Electrical system having online sampling check function and check method thereof

Abstract

The present application provides an electrical system with online sampling check function and a check method therefor, for use in high-voltage and medium-voltage electrical equipment, which includes an electrical equipment, a gas density relay, a gas density detection sensor, a temperature control mechanism, an online check contact signal sampling unit, and an intelligent control unit. The temperature control mechanism adjusts the temperature rise and fall of the temperature compensation element of the gas density relay to cause a contact operation in the gas density relay of the electrical equipment, and the contact operation is transmitted to the intelligent control unit via the online check contact signal sampling unit. The intelligent control unit detects an alarm / close contact signal operation value / return value based on the density value at the time of contact operation, allowing the inspection of the gas density relay to be completed without an inspector having to go to the site, improving the reliability and work efficiency of the power grid and reducing operation and maintenance costs, while also realizing mutual self-checking between the gas density relay and the gas density detection sensor, and further realizing maintenance-free operation.

Description

[Technical field]

[0001] The present invention relates to the field of electric power technology, and in particular to an electrical system (or electrical equipment) having an online sampling check function and a check method thereof, which is applied to high-voltage and medium-voltage electrical equipment. [Background technology]

[0002] Gas density relays are generally used to monitor and control the density of insulating gas in high-voltage electrical equipment. A contact signal control circuit is provided inside the gas density relay. The gas path of the gas density relay communicates with the air chamber of the high-voltage electrical equipment. When a gas leak is detected, the contacts of the gas density relay operate to generate a contact signal. The contact signal control circuit issues an alarm or closes the relay based on the contact signal, thereby protecting the safe operation of the electrical equipment.

[0003] At present, SF6 (sulfur hexafluoride) electrical equipment has been widely applied in the power sector, industrial and mining enterprises, promoting the rapid development of the power industry. When the density of SF6 gas in high-voltage electrical equipment decreases and the content of trace moisture exceeds the standard, it will have a serious impact on the safe operation of SF6 high-voltage electrical equipment. 1) When the density of SF6 gas decreases to a certain extent, it will lead to the loss of insulation and arc-extinguishing performance. 2) With the participation of some metal objects, SF6 gas can generate hydrolysis reaction with water at a high temperature of 200℃ or higher, generating active HF and SOF2, corroding insulation materials and metal materials, while generating a large amount of heat and increasing the pressure of the air chamber. 3) When the temperature decreases, the excess moisture may form condensation water, which will significantly reduce the insulation strength of the surface of the insulation material, and even cause flashover, resulting in serious harm. Therefore, the power grid operation protocol mandatorily stipulates that the density and moisture content of SF6 gas must be detected regularly both before and during the operation of the equipment.

[0004] With the networking and digitalization of unmanned substations and the continuous strengthening of requirements for remote control and remote measurement, online monitoring of the gas density and trace moisture content status of SF6 electrical equipment has important practical significance. With the continuous development of China's smart grid, smart high-voltage electrical equipment, as an important component and key node of smart substations, plays an important role in the safety of smart grid. Summary of the Invention

[0005] SUMMARY OF THE PRESENT DISCLOSURE In order to solve the problems presented in the above technical background, the present invention aims to provide an electrical system (or electrical device) having an online sampling check function and a check method thereof.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] A first aspect of the present application provides an electrical system having an online sampling check function, an electric device having an air chamber therein, the air chamber being filled with an insulating gas; a gas density relay mounted externally to the air chamber of the electrical device or mounted externally to the air chamber of the electrical device by a valve; a temperature control mechanism configured to control the temperature rise and fall of a temperature compensation element of the gas density relay to generate contact operation in the gas density relay; a gas density detection sensor communicating with the gas density relay; an online check contact signal sampling unit connected to the gas density relay and arranged to sample a contact signal generated when a contact of the gas density relay operates; an intelligent control unit respectively connected to the gas density detection sensor, the temperature adjustment mechanism and the online check contact signal sampling unit, and configured to complete the control of the temperature adjustment mechanism, the pressure value collection and temperature value collection, and / or the gas density value collection, and the detection of the contact signal operation value and / or the contact signal return value of the gas density relay; Here, the contact signal includes an alarm and / or a closure.

[0008] Preferably, the electric appliance comprises SF6 gas electric appliance, SF6 mixed gas electric appliance, environmentally friendly gas electric appliance, or other insulated gas electric appliance.

[0009] Specifically, the electrical equipment includes GIS, GIL, PASS, circuit breaker, current transformer, potential transformer, voltage transformer, gas-filled cabinet, and ring main cabinet.

[0010] Preferably, the electrical system includes a bracket, the electrical equipment air chamber is located above or below the bracket, the bracket includes a vertical frame and a horizontal frame, and the gas density relay is located in the internal accommodation space of the horizontal frame.

[0011] Preferably, the gas density relay includes, but is not limited to, bimetal sheet compensated gas density relay, gas compensated gas density relay, bimetal sheet and gas compensated mixed gas density relay, fully mechanical gas density relay, digital type gas density relay, combined mechanical and digital gas density relay, gas density relay with pointer display, digital display type gas density relay, gas density switch without display or indication, SF6 gas density relay, SF6 mixed gas density relay, N2 gas density relay.

[0012] Preferably, the gas density detection sensor is provided in the gas density relay, or the temperature adjustment mechanism is provided inside or outside the gas density relay, or the gas density detection sensor, the online check contact signal sampling unit and the intelligent control unit are provided in the gas density relay.

[0013] More preferably, the gas density relay and the gas density detection sensor are of an integrated structure, and preferably, the gas density relay and the gas density detection sensor are a remote transmission type gas density relay of an integrated structure.

[0014] Preferably, the gas density detection sensor is of integrated construction.

[0015] More preferably, the gas density detection sensor is an integrated gas density transmitter, and preferably, the online check contact signal sampling unit and the intelligent control unit are installed in the gas density transmitter.

[0016] Preferably, the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor, or the gas density detection sensor is a gas density transmitter composed of a pressure sensor and a temperature sensor, or the gas density detection sensor is a density detection sensor that employs quartz tuning fork technology.

[0017] More preferably, the pressure sensor probe is attached to a gas line of the gas density relay.

[0018] More preferably, the temperature sensor probe is mounted on or off the gas path of the gas density relay, or mounted within the gas density relay, or mounted external to the gas density relay.

[0019] More preferably, the temperature sensor may be a thermocouple, a thermistor, a semiconductor type, a contact type and a non-contact type, a thermal resistance and a thermocouple.

[0020] More preferably, the pressure sensor includes, but is not limited to, a relative pressure sensor and / or an absolute pressure sensor.

[0021] Furthermore, the pressure sensor may be a diffused silicon pressure sensor, a MEMS pressure sensor, a chip-based pressure sensor, a coil inductive pressure sensor (e.g., a pressure sensor with an inductive coil in a Bourdon tube), a resistive pressure sensor (e.g., a pressure sensor with a sliding line resistor in a Bourdon tube), an analog quantity pressure sensor, or a digital quantity pressure sensor.

[0022] More preferably, the at least one temperature sensor is provided near or on or integrated with a temperature compensating element of the gas density relay.Preferably, the at least one temperature sensor is provided at one end of the gas density relay close to a temperature compensating element of a pressure detector, where the pressure detector is a Bourdon tube or a corrugated tube, and the temperature compensating element employs a gas sealed in a temperature compensating sheet or case.

[0023] More preferably, the intelligent control unit compares the environmental temperature value with the temperature value collected by the temperature sensor to complete a check on the temperature sensor.

[0024] Preferably, the temperature adjustment mechanism is a heating element; or the temperature adjustment mechanism includes a heating element, a heat retaining material, a temperature controller, a temperature detector, and a temperature adjustment mechanism housing; or the temperature adjustment mechanism includes a heating element and a temperature controller; or the temperature adjustment mechanism includes a heating element, a heating power regulator, and a temperature controller; or the temperature adjustment mechanism includes a heating element, a cooling element, a heating power regulator, and a temperature controller; or the temperature adjustment mechanism includes a heating element, a heating power regulator, and a constant temperature controller; or the temperature adjustment mechanism includes a heating element, a temperature controller, and a temperature detector; or the temperature adjustment mechanism includes a heating element, a temperature controller, and a temperature detector; The temperature control mechanism is a heating element, and the heating element is disposed adjacent to the temperature compensation element; or the temperature control mechanism is a micro thermostatic box, in which the number of the heating elements is at least one, and the heating element includes, but is not limited to, a silicone rubber heater, a resistance wire, an electric heating belt, an electric heating rod, a thermal fan, an infrared heating element, and a semiconductor; the temperature controller is connected to the heating element for controlling the heating temperature of the heating element, and the temperature controller includes, but is not limited to, a PID controller, a controller combining PID and fuzzy control, a frequency conversion controller, and a PLC controller.

[0025] More preferably, the heating elements in the temperature adjustment mechanism include at least two heating elements having the same or different power, or a heating element whose heating power is adjustable.

[0026] More preferably, the installation positions of the at least two heating elements may be the same or different, and can be rationally installed as required.

[0027] Preferably, the temperature adjustment mechanism employs a multi-stage temperature control method.

[0028] Preferably, the temperature regulating mechanism is controlled by the intelligent control unit to measure the operating value of the gas density relay contact signal and request that the temperature change rate be less than 1.0°C per second when close to the operating value (or the requirement is set as needed), i.e., that the temperature rises or falls steadily.

[0029] Preferably, the electrical system with off-line sampling check function further includes a mutual self-calibration unit, and the intelligent control unit realizes maintenance-free operation of the gas density relay by comparing data detected by the mutual self-calibration unit, or realizes maintenance-free operation of the gas density relay by comparing data detected by the intelligent control unit and the mutual self-calibration unit.

[0030] Preferably, the intelligent control unit further includes a depth calculation unit, which provides a gas source with an appropriate initial density for checking the gas density relay that needs to be chucked according to gas pressure-temperature characteristics based on an environmental temperature value, a gas density value or a pressure value of an electrical equipment; or the intelligent control unit can provide a gas source with an appropriate initial density for checking the gas density relay that needs to be checked according to gas pressure-temperature characteristics based on an environmental temperature value at the time of checking, a gas pressure value of an air chamber of an electrical equipment, and a temperature value of the gas density relay that needs to be checked.

[0031] Preferably, one end of the valve is provided with a connection port communicating with an electrical device, and the other end of the valve communicates with a gas passage of the gas density relay.

[0032] Furthermore, the valve is also connected to the intelligent control unit, and the valve is controlled to be closed or opened by the intelligent control unit.

[0033] Preferably, the valve communicates with the electrical device by a connector.

[0034] Preferably, the valves are motorized and / or solenoid valves.

[0035] More preferably, the valve is a permanent magnet type solenoid valve.

[0036] Preferably, the valve is a piezo valve, or a temperature controlled valve, or a new type of valve made of smart memory material and opened and closed by electrical heating.

[0037] Preferably, the valve is realized by folding or pinching the hose to close or open.

[0038] Preferably, the valve is sealed within a cavity or case.

[0039] Preferably, a pressure sensor is provided on each side of the gas path of the valve, or a pressure detector is provided on each side of the gas path of the valve.

[0040] Preferably, the electrical system further comprises a self-sealing valve, the self-sealing valve being mounted between the electrical equipment and the valve, or the valve being mounted between the electrical equipment and the self-sealing valve.

[0041] Preferably, the electrical system with online sampling check function further includes a pressure regulating mechanism, the gas path of which is connected to the gas density relay, the pressure regulating mechanism is also connected to the intelligent control unit, and the intelligent control unit controls the pressure rise and fall of the gas density relay, and further engages and / or couples with a temperature regulating mechanism to cause the gas density relay to operate in contact; or further includes a heating device, and the intelligent control unit is connected to the heating device; or further includes an air chamber and a heating device, the air chamber is connected to the gas density relay, a heating device is provided outside or inside the air chamber, and the intelligent control unit is connected to the heating device.

[0042] More preferably, the valve and the pressure regulating mechanism are sealed within a single cavity or case.

[0043] More preferably, the pressure adjustment mechanism is sealed within a cavity or case.

[0044] More preferably, during checking, the pressure adjustment mechanism is a sealed air chamber, and a heating element and / or a cooling element are provided outside or inside the sealed air chamber, heating is performed by the heating element and / or cooling is performed by the cooling element, thereby causing a temperature change of the gas in the sealed air chamber, and further completing the pressure increase and decrease of the gas density relay.

[0045] Furthermore, the heating element and / or the cooling element are semiconductors.

[0046] Furthermore, the pressure adjustment mechanism further includes a heat retaining material, and the heat retaining material is provided outside the sealed air chamber.

[0047] More preferably, during checking, the pressure adjustment mechanism is a cavity with one open end, the other end of the cavity communicating with a gas path of the gas density relay, a piston within the cavity, an adjustment rod connected to one end of the piston, an outer end of the adjustment rod connected to a drive member, the other end of the piston extending into the opening and in sealing contact with an inner wall of the cavity, and the drive member driving the adjustment rod to further engage the piston to move within the cavity.

[0048] More preferably, during checking, the pressure adjustment mechanism is a sealed air chamber, a piston is provided inside the sealed air chamber, the piston is in sealing contact with an inner wall of the sealed air chamber, and a driving member is provided outside the sealed air chamber, and the driving member drives the piston to move within the cavity by electromagnetic force.

[0049] More preferably, the pressure adjustment mechanism is an airbag having one end connected to a drive member, the volume of the airbag changes when the drive member is driven, and the airbag is in communication with the gas density relay.

[0050] More preferably, the pressure regulating mechanism is a corrugated pipe, one end of the corrugated pipe is connected to the gas density relay, and the other end of the corrugated pipe is extended and retracted by driving the driving member.

