Double-floating-ball gas relay double alarm method based on oil pressure and baffle corner

Abstract

A double-floating-ball gas relay double alarm method based on oil pressure and a baffle rotation angle is characterized in that a gas relay experiment platform for simulating different degrees of faults of a transformer is designed, an embedded liquid pressure transmitter is installed in a pipeline in front of a double-floating-ball gas relay, and an angle sensor is installed on a baffle rotation shaft of the double-floating-ball gas relay; the rotation angle of the baffle is monitored in real time, the baffle of the double-floating-ball gas relay is subjected to the magnetic force of the magnet, the magnetic force is exponentially attenuated along with the distance, and the baffle leaves the magnet and rotates to the heavy gas alarm angle to cause heavy gas alarm. An oil pressure signal, an oil pressure curve graph, a baffle rotation angle curve graph and an oil pressure change trend of a pipeline are collected based on a pressure sensor to serve as a determined pipeline oil pressure setting value, whether a heavy gas action occurs or not is judged based on the pipeline oil pressure setting value which is alarmed twice, and the heavy gas alarm accuracy of the double-floating-ball gas relay is greatly improved. And a new method is provided for setting the heavy gas action of the transformer.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer heavy gas fault diagnosis, and relates to a double-float gas relay double alarm method based on oil pressure and baffle angle. Background Art

[0002] The gas relay is a relay protection device used in oil-immersed transformers and on-load tap changers. It is installed on the pipeline between the transformer oil tank and the oil conservator. When a fault occurs inside the transformer and causes oil flow surge, the fast-surging oil flow surges from the transformer oil tank to the oil conservator, impacting the gas relay installed on the pipeline. When the flow rate of the oil flow reaches the set value, the gas relay baffle rotates under the impact of the transient surging oil flow, connecting the reed contact behind the baffle, connecting the relay protection circuit, and sending out a heavy gas alarm signal. The baffle of the double-float gas relay is subject to the magnetic force of the magnet, and the magnetic force decays exponentially with distance.

[0003] The reliability of the heavy gas action flow rate setting value of the gas relay currently used in actual working conditions is low, and it can only provide a certain parameter range as a reference, which cannot accurately reflect the operating status of the gas relay. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a double-float gas relay double alarm method based on oil pressure and baffle angle, which accurately reflects the operating status of the gas relay.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a double-float gas relay double alarm method based on oil pressure and baffle angle, comprising the following steps: An experimental platform for gas relays is designed to simulate transformer faults of different degrees. An embedded liquid pressure transmitter is installed inside the pipe in front of the double-float gas relay. An angle sensor is installed on the baffle shaft of the double-float gas relay to monitor the baffle angle in real time. The baffle of the double-float gas relay is affected by the magnetic force of the magnet, and the magnetic force decays exponentially with distance. When the baffle of the double-float gas relay leaves the magnet, it will rotate to the angle of heavy gas alarm, causing a heavy gas alarm.

[0006] Apply different degrees of external excitation sources to the oil pipeline to generate different surging oil flows; collect pipeline oil pressure signals based on pressure sensors to generate pipeline oil pressure curves under different excitation sources; collect baffle angle signals based on double float gas relays and angle sensors to generate baffle angle curves under different excitation sources; Analyze and compare the pipeline oil pressure change trends under different excitation sources to determine the pipeline oil pressure setting value; record the pipeline oil pressure value at the moment the double-float gas relay baffle leaves the magnet, which is used as the oil pressure setting value of the first alarm, also known as the pre-alarm; record the pipeline oil pressure value when the double-float gas relay baffle rotates to the triggering angle of the reed switch, which is used as the oil pressure setting value of the second alarm, also known as the weighing gas alarm.

[0007] When the double-float gas relay baffle leaves the magnet, that is, when the baffle angle is greater than 0, the first alarm is issued to remind the operator to pay attention. If the pipeline oil pressure does not reach the pre-alarm oil pressure setting value at this time, it can be predicted that the baffle leaving the magnet may be caused by vibration, etc., and a lighter alarm sound is set; if the pipeline oil pressure also reaches the pre-alarm oil pressure setting value at this time, it indicates that the transformer is abnormal, but only a minor fault has occurred, and a heavier alarm sound is issued; The baffle of the double-float gas relay rotates to the triggering angle of the reed switch to issue a second alarm; when the pipeline oil pressure value does not reach the oil pressure setting value of the second alarm, a lighter alarm sound is set; when the pipeline oil pressure value reaches the oil pressure setting value of the second alarm, a heavier alarm sound is set, and a formal heavy gas alarm is issued, and the degree of the fault is determined based on the maximum value of the pipeline oil pressure.

