressure sensor 2 and temperature sensor 3, and calculates the estimated temperature difference between the gas density relay body 1 and the electrical equipment gas chamber 11. If there is a significant temperature difference (e.g., >2℃), but no simulation signal triggered by the natural temperature difference is detected within a preset waiting window (e.g., 5 minutes), it is determined that the displacement generated by the natural temperature difference is insufficient to trigger self-checking.

[0238] Scenario 2: Verification command triggers check

[0239] After receiving the remote start verification command from the background monitoring system, the intelligent control unit 7 first checks the current operating conditions (such as stable pressure and no alarm / lock signals). If no simulation signal triggered by natural temperature difference is detected within the command response timeout period (such as 1 minute), it is determined that active compensation is needed to achieve self-verification.

[0240] Step S22: Activate Active Temperature Compensation: The intelligent control unit 7 activates the temperature regulation mechanism 52 according to the preset configuration to perform low-power active compensation operation. The specific process is as follows:

[0241] (1) Heating temperature compensation element: The intelligent control unit 7 controls the temperature regulation mechanism 52 to start, applying a precisely controlled, low-power, short-time heating pulse to the compensation gas chamber 10207 inside the gas density relay body 1. In other embodiments, the temperature compensation element may be a bimetallic strip 10102.

[0242] (2) Equivalent density change: After the gas in the compensation chamber 10207 is heated and expands, the pressure increases, which pushes the free end of the bellows 10201 to move the fixed plate 10205 towards the fixed end of the bellows 10201 through the guide rod 10204. Its effect is equivalent to the displacement of the free end of the bellows 10201 caused by the decrease in gas density in the electrical equipment chamber 11.

[0243] Step S23, Drive Displacement and Contact Trigger: The equivalent density change described above drives the bellows 10201 to generate a small mechanical displacement, triggering the action of one of the simulated contacts 1030 in the stepped simulated contact group 103, generating the simulated signal FZ_Signal.

[0244] Step S24, Signal Acquisition and Data Recording: The intelligent control unit 7 captures the simulation signal FZ_Signal in real time and records the triggered simulation contact ID and the reading P of the pressure sensor 2 at the moment of action of simulation contact 1030. TFZDZ The temperature sensor 3 reads T at the moment of action of the simulated contact 1030.

[0245] Step S25: Perform verification calculation: Same as step S16 of Example 1.

[0246] Step S26: Restore the state before verification: After the verification calculation is completed, the intelligent control unit 7 controls the temperature regulation mechanism 52 to stop working. The gas in the compensation gas chamber 10207 cools naturally with the ambient temperature, causing the free end of the bellows 10201 to reset away from the fixed end, and the simulated contact 1030 of the stepped simulated contact group 103 is restored to its initial state.

[0247] Step S27, Data Reporting and Sleep Mode: The intelligent control unit 7 uploads the verification results and real-time device status information to the background monitoring system via the remote communication module 702. After the upload is completed, the intelligent control unit 7 resets the relevant control flags and re-enters the low-power sleep mode, waiting for the next trigger (periodic wake-up or remote command).

[0248] In this embodiment, when the natural temperature difference is insufficient to trigger the verification, the micro-drive mechanism 5 is intelligently activated for low-power active compensation. Only a small amount of pressure / temperature adjustment is needed to forcibly generate the simulation signal 1030, ensuring that the online self-verification function can be reliably executed under various environmental conditions such as small temperature difference and slow temperature change. This further improves the environmental adaptability of the gas density relay's online self-verification and maintains the system's low power consumption and long-term maintenance-free characteristics.

[0249] Example 3

[0250] This embodiment 3 provides a core implementation of scheme two, which actively controls the movement of the simulated contacts 1030 of the stepped simulated contact group 103 through the micro-drive mechanism 5, thereby achieving online self-verification. It should be noted that the driving method of the micro-drive mechanism 5 is not unique; it can employ either a pressure regulating mechanism 51 or a temperature regulating mechanism (which operates on the same principle as the temperature regulating mechanism 52 in embodiment 2, indirectly changing pressure / density by adjusting temperature). This embodiment uses the pressure regulating mechanism 51 as the primary example for illustration.