[0051] The driving member in the pressure regulating mechanism includes, but is not limited to, a magnetic force, an electric motor (variable frequency electric motor or stepping electric motor), a reciprocating mechanism, a Carnot circulation mechanism, and a pneumatic element.

[0052] More preferably, the pressure adjustment mechanism is a release valve.

[0053] Furthermore, the pressure regulating mechanism further includes a flow valve for controlling the gas release flow rate.

[0054] Furthermore, the release valve can be a solenoid valve or an electric valve, or other electric or gas type release valve.

[0055] Furthermore, the release valve releases gas to the zero position, and the intelligent control unit collects and compares the pressure value at that time, and completes a zero position check for the pressure sensor, and the intelligent control unit or background comparison judges the result, and if the error is bad, it issues an abnormal indication that there is a problem with the pressure sensor.

[0056] More preferably, the pressure regulating mechanism is a compressor.

[0057] More preferably, the pressure regulating mechanism is a pump, which includes, but is not limited to, a pressure generating pump, a pressurizing pump, an electric air pump, and an electromagnetic air pump.

[0058] More preferably, the gas density relay, the valve and the pressure adjustment mechanism are connected by a connecting pipe.

[0059] Furthermore, the gas path of the pressure adjustment mechanism is connected to the gas path of the gas density relay by a first connecting pipe, and the exhaust port of the valve is directly connected to the gas path of the gas density relay by a second connecting pipe, or the exhaust port of the valve is connected to the gas path of the pressure adjustment mechanism by a second connecting pipe, thereby connecting the valve to the gas path of the gas density relay.

[0060] Preferably, the online check contact signal sampling unit and the intelligent control unit are integrated together.

[0061] More preferably, the online check contact signal sampling unit and the intelligent control unit are sealed in one cavity or case.

[0062] Preferably, the sampling of the contact signal of the gas density relay by the online check contact signal sampling unit satisfies the following: the online check contact signal sampling unit has at least one set of independent sampling contacts, automatically completes checking for at least one contact at a time, and can continuously measure without the need to replace or reselect the contacts, where the contacts include but are not limited to one of the following: alarm contact, alarm contact+close contact, alarm contact+close 1 contact+close 2 contact, and alarm contact+close contact+overvoltage contact.

[0063] Preferably, the test voltage of the online check contact signal sampling unit for the contact signal operating value or its switching value of the gas density relay is 24V or more, that is, during checking, a voltage of 24V or more is applied between the corresponding terminals of the contact signal.

[0064] Preferably, the contacts of the gas density relay are normally open type gas density relays, and the online check contact signal sampling unit includes a first connection circuit and a second connection circuit, the first connection circuit is connected to the contacts of the gas density relay and a contact signal control circuit, and the second connection circuit is connected to the contacts of the gas density relay and the intelligent control unit, and in a non-check state, the second connection circuit is disconnected or isolated, and the first connection circuit is closed; in a check state, the online check contact signal sampling unit disconnects the first connection circuit, turns on the second connection circuit, and connects the contacts of the gas density relay to the intelligent control unit; or The contacts of the gas density relay are normally closed type density relays, and the online check contact signal sampling unit includes a first connection circuit and a second connection circuit, the first connection circuit is connected to the contacts of the gas density relay and a contact signal control circuit, and the second connection circuit is connected to the contacts of the gas density relay and the intelligent control unit, in a non-check state, the second connection circuit is disconnected or isolated and the first connection circuit is closed, and in a check state, the online check contact signal sampling unit closes the contact signal control circuit, disconnects the connection of the contacts of the gas density relay and the contact signal control circuit, turns on the second connection circuit, and connects the contacts of the gas density relay to the intelligent control unit.

[0065] More preferably, the first connection circuit includes a first relay, the second connection circuit includes a second relay, the first relay is provided with at least one normally closed contact, the second relay is provided with at least one normally open contact, the normally closed contact and the normally open contact are maintained in opposite open / closed states, the normally closed contact is connected in series to the contact signal control circuit, and the normally open contact is connected to a contact of the gas density relay, In a non-check state, the normally closed contact is closed and the normally open contact is disconnected, and the gas density relay monitors the output state of the contact in real time; in a check state, the normally closed contact is disconnected and the normally open contact is closed, and the contact of the gas density relay is connected to the intelligent control unit by the normally open contact. Note that, for the contact being a normally closed density relay, it can be adjusted accordingly.

[0066] Furthermore, the first relay and the second relay may be two independent relays or may be the same relay.

[0067] More preferably, the online check contact signal sampling unit is provided with a contact sampling circuit, the contact sampling circuit includes a photocoupler and a resistor, the photocoupler includes a light-emitting diode and a phototransistor, the light-emitting diode and the contact of the gas density relay are connected in series to form a closed circuit, the emitter of the phototransistor is grounded, the collector of the phototransistor is connected to the intelligent control unit, and the collector of the phototransistor is also connected to a power source by the resistor; When the contact is closed, the closed circuit is energized, the light emitting diode emits light, the light conducts through the phototransistor, and the collector of the phototransistor outputs a low level; When the contact is disconnected, the closed circuit is broken, the light emitting diode does not emit light, the phototransistor is turned off, and the collector of the phototransistor outputs a high level.

[0068] More preferably, the online check contact signal sampling unit is provided with a contact sampling circuit, the contact sampling circuit including a first photocoupler and a second photocoupler; the light-emitting diode of the first photocoupler and the light-emitting diode of the second photocoupler are respectively connected in parallel by a current limiting resistor or directly in parallel, and are connected in series with the contact of the gas density relay after being connected in parallel to form a closed circuit, and the connection directions of the light-emitting diodes of the first photocoupler and the second photocoupler are reversed; The collector of the phototransistor of the first photocoupler and the collector of the phototransistor of the second photocoupler are both connected to a power supply through a voltage dividing resistor, the emitter of the phototransistor of the first photocoupler is connected to the emitter of the phototransistor of the second photocoupler to form an output end, which is connected to the intelligent control unit and grounded through a resistor; When the contact is closed, a closed circuit is energized, the first photocoupler is turned on, the second photocoupler is turned off, and the emitter of the phototransistor of the first photocoupler outputs a high level; or the first photocoupler is turned off, the second photocoupler is turned on, and the emitter of the phototransistor of the second photocoupler outputs a high level; When the contact is disconnected, the closed circuit is interrupted, the first photocoupler and the second photocoupler are both turned off, and the emitters of the phototransistors of the first photocoupler and the second photocoupler output a low level.

[0069] Furthermore, the contact sampling circuit further includes a first Zener diode group and a second Zener diode group, the first Zener diode group and the second Zener diode group are connected in parallel in the contact signal control circuit, the first Zener diode group and the second Zener diode group are connected in opposite directions, and the first Zener diode group and the second Zener diode group are each configured with one, two or more Zener diodes connected in series. Alternatively, a diode can be used instead of the Zener diode.

[0070] Furthermore, the first Zener diode group includes a first Zener diode and a second Zener diode connected in series, the negative electrode of the first Zener diode is connected to the positive electrode of the second Zener diode, and the second Zener diode group includes a third Zener diode and a fourth Zener diode connected in series, the positive electrode of the third Zener diode is connected to the negative electrode of the fourth Zener diode.

[0071] More preferably, the online check contact signal sampling unit is provided with a contact sampling circuit, the contact sampling circuit includes a first Hall current sensor and a second Hall current sensor, the first Hall current sensor, the second Hall current sensor and the contact of the gas density relay are connected in series to form a closed circuit, and the contact of the gas density relay is connected between the first Hall current sensor and the second Hall current sensor, and the output end of the first Hall current sensor and the output end of the second Hall current sensor are both connected to the intelligent control unit; When the contacts are closed, a closed circuit is energized and a current flows between the first Hall current sensor and the second Hall current sensor, generating an induced potential; When the contacts are disconnected, the closed circuit is interrupted, no current flows between the first and second Hall current sensors, and the induced potential generated is zero.

[0072] More preferably, the online check contact signal sampling unit is provided with a contact sampling circuit, and the contact sampling circuit includes a first thyristor, a second thyristor, a third thyristor and a fourth thyristor; The first thyristor and the third thyristor are connected in series, and after the second thyristor and the fourth thyristor are connected in series, a series-parallel closed circuit is formed with the series connection line consisting of the first thyristor and the third thyristor, and one end of the contact of the gas density relay is electrically connected to the line between the first thyristor and the third thyristor by a line, and the other end is electrically connected to the line between the second thyristor and the fourth thyristor by a line.

[0073] Furthermore, the cathode of the first thyristor is connected to an intelligent control unit, the anode of the first thyristor is connected to the cathode of the third thyristor, control poles of the first thyristor and the third thyristor are connected to the intelligent control unit, the cathode of the second thyristor is connected to the intelligent control unit, the anode of the second thyristor is connected to the cathode of the fourth thyristor, and control poles of the second thyristor and the fourth thyristor are connected to the intelligent control unit.

[0074] Preferably, the intelligent control unit obtains the gas density value collected by the gas density detection sensor, or the intelligent control unit obtains the pressure value and temperature value collected by the gas density detection sensor, and completes online monitoring of the gas density relay for gas density, i.e., completes online monitoring of the gas density of the monitored electrical equipment of the gas density relay.

[0075] More preferably, the intelligent control unit adopts an averaging method to calculate the gas density value, and the averaging method is as follows: within a set time interval, a collection frequency is set, and N gas density values ​​at different time points are collected and averaged to obtain the gas density value; or within a set time interval, a temperature interval step width is set, and N density values ​​corresponding to N different temperature values ​​collected in all temperature ranges are collected and averaged to obtain the gas density value; or within a set time interval, a pressure interval step width is set, and N density values ​​corresponding to N different pressure values ​​collected in all pressure change ranges are collected and averaged to obtain the gas density value, where N is a positive integer equal to or greater than 1.

[0076] Preferably, the intelligent control unit obtains the gas density value collected by the gas density detection sensor when the gas density relay generates a contact signal or a switch, and completes an online check of the gas density relay; or The intelligent control unit obtains the pressure value and temperature value collected by the gas density detection sensor when a contact signal operation or switching occurs in the gas density relay, and converts them into a gas density value, which is a pressure value corresponding to 20°C, according to the gas pressure-temperature characteristics, to complete an online check of the gas density relay.

[0077] Preferably, the gas density relay has a comparison density value output signal which is connected to the intelligent control unit, or the gas density relay has a comparison pressure value output signal which is connected to the intelligent control unit.

[0078] More preferably, when the gas density relay outputs a comparative density value output signal, the intelligent control unit collects the gas density value at that time, performs a comparison, and completes checking the comparative density value for the gas density relay; the intelligent control unit or the background judges the comparison result, and issues an abnormal indication if the error is bad; or When the gas density relay outputs a comparison density value output signal, the intelligent control unit collects and compares the gas density value at that time, and completes the mutual check between the gas density relay and the gas density detection sensor. The intelligent control unit or the background judges the comparison result, and issues an abnormality indication if the error is bad; or When the gas density relay outputs a comparison density value output signal, the intelligent control unit collects and compares the pressure value at that time to complete a mutual check between the gas density relay and the gas density detection sensor. The intelligent control unit or background judges the comparison result. If the error is bad, an abnormality indication is issued.

[0079] Preferably, the electrical system with online sampling check function of the present application includes at least two gas density detection sensors, each of which includes one pressure sensor and one temperature sensor, and compares the gas density values ​​detected by each gas density detection sensor to complete a mutual check of each gas density detection sensor.

[0080] Preferably, the gas density detection sensor includes at least two pressure sensors, and compares the pressure values ​​collected by each pressure sensor to complete a mutual check of each pressure sensor.

[0081] Preferably, the gas density detection sensor includes at least two temperature sensors, and compares the temperature values ​​collected by each temperature sensor to complete a mutual check of each temperature sensor.

[0082] Preferably, the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor, and randomly arranges and combines the pressure values ​​collected by each pressure sensor and the temperature values ​​collected by each temperature sensor, converts each combination into gas density values ​​which are multiple pressure values ​​corresponding to 20°C according to the gas pressure-temperature characteristics, compares each gas density value, and completes mutual checking of each pressure sensor and each temperature sensor; or arranges and combines all the pressure values ​​collected by each pressure sensor and the temperature values ​​collected by each temperature sensor, and converts each combination into gas density values ​​which are multiple pressure values ​​corresponding to 20°C according to the gas pressure-temperature characteristics, compares each gas density value, and completes mutual checking of each pressure sensor and each temperature sensor; or compares the multiple gas density values ​​obtained by each pressure sensor and each temperature sensor with the comparison density value output signals output by the gas density relay, and completes mutual checking of the gas density relay, each pressure sensor, and each temperature sensor.

[0083] Preferably, after the gas density relay completes the check, the electrical system automatically generates a gas density relay check report, and if there is an abnormality, issues an alarm and uploads it to the remote end or transmits it to a designated receiver.

[0084] Preferably, the intelligent control unit automatically controls the entire checking process based on the built-in algorithms and control programs of the microprocessor embedded system, and includes all peripherals, logic and inputs / outputs.

[0085] More preferably, the intelligent control unit automatically controls the entire checking process based on the built-in algorithm and control program of a general-purpose computer, an industrial computer, an ARM chip, an AI chip, a CPU, an MCU, an FPGA, a PLC, etc., an industrial control main board, an embedded main control board, etc., and includes all peripheral devices, logic and input / output.

[0086] Preferably, the intelligent control unit is provided with an electrical interface, which completes storing test data, and / or deriving test data, and / or printing test data, and / or data communication with a host computer, and / or inputting analog quantity, digital quantity information.

[0087] More preferably, the electrical system supports input of basic information of the gas density relay, the basic information including, but not limited to, one or more of: shipping number, accuracy requirements, rating parameters, manufacturing plant, and operating location.

