A gas density relay with online self-calibration function and calibration method thereof

Abstract

The present application provides a gas density relay with an online self-calibration function and a calibration method thereof, comprising a gas density relay body, a first pressure sensor, a third pressure sensor, a temperature sensor, a pressure regulating mechanism, an online calibration contact signal sampling unit, and an intelligent control unit. The gas density relay body comprises a housing, a first sealed gas chamber in the housing that is connected to the insulating gas chamber of the electrical equipment, a second sealed gas chamber filled with a standard compensation gas, and a third gas chamber equipped with a signal generator and a signal regulating mechanism; the first pressure sensor is connected to the first sealed gas chamber, and the third pressure sensor is connected to the third sealed gas chamber; the intelligent control unit controls the pressure regulating mechanism to adjust the pressure rise and fall of the third sealed gas chamber, causing the gas density relay body to generate contact action, thereby completing the calibration of the gas density relay. This eliminates the need for maintenance personnel to go to the site for calibration, thereby improving work efficiency and reducing the sealing requirements of the power grid.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a gas density relay with an online self-calibration function and a calibration method thereof, which is applied to high-voltage and medium-voltage electrical equipment. Background Art

[0002] As unmanned substations evolve toward networking and digitalization, and as requirements for remote control and telemetry continue to intensify, online monitoring of the gas density and moisture content of SF6 electrical equipment has become increasingly important. With the continued vigorous development of China's smart grid, smart high-voltage electrical equipment, as a crucial component and key node of smart substations, plays a crucial role in the security of the smart grid. Currently, most high-voltage electrical equipment is SF6 gas-insulated. A decrease in gas density (e.g., due to leakage) can severely impact the electrical performance of the equipment, posing a serious risk to safe operation. Online monitoring of gas density in SF6 high-voltage electrical equipment is now commonplace, leading to a booming application of gas density monitoring systems (gas density relays). Current gas density monitoring systems (gas density relays) generally utilize: 1) remote SF6 gas density relays to collect and upload density, pressure, and temperature data for online gas density monitoring; 2) gas density transmitters to collect and upload density, pressure, and temperature data for online gas density monitoring. SF6 gas density relays are a core and key component.

[0003] Regular inspection of gas density relays on electrical equipment is a necessary preventative measure to ensure the safe and reliable operation of electrical equipment. Both the "Electricity Preventive Testing Regulations" and the "Twenty-Five Key Requirements for Preventing Major Accidents in Power Production" require regular calibration of gas density relays. Based on actual operational experience, regular calibration of gas density relays is a necessary measure to ensure the safe and reliable operation of electrical equipment. Therefore, calibration of gas density relays has become a highly valued and widespread practice within the power system, with power supply companies, power plants, and large industrial and mining enterprises implementing it. However, to conduct on-site calibration and testing of gas density relays, power supply companies, power plants, and large industrial and mining enterprises require test personnel, equipment vehicles, and high-value SF6 gas. Including operational losses from power outages during testing, a rough estimate puts the annual testing costs per high-voltage switch station at tens to hundreds of thousands of yuan. Furthermore, improper on-site calibration by test personnel can pose safety risks. To this end, it is very necessary to innovate in the existing gas density self-calibration gas density relay, especially the gas density online self-calibration gas density relay or system, so that the gas density relay that realizes gas density online monitoring or the monitoring system composed of it also has the calibration function of the gas density relay, thereby completing the regular calibration work of the (mechanical) gas density relay without the need for maintenance personnel to go to the site, thereby improving work efficiency and reducing operation and maintenance costs. Summary of the Invention

[0004] The object of the present invention is to provide a gas density relay with an online self-calibration function and a calibration method thereof, so as to solve the problems raised in the above technical background.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The first aspect of the present application provides a gas density relay with an online self-calibration function, comprising: a gas density relay body, a first pressure sensor, a third pressure sensor, a temperature sensor, a pressure regulating mechanism, an online calibration contact signal sampling unit, and an intelligent control unit;

[0007] The gas density relay body comprises: a housing, a first sealed gas chamber in the housing that is in communication with the insulating gas chamber of the electrical equipment, a second sealed gas chamber filled with standard compensation gas, and a third gas chamber provided with a signal generator and a signal adjustment mechanism;

[0008] The first pressure sensor is in communication with the first sealed air chamber;

[0009] The third pressure sensor is connected to the third sealed gas chamber of the gas density relay body;

[0010] The pressure regulating mechanism is provided outside the gas density relay body, the gas path of the pressure regulating mechanism is connected to the third sealed gas chamber, and is configured to adjust the gas pressure of the third sealed gas chamber to cause the gas density relay body to generate a contact signal action;

[0011] The online verification contact signal sampling unit is connected to the signal generator of the gas density relay body and is configured to sample the contact signal of the gas density relay body when the contact signal action occurs;

[0012] The intelligent control unit is connected to the pressure regulating mechanism, the first pressure sensor, the third pressure sensor, the temperature sensor and the online verification contact signal sampling unit respectively, and is configured to complete the control of the pressure regulating mechanism, pressure value acquisition and temperature value acquisition, and / or gas density value acquisition, and detect the contact signal action value and / or contact signal return value of the gas density relay body;

[0013] Wherein, the contact signal includes alarm and / or lock.

[0014] A second aspect of the present application provides a gas density monitoring device with an online self-calibration function, comprising: a gas density relay body, a first pressure sensor, a third pressure sensor, a temperature sensor, a pressure regulating mechanism, an online calibration contact signal sampling unit, and an intelligent control unit;

[0015] The gas density relay body comprises: a housing, a first sealed gas chamber in the housing that is in communication with the insulating gas chamber of the electrical equipment, a second sealed gas chamber filled with standard compensation gas, and a third gas chamber provided with a signal generator and a signal adjustment mechanism;

[0016] The first pressure sensor is in communication with the first sealed air chamber;

[0017] The third pressure sensor is connected to the third sealed gas chamber of the gas density relay body;

[0018] The pressure regulating mechanism is provided outside the gas density relay body, the gas path of the pressure regulating mechanism is connected to the third sealed gas chamber, and is configured to adjust the gas pressure of the third sealed gas chamber to cause the gas density relay body to generate a contact signal action;

[0019] The online verification contact signal sampling unit is connected to the signal generator of the gas density relay body and is configured to sample the contact signal of the gas density relay body when the contact signal action occurs;

[0020] The intelligent control unit is connected to the pressure regulating mechanism, the first pressure sensor, the third pressure sensor, the temperature sensor and the online verification contact signal sampling unit respectively, and is configured to complete the control of the pressure regulating mechanism, pressure value acquisition and temperature value acquisition, and / or gas density value acquisition, and detect the contact signal action value and / or contact signal return value of the gas density relay body;

[0021] Wherein, the contact signal includes alarm and / or lock.

[0022] Preferably, the gas density relay body includes: a shell, a first bellows, a second bellows, a signal generator, and a signal adjustment mechanism; wherein the first open end of the first bellows is fixed to the inner wall of the shell, the second open end of the first bellows is sealedly connected to the first seal, the inner wall of the first bellows, the first seal, and the inner wall of the shell together form a first sealed air chamber, and the first sealed air chamber is provided with an interface connected to the insulating gas of the electrical equipment; the first open end of the second bellows is sealedly connected to the first seal, the second open port of the second bellows is connected to the inner wall of the shell through the second seal, the outer wall of the first bellows, the first seal, the outer wall of the second bellows, the second seal and the inner wall of the shell together form a second sealed air chamber; the inner wall of the second bellows, the second seal and the inner wall of the shell together form a third sealed air chamber, the signal generator and the signal adjustment mechanism are arranged in the third sealed air chamber, the signal adjustment mechanism is connected to the first seal, and the signal generator is arranged corresponding to the signal adjustment mechanism.

[0023] The positions of the above-mentioned first sealed air chamber and the second sealed air chamber can be interchanged; for example, the inner wall of the first bellows, the first seal, and the inner wall of the outer shell together form the second sealed air chamber; the outer wall of the first bellows, the first seal, the outer wall of the second bellows, the second seal and the inner wall of the outer shell together form the first sealed air chamber, and the first sealed air chamber is provided with an interface connected to the insulating gas of the electrical equipment.

[0024] More preferably, the outer diameter of the first bellows is greater than the outer diameter of the second bellows.

[0025] More preferably, the signal adjustment mechanism includes a moving rod, one end of which extends into the second bellows, is connected to the first seal, and is displaced with the deformation of the first bellows; the other end of the moving rod extends out of the second bellows and is fixedly connected to a cross bar, the cross bar is provided with an adjusting screw, and the adjusting screw is used to trigger the signal generator under the pushing force of the moving rod.

[0026] Preferably, the third pressure sensor is arranged in the third sealed air chamber; or, the third pressure sensor is arranged on the third sealed air chamber and is connected to the air path of the third sealed air chamber.

[0027] Preferably, the signal generator includes a micro switch or a magnetic-actuated electric contact, and the gas density relay body outputs a contact signal through the signal generator.

[0028] Preferably, the gas density relay or the gas density detection device further comprises a second pressure sensor, and the second pressure sensor is connected to a second sealed gas chamber filled with standard compensation gas.