[0008] The pressure sensor is an embedded liquid pressure transmitter, which is inserted into the pipe to be tested. The measuring range is 0-0.4MPa and the resolution is 0.001MPa.

[0009] The rotating shaft of the double-float gas relay baffle is connected to one end of the coupling, and an angle sensor is installed at the other end of the coupling; the angle sensor consists of a fixed base and a rotatable encoder, and the resolution of the angle sensor is .

[0010] The pipeline oil pressure signal and the gas relay baffle angle signal are both output as voltage signals, and the signal acquisition device synchronously acquires the pipeline oil pressure signal and the gas relay baffle angle signal.

[0011] The specific calculation formula for the baffle angle of the gas relay is: ; in is the measured angle in degrees or radians; N is the encoder's rotation speed, that is, the number of rotations per second, in 1 / s; is the resolution of the encoder, that is, the angular velocity corresponding to each rotation of a coding stripe, in degrees / revolution or radians / revolution; is the number of encoding stripes on the encoder disk, that is, the number of encoding stripes on the encoder disk.

[0012] The rotation of the baffle of the double-float gas relay needs to overcome the magnetic force of the magnet on the baffle. The derivation formula of the magnetic force of the magnet on the baffle is: ; (1) ; (2) ; (3) ; (4)

[0013] ; (5) Where F is the magnetic force of the baffle, in Newtons; B is the magnetic induction intensity, in Teslas; B 0 is the magnetic induction intensity on the surface of the magnet; J m is the magnetization intensity, in amperes per meter; V is the volume of the baffle, in cubic meters; x is the distance from the baffle to the magnet; is the magnetic susceptibility; H is the external magnetic field strength, in amperes per meter; is the magnetic permeability.

[0014] The magnetic force of the magnet on the baffle decays exponentially with the distance from the baffle to the magnet. When the baffle of the double-float gas relay leaves the magnet, it will rotate to the angle of heavy gas alarm and cause a heavy gas alarm.

[0015] The baffle of the double-float gas relay rotates due to the oil pressure pushing it open, not entirely based on the flow rate. The oil pressure acts on the baffle earlier than the flow rate.

[0016] The main beneficial effects of the present invention are: By collecting the internal oil pressure of the pipeline and comparing it with the set values ​​of the first alarm and the second alarm, it is determined whether the double-float gas relay has a heavy gas fault, providing a new method with high reliability and accuracy for the diagnosis of heavy gas faults of the double-float gas relay.

[0017] Avoiding false operation of the double-float gas relay due to transformer vibration and minor faults, and improving the sensitivity and accuracy of the float gas relay's heavy gas alarm.

[0018] As the excitation pressure increases, the corresponding pipeline pressure when the baffle starts to move and the corresponding pipeline pressure when the baffle rotates to trigger the heavy gas alarm gradually increase. At the same time, the time taken by the baffle from the start of movement to the maximum angle gradually decreases; the pipeline pressure change precedes the heavy gas action. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1It is a flow chart of the present invention.

[0021] Figure 2 The overall structural diagram of the double-float gas relay with an angle sensor added to the present invention.

[0022] Figure 3 It is a schematic diagram of the main body of the angle sensor of the present invention.

[0023] Figure 4 This is a curve diagram of the baffle angle, heavy gas signal and pipeline pressure under 0.10MPa pressure excitation of the present invention.

[0024] Figure 5 This is a curve diagram of the baffle angle, heavy gas signal and pipeline pressure under 0.12MPa pressure excitation of the present invention.

[0025] Figure 6 This is a curve diagram of the baffle angle, heavy gas signal and pipeline pressure under 0.14MPa pressure excitation of the present invention.

[0026] Figure 7 This is a curve diagram of the baffle angle, heavy gas signal and pipeline pressure under 0.16MPa pressure excitation of the present invention.

[0027] Figure 8 This is a curve diagram of the baffle angle, heavy gas signal and pipeline pressure under 0.18MPa pressure excitation of the present invention.

[0028] Fig. 9 It is a curve diagram of pipeline oil pressure value under different pressure excitations of the present invention.