[0088] Preferably, the intelligent control unit further includes a communication module for realizing long-distance transmission of test data and / or checking results.

[0089] More preferably, the communication method of the communication module is a wired communication or a wireless communication method.

[0090] Furthermore, the wired communication method includes, but is not limited to, one or more of RS232 bus, RS485 bus, CAN-BUS bus, 4-20mA, Hart, IIC, SPI, Wire, coaxial cable, PLC power carrier, and cable.

[0091] Furthermore, the wireless communication method may include, but is not limited to, 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.

[0092] Preferably, the intelligent control unit is further provided with a clock, the clock being arranged to be used for periodically setting a check time of the gas density relay or recording a test time or recording an event time.

[0093] Preferably, the control of the intelligent control unit is local and / or background controlled.

[0094] More preferably, the electrical system completes an online check of the gas density relay based on the background installation or command, or completes an online check of the gas density relay based on a set check time of the gas density relay.

[0095] Preferably, the circuit of the intelligent control unit includes an intelligent control unit protection circuit, which includes, but is not limited to, one or more of anti-static interference circuits (e.g., ESD, EMI), surge protection circuits, electrical high-speed protection circuits, high-frequency electric field interference prevention circuits, pulse group interference prevention circuits, power supply short circuit protection circuits, power supply reverse connection protection circuits, electrical contact misconnection protection circuits, and charging protection circuits.

[0096] Preferably, the electrical system further includes a multi-way joint, and the gas density relay, the valve and the pressure regulating mechanism are provided in the multi-way joint, or the intelligent control unit is provided in the multi-way joint.

[0097] More preferably, the gas path of the gas density relay is connected to a first joint of the multi-way joint, the gas path of the pressure adjustment mechanism is connected to a second joint of the multi-way joint, the first joint communicates with the second joint, thereby connecting the gas path of the pressure adjustment mechanism to the gas path of the gas density relay, and the exhaust port of the valve communicates with a third joint of the multi-way joint, the third joint communicates with the first joint, thereby connecting the exhaust port of the valve to the gas path of the pressure adjustment mechanism and / or the gas path of the gas density relay.

[0098] Furthermore, a connection portion that is connected to the electric device is provided at the third joint of the multi-way joint, and the valve is fitted inside the connection portion.

[0099] More preferably, a connector is provided on the case of the gas density relay and the connector is fixed within the air chamber of the electrical device, or preferably, the case of the gas density relay is fixed to the multi-way joint and the multi-way joint is fixed within the air chamber.

[0100] Preferably, the electrical system further includes a gas refill port.

[0101] More preferably, the gas refill port is provided in the pressure regulating mechanism, or the gas refill port is provided in the electrical device, or the gas refill port is provided in the multi-way connector, or the gas refill port is provided in the self-sealing valve.

[0102] More preferably, the electrical system can collect statistics on the number of times gas is refilled, or the amount of gas refilled, or the time required for gas refilling.

[0103] Preferably, the electrical system is capable of providing on-line gas refueling.

[0104] Preferably, the electrical system is capable of providing on-line gas drying.

[0105] Preferably, the electrical system further includes a display interface for man-machine interaction, connected to the intelligent control unit, for displaying current check data in real time and / or supporting data input, specifically including real-time online gas density value display, pressure value display, temperature value display, change trend analysis, history data inquiry, real-time alarm, etc.

[0106] Preferably, the electrical system further includes micro-water sensors, each connected to the gas density relay and the intelligent control unit.

[0107] More preferably, the electrical system further includes a gas circulation mechanism, the gas circulation mechanism being respectively connected to the gas density relay and the intelligent control unit, the gas circulation mechanism including a capillary tube, a sealed chamber and a heating element, the heating element being used for heating, realizing gas flow, and monitoring the micro-water value inside the gas online.

[0108] Furthermore, the micro water sensor may be attached to a sealed chamber of the gas circulation mechanism, in a capillary, at the capillary mouth, or outside the capillary.

[0109] Preferably, the electrical system further comprises a fraction sensor, the fraction sensor being connected to the gas density relay and the intelligent control unit respectively.

[0110] Preferably, the electrical system further includes a camera for monitoring.

[0111] Preferably, the electrical system monitors the gas density, or density, pressure, or temperature values ​​online, or the electrical system transmits the monitored gas density, or density, pressure, or temperature values ​​remotely.

[0112] Preferably, the electrical system has a self-diagnosis function and can report abnormalities in a timely manner, such as a broken wire, a short circuit, or sensor damage.

[0113] Preferably, the electrical system has a safety protection function, which automatically stops the check and issues an alarm signal when the gas density or pressure value is lower than a set value.

[0114] Preferably, the electrical system is provided with a heater and / or a heat sink (e.g., a fan), which turns on the heater when the temperature is below a set value and turns on the heat sink (e.g., a fan) when the temperature is above a set value.

[0115] Preferably, the gas density relay further includes a contact resistance detection unit, which is connected to a contact signal or directly connected to a signal generator in the gas density relay, and under the control of the online check 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 operates and / or receives a command to detect the contact resistance of the contact, the contact resistance detection unit can detect the contact resistance value of the contact of the gas density relay.

[0116] Preferably, the gas density relay further includes an insulation resistance detection unit, which is connected to the contacts or directly connected to a signal generator in the gas density relay, and under the control of the online check contact signal sampling unit, the contacts of the gas density relay are isolated from their control circuits, and when the contacts of the gas density relay are operated and / or receive a command to detect the contact insulation resistance, the insulation resistance detection unit can detect the contact insulation resistance value of the gas density relay, and further detect the insulation performance of the gas density relay.

[0117] Preferably, at least two gas density relays, at least two multi-way joints, at least two temperature control mechanisms, at least two online check contact signal sampling units and an intelligent control unit, a gas density detection sensor complete the online check of the gas density relay; or At least two gas density relays, at least two multi-way joints, at least two temperature control mechanisms, at least two online check contact signal sampling units, at least two intelligent control units and a gas density detection sensor complete the online check of the gas density relays; or At least two gas density relays, at least two multi-way joints, at least two temperature adjustment mechanisms, at least two online check contact signal sampling units, at least two gas density detection sensors and one intelligent control unit complete the online check of the gas density relays.

[0118] A second aspect of the present application provides a method for checking a gas density relay, comprising: Under normal operating conditions, the gas density relay monitors a gas density value within the electrical equipment; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas density relay, and further increases the temperature of the temperature compensation element of the gas density relay, causing the gas density relay to make a contact operation. The contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit turns off the heating element of the temperature adjustment mechanism.

[0119] Preferably, the method for checking a gas density relay comprises the steps of: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas density relay, and further increases the temperature of the temperature compensation element of the gas density relay, causing the gas density relay to make a contact operation. The contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay. The intelligent control unit controls the temperature regulating mechanism to reduce the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is reduced, causing a contact reset in the gas density relay. The contact reset is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the check work of the contact signal return value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit turns off the heating element of the temperature regulating mechanism, adjusts the online check contact signal sampling unit to an operating state, and the contact signal control circuit of the gas density relay returns to a normal operating state and operates.

[0120] Preferably, the gas density relay further includes a pressure regulating mechanism, a gas passage of the pressure regulating mechanism communicates with a gas passage of the gas density relay, and a method of checking the gas density relay includes the steps of: Under normal operating conditions, the gas density relay monitors a gas density value within the electrical equipment; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, closing the valve with an intelligent control unit; The intelligent control unit drives the pressure regulating mechanism to gradually reduce the gas pressure, and the intelligent control unit controls the temperature regulating mechanism to increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay increases, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the checking work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the heating element of the temperature regulating mechanism.

[0121] Preferably, the gas density relay further includes a pressure regulating mechanism, a gas passage of the pressure regulating mechanism communicates with a gas passage of the gas density relay, and a method of checking the gas density relay includes the steps of: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, closing the valve with an intelligent control unit; The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature regulating mechanism to increase the temperature of the gas density relay, and then the temperature of the temperature compensation element of the gas density relay increases, and the intelligent control unit drives the pressure regulating mechanism to gradually reduce the gas pressure, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; The intelligent control unit controls the temperature regulating mechanism to reduce the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is reduced. The intelligent control unit drives the pressure regulating mechanism to gradually increase the gas pressure, causing a contact reset in the gas density relay. The contact reset is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the check work of the contact signal return value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the heating element of the temperature regulating mechanism, and adjusts the online check contact signal sampling unit to an operating state, and the control circuit of the contact signal of the gas density relay returns to a normal operating state and operates.

[0122] Preferably, the method for checking a gas density relay comprises the steps of: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the contact signal sampling unit to a check state, and in the check state, the contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas in the gas density relay, and closes the valve after the temperature reaches a set value; After the temperature or pressure of the gas density relay is reduced to the set value, the temperature of the gas density relay is further increased through the control of the temperature regulating mechanism of the intelligent control unit, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

[0123] Preferably, the gas density relay further includes an air chamber and a heating device, the air chamber is in communication with the gas density relay, and the heating device is provided outside or inside the air chamber, and a method for checking the gas density relay includes the following steps: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the contact signal sampling unit to a check state, and in the check state, the contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; Control the heating of the heating device by an intelligent control unit, resulting in a temperature change of the gas in the air chamber between the valve and the gas density relay, and close the valve by the intelligent control unit after reaching a set value, and further turn off the heating device by the intelligent control unit; After the temperature or pressure of the air chamber is reduced to the set value, the intelligent control unit controls the temperature regulating mechanism to further increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

[0124] Preferably, the gas density relay or electrical system further includes an air chamber and a heating device, the air chamber is in communication with the gas density relay, and the heating device is provided outside or inside the air chamber, and the method for checking the gas density relay includes: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the contact signal sampling unit to a check state, and in the check state, the contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; Control the heating of the heating device by an intelligent control unit, resulting in a temperature change of the gas in the air chamber, and after reaching a set value, close the valve by the intelligent control unit, and turn off the heating device by the intelligent control unit; After the temperature or pressure of the air chamber is reduced to the set value, the intelligent control unit controls the temperature regulating mechanism to further increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

[0125] More preferably, there is provided a method for checking a gas density relay, comprising the steps of: After completing the checking work of the contact signal operating value of the gas density relay, further control the temperature regulating mechanism of the intelligent control unit to reduce the temperature of the gas density relay, and further reduce the temperature of the temperature compensation element of the gas density relay, causing a contact reset in the gas density relay, and the contact reset is transmitted to the intelligent control unit through the contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the checking work of the contact signal return value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature regulating mechanism, adjusts the contact signal sampling unit to an operating state, and the control circuit for the contact signal of the gas density relay returns to a normal operating state and operates.

[0126] Preferably, the contact signal includes an alarm and / or a closure.

[0127] Preferably, the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor, or the gas density detection sensor is a gas density transmitter composed of a pressure sensor and a temperature sensor, or the gas density detection sensor is a density detection sensor that employs quartz tuning fork technology.

[0128] Preferably, after the gas density relay completes the check, if there is any abnormality, it can automatically issue an alarm and upload it to the remote end or send it to a designated receiver.

[0129] Preferably, the checking method further comprises displaying the gas density value and the check result on-site or displaying the gas density value and the check result in the background.

[0130] Preferably, the checking method further comprises that the control of the intelligent control unit is controlled locally and / or in the background.

[0131] Preferably, in the checking method, at least two gas density relays, at least two multi-way joints, at least two temperature control mechanisms, at least two online check contact signal sampling units and an intelligent control unit, a gas density detection sensor complete the online checking of the gas density relay; or At least two gas density relays, at least two multi-way joints, at least two temperature control mechanisms, at least two online check contact signal sampling units, at least two intelligent control units and a gas density detection sensor complete the online check of the gas density relays; or At least two gas density relays, at least two multi-way joints, at least two temperature adjustment mechanisms, at least two online check contact signal sampling units, at least two gas density detection sensors and one intelligent control unit complete the online check of the gas density relays.