[0251] like Figure 8 , Figures 9(a)-9(b) As shown, pressure sensor 2 is mounted on multi-port connector 9, or connected to multi-port connector 9 via a pipeline. Pressure sensor 2 is connected to the gas chamber 11 of electrical equipment through the gas passage of multi-port connector 9, and collects gas pressure data in real time within the gas chamber 11 of electrical equipment and the gas density relay body 1, transmitting the data to intelligent control unit 7. Temperature sensor 3 is mounted inside or outside the housing of gas density relay body 1, and collects gas temperature data in real time within the gas chamber 11 of electrical equipment and the housing of gas density relay body 1, transmitting the data to intelligent control unit 7.

[0252] The basic structural framework of this embodiment 3 differs from that of embodiment 2 in that:

[0253] (1) Difference in driving logic: The micro-drive mechanism 5 is no longer a supplementary drive for natural temperature difference, but the main driving force for self-calibration. The intelligent control unit 7 directly triggers the action of the simulation contact 1030 by actively controlling the start and stop of the micro-drive mechanism 5 (whether it is pressure regulation or temperature regulation), without relying on the ambient temperature difference.

[0254] (2) Pressure regulating mechanism 51: When the micro-drive mechanism 5 adopts the pressure regulating mechanism 51, the pressure regulating mechanism 51 increases or decreases the pressure of the gas in the pressure-sensing element (Baden tube 10101 or bellows 10201) in the gas density relay body 1. The pressure change causes the simulation contact 1030 in the stepped simulation contact group 103 to act, completing the self-calibration process. In this embodiment 3, the pressure regulating mechanism 51 adopts a thermodynamic pressure regulating mechanism, which changes the gas temperature in the cylinder through a heating device, thereby indirectly regulating the gas pressure detected by the pressure-sensing element in the gas density relay body 1. In a further optimized embodiment, the pressure regulating mechanism 51 can also adopt a mechanical pressure regulating unit, specifically selected from one of the piston drive mechanism, airbag deformation mechanism, or bellows telescopic mechanism, which directly changes the gas pressure in the gas density relay body 1 through physical deformation or displacement.

[0255] When the micro-drive mechanism 5 adopts the pressure regulating mechanism 51, the gas density relay also includes an electrically controlled valve 4. The electrically controlled valve 4 is installed on the gas connection line between the gas density relay body 1 and the electrical equipment gas chamber 11, and is controlled by the intelligent control unit 7. It is used to isolate the gas connection line between the gas density relay body 1 and the electrical equipment gas chamber 11 during self-calibration.

[0256] (3) Stepped contact density difference: The multiple contacts (e.g., 4) of the stepped simulated contact group 103 have an actuation trigger density value within the rated density value P. 20E The surrounding area is very densely and discretely distributed. For example: P 20E +0.02MPa, P 20E +0.01MPa, P 20E ,P 20E -0.01MPa, P 20E -0.02MPa. The interval between adjacent contact action values ​​is significantly reduced (e.g., ≤0.01MPa), and the minimum action trigger density value is still greater than the alarm contact action value of the gas density relay body 1 (e.g., P). 20E -0.05MPa).

[0257] Regardless of whether the micro-drive mechanism 5 uses pressure regulation or temperature regulation, the dense contact spacing can significantly reduce the amount of regulation required to trigger the simulation contact 1030—if it is pressure regulation, only a small pressure change is required; if it is temperature regulation, only a small temperature rise / fall is required, which greatly reduces the drive energy consumption required for a single verification.

