A transformer partial discharge detection device based on palladium alloy LC wireless passive sensor and its use method

Abstract

The present invention discloses a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor and a method for using the device, comprising: an LC sensor and a readout circuit for energy coupling and signal transmission through inductive coupling. The inductance of the LC sensor is made of a palladium alloy. When partial discharge occurs inside the transformer, the insulating oil is decomposed to produce hydrogen, which increases the hydrogen content in the oil. The palladium alloy absorbs hydrogen to increase the parasitic resistance of the inductor coil, thereby increasing the real impedance of the LC sensor. The real impedance value of the LC sensor is monitored by the readout circuit. When the real impedance value of the LC sensor increases to a warning value, it proves that the hydrogen content in the transformer insulating oil has increased, and the occurrence of partial discharge can be detected. The invention can be installed inside the transformer equipment to realize online detection of partial discharge, and has a simple structure and a concise detection process.

Description

Technical Field

[0001] The present invention relates to the technical field of LC sensors, and in particular to a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor and a use method thereof. Background Art

[0002] With the rapid construction and development of power grids, power transformers, as key equipment in power grid operation, are particularly important in terms of reliability. The reliable operation of power transformers has become one of the key factors in the reliable operation of power grids.

[0003] Among all the fault types that occur in transformer equipment, faults caused by insulation problems are the most common. Partial discharge is an important factor that induces insulation degradation or even insulation failure in transformer equipment. When partial discharge occurs, the insulating oil inside the transformer will decompose into hydrogen, carbon monoxide, carbon dioxide, and a variety of small molecular hydrocarbon gases, among which hydrogen is the main produced gas.

[0004] Palladium metal can absorb hydrogen, which is decomposed into hydrogen atoms by palladium metal, and the hydrogen atoms diffuse rapidly in the face-centered cubic lattice of palladium. Due to the limitation of the palladium metal lattice structure, only hydrogen will be absorbed by it. Hydrogen atoms occupy the lattice gap of palladium metal, causing the lattice to expand, which increases the resistance of palladium metal; at the same time, the hydrogen atoms doped inside the palladium metal crystal will hinder the movement of free electrons, which will also increase the resistance of palladium metal. These are the two basic bases for measuring the hydrogen concentration through the resistance value of palladium metal. In addition, palladium alloy can effectively eliminate the "hydrogen embrittlement" phenomenon and extend the service life.

[0005] The existing oil-gas analysis method is an offline test, and each test requires sampling, oil-gas separation,

[0006] The steps of component detection and data processing are greatly affected by human factors, the test results are inaccurate, the whole detection process is cumbersome and complicated, and the experiment time is long. Using the oil-gas separation method, it takes at least 1-2 days to make the gas in the gas chamber reach equilibrium with the gas in the oil, and it is still impossible to achieve full online monitoring. Therefore, it is very important to directly detect the fault gas in the oil without oil-gas separation. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor and a method of using the same, which realizes real-time detection of partial discharge in the transformer, improves the anti-interference ability of partial discharge detection, and solves the problem that traditional detection methods can only perform detection after oil and gas separation.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor, the device comprising:

[0010] An LC sensor comprising a palladium alloy inductor coil, and the palladium alloy inductor coil is used to absorb hydrogen generated in insulating oil when partial discharge occurs in the transformer;

[0011] A readout circuit, comprising a readout inductor and an impedance analysis circuit, wherein the readout inductor and the palladium alloy inductor are used for signal transmission via inductive coupling;

[0012] When the palladium alloy inductor coil absorbs hydrogen, the impedance analysis circuit detects the real part of the impedance of the LC sensor by reading the inductor coil, thereby detecting the occurrence of partial discharge.

[0013] Furthermore, the LC sensor is composed of a resonant circuit formed by a palladium alloy inductor coil and its own parasitic capacitance.

[0014] Furthermore, the LC sensor is arranged inside the transformer.

[0015] Furthermore, the readout circuit is arranged outside the transformer.

[0016] A method for using a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor, the method comprising:

[0017] Step S1, when partial discharge occurs inside the transformer equipment, the insulating oil inside the transformer is decomposed to generate hydrogen. When the palladium alloy inductor coil absorbs the hydrogen, its resistance increases, thereby increasing the real part of the impedance of the LC sensor;

[0018] Step S2, the readout circuit detects the impedance change of the LC sensor through the readout inductor coil. When the local discharge phenomenon occurs, the real part of the impedance of the LC sensor detected by the readout circuit increases;

[0019] Step S3: The impedance analysis circuit analyzes the signal to monitor whether partial discharge occurs.