[0132] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0133] The present application provides an electrical system with online sampling check function and a check method thereof, which is used in high-voltage electrical equipment, and includes an electrical equipment, a gas density relay, a gas density detection sensor, a temperature control mechanism, a valve, an online check contact signal sampling unit, and an intelligent control unit. The intelligent control unit closes the valve, so that the gas density relay is disconnected from the electrical equipment in the gas path, and the temperature control mechanism adjusts the temperature rise and fall of the temperature compensation element of the gas density relay to generate a contact operation in the gas density relay, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit detects the alarm and / or close contact signal operation value and / or return value of the gas density relay according to the density value at the time of contact operation, so that the density relay can be checked without disassembling the density relay and without adding a check valve, and the gas density relay can be checked without the need for an inspector to go to the site, thereby improving the reliability of the power grid, improving work efficiency, and reducing operation and maintenance costs. Some drawings constituting this application are used to provide a further understanding of the application, and the exemplary embodiments and the description thereof are used to explain the application, and are not intended to unduly limit the application. [Brief description of the drawings]

[0134] [Figure 1] FIG. 1 is a structural schematic diagram of an electrical system having online sampling check function according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a control circuit of the electric system according to the first embodiment. [Diagram 3] FIG. 11 is a structural schematic diagram of an electrical system with online sampling check function of the second embodiment. [Figure 4] FIG. 11 is a structural schematic diagram of an electrical system with online sampling check function of the third embodiment. [Diagram 5]FIG. 13 is a structural schematic diagram of an electrical system with online sampling check function of Example 4. [Figure 6] FIG. 13 is a structural schematic diagram of an electrical system with online sampling check function of Example 5. [Figure 7] FIG. 13 is a schematic diagram of a control circuit of an electrical system according to a sixth embodiment. [Figure 8] FIG. 13 is a schematic diagram of a control circuit of an electrical system according to a seventh embodiment. [Figure 9] FIG. 13 is a schematic diagram of a control circuit of an electrical system according to an eighth embodiment. [Figure 10] FIG. 13 is a schematic diagram of a control circuit for an electrical system according to a ninth embodiment. [Figure 11] FIG. 23 is a schematic diagram of a control circuit for an electrical system according to a tenth embodiment. [Figure 12] FIG. 23 is a schematic diagram of the gas path structure of the electrical system of Example 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0135] In order to make the objectives, technical solutions and effects of the present invention clearer and more precise, the present invention will be described in more detail below by way of examples with reference to the drawings. It is understood that the specific embodiments described herein are used to illustrate the present invention, and are not intended to limit the present invention. Example 1:

[0136] As shown in FIG. 1, the electrical system with online sampling check function provided by the first embodiment of the present invention includes an electrical device 8, a gas density relay 1, a pressure sensor 2, a temperature sensor 3, a temperature adjustment mechanism 5, an online check contact signal sampling unit 6, an intelligent control unit 7, a multi-way joint 9, a gas refill port 10 and a micro water sensor 12. The gas density relay 1, the micro water sensor 12 and the gas refill port 10 are provided in the multi-way joint 9. The probe 1201 of the micro water sensor 12 is provided in the main air passage between the electrical device 8 and the gas refill port 10, and the gas density relay 1, the pressure sensor 2, the temperature sensor 3, the online check contact signal sampling unit 6 and the intelligent control unit 7 are integrally provided. The temperature adjustment mechanism 5 is provided opposite to the gas density relay 1, and the temperature sensor 3 is provided in the case of the gas density relay 1. The pressure sensor 2, the online check contact signal sampling unit 6 and the intelligent control unit 7 may be provided in the gas density relay 1. The temperature adjustment mechanism 5 is provided outside the gas density relay 1. Specifically, the gas density relay 1 is connected to the electrical equipment 8 via a multi-way joint 9, the pressure sensor 2 is connected to the gas density relay 1 in a gas path, the online check contact signal sampling unit 6 is respectively connected to the gas density relay 1 and the intelligent control unit 7, the pressure sensor 2, the temperature sensor 3 and the temperature adjustment mechanism 5 are respectively connected to the intelligent control unit 7, and the gas refill port 10 is connected to the multi-way joint 9.

[0137] The electric device 8 has an air chamber therein, and the air chamber is filled with an insulating gas. The multi-way joint 9 is hermetically connected to the electric device 8 and communicates with the air chamber of the electric device 8, and the electric device 8 communicates with the gas density relay 1 through the multi-way joint 9.

[0138] The temperature adjustment mechanism 5 is arranged to adjust the temperature rise and fall of the temperature compensation element of the gas density relay 1 and generate a contact operation in the gas density relay 1, and the online check contact signal sampling unit 6 is connected to the gas density relay 1 and arranged to sample the contact signal of the gas density relay 1, where the contact signal includes alarm and / or closing, and the temperature adjustment mechanism 5 is mainly composed of a heating element 501, a heat retaining material 502, a controller 504, a temperature detector 3 (same as the temperature sensor), a temperature adjustment mechanism housing 503, etc. The controller 504 may adopt PID control, or may adopt a control method combining PID and fuzzy control. The electric heating operation power range of the heating element 501 is controlled by the controller 504 and the temperature rise and fall range setting value, and the temperature change range is controlled by the magnitude of different power. By setting the deviation, it can be heated or cooled earlier. When the temperature inside the temperature adjustment mechanism 5 is measured by the intelligent control unit 7 and the temperature controller 504 to determine the operating value of the contact signal of the gas density relay 1, the temperature change rate when close to the operating value is less than 1.0°C per second (or less than 0.5°C per second, or the requirement is set as required), that is, the temperature requirement rises or falls stably.

[0139] The operating principle is as follows.

[0140] The intelligent control unit 7 operates or controls the temperature adjustment mechanism 5 to increase the temperature of the gas density relay 1, and the temperature of the temperature compensation element of the gas density relay 1 also increases. When the temperature is close to the operating value, the temperature change rate is less than 1.0°C per second (or less than 0.5°C per second, or set the requirement as required), that is, the temperature requirement rises (or falls) steadily. Until the gas density relay 1 has a contact operation, the contact operation is transmitted to the intelligent control unit 7 through the online check contact signal sampling unit 6, and the intelligent control unit 7 obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay 1, and completes the check of the contact signal operation value of the gas density relay 1. For example, for a gas density relay whose density relay parameters are 0.6 / 0.52 / 0.50MPa (rated value 0.6MPa / alarm pressure value 0.52MPa / alarm pressure value 0.50MPa, relative pressure), when the environmental temperature is 5℃, the gas pressure in the air chamber of the electrical equipment 8 is 0.5562MPa (relative pressure), at this time in the checking system, when the pressure value does not change and the temperature rises to 29.5℃, the alarm contact will be activated, and the intelligent control unit 7 can obtain the alarm contact operating value of the gas density relay of 0.5317MPa (relative pressure) based on the pressure value of 0.5562MPa (relative pressure) and the temperature value of 29.5℃ when the contact is activated, and the intelligent control unit 7 can obtain the error of the alarm contact operating value of 0.0117MPa (0.5317MPa-0.52MPa=0.0117MPa), completing the checking of the alarm contact operating value of the density relay.

[0141] The intelligent control unit 7 operates or controls the temperature adjustment mechanism 5 to reduce the temperature of the gas density relay 1, and further reduces the temperature of the temperature compensation element of the gas density relay 1, causing a contact reset in the gas density relay 1. The contact reset is transmitted to the intelligent control unit 7 through the online check contact signal sampling unit 6, and the intelligent control unit 7 obtains the gas density value based on the pressure value and temperature value at the time of contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay 1, and completes the check work of the contact signal return value of the gas density relay 1. For example, for a gas density relay whose density relay parameters are 0.6 / 0.52 / 0.50MPa (rated value 0.6MPa / alarm pressure value 0.52MPa / alarm pressure value 0.50MPa, relative pressure), when the environmental temperature is 5℃, the gas pressure in the electrical equipment 8 is 0.5562MPa (relative pressure), and similarly, in the checking system at this time, if the pressure value does not change and the temperature drops to 24.8℃, a contact reset occurs at the alarm contact, and the intelligent control unit 7 can obtain the alarm contact return value of the gas density relay of 0.5435MPa (relative pressure) based on the pressure value of 0.5562MPa (relative pressure) and the temperature value of 24.8℃ when the contact is reset, and the intelligent control unit 7 can obtain the switching difference of the alarm contact of 0.0118MPa (0.5435MPa-0.5317MPa=0.0118MPa), thus completing the checking of the alarm contact operation value of the density relay 1. Upon request, the intelligent control unit 7 can determine the performance status (eg pass or fail) of the checked gas density relay based on the check result (check data).

[0142] After all the contact signal checking operations are completed, the intelligent control unit 7 turns off the heating element 501 of the temperature adjustment mechanism 5 .

[0143] 2 is a schematic diagram of a control circuit of an electrical system with online sampling check function according to a first embodiment of the present invention. As shown in FIG. 2, a protection circuit is provided in the online check contact signal sampling unit 6 of this embodiment, which includes a first connection circuit and a second connection circuit, the first connection circuit is connected to the contact of the gas density relay 1 and the contact signal control circuit, and the second connection circuit is connected to the contact of the gas density relay 1 and the intelligent control unit 7. In a non-check state, the second connection circuit is disconnected and the first connection circuit is closed; in a check state, the online check contact signal sampling unit 6 disconnects the first connection circuit and communicates with the second connection circuit, and connects the contact of the gas density relay 1 to the intelligent control unit 7.

[0144] Specifically, the first connection circuit includes a first relay J1, and the second connection circuit includes a second relay J2. The first relay J1 is provided with normally closed contacts J11 and J12, which are connected in series in the contact signal control circuit, and the second relay J2 is provided with normally open contacts J21 and J22, which are connected in series to the contact P of the gas density relay 1. J In the non-check state, the normally closed contacts J11 and J12 are closed, the normally open contacts J21 and J22 are disconnected, and the gas density relay 1 is connected to the contact P J The output state of the relay 1 is monitored in real time. In the check state, the normally closed contacts J11 and J12 are disconnected, the normally open contacts J21 and J22 are closed, and the contact P of the gas density relay 1 is J is connected to the intelligent control unit 7 by the normally open contacts J21 and J22.

[0145] The intelligent control unit 7 is respectively connected to the gas density detection sensor (pressure sensor 2 and temperature sensor 3), the temperature adjustment mechanism 5 and the online check contact signal sampling unit 6, and is arranged to complete the control of the temperature adjustment mechanism 5, the pressure value collection and temperature value collection, and / or the gas density value collection, and the detection of the contact signal operation value and / or the contact signal return value of the gas density relay. The intelligent control unit 7 is mainly composed of a processor 71 (U1) and a power supply 72 (U2). The processor 71 (U1) may be a general-purpose computer, an industrial computer, a CPU, a one-chip microcomputer, an ARM chip, an AI chip, an MCU, an FPGA, a PLC, etc., an industrial main board, an embedded main control board, etc., and other intelligent integrated circuits. The power supply 72 (U2) may be a switching power supply, an AC 220V, a DC power supply, an LDO, a programmable power supply, a solar cell, a storage battery, a rechargeable battery, a battery, etc. The pressure sensor 2 of the pressure collection P may be various pressure-sensitive elements such as a pressure sensor, a pressure transmitter, etc. The temperature sensor 3 of the temperature collector T can be various temperature sensing elements such as temperature sensors, temperature transmitters, etc., and can be thermocouples, thermistors, semiconductors, contact and non-contact, thermal resistance and thermocouples, digital and analog, such as DS18B20, pt100. The temperature control mechanism 5 is a heating element, or the temperature control mechanism is mainly composed of a heating element, a heat retaining material, a temperature controller, a temperature detector, a temperature control mechanism housing, etc., or the temperature control mechanism is mainly composed of a heating element and a temperature controller, where the temperature controller includes a PID controller, a controller combining PID and fuzzy control, a frequency conversion controller, and a PLC controller. Working principle:

[0146] The intelligent control unit 7 determines the corresponding pressure value P at 20° C. based on the gas pressure P and temperature T of the electrical equipment monitored by the pressure sensor 2 and temperature sensor 3. 20 (i.e., gas density value). If gas density relay 1 needs to be checked, the gas density value P 20 ≧Set safety check density value P SIt is.

[0147] Next, the intelligent control unit 7 controls the contact signal control circuit of the gas density relay 1 to be turned off, i.e., turns off the normally closed contacts J11 and J12 of the first relay J1 of the online check contact signal sampling unit 6, so that the safe operation of the electrical equipment 8 is not affected when the gas density relay 1 is checked online, and an alarm signal is not erroneously sent or the control circuit is not locked during the check. Before the check is started, the gas density value P 20 ≧Set safety check density value P S The gas in the electrical equipment 8 is monitored and judged to be within the safe operating range, and the gas leakage is in a slow process, so that it is safe to check. At the same time, the intelligent control unit 7 connects the contacts of the gas density relay 1 to the contact sampling circuit, that is, the normally open contacts J21 and J22 of the second relay J2 of the online check contact signal sampling unit 6 are closed, and at this time the contact P of the gas density relay 1 is J is connected to the intelligent control unit 7 by normally open contacts J21 and J22 of the second relay J2.

[0148] Next, the intelligent control unit 7 operates or controls the temperature adjustment mechanism 5 to increase the temperature of the gas density relay 1, and further increases the temperature of the temperature compensation element of the gas density relay. When the temperature compensation element is close to the operating value, the temperature change rate is less than 1.0°C per second (or less than 0.5°C per second, or set the requirement as required), that is, the temperature requirement is steadily increased. Until a contact signal operation occurs in the gas density relay 1, the contact signal operation is uploaded to the intelligent control unit 7 through the second relay J2 of the online check contact signal sampling unit 6, and the intelligent control unit 7 determines the pressure value P corresponding to 20°C according to the gas characteristics based on the pressure value P and temperature T value measured at the time of the contact signal operation. 20 When converted to density, the contact operating value P of the gas density relay is D20After all the contact signal operating values ​​of the alarm and / or close signal of the gas density relay 1 are detected, the temperature of the gas density relay 1 is further lowered by operating or controlling the temperature adjustment mechanism 5 of the intelligent control unit 7, and the temperature of the temperature compensation element of the gas density relay 1 is further lowered, which causes a contact reset in the gas density relay 1 and tests the return value of the alarm and / or close contact signal of the gas density relay 1. This is repeated multiple times (for example, 2 to 3 times) to check, and then the average value is calculated, thus completing the checking work of the gas density relay.

[0149] After the check is completed, the normally open contacts J21 and J22 of the second relay J2 of the online check contact signal sampling unit 6 are disconnected, and at this time the contact P of the gas density relay 1 is J is not connected to the intelligent control unit 7 by disconnecting the normally open contacts J21 and J22 of the second relay J2. The intelligent control unit 7 turns off the heating element 501 of the temperature adjustment mechanism 5. Then, the normally closed contacts J11 and J12 of the first relay J1 of the online check contact signal sampling unit 6 are closed, the contact signal control circuit of the gas density relay 1 operates normally, and the gas density relay safely monitors the gas density of the electric equipment 8, so that the electric equipment 8 operates safely and reliably. In this way, the online check of the gas density relay is easy to complete, and at the same time, the safe operation of the electric equipment 8 is not affected.