[0258] Combination Figure 10 As shown in the figure, this embodiment 3 also provides an online self-calibration method for a low-power gas density relay, the specific steps of which are as follows:

[0259] Step S31: Start the self-verification process: The intelligent control unit 7 actively wakes up from the low-power sleep state (or keeps running) and starts the online self-verification process according to preset conditions (such as responding to remote instructions from the background monitoring system, reaching the preset verification cycle, or detecting that the gas density deviates from the threshold and needs to be verified).

[0260] Step S32: Selecting the driving method and target contact: The intelligent control unit 7 selects the pressure regulation or temperature regulation method based on the current pressure, temperature, and equipment configuration parameters, and determines the desired simulated contact 1030 to be triggered. Typically, a simulated contact 1030 near the current pressure / density value is selected to ensure minimal adjustment of the micro-drive mechanism 5, further reducing energy consumption.

[0261] Step S33: The micro-drive mechanism 5 is controlled to simulate minute changes in gas density.

[0262] (1) Isolation gas path (only pressure regulation needs to be performed): If the pressure regulation method is selected, the intelligent control unit 7 first controls the electric control valve 4 to close, cutting off the gas path connection between the gas density relay body 1 and the electrical equipment gas chamber 11, forming an independent verification isolation chamber to avoid the verification process affecting the actual gas state of the electrical equipment gas chamber 11; if the temperature regulation method is selected, there is no need to isolate the gas path (only the temperature of the temperature compensation element is adjusted).

[0263] (2) Precise Pressure / Temperature Adjustment: If pressure adjustment is selected, the intelligent control unit 7 controls the pressure adjustment mechanism 51 to start, making extremely precise adjustments to the gas pressure in the isolation chamber (e.g., corresponding to pressure changes of ±0.01 to 0.03 MPa). Through pressurization or depressurization, it accurately simulates minute changes in gas density. If temperature adjustment is selected, the intelligent control unit 7 controls the temperature adjustment mechanism 52 to start, making minute temperature adjustments to the temperature compensation element (e.g., the gas in the compensation chamber 10207) (e.g., ±1 to 3°C). Through temperature changes, it indirectly simulates minute changes in gas density.

[0264] Step S34: Trigger the simulated contact action: The aforementioned minute pressure / density change drives the density detection element (such as the bellows 10201) to generate a corresponding mechanical displacement. When the displacement reaches the preset trigger position of the target simulated contact in the stepped simulated contact group 103, the simulated contact 1030 actuates, generating a simulated signal FZ_Signal. Due to the dense spacing of the simulated contacts 1030, the required pressure / temperature adjustment for this process is minimal.

[0265] Step S35, Signal Acquisition and Data Recording: The intelligent control unit 7 captures the simulation signal FZ_Signal in real time and simultaneously records the triggered simulation contact ID and the pressure reading P of the pressure sensor 2 at the moment of action of simulation contact 1030. T The temperature sensor 3 reads T at the instant of action of the simulated contact 1030.

[0266] Step S36: Perform verification calculation: Same as step S16 in Example 1, calculate the verification value of alarm / lock contact 10203.

[0267] Step S37: Restore the state before verification:

[0268] If the pressure regulation method is selected, after the verification calculation is completed, the intelligent control unit 7 controls the pressure regulation mechanism 51 to restore the pressure in the isolation chamber to the initial value before regulation. Then, it controls the electronic control valve 4 to reset, restoring the gas path connection between the gas density relay body 1 and the electrical equipment gas chamber 11. If the temperature regulation method is selected, the intelligent control unit 7 controls the temperature regulation mechanism 52 to stop working, allowing the temperature compensation element (such as the compensation gas chamber 10207) to naturally return to its initial value. Both methods require ensuring that the gas density relay returns to normal monitoring status.

[0269] Step S38, Data Reporting and Sleep Mode: The intelligent control unit 7 uploads the verification result and real-time device status information to the background monitoring system via the remote communication module 702. After the upload is completed, the intelligent control unit 7 resets the relevant control flags and re-enters low-power sleep mode, waiting for the next trigger.