[0020] Further, the method comprises:

[0021] The transformer partial discharge detection device is also provided with an alarm device;

[0022] When the real part of the impedance of the LC sensor rises to a preset value, the alarm device sounds an alarm.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention is an online monitoring device, which can detect the occurrence of partial discharge in real time without stopping the machine;

[0025] 2. The present invention can realize real-time detection of partial discharge phenomenon and monitor the hydrogen content in insulating oil without oil-gas separation;

[0026] 3. The present invention uses a palladium alloy inductor coil and its own parasitic capacitance to form an LC sensor, which has a simple structure;

[0027] 4. The inductor coil used in the present invention is made of palladium alloy and the present invention works under low hydrogen concentration, and does not need to be heated to avoid the "hydrogen embrittlement" phenomenon of palladium metal, so that the detection process of the present invention is concise and the structure is simple;

[0028] 5. The present invention can place the sensor inside the transformer device to achieve wireless signal transmission without opening a hole in the transformer box to affect the normal operation of the transformer device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor provided in Example 1;

[0030] Figure 2 A schematic diagram of an equivalent circuit diagram and an equivalent input impedance provided in Example 1;

[0031] Figure 3 is a curve showing a change in the real part of impedance of the LC sensor provided in Example 1;

[0032] In the attached figure:

[0033] LC sensor 1, palladium alloy inductor 11, readout circuit 2, readout inductor 21, impedance analysis circuit 22;

[0034] Palladium alloy inductor coil L S , parasitic resistance R of palladium alloy inductor S , parasitic capacitance C of palladium alloy inductor S ;

[0035] The impedance Z of the readout circuit R , the equivalent input impedance Z of the LC sensor in . DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0037] Example 1

[0038] See also Figure 1-Figure 3 This embodiment provides a transformer partial discharge detection device based on a palladium alloy LC wireless passive sensor, and the device specifically includes:

[0039] The LC sensor 1 is composed of a resonant circuit formed by a palladium alloy inductor coil 11 and its own parasitic capacitance;

[0040] The readout circuit 2 comprises: a readout inductor 21 and an impedance analysis circuit 22, wherein the readout inductor 21 and the palladium alloy inductor 11 perform signal transmission via inductive coupling;

[0041] The LC sensor 1 is installed inside the metal box of the transformer, and the readout circuit 2 is installed outside the transformer. The palladium alloy inductor 11 is used to absorb the hydrogen generated in the insulating oil when partial discharge occurs, so that its resistance increases. The impedance analysis circuit 22 detects the real part of the impedance of the LC sensor through the readout inductor 21. Figure 2 As shown, the occurrence of partial discharge is detected.

[0042] Example 2

[0043] This embodiment provides a method for using the transformer partial discharge detection device in Embodiment 1 on the basis of Embodiment 1. The method specifically includes:

[0044] Step S1, when partial discharge occurs inside the transformer device, the insulating oil inside the transformer will be decomposed to produce hydrogen. After the palladium alloy used to make the inductor coil absorbs the hydrogen, the resistance of the palladium alloy inductor coil (11) increases, thereby increasing the real part of the impedance of the LC sensor;

[0045] Step S2, the readout circuit 2 detects the impedance change of the LC sensor through the readout inductor 21. When the local discharge phenomenon occurs, the real part of the impedance of the LC sensor detected by the readout circuit 2 increases;

[0046] Step S3: the impedance analysis circuit 22 analyzes the signal. When the real part of the impedance of the LC sensor rises to a warning value, the device issues an alarm and detects the occurrence of partial discharge inside the transformer.

[0047] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

[0048] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A transformer partial discharge detection device based on palladium alloy LC wireless passive sensor, characterized in that: The device includes: An LC sensor comprising a palladium alloy inductor coil, and the palladium alloy inductor coil is used to absorb hydrogen generated in insulating oil when partial discharge occurs in the transformer; A readout circuit, comprising a readout inductor and an impedance analysis circuit, wherein the readout inductor and the palladium alloy inductor are used for signal transmission via inductive coupling; When the palladium alloy inductor coil absorbs hydrogen, the impedance analysis circuit detects the real part of the impedance of the LC sensor by reading the inductor coil, thereby detecting the occurrence of partial discharge; The LC sensor is composed of a resonant circuit formed by a palladium alloy inductor coil and its own parasitic capacitance; The LC sensor is arranged inside the transformer.

2. A transformer partial discharge detection device based on palladium alloy LC wireless passive sensor according to claim 1, characterized in that: The readout circuit is arranged outside the transformer.

3. The method for using the transformer partial discharge detection device based on the palladium alloy LC wireless passive sensor according to any one of claims 1 to 2, characterized in that: The method includes: Step S1, when partial discharge occurs inside the transformer equipment, the insulating oil inside the transformer is decomposed to generate hydrogen. When the palladium alloy inductor coil absorbs the hydrogen, its resistance increases, thereby increasing the real part of the impedance of the LC sensor; Step S2, the readout circuit detects the impedance change of the LC sensor through the readout inductor coil. When the local discharge phenomenon occurs, the real part of the impedance of the LC sensor detected by the readout circuit increases; Step S3: The impedance analysis circuit analyzes the signal to monitor whether partial discharge occurs.

4. The method for using the transformer partial discharge detection device based on the palladium alloy LC wireless passive sensor according to claim 3 is characterized in that: The method includes: The transformer partial discharge detection device is also provided with an alarm device; When the real part of the impedance of the LC sensor rises to a preset value, the alarm device sounds an alarm.

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