[0029] In the figure: 1. Angle sensor; 2. Coupling; 3. Baffle shaft; 4. Baffle; 5. Angle sensor base; 6. Angle sensor encoder. DETAILED DESCRIPTION

[0030] like Figure 1 to Figure 9 A double-float gas relay double alarm method based on oil pressure and baffle angle includes the following steps: An experimental platform for gas relays is designed to simulate transformer faults of different degrees. An embedded liquid pressure transmitter is installed inside the pipe in front of the double-float gas relay. An angle sensor is installed on the baffle shaft of the double-float gas relay to monitor the baffle angle in real time. The baffle of the double-float gas relay is affected by the magnetic force of the magnet, and the magnetic force decays exponentially with distance. When the baffle of the double-float gas relay leaves the magnet, it will rotate to the angle of heavy gas alarm, causing a heavy gas alarm.

[0031] In the preferred solution, different degrees of external excitation sources are applied to the oil pipeline to generate different surging oil flows; the oil pressure signal of the pipeline is collected based on the pressure sensor to generate pipeline oil pressure curves under different excitation sources; the baffle angle signal is collected based on the double float gas relay and the angle sensor to generate baffle angle curves under different excitation sources; Analyze and compare the pipeline oil pressure change trends under different excitation sources to determine the pipeline oil pressure setting value; record the pipeline oil pressure value at the moment when the double-float gas relay baffle leaves the magnet, which is used as the first alarm, also known as the pre-alarm oil pressure setting value; In the preferred solution, when the baffle of the double-float gas relay leaves the magnet, that is, when the baffle angle is greater than 0, the first alarm is issued to remind the operator to pay attention; Preferably, if the pipeline oil pressure does not reach the pre-alarm oil pressure setting value at this time, it can be predicted that the baffle leaving the magnet may be caused by vibration, etc., and a lighter alarm sound is set; Preferably, a warning is issued only when the baffle leaves the magnet and the pipeline oil pressure reaches the pre-alarm setting value.

[0032] Preferably, if the pipeline oil pressure also reaches the pre-alarm oil pressure setting value at this time, it indicates that the transformer is abnormal, but only a minor fault has occurred, and a heavier alarm sound is issued; The baffle of the double-float gas relay rotates to the triggering angle of the reed switch to issue a second alarm; when the pipeline oil pressure value does not reach the oil pressure setting value of the second alarm, a lighter alarm sound is set; when the pipeline oil pressure value reaches the oil pressure setting value of the second alarm, a heavier alarm sound is set, and a formal heavy gas alarm is issued, and the degree of the fault is determined based on the maximum value of the pipeline oil pressure.

[0033] Preferably, a formal alarm is issued when the baffle reaches the triggering angle of the reed switch and the pipeline oil pressure reaches the formal alarm setting value, and the fault degree is judged according to the maximum value of the pipeline oil pressure, and the formal alarm is used as the main alarm.

[0034] Preferably, whether heavy gas action occurs is determined based on the oil pressure setting values ​​of the two alarm pipelines and the movement status of the baffle.

[0035] In a preferred solution, the pressure sensor is an embedded liquid pressure transmitter, which is inserted into the pipe to be measured, has a measuring range of 0-0.4MPa, and a resolution of 0.001MPa.

[0036] Preferably, the double-float gas relay will only connect the reed contact when the baffle rotates to a certain angle, causing a heavy gas fault, and then output a 0-1 switch quantity. In order to convert the 0-1 switch quantity output by the double-float gas relay in the case of a heavy gas fault into a continuous state quantity, a modified double-float gas relay with an added angle sensor 1 that can output the baffle angle in real time is designed.

[0037] In the preferred embodiment, Figure 2 , Figure 3 As shown, the shaft 3 of the modified double-float gas relay baffle 4 is connected to one end of the coupling 2, and an angle sensor 1 is installed at the other end of the coupling. The angle sensor consists of a fixed base 6 and a rotatable encoder 5. The resolution of the angle sensor is .

[0038] Preferably, the baffle angle signal collected by the angle sensor is connected to the terminal of the double-float gas relay through a data transmission line.

[0039] In a preferred solution, both the pipeline oil pressure signal and the gas relay baffle angle signal are output as voltage signals, and the signal acquisition device synchronously acquires the pipeline oil pressure signal and the gas relay baffle angle signal.

[0040] Preferably, when the pipeline pressure reaches a certain value, the baffle and the baffle shaft begin to rotate under the action of pressure and oil flow, and drive the angle sensor encoder connected to the baffle shaft through the coupling to rotate. The baffle angle signal can be output through the encoder's speed, resolution and number of stripes.