[0150] After the gas density relay 1 (or density monitor) completes the check operation, the electrical system can make a judgment and report the detection result. The method is flexible, specifically, 1) the gas density relay can report on site, for example by displaying an indicator lamp, digital or liquid crystal display, etc.; 2) or uploading by online remote transmission communication method, for example uploading in the background; 3) or uploading to a specific terminal by wireless upload, for example uploading to a mobile phone; 4) or uploading by other means; 5) or uploading the abnormal result by an alarm signal line or a dedicated signal line; 6) uploading alone or combined with other signals. In short, after the electrical system completes the online check operation of the gas density relay 1, if there is an abnormality, it can automatically send an alarm, upload to the remote end, or send to a designated receiver, for example send to a mobile phone. Alternatively, after completing the check operation, if there is an abnormality, the intelligent control unit 7 can upload to the remote end (monitoring room, background monitoring platform, etc.) by the alarm contact signal of the gas density relay 1, and display the alarm at the site. The simple version of online check can upload the check result when there is an abnormality through the alarm signal line. It can be uploaded according to a certain rule, for example, when there is an abnormality, a contact can be connected in parallel to the alarm signal contact and opened and closed regularly, and the situation can be obtained through analysis, or uploaded through an independent check signal line. Specifically, it can upload when the condition is good, or when there is a problem, or the check result can be uploaded through a separate check signal line, or it can be displayed on-site, an alarm can be issued on-site, or it can be uploaded wirelessly by networking with a smartphone.The communication method may be wired or wireless, the wired communication method may be industrial buses such as RS232, RS485, CAN-BUS, optical fiber Ethernet, 4-20mA, Hart, IIC, SPI, Wire, coaxial cable, PLC power carrier, etc., and the wireless communication method may be 2G / 3G / 4G / 5G, etc., WIFI, Bluetooth, Lora, Lorawan, Zigbee, infrared, ultrasonic, sound wave, satellite, light wave, quantum communication, sonar, sensor-built-in 5G / NB-IOT communication module (such as NB-IOT), etc. In short, the reliable performance of the electrical system can be fully guaranteed by multiple methods and combinations of multiple types.

[0151] The electrical system has a safety protection function, i.e., when the gas density value is lower than the set value, the electrical system will not automatically perform online checks on the gas density relay 1 and will send an alarm signal. For example, when the gas density value is lower than the set value P S If it is detected to be smaller than this, no check is performed, and only if the gas density value is equal to or greater than (alarm pressure value + 0.02 MPa), an online check can be performed.

[0152] The electrical system may perform online checking based on a set time, or may perform online checking based on a set temperature (such as high limit, high temperature, low limit, low temperature, normal temperature, 20 degrees, etc.). When online checking at high, low, normal, and 20°C environmental temperatures, the error judgment requirements are different. For example, when checking at an environmental temperature of 20°C, the accuracy requirement of the gas density relay may be 1.0 or 1.6, and at high temperatures it may be 2.5. Specifically, it can be implemented according to the correlation standard according to the temperature requirements. For example, according to the provisions of Article 4.8 of the "Sulfur Hexafluoride Gas Density Relay Check Regulation", the accuracy requirements corresponding to each temperature value are:

[0153] The electrical system can compare its error performance at different temperatures and different time periods based on the gas density relay 1. That is, by comparing at different times and within the same temperature range, the performance of the gas density relay 1 and the electrical device 8 can be judged, and comparisons can be made between each period of history and between the history and the present.

[0154] The electrical equipment can be checked multiple times (e.g., 2-3 times), and the average value is calculated based on the results of each check. If necessary, an online check can be performed on the gas density relay 1 at any time.

[0155] Here, the gas density relay 1 includes a bimetal sheet compensated gas density relay, a gas compensated gas density relay, or a bimetal sheet and gas compensated mixed type gas density relay, a fully mechanical gas density relay, a digital type gas density relay, a mechanical and digital combined type gas density relay, a density relay with indication (a density relay with a pointer indication, or a density relay with a digital indication, or a density relay with a liquid crystal display), a density relay without indication (i.e., a density switch), an SF6 gas density relay, an SF6 mixed gas density relay, an N2 gas density relay, other gas density relays, etc.

[0156] Here, the type of pressure sensor 2 includes absolute pressure sensor, relative pressure sensor, or absolute pressure sensor and relative pressure sensor, and the number may be multiple. The type of pressure sensor may be a diffused silicon pressure sensor, a MEMS pressure sensor, a chip type pressure sensor, a coil induction pressure sensor (for example, a pressure measurement sensor with an induction coil attached to a Bourdon tube), a resistance pressure sensor (for example, a pressure measurement sensor with a sliding line resistor attached to a Bourdon tube), an analog quantity pressure sensor, or a digital quantity pressure sensor. Pressure is collected by various pressure-sensitive elements such as pressure sensors and pressure transmitters, for example, diffused silicon type, sapphire type, piezoelectric type, and strain gauge type (resistance strain gauge type, ceramic strain gauge type).

[0157] Here, the temperature sensor 3 may be a thermocouple, a thermistor, a semiconductor, a contact type or a non-contact type, or a thermal resistance or a thermocouple. In short, the temperature can be collected using various temperature sensing elements such as a temperature sensor, a temperature transmitter, etc.

[0158] Wherein, the temperature control mechanism 5 is a heating element, or the temperature control mechanism is mainly composed of a heating element, a heat retaining material, a temperature controller, a temperature detector, a temperature control mechanism housing, etc., or the temperature control mechanism is mainly composed of a heating element and a temperature controller, or the temperature control mechanism is mainly composed of a heating element, a heating power regulator, and a temperature controller, or the temperature control mechanism is mainly composed of a heating element, a cooling element, a heating power regulator, and a temperature controller, or the temperature control mechanism is mainly composed of a heating element, a heating power regulator, and a constant temperature controller, or the temperature control mechanism is mainly composed of a heating element, a temperature controller, a temperature detector, etc., or the temperature control mechanism is a heating element, and the heating element is disposed adjacent to the temperature compensation element, or the temperature control mechanism is a micro constant temperature box, wherein the heating element includes, but is not limited to, a silicone rubber heater, a resistance wire, an electric heating belt, an electric heating rod, a thermal fan, an infrared heating element, and a semiconductor, the heating element is composed of several heating element pairs, and the temperature controller includes, but is not limited to, a PID controller, a controller combining PID and fuzzy control, a frequency conversion controller, and a PLC controller.

[0159] Here, the online check contact signal sampling unit 6 mainly completes the contact signal sampling of the gas density relay 1. That is, the basic requirements or functions of the online check contact signal sampling unit 6 are as follows: 1) It does not affect the safe operation of the electrical equipment 8 during checking, that is, when the contact signal of the gas density relay 1 operates during checking, it does not affect the safe operation of the electrical equipment 8; 2) The contact signal control circuit of the gas density relay 1 does not affect the performance of the gas density relay, especially the performance of the intelligent control unit 7, and does not damage the gas density relay or affect the test work.

[0160] Here, the basic requirement or function of the intelligent control unit 7 is to complete the control of the valve 4, the control of the temperature control mechanism 5, the pressure control mechanism 11 and the signal collection by the intelligent control unit 7. Realization: It can detect the pressure value and the temperature value when the contact signal of the gas density relay 1 is activated, and obtain the corresponding pressure value P at 20°C. 20 (density value), that is, the contact operation value P of gas density relay 1 D20 The density value P when the contact signal of the gas density relay 1 is activated can be detected and the check operation of the gas density relay 1 is completed. D20 can be directly detected and the checking work of gas density relay 1 can be completed.

[0161] Of course, the intelligent control unit 7 can further realize test data storage, and / or test data deriving, and / or test data printing, and / or data communication with a host computer, and / or input of analog or digital information. The intelligent control unit 7 further includes a communication module, which realizes long-distance transmission of information such as test data and / or checking result through the communication module. When the rated pressure value of the gas density relay 1 outputs a signal, the intelligent control unit 7 simultaneously collects the density value at that time, and completes the checking of the rated pressure value of the gas density relay 1.

[0162] Here, the electric equipment includes SF6 gas electric equipment, SF6 mixed gas electric equipment, environmentally friendly gas electric equipment, or other insulated gas electric equipment. Specifically, the electric equipment includes GIS, GIL, PASS, circuit breaker, current transformer, potential transformer, transformer, gas-filled cabinet, ring main cabinet, etc.

[0163] The electrical system has pressure, temperature measurement and software conversion functions. Under the premise of not affecting the safe operation of the electrical equipment 8, the operating value and / or return value of the alarm and / or closed contact of the gas density relay 1 can be detected online. Of course, the return value of the alarm and / or closed contact signal may not require testing upon request.

[0164] When the electrical system completes the check of the gas density relay, it automatically performs a mutual comparison judgment, and if the error difference is large, it will issue an abnormality indication that there is a problem with the gas density relay, or the pressure sensor, or the temperature sensor. That is, the electrical system can complete the mutual check function of the gas density relay and the pressure sensor, the temperature sensor, or the density transmitter, and has the ability of artificial intelligence correction. After completing the check work, it can automatically generate a check report, and if there is an abnormality, it can automatically send an alarm, or send it to a designated receiver, such as a mobile phone, and display the gas density value and the check result on-site, or display the gas density value and the check result in the background. The specific manner is flexible, and has the functions of real-time data display of gas density value, pressure value, temperature value, etc., change trend analysis, history data inquiry, real-time alarm, etc. off-line, and can monitor the gas density value, or the gas density value, pressure value, and temperature value online, and has a self-diagnosis function, and can promptly report abnormalities, such as disconnection, short circuit alarm, sensor damage, etc., and can compare the error performance at different temperatures and different time periods according to the electrical system. That is, the performance of the electrical system is judged by comparing different periods and within the same temperature range. It has a comparison of each period of history, and a comparison of history and the present. It can perform normal and abnormal judgment, analysis, and comparison for the gas density value of the electric device 8 itself, the gas density relay 1, the pressure sensor 2, and the temperature sensor 3, and further includes an analysis system (professional management analysis system) to monitor the gas density, and perform detection, analysis, and judgment for the gas density relay and the monitoring element to know where the problem is, and can monitor the contact signal state of the gas density relay 1 and transmit the state remotely. It can know in the background whether the contact signal state of the gas density relay 1 is off or on, thereby monitoring more and improving reliability. It can detect or detect and judge the temperature compensation performance of the gas density relay 1, and can detect or detect and judge the contact resistance of the gas density relay 1, and has data analysis and data processing functions, and can perform corresponding fault diagnosis and prediction for the electric device 8. It can monitor the gas density of the electric device 8 online.

[0165] If the test data between the pressure sensor 2, temperature sensor 3, and gas density relay 1 match and are normal, the electrical system can be explained as normal, and there is no need to check the gas density relay, no need to check other devices, and no need to check over the entire service life. As long as the test data between the pressure sensor 2, temperature sensor 3, and gas density relay 1 of a certain electrical device in a substation do not match and are abnormal, maintenance personnel will be deployed to handle it. For a situation where the test data match and are normal, there is no need to check, thus greatly improving reliability, improving work efficiency, and reducing costs. Example 2:

[0166] As shown in FIG. 3, the electrical system with online sampling check function provided by the second embodiment of the present invention includes a gas density relay 1, a pressure sensor 2, a temperature sensor 3, a valve 4, a temperature regulating mechanism 5, an online check contact signal sampling unit 6, an intelligent control unit 7, a multi-way joint 9, a gas refill port 10, and a pressure regulating mechanism 11. One end of the valve 4 is hermetically connected to an electrical device 8, and the other end of the valve 4 is connected to the multi-way joint 9. The gas density relay 1 is mounted on the multi-way joint 9, the pressure sensor 2 and the temperature sensor 3 are mounted on the gas density relay 1, the pressure sensor 2 is connected to the gas density relay 1 in the gas path, the temperature regulating mechanism 5 is mounted on the gas density relay 1, and the temperature regulating mechanism 5 is mainly composed of a heating element 501 and is controlled by the intelligent control unit 7, that is, the controller of the heating element 501 is integrally mounted or designed with the intelligent control unit 7. The pressure regulating mechanism 11 is mounted on the multi-way joint 9, the pressure regulating mechanism 11 is connected to the gas density relay 1, and the online check contact signal sampling unit 6 and the intelligent control unit 7 are integrally mounted. The pressure sensor 2, the temperature sensor 3, the valve 4, the temperature adjustment mechanism 5 and the pressure adjustment mechanism 11 are each connected to an intelligent control unit 7. The gas refill port 10 communicates with a multi-way joint 9.

[0167] The difference from the first embodiment is that the present embodiment further includes a pressure adjustment mechanism 11. The pressure adjustment mechanism 11 includes a piston 1101, a driving mechanism 1102, and a seal ring 1110. The driving mechanism 1102 interlocks the piston 1101 to move within the pressure adjustment mechanism, and further completes the increase and decrease of pressure.

[0168] The operating principle is that the intelligent control unit 7 adjusts the online check contact signal sampling unit 6 to a check state. In the check state, the online check contact signal sampling unit 6 cuts off the control circuit of the contact signal of the gas density relay 1 and connects the contact of the gas density relay 1 to the intelligent control unit 7. The intelligent control unit 7 closes the valve 4 between the gas density relay 1 and the electrical equipment. The intelligent control unit 7 drives the pressure regulating mechanism 11 to gradually reduce the pressure of the gas density relay, and after it has reduced to the target pressure value, the operation can be stopped. Next, the intelligent control unit 7 operates or controls the temperature adjustment mechanism 5 to increase the temperature of the gas density relay 1, and further increases the temperature of the temperature compensation element of the gas density relay 1, causing the gas density relay 1 to make a contact operation, and the contact operation is transmitted to the intelligent control unit 7 through the online check contact signal sampling unit 6, and the intelligent control unit 7 obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay 1, and completes the checking work of the contact signal operation value of the gas density relay 1, which is similar to the operation in the first embodiment. The intelligent control unit 7 further includes a depth calculation unit, which calculates the gas density value according to the environmental temperature value, the gas density value or the pressure value of the electrical equipment, The intelligent control unit 7 operates or controls the temperature adjustment mechanism 5 to reduce the temperature of the gas density relay 1, and further reduces the temperature of the temperature compensation element of the gas density relay 1, causing a contact reset in the gas density relay 1. The contact reset is transmitted to the intelligent control unit 7 through the online check contact signal sampling unit 6, and the intelligent control unit 7 obtains the gas density value based on the pressure value and temperature value at the time of contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay 1, and completes the check work of the contact signal return value of the gas density relay 1.

