A method for setting transformer heavy gas action based on surging oil flow acceleration

Abstract

The present invention discloses a transformer heavy gas action setting method based on surging oil flow acceleration, including: applying different degrees of external excitation sources to the oil pipeline to generate different surging oil flows; collecting the flow velocity signal of the transient oil flow based on the flow velocity sensor to generate the flow velocity curve under different surging oil flows; collecting the gas relay baffle angle signal based on the gas relay to generate the baffle angle curve under different surging oil flows; based on the flow velocity curve and the baffle angle curve, analyzing and comparing the acceleration value and change trend of the surging oil flow corresponding to the heavy gas action under different surging oil flows, and determining the acceleration setting value of the surging oil flow when the heavy gas action occurs; judging whether the heavy gas action occurs based on the acceleration setting value of the surging oil flow. The present invention provides a new method for transformer heavy gas action setting by judging whether the heavy gas action occurs based on the surging oil flow acceleration value.

Description

Technical Field

[0001] The invention relates to the technical field of transformer heavy gas fault diagnosis, and more particularly to a transformer heavy gas action setting method based on surging oil flow acceleration. Background Art

[0002] The gas relay protection device is an important part of the transformer system and plays a key role in ensuring the safe operation of the transformer power system. The heavy gas action flow rate setting value of the gas relay currently used in actual working conditions has low reliability and can only provide a certain parameter range as a reference. Therefore, it is of great significance to study the internal flow field of the gas relay when a heavy gas fault occurs.

[0003] Therefore, how to provide a transformer heavy gas action setting method based on surging oil flow acceleration is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In view of this, the present invention provides a transformer heavy gas action setting method based on surging oil flow acceleration, which provides a new method for transformer heavy gas action setting by judging whether heavy gas action occurs based on the surging oil flow acceleration value.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A transformer heavy gas action setting method based on surging oil flow acceleration, comprising:

[0007] Apply different degrees of external excitation sources to the oil pipeline to generate different surging oil flows;

[0008] Collect the velocity signal of transient oil flow and generate velocity curves under different surging oil flows;

[0009] Collect the baffle angle signal of the gas relay and generate baffle angle curves under different surging oil flows;

[0010] Based on the flow velocity curve and the baffle angle curve, the average acceleration value and change trend of the surging oil flow corresponding to the heavy gas action under different surging oil flows are analyzed and compared, and the acceleration setting value of the surging oil flow when the heavy gas action occurs is determined;

[0011] Whether heavy gas action occurs is determined based on the acceleration setting value of the surging oil flow.

[0012] Preferably, the flow velocity signal of the transient oil flow is collected based on a flow velocity sensor, and the flow velocity sensor is an ultrasonic flow meter with a response time of 20 ms.

[0013] Preferably, the baffle angle signal of the gas relay is collected based on the Hall induction gas relay.

[0014] Preferably, the flow rate signal and the gas relay baffle angle signal are collected simultaneously.

[0015] Preferably, when the baffle starts to move, the speed of the oil flow is v0, and the speed of the surging oil flow when the angle is turned to the maximum angle is v1. The time taken by the baffle from the start of the action to the maximum angle is t. The acceleration value of the surging oil flow corresponding to the heavy gas action is calculated by the following formula:

[0016] a=(v1-v0) / t.

[0017] Preferably, the specific calculation formula of the baffle angle of the gas relay is:

[0018]

[0019] Among them, K H is the Hall sensitivity; I is the excitation current; B is the magnetic field strength; ΔU H is the change in Hall potential difference; L is the distance between the initial permanent magnet and the Hall current sensor; h is the straight-line distance from the center of mass of the baffle to the connection point of the shaft; Δθ is the baffle angle of the gas relay, and d represents the differential sign.

[0020] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a method for setting the heavy gas action of a transformer based on the acceleration of the surging oil flow. By collecting the surging oil flow velocity and analyzing its acceleration value, it is determined whether the transformer has a heavy gas action, which provides a new method for setting the heavy gas action of the transformer with high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 The accompanying drawing is a flow chart of a transformer heavy gas action setting method based on surging oil flow acceleration provided by the present invention.