[0041] In the preferred solution, the specific calculation formula for the baffle angle of the gas relay is: ; in is the measured angle in degrees or radians; N is the encoder's rotation speed, that is, the number of rotations per second, in 1 / s; is the resolution of the encoder, that is, the angular velocity corresponding to each rotation of a coding stripe, in degrees / revolution or radians / revolution; is the number of encoding stripes on the encoder disk, that is, the number of encoding stripes on the encoder disk.

[0042] In the preferred solution, the rotation of the baffle of the double-float gas relay needs to overcome the magnetic force of the magnet on the baffle. The derivation formula of the magnetic force of the magnet on the baffle is: ; (1) ; (2) ; (3) ; (4)

[0043] ; (5) Where F is the magnetic force of the baffle, in Newtons; B is the magnetic induction intensity, in Teslas; B 0 is the magnetic induction intensity on the surface of the magnet; J mis the magnetization intensity, in amperes per meter; V is the volume of the baffle, in cubic meters; x is the distance from the baffle to the magnet; is the magnetic susceptibility; H is the external magnetic field strength, in amperes per meter; is the magnetic permeability.

[0044] In the preferred solution, the magnetic force of the magnet on the baffle decays exponentially with the distance from the baffle to the magnet. When the baffle of the double-float gas relay leaves the magnet, it will rotate to the angle of the heavy gas alarm to cause the heavy gas alarm.

[0045] In the preferred solution, the baffle of the double-float gas relay rotates due to the oil pressure pushing it open, and is not entirely based on the flow rate. The oil pressure acts on the baffle earlier than the flow rate.

[0046] Embodiment 1, To prove the effectiveness of the technical solution of this application, the excitation pressure of the air cannon was set to 0.10MPa, 0.12MPa, 0.14MPa, 0.16MPa, and 0.18MPa for testing. The pipeline pressure, heavy gas action, and baffle angle obtained by the test were as follows: Figure 4~Figure 8 As shown in , the experimental device is in a stable environment, eliminating the possibility of baffle movement due to vibration.

[0047] Depend on Figure 4~Figure 8 It can be seen that as the excitation pressure gradually increases, the time taken by the baffle from the start of action to the maximum angle gradually decreases, and the maximum value of the pipeline pressure gradually increases. The specific values ​​are shown in Table 1.

[0048] Table 1 Values ​​of heavy gas action under different excitation pressures:

[0049] The data in Table 1 are plotted as follows Fig. 9 shown.

[0050] From Table 1 and Fig. 9 It can be seen that when the excitation pressure is 0.10Mpa, the maximum pressure of the pipeline is 1.35kpa, and the heavy gas does not operate. At this time, only a slight fault occurs inside the reaction transformer; when the excitation pressure is 0.12Mpa, the heavy gas operates, and the corresponding pipeline pressure when the baffle starts to operate is 2.32kpa. The corresponding pipeline oil pressure value of 2.32kpa at this time is used as the setting value of the pre-alarm; the pipeline pressure corresponding to the baffle reaching the maximum angle is 4.85kpa, and the corresponding pipeline oil pressure value of 4.85kpa ​​at this time is used as the setting value of the formal alarm; the degree of heavy gas fault of the double float gas relay can be judged according to the maximum value of the pipeline oil pressure.

[0051] The baffle leaving the magnet may be caused by vibration; the pipeline oil pressure reaching the pre-alarm setting value may only be a minor fault; a pre-alarm is issued only when the baffle leaves the magnet and the pipeline oil pressure reaches the pre-alarm setting value; a formal alarm is issued when the baffle reaches the triggering angle of the reed switch and the pipeline oil pressure reaches the formal alarm setting value. The degree of the fault can be judged based on the maximum value of the pipeline oil pressure, and the formal alarm is used as the main alarm.

[0052] Avoiding false operation of the double-float gas relay due to transformer vibration and minor faults, and improving the sensitivity and accuracy of the float gas relay's heavy gas alarm.

[0053] As the excitation pressure increases, the corresponding pipeline pressure when the baffle starts to move and the corresponding pipeline pressure when the baffle rotates to trigger the heavy gas alarm gradually increase. At the same time, the time taken by the baffle from the start of movement to the maximum angle gradually decreases; the pipeline pressure change precedes the heavy gas action.