[0029] Preferably, the intelligent control unit obtains the gas density value collected by the first pressure sensor and the temperature sensor; or, the intelligent control unit obtains the pressure value collected by the first pressure sensor and the temperature value collected by the temperature sensor to complete the online monitoring of the gas density of the monitored electrical equipment by the gas density relay.

[0030] Preferably, the gas density relay or gas density monitoring device further comprises a valve, one end of the valve is provided with a connection port connected to the atmosphere, and the other end of the valve is connected to the pressure regulating mechanism or the third sealed gas chamber.

[0031] More preferably, the valve is further connected to the intelligent control unit and is closed or opened under the control of the intelligent control unit.

[0032] More preferably, the valve is an electric valve, and / or a solenoid valve, or a piezoelectric valve, or a temperature-controlled valve, or a new type of valve made of intelligent memory material and opened or closed by electric heating.

[0033] More preferably, during calibration, the valve is in an open state; during non-calibration, the valve is in a closed state.

[0034] Preferably, the pressure regulating mechanism is sealed within a cavity or housing.

[0035] Preferably, the pressure regulating mechanism is a sealed air chamber, and a heating element and / or a cooling element is provided outside or inside the sealed air chamber. By heating the heating element and / or cooling the cooling element, the temperature of the gas in the sealed air chamber changes, thereby completing the pressure increase or decrease of the third sealed air chamber; or

[0036] The pressure regulating mechanism is a cavity with an opening at one end, the other end of which is connected to the third sealed air chamber; a piston is arranged in the cavity, one end of the piston is connected to an adjusting rod, the outer end of the adjusting rod is connected to a driving component, the other end of the piston extends into the opening and is in sealing contact with the inner wall of the cavity, and the driving component drives the adjusting rod and thereby drives the piston to move in the cavity; or,

[0037] The pressure regulating mechanism is a sealed air chamber, a piston is provided inside the sealed air chamber, the piston is in sealing contact with the inner wall of the sealed air chamber, and a driving component is provided outside the sealed air chamber, the driving component drives the piston to move in the cavity through electromagnetic force; or,

[0038] The pressure regulating mechanism is an airbag with one end connected to a driving component, the airbag changes in volume under the drive of the driving component, and the airbag is connected to the third sealed air chamber; or,

[0039] The pressure regulating mechanism is a bellows, one end of the bellows is connected to the third sealed air chamber, and the other end of the bellows is driven by a driving component to expand and contract; or,

[0040] The pressure regulating mechanism is a bleed valve, which is a solenoid valve or an electric valve, or a bleed valve realized by electricity or gas; or,

[0041] The pressure regulating mechanism is a compressor; or,

[0042] The pressure regulating mechanism is a pump, which includes one of a pressure-generating pump, a booster pump, an electric air pump, and an electromagnetic air pump; or

[0043] The pressure regulating mechanism is a boost valve;

[0044] Among them, the driving component includes one of magnetism, motor, reciprocating motion mechanism, Carnot cycle mechanism, magnetic coupling thrust mechanism, heating thrust mechanism, electric heating thrust mechanism, chemical reaction thrust mechanism, and pneumatic element.

[0045] More preferably, when the pressure regulating mechanism is a sealed air chamber, the pressure regulating mechanism further includes a heat-insulating component, and the heat-insulating component is arranged outside the sealed air chamber.

[0046] Preferably, the gas density relay body and the first pressure sensor are an integrated structure; or the gas density relay body, the first pressure sensor and the temperature sensor are a remote gas density relay with an integrated structure.

[0047] Preferably, the first pressure sensor and temperature sensor are an integrated structure; or, the first pressure sensor and temperature sensor are a gas density transmitter with an integrated structure; or, the first pressure sensor and temperature sensor constitute a density detection sensor using quartz tuning fork technology; preferably, the online calibration contact signal sampling unit and the intelligent control unit are arranged on the gas density transmitter.

[0048] Preferably, the online verification contact signal sampling unit and the intelligent control unit are arranged together; preferably, the online verification contact signal sampling unit and the intelligent control unit are sealed in a cavity or shell.

[0049] Preferably, the first pressure sensor includes at least one pressure sensor; or, the first pressure sensor adopts a gas density transmitter composed of a pressure sensor and a temperature sensor; or, the first pressure sensor adopts a density detection sensor using quartz tuning fork technology.

[0050] Preferably, the first pressure sensor is installed on the gas path of the gas density relay body; the temperature sensor is installed on the gas path of the gas density relay body or outside the gas path, or inside the gas density relay body, or outside the gas density relay body.

[0051] Preferably, the gas density relay body has a comparative density value output signal, which is connected to the intelligent control unit; or, the gas density relay body has a comparative pressure value output signal, which is connected to the intelligent control unit.

[0052] Preferably, the online verification contact signal sampling unit includes an isolation sampling element, which is controlled by the gas density relay body, or the pressure regulating mechanism, or the intelligent control unit; in the non-verification state, the online verification contact signal sampling unit and the contact signal of the gas density relay body are relatively isolated in the circuit; in the verification state, the online verification contact signal sampling unit cuts off the contact signal control circuit of the gas density relay body and connects the contact of the gas density relay body with the intelligent control unit; wherein, the isolation sampling element includes one of a travel switch, a micro switch, a button, an electric switch, a displacement switch, an electromagnetic relay, an optocoupler, and a thyristor.

[0053] Preferably, the contact signal sampling of the gas density relay body by the online verification contact signal sampling unit satisfies the following requirements: the online verification contact signal sampling unit has at least two independent groups of sampling contacts, can automatically complete the verification of at least two contacts at the same time, and continuously measure without replacing or reselecting contacts; wherein, the contacts include, but are not limited to, one of the alarm contacts, alarm contact + lockout contact, alarm contact + lockout 1 contact + lockout 2 contact, and alarm contact + lockout contact + overpressure contact.

[0054] Preferably, the test voltage of the online verification contact signal sampling unit for the contact signal action value or switching value of the gas density relay body is not less than 24V, that is, during verification, a voltage of not less than 24V is applied between the corresponding terminals of the contact signal.

[0055] Preferably, the gas density relay or gas density monitoring device further comprises a multi-way connector, and the gas density relay body and the first pressure sensor are arranged on the multi-way connector; or,

[0056] The pressure regulating mechanism is fixed on the multi-way connector; or,

[0057] The gas density relay body, the first pressure sensor, and the pressure regulating mechanism are arranged on the multi-way connector; or,

[0058] The online verification contact signal sampling unit, the intelligent control unit, and the temperature sensor are arranged on the multi-way connector.

[0059] Preferably, the gas density relay or gas density monitoring device further comprises a trace water sensor connected to the gas density relay body and the intelligent control unit respectively, and / or a decomposition product sensor connected to the gas density relay body and the intelligent control unit respectively.

[0060] Preferably, at least two gas density relay bodies, at least two first pressure sensors, at least two third pressure sensors, at least two pressure regulating mechanisms, at least two online calibration contact signal sampling units and one intelligent control unit, and one temperature sensor are used to complete the online calibration of the gas density relay; or,

[0061] At least two gas density relay bodies, at least two first pressure sensors, at least two third pressure sensors, at least two pressure regulating mechanisms, at least two temperature sensors, at least two online calibration contact signal sampling units and an intelligent control unit are used to complete the online calibration of the gas density relay.

[0062] Preferably, the first pressure sensor or the third pressure sensor can be an absolute pressure sensor, a relative pressure sensor, or an absolute pressure sensor and a relative pressure sensor; it can be a diffused silicon pressure sensor, a MEMS pressure sensor, a chip-type pressure sensor, a coil induction pressure sensor (such as a pressure sensor with an induction coil attached to a Baden tube), a resistance pressure sensor (such as a pressure sensor with a sliding wire resistor attached to a Baden tube); it can be an analog pressure sensor or a digital pressure sensor.

[0063] Preferably, the temperature sensor may be a thermocouple, a thermistor, or a semiconductor type; may be a contact type or a non-contact type; may be a thermal resistor or a thermocouple.

[0064] Preferably, the electrical equipment includes SF6 gas electrical equipment, SF6 mixed gas electrical equipment, environmentally friendly gas electrical equipment, or other insulating gas electrical equipment.

[0065] Specifically, the electrical equipment includes GIS, GIL, PASS, circuit breakers, current transformers, voltage transformers, transformers, gas charging cabinets, and ring network cabinets.

[0066] Preferably, the intelligent control unit is based on an embedded system algorithm and control program of a microprocessor to automatically control the entire verification process, including all peripherals, logic and input and output.

[0067] More preferably, the intelligent control unit is based on the embedded algorithms and control programs of general-purpose computers, industrial computers, ARM chips, AI chips, CPUs, MCUs, FPGAs, PLCs, industrial control motherboards, embedded main control boards, etc., to automatically control the entire verification process, including all peripherals, logic, and input and output.

[0068] Preferably, the intelligent control unit has an electrical interface, which completes test data storage, and / or test data export, and / or test data printing, and / or data communication with the host computer, and / or inputs analog and digital information.

[0069] Preferably, the gas density relay (or monitoring device) supports input of basic information of the gas density relay (or monitoring device), and the basic information includes one or more of factory number, accuracy requirements, rated parameters, manufacturer, and operating location.