[0023] Figure 2 shows the flow rate, baffle and heavy gas signals under different pressure excitations, where Figure 2(a) is 0.10MPa pressure excitation, Figure 2(b) is 0.12MPa pressure excitation, Figure 2(c) is 0.14MPa pressure excitation, Figure 2(d) is 0.16MPa pressure excitation, and Figure 2(e) is 0.18MPa pressure excitation.

[0024] Figure 3 The attached figure shows the oil flow velocity and its average acceleration when heavy gas action occurs under different pressure excitations.

[0025] Figure 4 The attached figure shows the displacement measurement principle of the Hall element. Among them, 1. baffle, 2. permanent magnet, 3. Hall sensor, 4. rotating shaft. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The embodiment of the present invention discloses a transformer heavy gas action setting method based on surging oil flow acceleration, such as Figure 1 As shown, including:

[0028] Apply different degrees of external excitation sources to the oil pipeline to generate different surging oil flows;

[0029] The flow velocity signal of transient oil flow is collected based on the flow velocity sensor, and the flow velocity curve diagram under different surging oil flows is generated;

[0030] Based on the gas relay, the baffle angle signal of the gas relay is collected to generate a baffle angle curve diagram under different surging oil flows;

[0031] Based on the flow velocity curve and the baffle angle curve, the average acceleration value and change trend of the surging oil flow corresponding to the heavy gas action under different surging oil flows are analyzed and compared, and the acceleration setting value of the surging oil flow when the heavy gas action occurs is determined;

[0032] Whether heavy gas action occurs is determined based on the acceleration setting value of the surging oil flow.

[0033] Specifically, the flow rate sensor and the Hall induction gas relay simultaneously monitor the surging oil flow rate and the baffle angle signal. When the baffle rotates to a certain angle and touches the lower dry reed contact, the heavy gas trips. The upper computer can determine the oil flow speed v0 when the baffle starts to move and the surging oil flow speed v1 when the angle is turned to the maximum angle. In addition, the time t taken by the baffle from the start of movement to the maximum angle can also be determined. Therefore, the corresponding average acceleration of the oil flow during the heavy gas action process can be determined by a=(v1-v0) / t.

[0034] At the same time, the existing gas relay will only generate a heavy gas alarm when the baffle rotates to a certain angle to trigger the lower reed, and then output a 0-1 switch value. In order to explore the continuous state quantity of the gas relay baffle during rotation, a new gas relay based on Hall induction that can output the baffle angle in real time was developed. The new Hall induction gas relay uses a Hall current sensor 3 to replace a set of reed switches behind the existing gas relay baffle, and obtains the baffle angle signal by monitoring the output voltage of the Hall integrated circuit, such as Figure 4 shown.

[0035] The Hall induction gas relay of the present invention detects the magnetic field generated by the permanent magnet 2 behind the baffle 1, and then indirectly measures the state quantity of the baffle 1 during rotation. The principle is that when the surging oil flow impacts the baffle 1 of the gas relay, the permanent magnet on the baffle 1 moves accordingly, causing the distance between it and the Hall current sensor to change, thereby causing the change of the magnetic field, and the Hall voltage changes with the change of the magnetic induction intensity, so the baffle angle can be judged by monitoring the output voltage of the Hall integrated circuit.

[0036] The specific calculation process is:

[0037] The Hall current sensor converts the changing magnetic field strength B into the Hall electromotive force U H The equation is as follows:

[0038] U H =K H IB (1)

[0039] Where: K H is the Hall sensitivity; I is the excitation current; B is the magnetic field intensity. The change in the Hall potential difference is:

[0040]

[0041] Where: L is the initial distance between the permanent magnet and the Hall sensor; ΔL is the displacement that changes during the rotation process. Therefore, the change in the baffle angle is:

[0042]

[0043] Where h is the straight-line distance from the center of mass of the baffle to the connection point of the rotating shaft 4. From equations (2) and (3), we have

[0044]

[0045] To prove the effectiveness of the method of the present invention, the excitation pressures of the air flow aid were set to 0.10MPa, 0.12MPa, 0.14MPa, 0.16MPa, and 0.18MPa for testing, and the sampling frequency was set to 1kHz to ensure sufficient acquisition of the baffle action process signal. The flow rate of the pipeline surging oil flow, the heavy gas action, and the baffle angle obtained by the test are shown in Figure 2.