[0054] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A double-float gas relay double alarm method based on oil pressure and baffle angle, characterized in that: The steps include: Design a gas relay experimental platform that simulates transformer faults of different degrees; install the embedded liquid pressure transmitter inside the pipeline in front of the double-float gas relay; install an angle sensor on the baffle shaft of the double-float gas relay to monitor the baffle angle in real time; The double-float gas relay baffle is affected by the magnetic force of the magnet, and the magnetic force decays exponentially with distance. When the double-float gas relay baffle leaves the magnet, it will rotate to the angle of heavy gas alarm and cause a heavy gas alarm.

2. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1 is characterized by: Apply different degrees of external excitation sources to the oil pipeline to generate different surging oil flows; collect pipeline oil pressure signals based on pressure sensors to generate pipeline oil pressure curves under different excitation sources; collect baffle angle signals based on double float gas relays and angle sensors to generate baffle angle curves under different excitation sources; Analyze and compare the pipeline oil pressure change trends under different excitation sources to determine the pipeline oil pressure setting value; record the pipeline oil pressure value at the moment the double-float gas relay baffle leaves the magnet, which is used as the oil pressure setting value of the first alarm, also known as the pre-alarm; record the pipeline oil pressure value when the double-float gas relay baffle rotates to the triggering angle of the reed switch, which is used as the oil pressure setting value of the second alarm, also known as the weighing gas alarm.

3. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 2 is characterized by: When the double-float gas relay baffle leaves the magnet, that is, when the baffle angle is greater than 0, the first alarm is issued to remind the operator to pay attention. If the pipeline oil pressure does not reach the pre-alarm oil pressure setting value at this time, it can be predicted that the baffle leaving the magnet may be caused by vibration, etc., and a lighter alarm sound is set; if the pipeline oil pressure also reaches the pre-alarm oil pressure setting value at this time, it indicates that the transformer is abnormal, but only a minor fault has occurred, and a heavier alarm sound is issued; The baffle of the double-float gas relay rotates to the triggering angle of the reed switch to issue a second alarm; when the pipeline oil pressure value does not reach the oil pressure setting value of the second alarm, a lighter alarm sound is set; when the pipeline oil pressure value reaches the oil pressure setting value of the second alarm, a heavier alarm sound is set, and a formal heavy gas alarm is issued, and the degree of the fault is determined based on the maximum value of the pipeline oil pressure.

4. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 2 is characterized by: The pressure sensor is an embedded liquid pressure transmitter, which is inserted into the pipe to be tested. The measuring range is 0-0.4MPa and the resolution is 0.001MPa.

5. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1 is characterized by: The rotating shaft of the double-float gas relay baffle is connected to one end of the coupling, and an angle sensor is installed at the other end of the coupling; the angle sensor consists of a fixed base and a rotatable encoder, and the resolution of the angle sensor is .

6. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1 is characterized by: The pipeline oil pressure signal and the gas relay baffle angle signal are both output as voltage signals, and the signal acquisition device synchronously acquires the pipeline oil pressure signal and the gas relay baffle angle signal.

7. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1, characterized in that: The specific calculation formula for the baffle angle of the gas relay is: in is the measured angle in degrees or radians; N is the encoder's rotation speed, that is, the number of rotations per second, in 1 / s; is the resolution of the encoder, that is, the angular velocity corresponding to each rotation of a coding stripe, in degrees / revolution or radians / revolution; is the number of encoding stripes on the encoder disk, that is, the number of encoding stripes on the encoder disk.

8. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1, characterized in that: The rotation of the baffle of the double-float gas relay needs to overcome the magnetic force of the magnet on the baffle. The derivation formula of the magnetic force of the magnet on the baffle is: ；(1) ； (2) ；(3) ；(4) ；(5) Where F is the magnetic force of the baffle, in Newton; B is the magnetic induction intensity, in Tesla; B0 is the magnetic induction intensity on the magnet surface; J m is the magnetization intensity, in amperes per meter; V is the volume of the baffle, in cubic meters; x is the distance from the baffle to the magnet; is the magnetic susceptibility; H is the external magnetic field strength, in amperes per meter; is the magnetic permeability.

9. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 7, characterized in that: The magnetic force of the magnet on the baffle decays exponentially with the distance from the baffle to the magnet. When the baffle of the double-float gas relay leaves the magnet, it will rotate to the angle of heavy gas alarm and cause a heavy gas alarm.

10. The double-float gas relay double alarm method based on oil pressure and baffle angle according to claim 1, characterized in that: The baffle of the double-float gas relay rotates due to the oil pressure pushing it open, not entirely based on the flow rate. The oil pressure acts on the baffle earlier than the flow rate.

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