[0169] After all the contact signal checking operations are completed, the intelligent control unit 7 turns off the heating element of the temperature regulating mechanism 5 and adjusts the online check contact signal sampling unit 6 to the working state, and the contact signal control circuit of the gas density relay 1 returns to the normal working state and operates. In this embodiment, the operation sequence of the temperature regulating mechanism and the pressure regulating mechanism can be flexible, that is, the pressure regulating mechanism can be operated first and then the temperature regulating mechanism, or the temperature regulating mechanism can be operated first and then the pressure regulating mechanism, or the pressure regulating mechanism and the temperature regulating mechanism can be operated simultaneously.

[0170] The control of the valve 4 can adopt various transmission methods, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic hydraulic, electro-hydraulic, gas-hydraulic, spur gear, bevel gear drive, etc., and can operate according to a predetermined requirement under the action of pressure, temperature or other types of sensing signals, or can simply open and close without depending on the sensing signals. The valve can be driven or automatically to lift, slide, rotate or rotate the opening and closing member, thereby changing the size of its flow area to realize its control function. The valve can be an automatic valve, a power-driven valve, or a manual valve according to the driving method. Note that the automatic valve can include an electromagnetic drive, an electromagnetic-hydraulic drive, an electro-hydraulic drive, a turbine drive, a spur gear drive, a bevel gear drive, an air pressure drive, a hydraulic drive, a gas-hydraulic drive, an electric drive, and an electric (motor) drive. The valve 4 can be automatic, manual, or semi-automatic. The check process can be completed automatically, or can be completed manually in cooperation with semi-automatic. The valve 4 is directly or indirectly connected to the electric device 8 by a self-sealing valve, a manual valve, or a non-disassembly valve, and is connected integrally or separately. The valve 4 may be of a normally open or normally closed type, and may be of a one-way or two-way type, as required. In short, the opening and closing of the gas path is realized by the electric control valve. The method adopted by the electric control valve may be a solenoid valve, an electric control ball valve, an electric valve, an electric control proportional valve, etc. The valve 4 may be a component that can open and close the gas path and further control the flow rate, such as a solenoid valve, an electric valve, an air valve, a ball valve, a needle valve, a control valve, a cut-off valve, etc. The semi-automatic may be a manual valve. The pressure regulating mechanism 11 may be an electric regulating piston, an electric regulating cylinder, a pressure pump, a gas cylinder pressure, and a valve, a solenoid valve, a flow rate controller, etc. The semi-automatic may be a pressure regulating mechanism that is manually adjusted.

[0171] The pressure adjusting mechanism 5 of this embodiment is a cavity with an open end, a piston 1101 is located in the cavity, a seal ring 1110 is provided on the piston 1101, an adjusting rod is connected to one end of the piston 1101, an outer end of the adjusting rod is connected to a driving member 1102, the other end of the piston 1101 extends into the opening and contacts the inner wall of the cavity, and the driving member 1102 drives the adjusting rod to further move the piston 1101 in the cavity. The driving member 1102 includes, but is not limited to, a magnetic force, a motor (variable frequency motor or stepping motor), a reciprocating mechanism, a Carnot circulation mechanism, and a pneumatic element. Example 3:

[0172] As shown in FIG. 4, the electrical system with online sampling check function provided by the third embodiment of the present invention includes a gas density relay 1, a first pressure sensor 21, a second pressure sensor 22, a first temperature sensor 31, a second temperature sensor 32, a temperature adjustment mechanism 5, an online check contact signal sampling unit 6, an intelligent control unit 7, a multi-way joint 9, a gas refill port 10, and a self-sealing valve 11. One end of the self-sealing valve 11 is hermetically connected to an electrical device, and the other end of the self-sealing valve 11 is connected to the multi-way joint 9. The gas density relay 1, the second pressure sensor 22, the second temperature sensor 32, the temperature adjustment mechanism 5, and the gas refill port 10 are provided in the multi-way joint 9, and the first pressure sensor 21 and the first temperature sensor 31 are provided in the gas density relay 1. The first pressure sensor 21, the second pressure sensor 22, the first temperature sensor 31, and the second temperature sensor 32 are respectively connected to the intelligent control unit 7. The first pressure sensor 21, the second pressure sensor 22, and the gas density relay 1 communicate with each other in a gas path.

[0173] The difference from the first embodiment is that there are two pressure sensors, a first pressure sensor 21 and a second pressure sensor 22, and there are two temperature sensors, a first temperature sensor 31 and a second temperature sensor 32. This embodiment provides a plurality of pressure sensors and temperature sensors, and the pressure values ​​obtained by monitoring the first pressure sensor 21 and the second pressure sensor 22 can be compared and checked against each other, the temperature values ​​obtained by monitoring the first temperature sensor 31 and the second temperature sensor 32 can be compared and checked against each other, and the density value P1 obtained by monitoring the first pressure sensor 21 and the first temperature sensor 31 can be compared and checked against each other. 20 and the density value P2 obtained by monitoring the second pressure sensor 22 and the second temperature sensor 32. 20 and can be compared and checked against each other, and even online check the density value Pe of the rated value of the gas density relay 1 20 The purpose is to obtain, compare and check each other. Example 4:

[0174] As shown in Figure 5, the electrical system with online sampling check function provided by the fourth embodiment of the present invention includes a gas density relay 1, a pressure sensor 2, a temperature sensor 3, a valve 4, a temperature control mechanism 5 (mainly composed of a heating element 501, a heat retaining material 502, and a temperature control mechanism housing 503), an online check contact signal sampling unit 6, an intelligent control unit 7, an electrical device 8, a multi-way joint 9, a gas refill port 10, a pressure control mechanism 11, and a micro water sensor 12. One end of the valve 4 is hermetically connected to the electrical device 8, and the other end of the self-sealing valve 4 is connected to the multi-way joint 9, and the exhaust port of the valve 4 is connected to the gas density relay 1, the pressure sensor 2, the pressure control mechanism 11, and the gas refill port 10 in a gas path through the multi-way joint 9. The pressure sensor 2 and the temperature sensor 3 are integrally provided and may be configured as a gas density transmitter, which directly obtains the gas density value, pressure value and temperature value, the pressure regulating mechanism 11 is connected to the gas density relay 1 through a multi-way joint 9, and the online check contact signal sampling unit 6 and the intelligent control unit 7 are integrally provided. The pressure sensor 2 and the temperature sensor 3 are directly or indirectly connected to the intelligent control unit 7, the valve 4 is connected to the intelligent control unit 7, and the temperature regulating mechanism 5 and the pressure regulating mechanism 11 are connected to the intelligent control unit 7.

[0175] The differences from the first embodiment are as follows. 1) The pressure adjustment mechanism 11 of this embodiment is mainly composed of an air chamber 1107, a heater 1108, a heat retaining material 1109, and a housing 1111. Under the control of the intelligent control unit 7, the pressure adjustment mechanism 11 generates a temperature change in the air chamber 1107, generates a pressure change in the sealed cavity, and completes the increase and decrease of pressure. 2) The pressure sensor 2 and the temperature sensor 3 are integrally provided to form a gas density transmitter, which directly obtains the density value, pressure value, and temperature value of the gas. The temperature adjustment by the temperature adjustment mechanism 5 and the pressure adjustment by the pressure adjustment mechanism 11 cause the gas density relay 1 to make a contact operation, and the contact operation is transmitted to the intelligent control unit 7 via the online check contact signal sampling unit 6. The intelligent control unit 7 detects the alarm and / or closed contact operation value and / or return value of the gas density relay 1 based on the density value at the time of contact operation of the gas density relay 1, as well as the pressure value and temperature value, and completes the check operation for the gas density relay 1. Alternatively, the intelligent control unit 7 detects and obtains only the alarm and / or closed contact operation value of the gas density relay 1, and completes the check operation for the gas density relay 1. Example 5:

[0176] As shown in FIG. 6 , the electrical system with online sampling check function provided by Example 5 of the present invention includes a gas density relay 1, a pressure sensor 2, a temperature sensor 3, a valve 4, a temperature control mechanism 5, an online check contact signal sampling unit 6, an intelligent control unit 7, an electrical device 8, a multi-way joint 9, and a gas refill port 10.

[0177] In the normal operating state, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit. When the intelligent control unit or the gas density relay is allowed and / or checked based on the set check time and / or check command, and the gas density value situation and / or temperature value situation, the intelligent control unit 7 adjusts the contact signal sampling unit 6 to a check state, and in the check state, the online check contact signal sampling unit 6 disconnects the control circuit of the contact signal of the gas density relay 1, connects the contact of the gas density relay 1 to the intelligent control unit 7, and controls the temperature adjustment mechanism 5 of the intelligent control unit 7 to increase the temperature of the gas in the gas density relay 1, and after it reaches the set value, the intelligent control unit 7 closes the valve 4, and the gas temperature or pressure of the gas in the gas density relay 1 is detected. After the pressure value and temperature value decrease to an appropriate value, the intelligent control unit 7 further controls the temperature regulating mechanism 5 to increase the temperature of the gas density relay 1, and the temperature of the temperature compensation element of the gas density relay 1 further increases, causing the gas density relay 1 to make a contact operation. The contact operation is transmitted to the intelligent control unit 7 through the contact signal sampling unit 6. The intelligent control unit 7 obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay 1, and completes the checking work of the contact signal operation value of the gas density relay 1. After all the contact signal checking work is completed, the intelligent control unit 7 opens the valve 4, and the intelligent control unit 7 turns off the temperature regulating mechanism 5. Example 6:

[0178] 7, the online check contact signal sampling unit 6 is provided with a contact sampling circuit. In this embodiment, the contact sampling circuit includes a photocoupler OC1 and a resistor R1, the photocoupler OC1 includes a light-emitting diode and a phototransistor, and the anode of the light-emitting diode and the contact P of the gas density relay 1 are connected to each other. Jare connected in series to form a closed circuit, the emitter of the phototransistor is grounded, the collector of the phototransistor is connected to the intelligent control unit 7 as the output end out6 of the online check contact signal sampling unit 6, and the collector of the phototransistor is connected to the power supply through the resistor R1.

[0179] The contact sampling circuit above detects the contact P of the gas density relay 1. J It is easy to know whether the contact P is in an open or closed state. J When the contact P is closed, the closed circuit is energized, the light-emitting diode emits light, the light turns on the phototransistor, and the collector of the phototransistor outputs a low level, and the contact P J is turned off, the closed circuit is turned off, the LED does not emit light, the phototransistor is turned off, and the collector of the phototransistor outputs a high level, so that the output terminal out6 of the online check contact signal sampling unit 6 outputs a high or low level.

[0180] In this embodiment, the intelligent control unit 7 and the contact signal control circuit are separated by photoelectric separation. J If gas leakage occurs, contact P J At this time, both contacts detect the low level output from the collector of the phototransistor. J The time for which the contact is closed is controlled to a predetermined length, and if there is no gas leakage, the contact P J The length of time that contact P remains closed is determined and, in the process, the duration of the low level received is monitored. J Therefore, by recording the time when the check is performed, it is possible to determine that the alarm signal issued from the gas density relay 1 is the alarm signal issued when the check is performed, and not the alarm signal issued when a gas leak occurs.

[0181] In this embodiment, the intelligent control unit 7 mainly comprises a processor 71 (U1) and a power supply 72 (U2). Example 7:

[0182] As shown in FIG. 8, the online check contact signal sampling unit 6 is provided with a contact sampling circuit, and in this embodiment, the contact sampling circuit includes a first photocoupler OC1 and a second photocoupler OC2.

[0183] The light-emitting diode of the first photocoupler OC1 and the light-emitting diode of the second photocoupler OC2 are respectively connected in parallel by current-limiting resistors, and then connected in series with the contacts of the gas density relay to form a closed circuit; the light-emitting diodes of the first photocoupler OC1 and the second photocoupler OC2 are connected in opposite directions; the collector of the phototransistor of the first photocoupler OC1 and the collector of the phototransistor of the second photocoupler OC2 are both connected to a power supply by voltage-dividing resistors; the emitter of the phototransistor of the first photocoupler OC1 is connected to the emitter of the phototransistor of the second photocoupler OC2 to form an output terminal out6, which is connected to the intelligent control unit 7 and grounded by a resistor R5.

[0184] The contact sampling circuit above detects the contact P of the gas density relay 1. J It is easy to know whether the contact P is in an open or closed state. J When the contact P is closed, the closed circuit is energized, the first photocoupler OC1 is turned on, the second photocoupler OC2 is turned off, and the emitter of the phototransistor of the first photocoupler OC1 (i.e., the output terminal out6) outputs a high level; alternatively, the first photocoupler OC1 is turned off, the second photocoupler OC2 is turned on, and the emitter of the phototransistor of the second photocoupler OC2 (i.e., the output terminal out6) outputs a high level. Jis turned off, the closed circuit is turned off, the first photocoupler OC1 and the second photocoupler OC2 are both turned off, and the emitters (i.e., the output terminal out6) of the phototransistors of the first photocoupler OC1 and the second photocoupler OC2 output a low level.