[0046] It can be seen from Figure 2 that as the excitation pressure gradually increases, the maximum flow rate of the surging oil flow gradually increases, and the average acceleration of the surging oil flow when the heavy gas action occurs also shows an increasing trend. The specific values ​​are shown in Table 1.

[0047] Table 1 Numerical values ​​of heavy gas action under different excitation pressures

[0048]

[0049]

[0050] The data in Table 1 are plotted as follows Figure 3 shown.

[0051] From Table 1 and Figure 3 It can be seen that when the excitation pressure is 0.10Mpa, the maximum flow rate of the surging oil flow in the pipeline is 0.41m / s, and the heavy gas does not act. At this time, only a slight fault occurs inside the reaction transformer; when the excitation pressure is 0.12Mpa, the heavy gas action occurs, and the corresponding surging oil flow velocity when the baffle starts to act is 0.172m / s. When the baffle rotates to trigger the heavy gas alarm, the surging oil flow velocity is 0.63m / s. In this process, the average acceleration of the oil flow in the heavy gas action is 3.52m / s 2 , the average acceleration is 3.52m / s 2 As the setting value of heavy gas action acceleration, that is, a st =3.52m / s 2 ; With the increase of excitation pressure, the corresponding flow velocity when the baffle starts to move and the corresponding flow velocity when the baffle rotates to trigger the heavy gas alarm gradually decrease. At the same time, the time taken by the baffle from the start of movement to the maximum angle also gradually decreases, but the average acceleration of the surging oil flow during the heavy gas action gradually increases; and with the increase of heavy gas fault energy, the corresponding acceleration value during the heavy gas action increases, but the corresponding flow velocity value lags behind, that is, when the flow velocity setting value used in the actual site is not reached, the heavy gas action still occurs.

[0052] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0053] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transformer heavy gas action setting method based on surging oil flow acceleration, characterized in that: include: Apply different degrees of external excitation sources to the oil pipeline to generate different surging oil flows; Collect the velocity signal of transient oil flow and generate velocity curves under different surging oil flows; Collect the baffle angle signal of the gas relay and generate baffle angle curves under different surging oil flows; Based on the velocity curve and the baffle angle curve, the average acceleration value and change trend of the surging oil flow corresponding to the heavy gas action under different surging oil flows are analyzed and compared, and the acceleration setting value of the surging oil flow with heavy gas action is determined; When the baffle starts to move, the speed of the oil flow is v0, and the speed of the surging oil flow when the angle is turned to the maximum angle is v1. The time taken by the baffle from the start of movement to the maximum angle is t. The acceleration value of the surging oil flow corresponding to the heavy gas action is calculated by the following formula: a=(v1-v0) / t; Whether heavy gas action occurs is determined based on the acceleration setting value of the surging oil flow.

2. A transformer heavy gas action setting method based on surging oil flow acceleration according to claim 1, characterized in that: The flow velocity signal of the transient oil flow is collected based on the flow velocity sensor, which is an ultrasonic flow meter with a response time of 20ms.

3. The transformer heavy gas action setting method based on surging oil flow acceleration according to claim 1 is characterized in that: The baffle angle signal of the gas relay is collected based on the Hall induction gas relay.

4. The transformer heavy gas action setting method based on surging oil flow acceleration according to claim 1 is characterized in that: The flow rate signal and the gas relay baffle angle signal are collected simultaneously.

5. The transformer heavy gas action setting method based on surging oil flow acceleration according to claim 3 is characterized in that: The specific calculation formula for the baffle angle of the gas relay is: Among them, K H is the Hall sensitivity; I is the excitation current; B is the magnetic field strength; ΔU H is the change in Hall potential difference; L is the distance between the initial permanent magnet and the Hall current sensor; h is the straight-line distance from the center of mass of the baffle to the connection point of the shaft; Δθ is the baffle angle of the gas relay, and d represents the differential sign.

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