[0070] Preferably, the intelligent control unit further comprises a communication module for realizing long-distance transmission of test data and / or verification results.

[0071] More preferably, the communication mode of the communication module is wired communication or wireless communication.

[0072] Furthermore, the wired communication method includes one or more of RS232 bus, RS422 bus, RS485 bus, CAN-BUS bus, 4-20mA, Hart, IIC, SPI, Wire, coaxial cable, PLC power carrier, and cable.

[0073] Furthermore, the wireless communication method includes one or more of NB-IOT, 2G / 3G / 4G / 5G, WIFI, Bluetooth, Lora, Lorawan, Zigbee, infrared, ultrasonic, sound wave, satellite, light wave, quantum communication, and sonar.

[0074] Preferably, the intelligent control unit is further provided with a clock, and the clock is configured to periodically set the calibration time of the gas density relay, or record the test time, or record the event time.

[0075] Preferably, the intelligent control unit is controlled through on-site control and / or background control.

[0076] More preferably, the gas density relay or gas density monitoring device completes the online calibration of the gas density relay according to the settings or instructions of the background; or

[0077] According to the set calibration time of the gas density relay, the online calibration of the gas density relay is completed.

[0078] Preferably, the gas density relay or gas density monitoring device further comprises: a display interface for human-computer interaction, connected to the intelligent control unit, displaying current calibration data in real time, and / or supporting data input.

[0079] Preferably, the gas density relay or gas density monitoring device further includes: a camera for monitoring.

[0080] Preferably, the gas density relay body or the gas density monitoring device further comprises a contact resistance detection unit; the contact resistance detection unit is connected to the contact signal or directly connected to the signal generator; under the control of the online verification contact signal sampling unit, the contact signal of the gas density relay body is isolated from its control circuit, and when the contact signal is actuated and / or when an instruction to detect the contact resistance of the contact is received, the contact resistance detection unit can detect the contact resistance value of the gas density relay body.

[0081] Preferably, the gas density relay body or the gas density monitoring device further comprises an insulation resistance detection unit; the insulation resistance detection unit is connected to the contact signal or directly connected to the signal generator; under the control of the online verification contact signal sampling unit, the contact signal of the gas density relay is isolated from its control circuit, and when the contact signal of the gas density relay is actuated, and / or when an instruction to detect the contact insulation resistance is received, the insulation resistance detection unit can detect the contact insulation resistance value of the gas density relay.

[0082] A third aspect of the present application provides a method for calibrating a gas density relay, comprising:

[0083] In normal working state, the gas density relay or gas density monitoring device monitors the gas density value in the electrical equipment. At the same time, the gas density relay or gas density monitoring device monitors the gas density value in the electrical equipment online through the first pressure sensor, temperature sensor and intelligent control unit;

[0084] The gas density relay or gas density monitoring device shall, according to the set calibration time and / or calibration instruction, as well as the gas density value, under conditions where calibration of the gas density relay is permitted:

[0085] The online verification contact signal sampling unit is adjusted to the verification state through the intelligent control unit. In the verification state, the online verification contact signal sampling unit cuts off the control loop of the contact signal of the gas density relay body and connects the contact of the gas density relay body to the intelligent control unit;

[0086] The intelligent control unit adjusts the pressure rise and fall of the third sealed gas chamber by controlling the pressure regulating mechanism, so that the gas density relay body generates contact action, and the contact action is transmitted to the intelligent control unit through the online verification contact signal sampling unit. The intelligent control unit can detect the contact action of the gas density relay body; or

[0087] The intelligent control unit controls the pressure regulating mechanism to adjust the pressure rise and fall of the third sealed gas chamber, causing the gas density relay body to generate contact action. The contact action is transmitted to the intelligent control unit through the online verification contact signal sampling unit. The intelligent control unit can detect the occurrence of contact action of the gas density relay body and the gas density value of the third sealed gas chamber detected by the intelligent control unit, thereby completing the direct or indirect verification of the contact signal action value of the gas density relay body.

[0088] When all contact signal verification work is completed, the intelligent control unit restores the pressure adjustment mechanism and adjusts the online verification contact signal sampling unit to the working state, and the control circuit of the contact signal of the gas density relay body resumes normal operation.

[0089] Preferably, a method for calibrating a gas density relay comprises:

[0090] The gas path of the pressure regulating mechanism is connected to the third sealed gas chamber of the gas density relay body, thereby connecting the gas path of the pressure regulating mechanism with the third sealed gas chamber and the third pressure sensor provided in the third sealed gas chamber;

[0091] In normal working state, the gas density relay or gas density monitoring device monitors the gas density value in the electrical equipment. At the same time, the gas density relay or gas density monitoring device monitors the gas density value in the electrical equipment online through the first pressure sensor, temperature sensor and intelligent control unit;

[0092] The gas density relay or gas density monitoring device shall, according to the set calibration time and / or calibration instruction, as well as the gas density value, under conditions where calibration of the gas density relay is permitted:

[0093] The online verification contact signal sampling unit is adjusted to the verification state through the intelligent control unit. In the verification state, the online verification contact signal sampling unit cuts off the control loop of the contact signal of the gas density relay body and connects the contact of the gas density relay body to the intelligent control unit;

[0094] The intelligent control unit adjusts the pressure rise and fall of the third sealed gas chamber by controlling the pressure regulating mechanism, so that the gas density relay body generates a contact signal action; the intelligent control unit obtains the pressure value P1 collected by the first pressure sensor and the temperature value T collected by the temperature sensor when the gas density relay body generates a contact signal action or switching, as well as the pressure value P3 collected by the third pressure sensor, and calculates the equivalent gas pressure value P based on the pressure value P1 and the pressure value P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or,

[0095] The intelligent control unit obtains the gas density value P1 collected by the first pressure sensor and the temperature sensor when the contact signal of the gas density relay body is actuated or switched. 20 , and the gas density value P3 collected by the third pressure sensor and temperature sensor 20 , and according to the gas density value P1 20 And gas density value P3 20 Calculate the gas density value P 20 , complete the online calibration of the gas density relay;

[0096] When all contact signal verification work is completed, the intelligent control unit restores the pressure adjustment mechanism and adjusts the online verification contact signal sampling unit to the working state, and the control circuit of the contact signal of the gas density relay body resumes normal operation.

[0097] More preferably, when the gas density relay body generates a contact signal action or switching, its equivalent gas pressure value P = P1-P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or,

[0098] When the gas density relay body generates a contact signal action or switching, its equivalent gas pressure value P = P1-P3*K, where K is a preset coefficient; according to the equivalent gas pressure value P, temperature value T, and the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay.

[0099] More preferably, when the gas density relay body generates a contact signal action or switching, the gas density value P 20 and gas density value P1 20 、P3 20 The corresponding relationship between them is designed into a data table, and according to the gas density value P1 20 and gas density value P3 20 Query the data table to obtain the corresponding gas density value P 20 , complete the online calibration of the gas density relay; or,

[0100] When the gas density relay body generates a contact signal action or switches, the gas density value P 20 The corresponding relationship between the gas pressure values ​​P1, P3 and the temperature value T is designed into a data table, and the corresponding gas density value P is obtained by querying the data table according to the gas pressure values ​​P1, P3 and the temperature value T. 20 , complete the online calibration of the gas density relay.

[0101] Preferably, the first pressure sensor and the third pressure sensor are absolute pressure sensors; or, the first pressure sensor and the third pressure sensor are relative pressure sensors; or, when the first pressure sensor and the third pressure sensor are not the same type of sensors, atmospheric pressure correction is performed.

[0102] Preferably, the contact signal includes an alarm and / or a lock.

[0103] Preferably, the first pressure sensor and temperature sensor are an integrated structure; or, the first pressure sensor and temperature sensor are a gas density transmitter with an integrated structure; or, the first pressure sensor and temperature sensor constitute a density detection sensor using quartz tuning fork technology.

[0104] Preferably, after the gas density relay completes the calibration, if there is any abnormality, it can automatically issue an alarm and upload it to a remote end or send it to a designated receiver.

[0105] Preferably, the verification method further comprises: displaying the gas density value and the verification result on-site, or displaying the gas density value and the verification result through the background.

[0106] Preferably, the verification method further comprises: controlling the intelligent control unit through on-site control and / or background control.