[0270] In one embodiment, the intelligent control unit 7 can control the micro-drive mechanism 5 (whether for pressure regulation or temperature regulation) to sequentially trigger multiple different target simulated contacts in the stepped simulated contact group 103 (e.g., a contact with a density value higher than the rated density P). 20EH The simulated contact point has a density value P lower than the rated density value. 20EL By acquiring multi-point verification data (simulated contact points), a more comprehensive analysis can be conducted to further improve the accuracy of the verification results.

[0271] This embodiment achieves low-power driving: by using the rated density value P 20E The densely arranged stepped simulated contact groups 103 allow the micro-drive mechanism 5 to trigger the simulated contact 1030 with only extremely small adjustments (e.g., pressure adjustment <0.005MPa, temperature adjustment <1℃). Compared to existing technologies that require significant changes in pressure / temperature (e.g., >0.05MPa or >5℃) to trigger a single simulated contact 1030, the verification energy consumption in this embodiment is reduced from 20W-30W to 3W-5W, significantly extending the battery life of the battery-powered device and the battery's lifespan.

[0272] Furthermore, in this embodiment, the intelligent control unit 7 can autonomously initiate the verification process, precisely controlling the adjustment amplitude and direction of the micro-drive mechanism 5 to trigger any target simulation contact 1030 (higher or lower than the rated density value P) as needed. 20E This enables flexible and programmable online self-calibration. Simultaneously, the minute adjustments avoid excessive interference with the system's pneumatic circuitry or temperature compensation components. The dense contact distribution combined with high-precision sensor data allows for multi-point linear calibration, improving the accuracy and reliability of the calculation of the alarm / lockout contact 10203 calibration value.

[0273] The ultra-low power consumption of this embodiment enables the device to support regular online self-calibration (such as once a month) for several years or more with only a small battery or self-powered module, completely eliminating the need for wired power supply upgrades. It is especially suitable for old substations or passive scenarios without external power supply, reducing on-site deployment and maintenance costs.

[0274] It should be noted that the gas density relay mentioned in this invention generally refers to a structure in which its components are designed as an integrated structure; while the gas density monitoring device generally refers to a structure in which its components are designed as separate structures, which can be flexibly assembled through standardized interfaces.

[0275] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention.

Claims

1. A low power gas density relay characterized by, The gas density relay comprises: a gas density relay body installed outside or inside an electrical equipment gas chamber for detecting the gas density in the electrical equipment gas chamber; a gas density detection sensor for monitoring one or more parameters of the density, pressure and temperature of the gas in the electrical equipment gas chamber and / or the gas density relay body; The stepped simulation contact group arranged in the gas density relay body comprises at least two simulation contacts which are discretely arranged along the mechanical displacement direction of the density detection element in the gas density relay body; wherein each simulation contact has different trigger positions distributed along the mechanical displacement direction, and each trigger position corresponds to an action trigger density value, the action trigger density value is discretely distributed above and / or below the rated density value P 20E , and the minimum action trigger density value is greater than the alarm contact action value of the gas density relay body. a smart control unit connected to the gas density detection sensor and each simulation contact, configured to collect pressure values and temperature values and / or gas density values, and detect the signal action value and / or signal return value of the triggered simulation contact.

2. The low power gas density relay of claim 1, wherein, The discrete distribution of the action trigger density value and the rated density value P 20E Together constitute an ordered sequence S, the difference between any two adjacent items in the ordered sequence S is the same or different, forming a stepped deviation characteristic.

3. The low power gas density relay of claim 1, wherein, The triggering mode of the simulation contact and the alarm / latching contact is a micro switch contact, a magnetic assisted electric contact or a dry reed contact.

4. The low power gas density relay of claim 1, wherein, The action triggering density value of the stepped simulation contact group satisfies: In the stepped simulation contact group, the action trigger density value of at least one simulation contact is greater than the rated density value P 20E , and / or The action trigger density value of the at least one simulated contact is less than the rated density value P 20E and greater than the alarm contact action value of the gas density relay body.