[0185] In a preferred embodiment, the contact sampling circuit further includes a first Zener diode group and a second Zener diode group, the first Zener diode group and the second Zener diode group are connected in parallel in the contact signal control circuit, the first Zener diode group and the second Zener diode group are connected in opposite directions, and the first Zener diode group and the second Zener diode group are each composed of one, two or more Zener diodes connected in series.

[0186] In this embodiment, the first Zener diode group includes a first Zener diode D1 and a second Zener diode D2 connected in series, the negative electrode of the first Zener diode D1 is connected to the positive electrode of the second Zener diode D2, the second Zener diode group includes a third Zener diode D3 and a fourth Zener diode D4 connected in series, and the positive electrode of the third Zener diode D3 is connected to the negative electrode of the fourth Zener diode D4.

[0187] The contact sampling circuit is contact P of gas density relay 1. J The state of the contact P is easily monitored. J whether the contact signal is in an open or closed state, and performs corresponding processing, and implements remote transmission, and knows the contact signal state from the background, which greatly improves the reliability of the power grid.

[0188] In this embodiment, the intelligent control unit 7 mainly comprises a processor 71 (U1) and a power supply 72 (U2). Example 8:

[0189] As shown in Fig. 9, the differences between this embodiment and embodiment 8 are as follows: The intelligent control unit 7 is mainly composed of a processor 71 (U1), a power supply 72 (U2), a communication module 73 (U3), an intelligent control unit protection circuit 74 (U4), a display and output 75 (U5), a data storage 76 (U6) and the like.

[0190] Here, the communication method of the communication module 73 (U3) may be wired, such as RS232, RS485, industrial bus such as CAN-BUS, optical fiber Ethernet, 4-20mA, Hart, IIC, SPI, Wire, coaxial cable, PLC power carrier, etc., or wireless, such as 2G / 3G / 4G / 5G, WIFI, Bluetooth, Lora, Lorawan, Zigbee, infrared, ultrasonic, sound wave, satellite, light wave, quantum communication, sonar, etc. The intelligent control unit protection circuit 74 (U4) may be an electrostatic interference prevention circuit (such as ESD, EMI), surge resistance circuit, electrical high-speed protection circuit, radio frequency field interference resistance circuit, pulse group interference resistance circuit, power supply short circuit protection circuit, power supply reverse connection protection circuit, electrical contact misconnection protection circuit, charging protection circuit, etc. These intelligent control unit protection circuits may be one or a flexible combination of multiple types. The display and output 75 (U5) can be digital tube, LED, LCD, HMI, display, matrix screen, printer, facsimile, projector, mobile phone, etc., or a flexible combination of one or more types. The data storage 76 (U6) can be FLASH, RAM, ROM, hard disk, flash memory card such as SD, magnetic tape, punched paper tape, optical disk, U disk, disk, film, etc., or a flexible combination of one or more types. Example 9:

[0191] As shown in FIG. 10, the online check contact signal sampling unit 6 is provided with a contact sampling circuit. In this embodiment, the contact sampling circuit includes a first Hall current sensor H1 and a second Hall current sensor H2. The first Hall current sensor H1, the second Hall current sensor H2 and the contact P of the gas density relay are sampled. Jare connected in series to form a closed circuit, and the contact P of the gas density relay 1 J is connected between the first Hall current sensor H1 and the second Hall current sensor H2, and the output terminal of the first Hall current sensor H1 and the output terminal of the second Hall current sensor H2 are both connected to the intelligent control unit 7.

[0192] The contact sampling circuit above detects the contact P of the gas density relay 1. J It is easy to know whether the contact P is in an open or closed state. J When the contact P is closed, a closed circuit is energized, and a current flows between the first Hall current sensor H1 and the second Hall current sensor H2, generating an induced potential. J When is turned off, the closed circuit is disconnected, no current flows between the first Hall current sensor H1 and the second Hall current sensor H2, and the induced potential generated is zero.

[0193] In this embodiment, the intelligent control unit 7 mainly consists of a processor 71 (U1), a power supply 72 (U2), a communication module 73 (U3), an intelligent control unit protection circuit 74 (U4), a display and output 75 (U5), a data storage 76 (U6) and the like. Example 10:

[0194] As shown in FIG. 11, the online check contact signal sampling unit 6 is provided with a contact sampling circuit, which in this embodiment includes a first thyristor SCR1, a second thyristor SCR2, a third thyristor SCR3 and a fourth thyristor SCR4.

[0195] The first thyristor SCR1 and the third thyristor SCR3 are connected in series, and the second thyristor SCR2 and the fourth thyristor SCR4 are connected in series to form a series-parallel closed circuit with the series connection line formed by the first thyristor SCR1 and the third thyristor SCR3, and the contact P of the gas density relay 1 JOne end of the first thyristor SCR1 and the third thyristor SCR3 is electrically connected by a line to the line between the second thyristor SCR2 and the fourth thyristor SCR4. Here, the series-parallel connection is a mixed connection circuit in which the above components are connected in parallel and in series, as shown in FIG.

[0196] Specifically, the anode of the first thyristor SCR1 and the cathode of the second thyristor SCR2 are connected to form the output end of the online check contact signal sampling unit 6, which is connected to the intelligent control unit 7, the cathode of the first thyristor SCR1 is connected to the cathode of the third thyristor SCR3, the anode of the second thyristor SCR2 is connected to the anode of the fourth thyristor SCR4, and the anode of the third thyristor SCR3 and the cathode of the fourth thyristor SCR4 are connected to the input end of the online check contact signal sampling unit 6. Here, the control poles of the first thyristor SCR1, the second thyristor SCR2, the third thyristor SCR3 and the fourth thyristor SCR4 are all connected to the intelligent control unit 7. The intelligent control unit 7 can control the on or off of the corresponding thyristor.

[0197] The operation process of this embodiment is as follows.

[0198] If no check is performed and the device operates normally, the contact P J is disconnected, the contact sampling circuit triggers the third thyristor SCR3 and the fourth thyristor SCR4, the third thyristor SCR3 and the fourth thyristor SCR4 are in the ON state, and the contact signal control circuit is in the operating state. At this time, the contact sampling circuit does not trigger the first thyristor SCR13 and the second thyristor SCR2, there is no voltage output to the cathodes of the first thyristor SCR1 and the second thyristor SCR2, and they are in a non-conducting state.

[0199] When the check is performed, the contact sampling circuit does not trigger the third thyristor SCR3 and the fourth thyristor SCR4, but triggers the first thyristor SCR1 and the second thyristor SCR2. At this time, the third thyristor SCR3 and the fourth thyristor SCR4 are in the OFF state, and the contact P J The first thyristor SCR1 and the second thyristor SCR2 are in the ON state, and the contact P J is connected to the online check contact signal sampling unit 6 and is connected to the intelligent control unit 7.

[0200] The online check contact signal sampling unit 6 may be flexibly constructed by a solid state relay or a mixture of an electromagnetic relay and a thyristor.

[0201] In this embodiment, the intelligent control unit 7 mainly consists of a processor 71 (U1), a power supply 72 (U2), a communication module 73 (U3), an intelligent control unit protection circuit 74 (U4), a display and output 75 (U5), a data storage 76 (U6) and the like. Example 11:

[0202] Fig. 12 is a schematic diagram of the gas path structure of an electrical system according to a preferred embodiment of the present invention. As shown in Fig. 12, the electrical device 8 is a sulfur hexafluoride high-voltage circuit breaker, and includes an air chamber 802 installed in the electrical device 8. The gas density relay 1 is mounted in the internal storage space of the horizontal frame, one end of the connecting pipe is connected to the inlet of the valve 4, and the other end of the connecting pipe extends along the horizontal frame to the bottom of the air chamber 802 and communicates with the air chamber 802 from below. The inlet of the valve 4 is hermetically connected to the air chamber 802 of the electrical device 8 by the connecting pipe, and the exhaust port of the valve 4 communicates with the gas path of the gas density relay 1. The probe of the pressure sensor 2 is located in the gas path of the gas density relay 1, the temperature control mechanism 5 is installed outside the gas density relay 1, the online check contact signal sampling unit 6 is respectively connected to the gas density relay 1 and the intelligent control unit 7, and the pressure sensor 2, the temperature sensor 3, the valve 4, and the temperature control mechanism 5 are also respectively connected to the intelligent control unit 7. The pressure sensor 2 other than the probe, the temperature sensor 3 other than the probe, the temperature adjustment mechanism 5, the online check contact signal sampling unit 6, and the intelligent control unit 7 are all fixed to the mounting plate of the vertical frame.

[0203] When the electrical system with online sampling check function checks the contact of the density relay at high temperature, low temperature, normal temperature, and 20℃ environmental temperature, the judgment requirements for the error may be different, specifically, it can be implemented according to the temperature requirements and the relevant standards, and the gas density relay can be compared for its error performance at different temperatures and different time periods, that is, comparisons can be made at different times and within the same temperature range, and the performance of the density relay can be judged. Comparisons of each period of history, and comparisons of history and the present can be made. The density relay can also be checked. If necessary, the density relay contact signal can be checked at any time, and the density value of the monitored electrical equipment can be judged to be normal or abnormal. That is, the density value of the electrical equipment itself, the gas density relay, the pressure sensor, and the temperature sensor can be judged, analyzed, and compared to be normal or abnormal, and the gas density monitoring of the electrical equipment, the judgment, comparison, and analysis of the status of the density relay, etc. can be realized, and the contact signal status of the gas density relay can be monitored and the status can be transmitted remotely. The contact signal status of the gas density relay can be known in the background. Whether it is off or not, it can be more monitored, reliability can be improved, and the temperature compensation performance of the gas density relay can be detected or detected and judged, the contact resistance of the contact of the gas density relay can be detected or detected and judged, and the insulation performance of the gas density relay can be detected or detected and judged. In addition, for SF6 gas, the specific conversion method of the SF6 gas pressure-temperature characteristics can be calculated based on the Bettie-Bridgeman equation, and for SF6 mixed gas, the specific conversion method of the SF6 mixed gas pressure-temperature characteristics can be calculated based on the Dalton partial pressure law, the Bettie-Bridgeman equation, and the ideal gas state equation. The temperature adjustment mechanism is provided inside or outside the case of the gas density relay, including being provided on the case.The signal generator includes, but is not limited to, a microswitch, a magnetically assisted electrical contact, a reed switch, and a miniature switch; the gas density relay outputs a contact signal through the signal generator; the pressure detector includes, but is not limited to, a Bourdon tube, a corrugated tube, a corrugated tube + spring, and a pressure sensor; and the temperature compensation element includes, but is not limited to, a temperature compensation sheet, a gas sealed in a case, and a temperature compensation sheet + a gas sealed in a case.

[0204] As described above, the electrical system with online sampling check function and the check method thereof provided by the present invention are composed of a gas line (may be via a pipe) connection part, a pressure adjustment part, a signal measurement and control part, etc., and its main function is to perform online check measurement of the contact value (pressure value at the time of alarm / close operation) of the gas density relay at the ambient temperature, and automatically convert it to the corresponding pressure value at 20°C, thereby realizing online performance detection of the contact (alarm and close) value of the gas density relay. The mounting positions of the gas density relay, pressure sensor, temperature sensor, pressure adjustment mechanism, valve, online check contact signal sampling unit, and intelligent control unit can be flexibly combined. For example, the gas density relay, pressure sensor, temperature sensor, online check contact signal sampling unit, and intelligent control unit can be combined together, and may be designed as an integrated unit or designed separately, and may be attached to a case or a multi-way joint, or may be connected together by a connecting pipe. The valve may be directly connected to the electrical equipment, or may be connected by a self-sealing valve or a gas pipe. The pressure sensor, the temperature sensor, the online check contact signal sampling unit and the intelligent control unit can be combined and designed as an integrated unit; the pressure sensor, the temperature sensor can be combined and designed as an integrated unit; the online check contact signal sampling unit and the intelligent control unit can be combined and designed as an integrated unit; in short, the structure is not limited.

[0205] The gas density relay relating to the electrical system having an online sampling check function and the checking method thereof described in the present invention may refer to a gas density relay whose components are designed as an integrated structure, or may refer to a gas density relay whose components are designed as separate structures, and may generally be referred to as a gas density monitoring device.

[0206] The present application has a compact and reasonable structural layout, each component has excellent anti-corrosion and anti-vibration capabilities, is firmly installed, and is reliable to use. The connection and disconnection of each pipe in the electrical system is easy to operate, and the equipment and components are easy to maintain. The present application does not require inspectors to go to the site to complete the inspection work of the gas density relay, greatly improving the reliability of the power grid, improving work efficiency, and reducing the cost of operation and maintenance.

[0207] Although the specific embodiment of the present invention has been described in detail above, it is merely illustrative and the present invention is not limited to the specific embodiment described above. Any equivalent modifications and replacements made to the present invention by those skilled in the art are also within the scope of the present invention. Therefore, any equivalent conversions and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention.