[0107] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0108] The pressure regulating mechanism of the present application is not connected to the SF6 main gas circuit of the gas density relay body or electrical equipment, but is connected to the third sealed gas chamber of the gas density relay body. Through the action of the pressure regulating mechanism, the gas density relay body undergoes contact action, and the contact action is transmitted to the intelligent control unit through the online verification contact signal sampling unit. The intelligent control unit can detect the contact action of the gas density relay body and complete the verification of the contact signal action value of the gas density relay body. There is no need for maintenance personnel to go to the site for verification, and the intelligent management of the gas density relay throughout its life cycle is realized: repair only when there is a problem, and no operation and maintenance service is required if there is no problem. The present application improves the reliability of the power grid, greatly reduces its sealing requirements, improves efficiency, reduces operation and maintenance costs, and improves the convenience and flexibility of on-site installation. It can realize maintenance-free gas density relays. At the same time, the entire verification process achieves zero emission of SF6 gas, which meets the requirements of environmental protection regulations. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0110] Figure 1 1 is a schematic structural diagram of a gas density relay with an online self-calibration function according to the first embodiment;

[0111] Figure 2 2 is a schematic structural diagram of a gas density relay with an online self-calibration function according to a second embodiment;

[0112] Figure 3Schematic diagram of the structure of a gas density relay with online self-calibration function according to the third embodiment. DETAILED DESCRIPTION

[0113] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0114] Example 1:

[0115] like Figure 1 As shown, this embodiment provides a gas density relay or gas density monitoring device with an online self-calibration function, comprising: a gas density relay body 1, a first pressure sensor 2, a second pressure sensor 4, a third pressure sensor 14, a temperature sensor 3, a pressure regulating mechanism 5, an online calibration contact signal sampling unit 6, an intelligent control unit 7, a multi-way connector 9, and a valve 12. The gas density relay body 1, the pressure sensor 2, the temperature sensor 3, the online calibration contact signal sampling unit 6, and the intelligent control unit 7 are disposed on the multi-way connector 9.

[0116] The gas density relay body 1 mainly includes: a housing, a first bellows 104, a second bellows 103, a signal generator (a micro switch in this embodiment) 102, and a signal adjustment mechanism 101. The first open end of the first bellows 104 is fixed to the inner wall of the housing, and the second open end of the first bellows 104 is sealed with a first seal 108. The inner wall of the first bellows 104, the first seal 108, and the inner wall of the housing together form a first sealed air chamber G1. The first sealed air chamber G1 is filled with a gas with a density of P 20BCThe standard compensation gas, that is, the first sealed air chamber G1 in this embodiment is a temperature compensation standard air chamber. The second pressure sensor 4 is connected to the first sealed air chamber G1 and is used to collect the gas pressure in the first sealed air chamber G1. The first open end of the second bellows 103 is sealed and connected to the first seal 108, and the second open end of the second bellows 103 is fixedly connected to the inner wall of the shell through the second seal 109. The outer wall of the first bellows 104, the first seal 108, the outer wall of the second bellows 103, the second seal 109 and the inner wall of the shell together form a second sealed air chamber G2. The second sealed air chamber G2 is connected to the electrical equipment connector 13 through the multi-way connector 9, that is, the second sealed air chamber G2 is connected to the insulating gas of the electrical equipment. The inner wall of the second bellows 103, the second seal 109 and the inner wall of the shell together form a third sealed air chamber G3, and the third pressure sensor 14 is arranged in the third sealed air chamber G3. The signal adjustment mechanism 101 and the signal generator 102 are disposed within the third sealed gas chamber G3. The signal adjustment mechanism 101 is connected to the first sealing member 108. The signal generator 102 is disposed corresponding to the signal adjustment mechanism 101. The gas density relay body 1 outputs a contact signal via the signal generator 102. In this embodiment, the signal adjustment mechanism 101 includes a movable rod, one end of which extends into the second bellows 103, is connected to the first sealing member 108, and is displaced in response to the deformation of the first bellows 104. The other end of the movable rod extends out of the second bellows 103 and is fixedly connected to a crossbar (or plate). The crossbar (or plate) is provided with a plurality of adjustment screws 10101. When the gas pressure in the third sealed air chamber G3 changes, the balance of forces acting on the upper end surface of the first bellows 104 by the first sealed air chamber G1 and the third sealed air chamber G3 is broken, causing the first bellows 104 to deform with the pressure change and produce a certain displacement, driving the moving rod 101 to move, and the moving rod 101 drives the adjusting screw 10101 to touch the button of the signal generator 102, and the signal generator 102 sends an alarm and locking signal.

[0117] In this embodiment, the first pressure sensor 2 is connected to the second sealed gas chamber G2 of the gas density relay body 1; the second pressure sensor 4 is connected to the first sealed gas chamber G1 of the gas density relay body 1; and the third pressure sensor 14 is connected to the third sealed gas chamber G3 of the gas density relay body 1. The pressure regulating mechanism 5 is disposed outside the gas density relay body 1. The gas circuit of the pressure regulating mechanism 5 is connected to the third sealed gas chamber G3 and is configured to regulate the gas pressure in the third sealed gas chamber G3 to cause the gas density relay body 1 to generate a contact signal. The online verification contact signal sampling unit 6 is directly or indirectly connected to the signal generator 102 of the gas density relay body 1 and is configured to sample the contact signal of the gas density relay body 1 when the contact signal is generated. The contact signal includes an alarm and / or a lockout. The intelligent control unit 7 is connected to the pressure regulating mechanism 5, the first pressure sensor 2, the second pressure sensor 4, the third pressure sensor 14, the temperature sensor 3 and the online verification contact signal sampling unit 6, respectively, and is configured to complete the control of the pressure regulating mechanism 5, the pressure value acquisition and temperature value acquisition, and / or gas density value acquisition, and detect the contact signal action value and / or contact signal return value of the gas density relay body 1. The third pressure sensor 14 can be set on the third sealed gas chamber G3, or the third pressure sensor 14 can also be set on the pressure regulating mechanism 5, or on the gas path connected to its third sealed G3 gas chamber. In short, the third pressure sensor 14 is connected to the third sealed gas chamber G3 on the gas path.

[0118] The pressure regulating mechanism 5 of this embodiment primarily consists of an airbag 51, a piston 52, a sealing ring 53, a connecting rod 54, and a driving component 55. The airbag 51 is connected to the third sealed gas chamber G3 of the gas density relay body 1. Under the control of the intelligent control unit 7, the pressure regulating mechanism 5 causes the driving component 55 to push the connecting rod 54, which in turn pushes the piston 52, which in turn causes the airbag 51 to change volume, thereby increasing or decreasing the gas pressure in the third sealed gas chamber G3. The driving component 55 includes, but is not limited to, one of a magnetic force, a motor, a reciprocating motion mechanism, a Carnot cycle mechanism, a magnetic coupling thrust mechanism, a heating thrust mechanism, an electric heating thrust mechanism, a chemical reaction thrust mechanism, and a pneumatic element.

[0119] A valve 12 is installed in the air path connecting the pressure regulating mechanism 5 and the third sealed air chamber G3 of the gas density relay body 1. Specifically, one end of valve 12 communicates with the third sealed air chamber G3 and the airbag 51 of the pressure regulating mechanism 5, and the other end is provided with a protective cover 1201. Valve 12 is an electric valve, a solenoid valve, a piezoelectric valve, a temperature-controlled valve, or a novel valve made of intelligent memory material that opens and closes using electrical heating. When not in calibration mode, valve 12 is closed; during calibration, valve 12 is open.

[0120] Of course, the positions of the first sealed air chamber and the second sealed air chamber in this embodiment can be interchanged. For example, the inner wall of the first bellows 104, the first sealing member 108, and the inner wall of the housing together form the second sealed air chamber, which is filled with a gas having a density of P. 20BC The outer wall of the first bellows 104, the first seal 108, the outer wall of the second bellows 103, the second seal 109, and the inner wall of the housing together form a first sealed air chamber. The first sealed air chamber has an interface for communicating with the insulating gas of the electrical equipment. Specifically, the positions of the first and second sealed air chambers can be flexibly designed as needed.

[0121] Working principle:

[0122] The intelligent control unit 7 monitors the gas pressure and temperature of the electrical equipment according to the first pressure sensor 2 and the temperature sensor 3, and obtains the corresponding 20°C pressure value P 20 (i.e., the gas density value), can be remotely transmitted for online monitoring, that is, the intelligent control unit 7 obtains the gas density value collected by the first pressure sensor 2 and the temperature sensor 3; or, the intelligent control unit 7 obtains the pressure value and temperature value collected by the first pressure sensor 2 and the temperature sensor 3, and completes the online monitoring of the gas density of the monitored electrical equipment by the gas density relay. At the same time, the intelligent control unit 7 obtains the gas density value collected by the third pressure sensor 14 and the temperature sensor 3; or, the intelligent control unit 7 obtains the pressure value collected by the third pressure sensor 14 and the temperature value collected by the temperature sensor 3, and completes the online monitoring of the gas density value of the third sealed gas chamber G3. At this time, the gas density value of the first sealed gas chamber G1 is greater than the gas density value of the third sealed gas chamber G3, that is, the difference between the gas density value of the first sealed gas chamber G1 and the gas density value of the third sealed gas chamber G3 is greater than a certain set value, and the gas density value of the third sealed gas chamber G3 is greater than the set value. Figure 1 It can be seen that there is a corresponding distance between the adjusting screw 10101 of the signal adjustment mechanism 101 and the signal generator 102. At this time, the adjusting screw 10101 does not contact the signal generator 102, that is, the signal generator 102 is not triggered, the signal generator 102 does not move, and its contact signal is not output.