5. The low power gas density relay of claim 4, wherein, In the stepped simulation contact group, the number of simulation contacts with the action trigger density value greater than the rated density value P is greater than the number of simulation contacts with the action trigger density value less than the rated density value P. 20E In the stepped simulation contact group, the number of simulation contacts with the action trigger density value greater than the rated density value P is greater than the number of simulation contacts with the action trigger density value less than the rated density value P. 20E In the stepped simulation contact group, the number of simulation contacts with the action trigger density value greater than the rated density value P is greater than the number of simulation contacts with the action trigger density value less 6. The low power gas density relay of claim 1, wherein, The density detection element comprises a pressure sensing element or a temperature compensation element, wherein the pressure sensing element comprises a bellows or a barden tube, and the temperature compensation element comprises a bimetallic strip or a compensation gas chamber gas.

7. The low power gas density relay of claim 1, wherein, The smart control unit is configured to start the online self-checking function under at least one of the following triggering conditions: (a) in response to the edge interruption of the simulation signal generated when at least one simulation contact in the stepped simulation contact group acts; (b) in response to a remote instruction from a background monitoring system; (c) based on a preset periodic wake-up mechanism.

8. The low power gas density relay of claim 7, wherein, The edge interruption includes a rising edge interruption or a falling edge interruption.

9. The low power gas density relay of claim 1, wherein, The gas density detection sensor comprises at least one pressure sensor and at least one temperature sensor; or The gas density detection sensor adopts a gas density transmitter composed of a pressure sensor and a temperature sensor; or The gas density detection sensor adopts a density detection sensor using a quartz tuning fork technology.

10. The low power gas density relay of claim 9, wherein, The pressure sensor is installed on the gas path of the gas density relay body, and the temperature sensor is installed inside or outside the gas path of the gas density relay body, or inside or outside the gas density relay body.

11. The low power gas density relay of claim 1, wherein, The gas density relay further comprises a remote communication module connected to the smart control unit, for sending all or part of the following information to a background monitoring system or a remote terminal: (a) the simulation contact check value calculated by the smart control unit; (b) the check value of the alarm contact or the latching contact; (c) the real-time temperature and pressure data collected by the gas density detection sensor; (d) the running state information of the gas density relay; (e) the self-checking result and state information; The remote communication module comprises a wireless communication interface and / or a wired communication interface.

12. The low power gas density relay of claim 1, wherein, The gas density relay is powered by a battery pack or a self-powered mode.

13. The low power gas density relay of claim 1, wherein, The gas density relay further comprises a micro drive mechanism installed inside or outside the gas density relay body and connected to the smart control unit; The micro drive mechanism is configured to change the gas density of the gas density relay body or the temperature of the temperature compensation element by at least one of (a) and (b) to simulate the change of the gas density and trigger the action of at least one simulation contact in the stepped simulation contact group to generate a simulation signal: (a) changing the gas pressure in the gas density relay body by a pressure adjusting mechanism, the pressure adjusting mechanism comprising: a mechanical pressure adjusting unit selected from one of a piston driving mechanism, a gas bag deformation mechanism or a bellows expansion mechanism, directly changing the gas pressure in the gas density relay body by physical deformation or displacement; or a thermodynamic pressure adjusting mechanism comprising a cylinder temperature adjusting mechanism, indirectly adjusting the gas pressure in the gas density relay body by changing the temperature of the gas in the cylinder through a heating or refrigeration device; wherein, when the pressure adjusting mode is adopted, the gas density relay further comprises an electrically controlled valve, which is arranged on the gas path between the gas density relay body and the electrical equipment gas chamber, for isolating the gas path communication between the two when adjusting the pressure, and resetting the electrically controlled valve to restore the gas path communication between the two after the adjustment is completed; (b) changing the temperature of the temperature compensation element of the gas density relay body by a temperature adjusting mechanism, the temperature adjusting mechanism comprising a heating element or a refrigeration element.

14. A low power gas density monitoring device, characterized by, The gas density monitoring device comprises the low-power gas density relay according to any one of claims 1-13.