[0208] This application claims priority to a Chinese patent application with application number 201910830196.X (title of invention: Electrical system with online sampling check function and checking method therefor) filed on September 4, 2019. [Explanation of symbols]

[0209] 1 Gas Density Relay 2. Pressure Sensor 3 Temperature Sensor 4 Valves 5 Temperature control mechanism 6 Online check contact signal sampling unit 7. Intelligent Control Unit 8. Electrical Equipment 9 Multi-way joints 10 Gas refill port 11 Pressure adjustment mechanism 12 Micro Water Sensor 21 First pressure sensor 22 Second pressure sensor 31 First temperature sensor 32 Second temperature sensor 71 Processor 72 Power supply 73 Communication Module 74 Intelligent control unit protection circuit 75 Display and Output 76 Data Storage

Claims

1. An electrical system having an online sampling check function, an electric device having an air chamber therein, the air chamber being filled with an insulating gas; a gas density relay mounted externally to the air chamber of the electrical device or mounted externally to the air chamber of the electrical device by a valve; a temperature control mechanism configured to control the temperature rise and fall of a temperature compensation element of the gas density relay to generate contact operation in the gas density relay; a gas density detection sensor communicating with the gas density relay; an online check contact signal sampling unit connected to the gas density relay and arranged to sample a contact signal generated when a contact of the gas density relay operates; an intelligent control unit respectively connected to the gas density detection sensor, the temperature adjustment mechanism and the online check contact signal sampling unit, and configured to complete the control of the temperature adjustment mechanism, the pressure value collection and the temperature value collection, and / or the gas density value collection, and the detection of the contact signal operation value and / or the contact signal return value of the gas density relay; Here, the contact signal includes an alarm and / or a closure. An electrical system having an online sampling check function.

2. The contacts of the gas density relay are normally open type density relays, and the online check contact signal sampling unit includes a first connection circuit and a second connection circuit, the first connection circuit is connected to the contacts of the gas density relay and a contact signal control circuit, and the second connection circuit is connected to the contacts of the gas density relay and the intelligent control unit, in a non-check state, the second connection circuit is disconnected or isolated, and the first connection circuit is closed; in a check state, the online check contact signal sampling unit disconnects the first connection circuit, turns on the second connection circuit, and connects the contacts of the gas density relay to the intelligent control unit; or The contacts of the gas density relay are normally closed type density relays, and the online check contact signal sampling unit includes a first connection circuit and a second connection circuit, the first connection circuit is connected to the contacts of the gas density relay and a contact signal control circuit, and the second connection circuit is connected to the contacts of the gas density relay and the intelligent control unit, in a non-check state, the second connection circuit is disconnected or isolated and the first connection circuit is closed, and in a check state, the online check contact signal sampling unit closes the contact signal control circuit, disconnects the contacts of the gas density relay and the contact signal control circuit, turns on the second connection circuit, and connects the contacts of the gas density relay to the intelligent control unit.

2. The electrical system having an online sampling check function according to claim 1.

3. the first connection circuit includes a first relay, the second connection circuit includes a second relay, the first relay and the second relay are two independent relays or are the same relay, the first relay is provided with at least one normally closed contact, the second relay is provided with at least one normally open contact, the normally closed contact and the normally open contact maintain opposite switching states, the normally closed contacts are connected in series in the contact signal control circuit, and the normally open contacts are connected to contacts of the gas density relay; In a non-check state, the normally closed contacts are closed and the normally open contacts are disconnected, and the gas density relay monitors the output state of the contacts in real time; in a check state, the normally closed contacts are disconnected, the normally open contacts are closed, and the contacts of the gas density relay are connected to the intelligent control unit by the normally open contacts.

3. The electrical system having an online sampling check function according to claim 2.

4. The online check contact signal sampling unit is provided with a contact sampling circuit, the contact sampling circuit includes a photocoupler and a resistor, the photocoupler includes a light emitting diode and a phototransistor, the light emitting diode and the contact of the gas density relay are connected in series to form a closed circuit, the emitter of the phototransistor is grounded, the collector of the phototransistor is connected to the intelligent control unit, and the collector of the phototransistor is also connected to a power source by the resistor, when the contact is closed, the closed circuit is energized, the light emitting diode emits light, the light turns on the phototransistor, and the collector of the phototransistor outputs a low level; when the contact is disconnected, the closed circuit is interrupted, the light emitting diode does not emit light, the phototransistor is turned off, and the collector of the phototransistor outputs a high level; or The contact sampling circuit includes a first photocoupler and a second photocoupler, the light emitting diode of the first photocoupler and the light emitting diode of the second photocoupler are respectively connected in parallel by a current limiting resistor or directly in parallel, and then connected in series with the contact of the gas density relay to form a closed circuit, and the connection directions of the light emitting diodes of the first photocoupler and the second photocoupler are opposite, the collector of the phototransistor of the first photocoupler and the collector of the phototransistor of the second photocoupler are both connected to a power supply by a voltage dividing resistor, and the emitter of the phototransistor of the first photocoupler is connected to the emitter of the phototransistor of the second photocoupler. a contact connected to said intelligent control unit and grounded by a resistor; when said contact is closed, a closed circuit is energized, said first photocoupler is turned on, said second photocoupler is turned off, and the emitter of the phototransistor of said first photocoupler outputs a high level; or when said contact is turned off, said first photocoupler is turned on, and the emitter of the phototransistor of said second photocoupler outputs a high level; when said contact is turned off, the closed circuit is disconnected, said first photocoupler and said second photocoupler are both turned off, and the emitters of the phototransistors of said first photocoupler and said second photocoupler output a low level; or the contact sampling circuit includes a first Hall current sensor and a second Hall current sensor, the first Hall current sensor, the second Hall current sensor and the contact of the gas density relay are connected in series to form a closed circuit, and the contact of the gas density relay is connected between the first Hall current sensor and the second Hall current sensor, and the output end of the first Hall current sensor and the output end of the second Hall current sensor are both connected to the intelligent control unit, when the contact is closed, the closed circuit is energized, a current flows between the first Hall current sensor and the second Hall current sensor, and an induced potential is generated; when the contact is disconnected, the closed circuit is disconnected, no current flows between the first Hall current sensor and the second Hall current sensor, and the induced potential generated is zero; or The contact sampling circuit includes a first thyristor, a second thyristor, a third thyristor and a fourth thyristor, the first thyristor and the third thyristor are connected in series, and the second thyristor and the fourth thyristor are connected in series to form a series-parallel closed circuit with a series connection line formed by the first thyristor and the third thyristor, one end of a contact of the gas density relay is electrically connected to the line between the first thyristor and the third thyristor by a line, and the other end is electrically connected to the line between the second thyristor and the fourth thyristor by a line.

3. The electrical system having an online sampling check function according to claim 2.

5. the gas density relay has a comparative density value output signal, which is connected to the intelligent control unit; or the gas density relay has a comparative pressure value output signal, which is connected to the intelligent control unit; When the gas density relay outputs a comparative density value output signal, the intelligent control unit collects the gas density value at that time, performs a comparison, and completes the check of the comparative density value for the gas density relay. The intelligent control unit or the background judges the comparison result, and issues an abnormal indication if the error is bad; or When the gas density relay outputs a comparison density value output signal, the intelligent control unit collects and compares the gas density value at that time, and completes the mutual check between the gas density relay and the gas density detection sensor. The intelligent control unit or the background judges the comparison result, and issues an abnormality indication if the error is bad; or When the gas density relay outputs a comparison density value output signal, the intelligent control unit collects and compares the pressure value at that time, and completes a mutual check between the gas density relay and the gas density detection sensor. The intelligent control unit or background judges the comparison result, and issues an abnormality indication if the error is significant.

2. The electrical system having an online sampling check function according to claim 1.

6. The electrical system includes at least two gas density detection sensors, each of which includes a pressure sensor and a temperature sensor, and compares the gas density values ​​detected by each gas density detection sensor to complete a mutual check of each gas density detection sensor.

2. The electrical system having an online sampling check function according to claim 1.

7. The gas density detection sensor includes at least two pressure sensors, and compares the pressure values ​​collected by each pressure sensor to complete a mutual check of each pressure sensor.

2. The electrical system having an online sampling check function according to claim 1.

8. The gas density detection sensor includes at least two temperature sensors, and the temperature values ​​collected by each temperature sensor are compared to complete a mutual check of each temperature sensor.

2. The electrical system having an online sampling check function according to claim 1.

9. the gas density detection sensor includes at least one pressure sensor and at least one temperature sensor; The pressure values ​​collected by the pressure sensors and the temperature values ​​collected by the temperature sensors are randomly arranged and combined, and each combination is converted into a gas density value, which is a plurality of pressure values ​​corresponding to 20°C according to the gas pressure-temperature characteristics, and each gas density value is compared to complete a cross-check of each pressure sensor and each temperature sensor; or The pressure values ​​collected by each pressure sensor and the temperature values ​​collected by each temperature sensor are all arranged and combined, and each combination is converted into a gas density value, which is a plurality of pressure values ​​corresponding to 20°C according to the gas pressure-temperature characteristics, and each gas density value is compared to complete a mutual check of each pressure sensor and each temperature sensor; or The gas density values ​​obtained by each pressure sensor and each temperature sensor are compared with the comparative density value output signal output by the gas density relay, and a mutual check of the gas density relay, each pressure sensor, and each temperature sensor is completed.

2. The electrical system having an online sampling check function according to claim 1.

10. 1. A method for checking a gas density relay, comprising: Under normal operating conditions, the gas density relay monitors a gas density value within the electrical equipment; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas density relay, and further increases the temperature of the temperature compensation element of the gas density relay, causing the gas density relay to make a contact operation. The contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit turns off the heating element of the temperature control mechanism.

13. A method for checking a gas density relay comprising:

11. Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas density relay, and further increases the temperature of the temperature compensation element of the gas density relay, causing the gas density relay to make a contact operation. The contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay. The intelligent control unit controls the temperature regulating mechanism to reduce the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is reduced, causing a contact reset in the gas density relay. The contact reset is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the check work of the contact signal return value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit turns off the heating element of the temperature control mechanism, adjusts the online check contact signal sampling unit to a working state, and the contact signal control circuit of the gas density relay returns to a normal working state and operates.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

12. The gas density relay further includes a pressure regulating mechanism, a gas passage of the pressure regulating mechanism communicates with a gas passage of the gas density relay, and the checking method includes: Under normal operating conditions, the gas density relay monitors a gas density value within the electrical equipment; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, closing the valve with an intelligent control unit; The intelligent control unit drives the pressure regulating mechanism to gradually reduce the gas pressure, and the intelligent control unit controls the temperature regulating mechanism to increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay increases, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the checking work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the heating element of the temperature control mechanism.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

13. The gas density relay further includes a pressure regulating mechanism, a gas passage of the pressure regulating mechanism communicates with a gas passage of the gas density relay, and the checking method includes: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, closing the valve with an intelligent control unit; The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature regulating mechanism to increase the temperature of the gas density relay, and then the temperature of the temperature compensation element of the gas density relay increases, and the intelligent control unit drives the pressure regulating mechanism to gradually reduce the gas pressure, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; The intelligent control unit controls the temperature regulating mechanism to reduce the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is reduced. The intelligent control unit drives the pressure regulating mechanism to gradually increase the gas pressure, causing a contact reset in the gas density relay. The contact reset is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the check work of the contact signal return value of the gas density relay. After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the heating element of the temperature control mechanism, and adjusts the online check contact signal sampling unit to a working state, and the control circuit of the contact signal of the gas density relay returns to a normal working state and operates.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

14. Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; The intelligent control unit controls the temperature adjustment mechanism to increase the temperature of the gas in the gas density relay, and closes the valve after the temperature reaches a set value; After the temperature or pressure of the gas density relay is reduced to the set value, the intelligent control unit controls the temperature regulating mechanism to further increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

15. The gas density relay further includes an air chamber and a heating device, the air chamber is in communication with the gas density relay, and the heating device is provided outside or inside the air chamber, and the checking method includes: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; Control the heating of the heating device by an intelligent control unit, resulting in a temperature change of the gas in the air chamber between the valve and the gas density relay, and close the valve by the intelligent control unit after reaching a set value, and further turn off the heating device by the intelligent control unit; After the temperature or pressure of the air chamber is reduced to the set value, the intelligent control unit controls the temperature regulating mechanism to further increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

16. The gas density relay further includes an air chamber and a heating device, the air chamber is in communication with the gas density relay, and the heating device is provided outside or inside the air chamber, and the checking method includes: Under normal operation, the gas density relay monitors the gas density value in the electrical equipment, and at the same time, the gas density relay monitors the gas density value in the electrical equipment online through the gas density detection sensor and the intelligent control unit; The intelligent control unit or gas density relay can enable and / or check the gas density relay based on the set check time and / or check command, and the gas density value status and / or the temperature value status, The intelligent control unit adjusts the online check contact signal sampling unit to a check state, and in the check state, the online check contact signal sampling unit cuts off the control circuit of the contact signal of the gas density relay and connects the contact of the gas density relay to the intelligent control unit; Control the heating of the heating device by an intelligent control unit, resulting in a temperature change of the gas in the air chamber, and after reaching a set value, close the valve by the intelligent control unit, and turn off the heating device by the intelligent control unit; After the temperature or pressure of the air chamber is reduced to the set value, the intelligent control unit controls the temperature regulating mechanism to further increase the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further increased, causing the gas density relay to make a contact operation, and the contact operation is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of contact operation, or directly obtains the gas density value, detects the contact signal operation value of the gas density relay, and completes the check work of the contact signal operation value of the gas density relay; After all the contact signal checking operations are completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature adjustment mechanism.

11. The method of claim 10, wherein the gas density relay is connected to a power supply.

17. After the check work of the contact signal operating value of the gas density relay is completed, the intelligent control unit further controls the temperature regulating mechanism to reduce the temperature of the gas density relay, and the temperature of the temperature compensation element of the gas density relay is further reduced, causing the gas density relay to generate a contact reset. The contact reset is transmitted to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit obtains the gas density value according to the pressure value and temperature value at the time of the contact reset, or directly obtains the gas density value, detects the contact signal return value of the gas density relay, and completes the check work of the contact signal return value of the gas density relay. After all the contact signal check work is completed, the intelligent control unit opens the valve, and the intelligent control unit turns off the temperature regulating mechanism and adjusts the online check contact signal sampling unit to a working state, and the contact signal control circuit of the gas density relay returns to a normal working state and operates.

17. A method for checking a gas density relay according to claim 14, 15 or 16.

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