[0123] When it is necessary to calibrate the density relay body 1, if the gas density value P 20 ≥Set safety verification density value P S The gas density relay issues a command, and the intelligent control unit 7 disconnects the control circuit of the gas density relay body 1, so that the online calibration of the gas density relay body 1 will not affect the safe operation of the electrical equipment, nor will it mistakenly send an alarm signal or lock the control circuit during the calibration. Because the gas density relay has already measured the gas density value P before starting the calibration, 20 ≥Set safety verification density value P S The monitoring and judgment of the electrical equipment shows that the gas is within the safe operating range. Moreover, gas leakage is a slow process and is safe during verification. At the same time, the intelligent control unit 7 is connected to the contact sampling circuit of the gas density relay body 1.

[0124] Next, the valve 12 is opened by the intelligent control unit 7 so that the third sealed gas chamber G3 of the gas density relay body 1 is connected to the gas path of the pressure regulating mechanism 5 in the gas path. Then, the intelligent control unit 7 controls the driving component 55 of the pressure regulating mechanism 5 (which can be mainly implemented by an electric motor and gears, and its methods are diverse and flexible), and then adjusts the piston 52 of the pressure regulating mechanism 5, so that the sealed cavity composed of the piston 52, the airbag 51, and the third sealed air chamber G3 of the gas density relay body 1 undergoes a volume change (volume reduction), and the pressure of the gas in the third sealed air chamber G3 of the gas density relay body 1 gradually increases, and the pressure acting on the upper end surface of the first bellows 104 increases, causing the upper end surface of the first bellows 104 and the moving rod driving the adjusting screw 10101 to displace downward, and the distance between the adjusting screw 10101 and the signal generator 102 will decrease. When the distance is less than the corresponding value, the adjusting screw 10101 of the signal regulating mechanism 101 contacts the signal generator 102, that is, the signal generator 102 is triggered, and the contact of the signal generator 102 is actuated (connected), and a corresponding contact signal (alarm or lock) is issued. The contact action is uploaded to the intelligent control unit 7 through the online verification contact signal sampling unit 6. The intelligent control unit 7 obtains the pressure value P1 collected by the first pressure sensor 2 and the temperature value T collected by the temperature sensor 3 when the contact signal action or switching occurs in the gas density relay body 1, and the pressure value P3 collected by the third pressure sensor 14, and calculates the equivalent gas pressure value P based on the pressure value P1 and the pressure value P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20Alternatively, the intelligent control unit 7 obtains the gas density value P1 collected by the first pressure sensor 2 and the temperature sensor 3 when the contact signal of the gas density relay body 1 is activated or switched. 20 , and the gas density value P3 collected by the third pressure sensor 14 and the temperature sensor 3 20 , and according to the gas density value P1 20 And gas density value P3 20 Calculate the gas density value P 20 , complete the online calibration of the gas density relay. Further, when the gas density relay body 1 generates a contact signal action or switching, its equivalent gas pressure value P = P1-P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristics, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or, when the contact signal action or switching occurs on the gas density relay body 1, its equivalent gas pressure value P = P1-P3*K, where K is a preset coefficient, obtained according to the characteristics of the density relay body; according to the equivalent gas pressure value P, temperature value T, and according to the gas pressure-temperature characteristics, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 Alternatively, when the gas density relay body 1 generates a contact signal action or switching, the gas density value P 20 and gas density value P1 20 、P3 20 The corresponding relationship between them is designed into a data table, and according to the gas density value P1 20 And gas density value P3 20 Query the data table to obtain the corresponding gas density value P 20 , complete the online calibration of the gas density relay; or, when the gas density relay body 1 contacts the signal action or switch, the gas density value P 20 The corresponding relationship between the gas pressure values ​​P1, P3 and the temperature value T is designed into a data table, and the corresponding gas density value P is obtained by querying the data table according to the gas pressure values ​​P1, P3 and the temperature value T. 20 , complete the online calibration of the gas density relay. For example, take the parameters of the SF6 gas density relay to be verified: rated pressure value 0.7MPa, alarm pressure value 0.65MPa, lock pressure value 0.60MPa (abs.) as an example. Assuming that the calibration temperature T = 10℃, at the beginning of this calibration, the intelligent control unit 7 detects the gas pressure value P of the first sealed gas chamber G1 (i.e., the temperature compensation standard gas chamber). BCCS =0.6186MPa(abs.), the corresponding gas density value is P20BCCS =0.645MPa(abs.). Assuming that when checking the action of the alarm contact signal, the pressure value P1=0.6756MPa and the temperature value T=10℃ collected by the first pressure sensor 2 and the temperature sensor 3, and the pressure value P3=0.11MPa collected by the third pressure sensor 14, are obtained according to the characteristics of the density relay body. The preset coefficient K=0.5 is obtained; then its equivalent gas pressure value P=P1-P3*K=0.6756-0.11*0.5=0.6206MPa(abs.); according to the equivalent gas pressure value P=0.6206MPa(abs.), and according to the gas pressure-temperature characteristics, it is converted into a pressure value corresponding to 20℃, that is, the action value P of the alarm contact. BJD20 It is 0.6471MPa (abs.), and its error is 0.6471-0.65=-0.0029MPa, so the online verification of the alarm contact of the gas density relay is conveniently completed; assuming that when the locking contact signal action is verified, the pressure value P1=0.6756MPa and the temperature value T=10°C collected by the first pressure sensor 2 and the temperature sensor 3, and the pressure value P3=0.182MPa collected by the third pressure sensor 14, the equivalent gas pressure value P=P1-P3*K=0.6756-0.182*0.5=0.5846MPa (abs.); according to the equivalent gas pressure value P=0.5846MPa (abs.), and converted into a pressure value corresponding to 20°C according to the SF6 gas pressure-temperature characteristic, that is, the action value P of the locking alarm contact BSD20 The error is 0.6093 MPa (abs.), which is 0.6093-0.60=-0.0093 MPa. This conveniently completes the online calibration of the gas density relay locking contact. Repeat this calibration multiple times (for example, 2-3 times), and then calculate the average value, thus completing the calibration of the gas density relay body 1.

[0125] Then, the intelligent control unit 7 disconnects the contact sampling circuit of the gas density relay body 1, and the contacts of the gas density relay body 1 are now disconnected from the intelligent control unit 7. Simultaneously, the intelligent control unit 7 controls the driving component 55 of the pressure regulating mechanism 5, thereby adjusting the piston 52 of the pressure regulating mechanism 5. This causes the volume of the sealed cavity formed by the piston 52, the airbag 51, and the third sealed gas chamber G3 of the gas density relay body 1 to change (increase). The pressure of the gas in the third sealed gas chamber G3 of the gas density relay body 1 gradually decreases, and the pressure acting on the upper end surface of the first bellows 104 decreases. After adjusting the gas density value of the third sealed gas chamber G3 to the specified set value, the gas pressure in the first sealed gas chamber G1 is greater than the gas pressure in the third sealed gas chamber G3, which will push the upper end surface of the first bellows 104 and the moving rod with the adjusting screw 10101 upward, so that there is a corresponding distance between the adjusting screw 10101 and the signal generator 102, and the adjusting screw 10101 does not contact the signal generator 102. At the same time, the intelligent control unit 7 immediately closes the valve 12, so that the third sealed gas chamber G3 of the gas density relay body 1 is not connected to the pressure regulating mechanism 5 in the gas path. The control circuit of the gas density relay body 1 is connected through the intelligent control unit 7, and the density monitoring circuit of the gas density relay body 1 operates normally. The gas density relay body 1 safely monitors the gas density of the electrical equipment, allowing the electrical equipment to operate safely and reliably. This facilitates the online verification of the gas density relay body 1, and at the same time, the online verification of the gas density relay body 1 will not affect the safe operation of the electrical equipment.

[0126] After the gas density relay 1 completes its calibration, it determines the test result and displays it. This flexibility allows for: 1) local notification via an indicator light, digital display, or LCD; 2) uploading via online remote communication, such as to the backend of an online monitoring system; 3) wireless uploading to a specific terminal, such as a mobile phone; 4) other methods; 5) uploading abnormal results via an alarm signal line or dedicated signal line; 6) uploading individually or bundled with other signals. In summary, after the gas density relay completes its online calibration, if an abnormality is detected, it automatically issues an alarm, which can be uploaded to a remote location or sent to a designated receiver, such as a mobile phone. Alternatively, if an abnormality is detected after the gas density relay completes its calibration, the intelligent control unit 7 can transmit the alarm contact signal from the gas density relay 1 to a remote location (e.g., a monitoring room, backend monitoring platform), or display the result locally. A simpler version of the gas density relay online calibration allows abnormal calibration results to be uploaded via the alarm signal line. Data can be uploaded regularly. For example, when an anomaly occurs, a contact is connected in parallel with the alarm signal contact, closing and opening it regularly, allowing analysis to reveal the status. Data can also be uploaded via a separate calibration signal line. Specifically, data can be uploaded when the status is good or when there are problems. Data can also be uploaded via remote density online monitoring, verification results can be uploaded via a separate calibration signal line, local display and alarm, or wirelessly uploaded via smartphone networking. Communication methods can be wired or wireless. Wired communication methods can include industrial buses such as RS232, RS485, CAN-BUS, fiber optic Ethernet, 4-20mA, HART, IIC, SPI, Wire, coaxial cable, PLC power carrier, etc. Wireless communication methods can include 2G / 3G / 4G / 5G, Wi-Fi, Bluetooth, Lora, Lorawan, Zigbee, infrared, ultrasonic, sound waves, satellite, optical waves, quantum communication, sonar, and sensors with built-in 5G / NB-IOT communication modules (such as NB-IOT). In short, multiple methods and combinations can be used to fully ensure the reliable performance of the gas density relay.