15. An on-line self-checking method of a low-power gas density relay, characterized by, comprising: utilizing the gas density difference generated by the environmental temperature difference between the electrical equipment gas chamber and the gas density relay body to drive the density detection element of the gas density relay body to produce mechanical displacement; the mechanical displacement triggers at least one simulation contact in the step-by-step simulation contact group to act, generating a simulation signal; in response to the simulation signal, the intelligent control unit detects the signal action value and / or signal return value of the triggered simulation contact; The stepped simulation contact group is arranged in the gas density relay body, and includes at least two simulation contacts. The simulation contacts are discretely arranged along the mechanical displacement direction of the density detection element in the gas density relay body. Each simulation contact has different trigger positions distributed along the mechanical displacement direction, and each trigger position corresponds to an action trigger density value. The action trigger density value is discretely distributed above and / or below the rated density value P 20E , and the minimum action trigger density value is greater than the alarm contact action value of the gas density relay body.

16. The online self-checking method of claim 15, wherein, the method further comprises: after the intelligent control unit detects the signal action value and / or signal return value of the triggered simulation contact, 17. The online self-checking method of claim 16, wherein, based on the signal action value and / or signal return value of the triggered simulation contact, the real-time temperature value and real-time pressure value at the time of the triggered simulation contact action, the factory calibration value of the triggered simulation contact, and the factory calibration value of the alarm contact and / or the latching contact, the intelligent control unit calculates the verification value of the alarm contact and / or the latching contact.

18. The online self-checking method of claim 15, wherein, The method further comprises: uploading the verification value of the alarm contact and / or the latching contact calculated by the intelligent control unit, the real-time temperature and pressure data collected by the gas density detection sensor, the running state information of the gas density relay, and the self-checking result to the background monitoring system or the remote terminal through the remote communication module. The trigger conditions for the intelligent control unit to start the online self-checking function include at least one of the following: (a) performing detection after being awakened by the edge of the simulation signal in the sleep state; (b) performing detection in response to a remote instruction issued by the background monitoring system; 19. The online self-checking method of claim 15, wherein, (c) performing detection after being awakened at a preset period. The method further comprises: after generating the simulation signal and before the intelligent control unit detects the signal action value and / or signal return value of the triggered simulation contact, determining whether the current simulation signal is triggered by an effective temperature difference, comprising: determining whether the temperature change rate of the gas in the gas density relay body is greater than or equal to a first preset threshold; and / or determining whether the gas pressure change rate of the electrical equipment gas chamber is less than or equal to a second preset threshold; If the condition is met, the verification value is calculated; Otherwise, the current verification is discarded; After the simulation contact is reset, the online self-checking is exited and the intelligent control unit is put into the hibernation state.

20. The online self-checking method of claim 15, wherein, The gas density relay further comprises a micro driving mechanism, which is arranged inside or outside the gas density relay body and connected with the intelligent control unit. When the simulation signal triggered by the natural temperature difference is not detected within a set time length, the gas density is simulated to trigger the simulation contact action in the following (a) or (b) ways: (a) When the pressure regulation mode is adopted: The electric control valve is started to isolate the gas path between the gas density relay body and the gas chamber of the electrical equipment; The gas pressure of the gas path of the gas density relay body is changed by the pressure regulation mechanism; The change of the gas density triggers the simulation contact action to generate the simulation signal; The intelligent control unit responds to the simulation signal and calculates the verification value; After the verification is completed, the electric control valve is reset and the gas path between the gas density relay body and the gas chamber of the electrical equipment is restored; (b) When the temperature regulation mode is adopted: The temperature of the temperature compensation element of the gas density relay body is changed by the temperature regulation mechanism; The change of the temperature of the temperature compensation element triggers the simulation contact action to generate the simulation signal; The intelligent control unit responds to the simulation signal and calculates the verification value; After the verification is completed, the temperature regulation mechanism is controlled to stop working.

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