[0127] The first pressure sensor 2 and the third pressure sensor 14 can be of the following types: absolute pressure sensor, relative pressure sensor, or both, and the number of such sensors can be multiple. The pressure sensors can be diffused silicon pressure sensors, MEMS pressure sensors, chip-type pressure sensors, coil-type pressure sensors (such as a Baden tube with an induction coil), or resistance pressure sensors (such as a Baden tube with a sliding resistor). They can be either analog or digital. Pressure acquisition is performed using various pressure-sensing elements, such as diffused silicon, sapphire, piezoelectric, and strain gauges (resistance strain gauges and ceramic strain gauges).

[0128] The temperature sensor 3 can be a thermocouple, a thermistor, or a semiconductor type; it can be a contact type or a non-contact type; it can be a thermal resistor or a thermocouple. In short, temperature acquisition can be performed using various temperature sensing elements such as temperature sensors and temperature transmitters.

[0129] The valve 12 can be controlled using a variety of drive methods, including manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic-hydraulic, electro-hydraulic, gas-hydraulic, spur gear, and bevel gear drive. It can operate according to predetermined requirements based on pressure, temperature, or other sensor signals, or simply open or close independently of sensor signals. The valve relies on a drive or automated mechanism to cause the opening and closing member to move upward, downward, downward, downward, downward, downward, or downwardly, thereby changing the flow area to achieve its control function. The valve 12 can be driven by automatic, power-driven, or manual valves. Automatic valves can include electromagnetic, electromagnetic-hydraulic, electro-hydraulic, turbine, spur gear, bevel gear, pneumatic, hydraulic, gas-hydraulic, electric, and electric motors. The valve can be automatic, manual, or semi-automatic. Calibration can be automated or semi-automated with manual assistance. The valve can be directly or indirectly connected to electrical equipment through self-sealing valves, manual valves, or non-disassembly valves, either integrated or separate. Depending on the needs, valves can be normally open or normally closed, and can be one-way or two-way. In short, electronically controlled valves are used to open or close the gas path. Electronically controlled valves can be solenoid valves, electronically controlled ball valves, electric valves, electronically controlled proportional valves, and more.

[0130] The online verification contact signal sampling unit 6 primarily performs contact signal sampling on the gas density relay body 1. The basic requirements or functions of the online verification contact signal sampling unit 6 are: 1) verification without affecting the safe operation of electrical equipment. Specifically, during verification, the contact signal activation of the gas density relay body 1 does not affect the safe operation of electrical equipment; and 2) the contact signal control circuit of the gas density relay body 1 does not affect the performance of the gas density relay, particularly the performance of the intelligent control unit 7, causing no damage to the gas density relay or affecting testing operations.

[0131] The basic requirements or functions of the intelligent control unit 7 are: to complete the control of the valve 12, the control of the pressure regulating mechanism 5 and the signal acquisition through the intelligent control unit 7. Implementation: to detect the pressure value and temperature value when the contact signal of the gas density relay body 1 is actuated, and convert them into the corresponding pressure value P at 20°C. 20 (density value), that is, the contact action value P of the gas density relay body 1 can be detected D20 , complete the calibration work of the gas density relay body 1. Alternatively, it is possible to directly detect the density value P when the contact signal of the gas density relay body 1 is activated. D20 , complete the calibration work of the gas density relay body 1.

[0132] Of course, the intelligent control unit 7 can also achieve: completing test data storage; and / or test data export; and / or test data printing; and / or data communication with the host computer; and / or inputting analog and digital information. The intelligent control unit 7 also includes a communication module, which realizes long-distance transmission of test data and / or verification results and other information through the communication module; when the rated pressure value of the gas density relay body 1 outputs a signal, the intelligent control unit 7 simultaneously collects the density value at that time and completes the rated pressure value verification of the gas density relay body 1. At the same time, through the test of the rated pressure value of the gas density relay body 1, the self-calibration work between the gas density relay body 1, the pressure sensor 2, and the temperature sensor 3 can be completed, achieving maintenance-free.

[0133] Electrical equipment, including SF6 gas electrical equipment, SF6 mixed gas electrical equipment, environmentally friendly gas electrical equipment, or other insulated gas electrical equipment. Specifically, electrical equipment includes GIS, GIL, PASS, circuit breakers, current transformers, voltage transformers, transformers, gas charging cabinets, ring main cabinets, etc.

[0134] The gas density relay body 1, first pressure sensor 2, temperature sensor 3, valve 12, pressure regulating mechanism 5, online calibration contact signal sampling unit 6, intelligent control unit 7, and multi-way connector 9 can be flexibly arranged as needed. For example, the gas density relay body 1, first pressure sensor 2, and temperature sensor 3 can be arranged together; or the valve 12 and pressure regulating mechanism 5 can be arranged together. In short, the arrangements among them can be flexibly arranged and combined.

[0135] The gas density relay has a safety protection function. Specifically, when the gas density value is lower than the set value, the gas density relay will automatically stop online calibration of the density relay and send a warning signal. For example, when the gas density value of the equipment is less than the set value P S For example, online calibration can only be performed when the gas density value of the equipment is ≥ (alarm pressure value + 0.02MPa).

[0136] Gas density relays can be calibrated online at a set time or at a set temperature (e.g., extreme high temperature, high temperature, extreme low temperature, low temperature, normal temperature, 20°C, etc.). The error determination requirements for online calibration at high temperature, low temperature, normal temperature, and 20°C ambient temperature are different. For example, when calibrating at 20°C ambient temperature, the gas density relay's accuracy requirements can be set to 1.0 or 1.6, while at high temperature, it can be set to 2.5. Specific implementation can be based on temperature requirements and in accordance with relevant standards. For example, according to Article 4.8 of DL / T 259, "Calibration Procedure for Sulfur Hexafluoride Gas Density Relays," which stipulates temperature compensation performance, the accuracy requirements corresponding to each temperature value are determined.

[0137] The gas density relay can compare its error performance at different temperatures and time periods. This allows comparisons within the same temperature range over different time periods to determine the performance of the gas density relay and electrical equipment. This allows comparisons across historical periods and between historical and current periods.

[0138] The gas density relay can be calibrated repeatedly (for example, 2 to 3 times), and the average value can be calculated based on the calibration results of each time. If necessary, the gas density relay can be calibrated online at any time.

[0139] The gas density relay features pressure and temperature measurement and software conversion capabilities. Without affecting the safe operation of electrical equipment, it can detect the alarm and / or lockout contact action and / or return values ​​of the gas density relay body 1 online. Of course, the return values ​​of the alarm and / or lockout contact signals can be omitted upon request. Furthermore, the gas density relay can monitor the gas density, pressure, and / or temperature values ​​of electrical equipment online and upload them to the target device for online monitoring.

[0140] Example 2:

[0141] like Figure 2 As shown, a gas density relay or gas density monitoring device with an online self-calibration function provided by Embodiment 2 of the present invention includes: a gas density relay body 1, a first pressure sensor 2, a third pressure sensor 14, a temperature sensor 3, a pressure regulating mechanism 5, an online calibration contact signal sampling unit 6, an intelligent control unit 7, a multi-way connector 9, and a valve 12. The gas density relay body 1, the pressure sensor 2, the temperature sensor 3, the online calibration contact signal sampling unit 6, and the intelligent control unit 7 are disposed on the multi-way connector 9; the third pressure sensor 14 is disposed within or on the third sealed gas chamber G3 and is in communication with the third sealed gas chamber G3.

[0142] The difference from the first embodiment is that:

[0143] 1) The first sealed air chamber G1 in this embodiment is connected to the electrical equipment connector 13 through the multi-way connector 9, that is, the first sealed air chamber G1 is connected to the insulating gas of the electrical equipment. The second sealed air chamber G2 in this embodiment is filled with a gas having a density of P 20BC The standard compensation gas of the second sealed gas chamber G2 is the temperature compensation standard gas chamber.

[0144] 2) The pressure regulating mechanism 5 of this embodiment comprises a cavity 51 with an open end. A piston 52 is located within the cavity 51. The piston 52 is equipped with a sealing ring 53. One end of the piston 52 is connected to an adjusting rod 54. The outer end of the adjusting rod 54 is connected to a driving component 55. The other end of the piston 52 extends into the opening and contacts the inner wall of the cavity 51. The driving component 55 drives the adjusting rod 54, thereby driving the piston 52 within the cavity 51. The driving component 55 includes, but is not limited to, a magnetic force, a motor, a reciprocating motion mechanism, a Carnot cycle mechanism, a magnetic coupling thrust mechanism, a heating thrust mechanism, an electric heating thrust mechanism, a chemical reaction thrust mechanism, or a pneumatic element. In a preferred embodiment, the pressure regulating mechanism 5 further comprises a sealing connector 58 disposed between the cavity 51 and the driving component 55. The adjusting rod 54 passes through the sealing connector 58 and is connected to the driving component 55, ensuring excellent sealing performance for the entire pressure regulating mechanism 5. The sealing connector 58 includes, but is not limited to, a bellows, an airbag, and a sealing ring.

[0145] Example 3:

[0146] like Figure 3As shown, a gas density relay or gas density monitoring device with an online self-calibration function provided by Embodiment 3 of the present invention includes: a gas density relay body 1, a first pressure sensor 2, a third pressure sensor 14, a temperature sensor 3, a pressure regulating mechanism 5, an online calibration contact signal sampling unit 6, an intelligent control unit 7, a multi-way connector 9, and a valve 12. The gas density relay body 1, pressure sensor 2, and temperature sensor 3 are disposed on the multi-way connector 9; the third pressure sensor 14 is disposed within or on the third sealed gas chamber G3 and is in communication with the third sealed gas chamber G3.

[0147] The difference from the second embodiment is that:

[0148] 1) The valve 12 and the pressure regulating mechanism 5 are independently connected to the third sealed air chamber G3.

[0149] 2) The pressure regulating mechanism 5 of this embodiment primarily consists of an airbag 51 and a drive component 55. Under the control of the intelligent control unit 7, the drive component 55 propels the airbag 51 to change volume, thereby increasing or decreasing the gas pressure in the third sealed gas chamber G3. The online verification contact signal sampling unit 6 and the intelligent control unit 7 are integrated with the pressure regulating mechanism 5.

[0150] In another preferred embodiment, the pressure regulating mechanism 5 can also be a solenoid valve sealed inside a housing. The pressure regulating mechanism 5 opens the solenoid valve under the control of the intelligent processor 7, causing pressure changes, thereby completing the increase and decrease of the gas pressure in the third sealed gas chamber G3.

[0151] In another preferred embodiment, the pressure regulating mechanism 5 may also comprise a bellows and a drive component. The bellows is hermetically connected to the third sealed gas chamber G3 of the gas density relay body 1 to form a reliably sealed cavity. Under the control of the intelligent processor 7, the pressure regulating mechanism 5 causes the drive component to drive the bellows to change volume, thereby causing the sealed cavity to change volume, thereby increasing or decreasing the gas pressure in the third sealed gas chamber G3.

[0152] In another preferred embodiment, the pressure regulating mechanism 5 can also be composed of an air chamber, a heating element, and a thermal insulation component. The air chamber is sealed and connected to the third sealed air chamber G3 of the gas density relay body 1. The outside (or inside) of the air chamber is provided with a heating element. By heating, the temperature changes, thereby completing the rise and fall of the gas pressure in the third sealed air chamber G3.

[0153] Of course, the pressure regulating mechanism 5 can also have many other forms, not limited to those listed above, and other mechanisms that can achieve the pressure raising and lowering function are also covered within the protection scope of this application.

[0154] In summary, the pressure regulating mechanism 5 of the present application is not connected to the gas density relay body 1 or the SF6 main gas circuit of the electrical equipment, but is connected to the third sealed gas chamber G3 of the gas density relay body 1. Through the action of the pressure regulating mechanism 5, the gas density relay body 1 undergoes contact action, and the contact action is transmitted to the intelligent control unit 7 through the online verification contact signal sampling unit 6. The intelligent control unit 7 can detect the contact action of the gas density relay body 1 and complete the verification of the contact signal action value of the gas density relay body. There is no need for maintenance personnel to go to the site for verification, and the intelligent management of the gas density relay throughout its life cycle is realized: repair only when there is a problem, and no operation and maintenance service is required if there is no problem. The present application improves the reliability of the power grid, greatly reduces its sealing requirements, improves efficiency, reduces costs, and improves the convenience and flexibility of on-site installation. It can realize maintenance-free gas density relays. At the same time, the entire verification process achieves zero emission of SF6 gas, which meets the requirements of environmental protection regulations.

[0155] This application has made a technical innovation: the pressure regulating mechanism is not connected to the gas density relay body or the SF6 main gas circuit of the electrical equipment, thereby greatly improving the reliability of the power grid, reducing its sealing requirements, and greatly reducing manufacturing costs, and improving the convenience and flexibility of on-site installation.

[0156] It should be noted that a gas density relay with online self-calibration generally refers to a device whose components are designed as an integrated structure, while a gas density monitoring device generally refers to a device whose components are designed as separate structures for flexible assembly. The gas density relay can be upgraded by reusing the existing gas density relay in the substation.

[0157] While the specific embodiments of the present invention have been described in detail above, these are merely exemplary and the present invention is not limited thereto. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, any equivalent changes and modifications made without departing from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention.

Claims

1. A gas density relay with an online self-calibration function, characterized in that: include: Gas density relay body, first pressure sensor, third pressure sensor, temperature sensor, pressure regulating mechanism, online calibration contact signal sampling unit and intelligent control unit; The gas density relay body comprises: a housing, a first sealed gas chamber in the housing that is in communication with the insulating gas chamber of the electrical equipment, a second sealed gas chamber filled with standard compensation gas, and a third gas chamber provided with a signal generator and a signal adjustment mechanism; The first pressure sensor is in communication with the first sealed air chamber; The third pressure sensor is connected to the third sealed gas chamber of the gas density relay body; The pressure regulating mechanism is provided outside the gas density relay body, the gas path of the pressure regulating mechanism is connected to the third sealed gas chamber, and is configured to adjust the gas pressure of the third sealed gas chamber to cause the gas density relay body to generate a contact signal action; The online verification contact signal sampling unit is connected to the signal generator of the gas density relay body and is configured to sample the contact signal of the gas density relay body when the contact signal action occurs; The intelligent control unit is connected to the pressure regulating mechanism, the first pressure sensor, the third pressure sensor, the temperature sensor and the online verification contact signal sampling unit respectively, and is configured to complete the control of the pressure regulating mechanism, pressure value acquisition and temperature value acquisition, and / or gas density value acquisition, and detect the contact signal action value and / or contact signal return value of the gas density relay body; Wherein, the contact signal includes alarm and / or lock; In the calibration state, the online calibration contact signal sampling unit cuts off the control loop of the contact signal of the gas density relay body and connects the contacts of the gas density relay body to the intelligent control unit; The intelligent control unit adjusts the pressure rise and fall of the third sealed gas chamber by controlling the pressure regulating mechanism, so that the gas density relay body generates a contact signal action; the intelligent control unit obtains the pressure value P1 collected by the first pressure sensor and the temperature value T collected by the temperature sensor when the gas density relay body generates a contact signal action or switching, as well as the pressure value P3 collected by the third pressure sensor, and calculates the equivalent gas pressure value P based on the pressure value P1 and the pressure value P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or, The intelligent control unit obtains the gas density value P1 collected by the first pressure sensor and the temperature sensor when the contact signal of the gas density relay body is actuated or switched. 20 , and the gas density value P3 collected by the third pressure sensor and temperature sensor 20 , and according to the gas density value P1 20 And gas density value P3 20 Calculate the gas density value P 20 , complete the online calibration of the gas density relay.

2. The gas density relay according to claim 1, characterized in that: The gas density relay body includes: a housing, a first bellows, a second bellows, a signal generator, and a signal adjustment mechanism; wherein the first open end of the first bellows is fixed to the inner wall of the housing, the second open end of the first bellows is sealedly connected to the first seal, the inner wall of the first bellows, the first seal, and the inner wall of the housing together form a first sealed air chamber, and the first sealed air chamber is provided with an interface connected to the insulating gas of the electrical equipment; the first open end of the second bellows is sealedly connected to the first seal, the second open end of the second bellows is connected to the inner wall of the housing via the second seal, the outer wall of the first bellows, the first seal, the outer wall of the second bellows, the second seal, and the inner wall of the housing together form a second sealed air chamber; the inner wall of the second bellows, the second seal, and the inner wall of the housing together form a third sealed air chamber, the signal generator and the signal adjustment mechanism are disposed in the third sealed air chamber, the signal adjustment mechanism is connected to the first seal, and the signal generator is disposed corresponding to the signal adjustment mechanism.

3. The gas density relay according to claim 2, characterized in that: The outer diameter of the first bellows is greater than the outer diameter of the second bellows.

4. The gas density relay according to claim 2, characterized in that: The signal adjustment mechanism includes a moving rod, one end of which extends into the second bellows, is connected to the first sealing member, and is displaced with the deformation of the first bellows; the other end of the moving rod extends out of the second bellows and is fixedly connected to a cross bar, the cross bar is provided with an adjustment screw, and the adjustment screw is used to trigger the signal generator under the pushing force of the moving rod.

5. The gas density relay according to claim 1, characterized in that: The third pressure sensor is arranged in the third sealed air chamber; or, the third pressure sensor is arranged on the third sealed air chamber and is connected to the air path of the third sealed air chamber.

6. The gas density relay according to claim 1, characterized in that: The signal generator includes a micro switch or a magnetic auxiliary electric contact, and the gas density relay body outputs a contact signal through the signal generator.

7. The gas density relay according to claim 1, characterized in that: The device further includes a second pressure sensor, which is connected to the first sealed gas chamber or the second sealed gas chamber filled with standard compensation gas.

8. The gas density relay according to claim 1, characterized in that: The intelligent control unit obtains the gas density value collected by the first pressure sensor and the temperature sensor; or, the intelligent control unit obtains the pressure value collected by the first pressure sensor and the temperature value collected by the temperature sensor to complete the online monitoring of the gas density of the monitored electrical equipment by the gas density relay.

9. The gas density relay according to claim 1, characterized in that: It also includes a valve, one end of which is provided with a connection port connected to the atmosphere, and the other end of the valve is connected to the pressure regulating mechanism or the third sealed air chamber.

10. The gas density relay according to claim 1, characterized in that: The pressure regulating mechanism is a sealed air chamber, and a heating element and / or a cooling element are provided outside or inside the sealed air chamber. The heating by the heating element and / or the cooling by the cooling element cause the temperature of the gas in the sealed air chamber to change, thereby completing the pressure increase or decrease of the third sealed air chamber; or The pressure regulating mechanism is a cavity with an opening at one end, the other end of which is connected to the third sealed air chamber; a piston is arranged in the cavity, one end of the piston is connected to an adjusting rod, the outer end of the adjusting rod is connected to a driving component, the other end of the piston extends into the opening and is in sealing contact with the inner wall of the cavity, and the driving component drives the adjusting rod and thereby drives the piston to move in the cavity; or, The pressure regulating mechanism is a sealed air chamber, a piston is provided inside the sealed air chamber, the piston is in sealing contact with the inner wall of the sealed air chamber, and a driving component is provided outside the sealed air chamber, the driving component drives the piston to move in the cavity through electromagnetic force; or, The pressure regulating mechanism is an airbag with one end connected to a driving component, the airbag changes in volume under the drive of the driving component, and the airbag is connected to the third sealed air chamber; or, The pressure regulating mechanism is a bellows, one end of which is connected to the third sealed air chamber, and the other end of which is driven by a driving component to expand and contract; or, The pressure regulating mechanism is a bleed valve, and the bleed valve includes an electric valve; or The pressure regulating mechanism is a compressor; or, The pressure regulating mechanism is a pump, and the pump includes a booster pump or an electric air pump; or, The pressure regulating mechanism is a boost valve; Wherein, the driving component includes one of a magnetic force, a motor, a reciprocating motion mechanism, a Carnot cycle mechanism, a heating thrust generating mechanism, a chemical reaction thrust generating mechanism, and a pneumatic element.

11. The gas density relay according to claim 1, characterized in that: The gas density relay body and the first pressure sensor are an integrated structure; or the gas density relay body, the first pressure sensor, and the temperature sensor are a remote gas density relay with an integrated structure.

12. The gas density relay according to claim 1, characterized in that: The first pressure sensor and the temperature sensor are integrated into one structure.

13. The gas density relay according to claim 12, characterized in that: The first pressure sensor and the temperature sensor are integrated into a gas density transmitter.

14. The gas density relay according to claim 1, characterized in that: The first pressure sensor and the temperature sensor constitute a density detection sensor based on quartz tuning fork technology.

15. The gas density relay according to claim 1, characterized in that: The online verification contact signal sampling unit and the intelligent control unit are arranged together.

16. The gas density relay according to claim 1, characterized in that: The first pressure sensor includes at least one pressure sensor; or, the first pressure sensor adopts a gas density transmitter composed of a pressure sensor and a temperature sensor; or, the first pressure sensor adopts a density detection sensor using quartz tuning fork technology.

17. The gas density relay according to claim 1, characterized in that: The first pressure sensor is installed on the gas path of the gas density relay body; the temperature sensor is installed on the gas path of the gas density relay body or outside the gas path, or inside the gas density relay body, or outside the gas density relay body.

18. The gas density relay according to claim 1, characterized in that: The online verification contact signal sampling unit includes an isolation sampling element, which is controlled by the gas density relay body, or the pressure regulating mechanism, or the intelligent control unit; in the non-verification state, the online verification contact signal sampling unit is relatively isolated from the contact signal of the gas density relay body in the circuit through the isolation sampling element; in the verification state, the online verification contact signal sampling unit cuts off the contact signal control circuit of the gas density relay body through the isolation sampling element, and connects the contact of the gas density relay body with the intelligent control unit; wherein, the isolation sampling element includes one of a travel switch, a micro switch, a button, an electric switch, an electromagnetic relay, an optocoupler, and a thyristor.

19. The gas density relay according to claim 1, characterized in that: It also includes a multi-way connector, on which the gas density relay body and the first pressure sensor are arranged; or The pressure regulating mechanism is fixed on the multi-way connector; or, The gas density relay body, the first pressure sensor, and the pressure regulating mechanism are arranged on the multi-way connector; or, The online verification contact signal sampling unit, the intelligent control unit, and the temperature sensor are arranged on the multi-way connector.

20. The gas density relay according to claim 1, characterized in that: At least two gas density relay bodies, at least two first pressure sensors, at least two third pressure sensors, at least two pressure regulating mechanisms, at least two online calibration contact signal sampling units and an intelligent control unit, and a temperature sensor to complete the online calibration of the gas density relay; or, At least two gas density relay bodies, at least two first pressure sensors, at least two third pressure sensors, at least two pressure regulating mechanisms, at least two temperature sensors, at least two online calibration contact signal sampling units and an intelligent control unit are used to complete the online calibration of the gas density relay.

21. The gas density relay according to claim 1, characterized in that: The intelligent control unit is controlled through on-site control and / or background control.

22. A gas density monitoring device with an online self-calibration function, characterized in that: The gas density monitoring device comprises a gas density relay with an online self-calibration function as described in any one of claims 1 to 21.

23. A calibration method for a gas density relay with an online self-calibration function as claimed in claim 1, characterized in that: include: The gas path of the pressure regulating mechanism is connected to the third sealed gas chamber of the gas density relay body, thereby connecting the gas path of the pressure regulating mechanism with the third sealed gas chamber and the third pressure sensor provided in the third sealed gas chamber; In normal working state, the gas density relay monitors the gas density value in the electrical equipment. At the same time, the gas density relay monitors the gas density value in the electrical equipment online through the first pressure sensor, temperature sensor and intelligent control unit; The gas density relay will perform the following operations according to the set calibration time and / or calibration instruction, as well as the gas density value, under conditions where calibration of the gas density relay is permitted: The online verification contact signal sampling unit is adjusted to the verification state through the intelligent control unit. In the verification state, the online verification contact signal sampling unit cuts off the control loop of the contact signal of the gas density relay body and connects the contact of the gas density relay body to the intelligent control unit; The intelligent control unit adjusts the pressure rise and fall of the third sealed gas chamber by controlling the pressure regulating mechanism, so that the gas density relay body generates a contact signal action; the intelligent control unit obtains the pressure value P1 collected by the first pressure sensor and the temperature value T collected by the temperature sensor when the gas density relay body generates a contact signal action or switching, as well as the pressure value P3 collected by the third pressure sensor, and calculates the equivalent gas pressure value P based on the pressure value P1 and the pressure value P3; according to the equivalent gas pressure value P, and according to the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or, The intelligent control unit obtains the gas density value P1 collected by the first pressure sensor and the temperature sensor when the contact signal of the gas density relay body is actuated or switched. 20 , and the gas density value P3 collected by the third pressure sensor and temperature sensor 20 , and according to the gas density value P1 20 And gas density value P3 20 Calculate the gas density value P 20 , complete the online calibration of the gas density relay; When all contact signal verification work is completed, the intelligent control unit restores the pressure adjustment mechanism and adjusts the online verification contact signal sampling unit to the working state, and the control circuit of the contact signal of the gas density relay body resumes normal operation.

24. The calibration method for a gas density relay with an online self-calibration function according to claim 23, characterized in that: include: When the gas density relay body generates a contact signal action or switching, the equivalent gas pressure value P = P1-P3; according to the equivalent gas pressure value P and the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay; or, When the gas density relay body generates a contact signal action or switching, its equivalent gas pressure value P = P1-P3*K, where K is a preset coefficient; according to the equivalent gas pressure value P, temperature value T, and the gas pressure-temperature characteristic, it is converted into a pressure value corresponding to 20°C, that is, the gas density value P 20 , complete the online calibration of the gas density relay.

25. The calibration method for a gas density relay with an online self-calibration function according to claim 23, characterized in that: include: When the gas density relay body generates a contact signal action or switches, the gas density value P 20 and gas density value P1 20 、P3 20 The corresponding relationship between them is designed into a data table, and according to the gas density value P1 20 and gas density value P3 20 Query the data table to obtain the corresponding gas density value P 20 , complete the online calibration of the gas density relay; or, When the gas density relay body generates a contact signal action or switches, the gas density value P 20 The corresponding relationship between the gas pressure values ​​P1, P3 and the temperature value T is designed into a data table, and the corresponding gas density value P is obtained by querying the data table according to the gas pressure values ​​P1, P3 and the temperature value T. 20 , complete the online calibration of the gas density relay.

26. The calibration method for a gas density relay with an online self-calibration function according to claim 23, characterized in that: Including: the first pressure sensor and the third pressure sensor are absolute pressure sensors; or the first pressure sensor and the third pressure sensor are relative pressure sensors; or when the first pressure sensor and the third pressure sensor are not the same type of sensors, atmospheric pressure correction is performed.

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