Device and method for collecting transformer impedance data

Abstract

The present invention provides a collection device and a collection method for transformer impedance data, which belongs to the technical field of transformer winding fault detection. The device includes: an experimental transformer, a short-circuit power supply, a sweep signal generator, a wide-band power amplifier, a measuring device and a stabilizing component; wherein the short-circuit power supply short-circuits the low-voltage winding of the experimental transformer through a first wire group with a wire clamp, the sweep signal generator is electrically connected to the high-voltage winding through the second wire group with a wire clamp to form a loop, the sweep signal generator is electrically connected to the wide-band power amplifier, the measuring device is connected in parallel to the high-voltage winding, and the stabilizing component is fixedly installed on the shell of the experimental transformer to reduce the resonance frequency of the shell of the experimental transformer body.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer winding fault detection, and in particular to a device and method for collecting transformer impedance data. Background Art

[0002] Transformers are one of the important electrical equipment in the power system. Their safe operation is of great significance to ensuring the safety of the power grid. Transformer windings are the main part of transformer accidents. Most transformer failures are caused by deformation of the internal windings. The transformer winding itself can be regarded as a passive linear network composed of distributed parameters such as linear resistance, inductance and capacitance. When the winding is mechanically deformed, it will inevitably cause changes in the distributed parameters such as inductance, longitudinal capacitance, capacitance to ground and mutual inductance of the corresponding part, and also change the leakage magnetic field distribution at that place, especially the radial leakage magnetic field. Therefore, it is necessary to monitor the transformer winding in real time to see if there is a deformation fault; in addition, during the monitoring process, the transformer will vibrate when it is powered on, and the resonance of the body shell will bring resonance interference to the winding, affecting the authenticity of the monitoring data. Summary of the invention

[0003] In view of this, the present invention provides a device and method for collecting transformer impedance data, which are used to collect transformer impedance data to understand whether the transformer winding is deformed, while reducing resonance interference of the transformer body shell during the collection process.

[0004] The technical solution adopted by the embodiment of the present invention to solve the technical problem is:

[0005] A device for collecting transformer impedance data comprises an experimental transformer (1), a short-circuit power supply (4), a sweep signal generator (5), a wide-band power amplifier (6), a measuring device (7) and a stabilizing component (8); wherein the short-circuit power supply (4) short-circuits a low-voltage winding of the experimental transformer (1) via a first wire group (91) with a wire clamp (3); the sweep signal generator (5) is electrically connected to the high-voltage winding via a second wire group (92) with a wire clamp (3) to form a loop; the sweep signal generator (5) is electrically connected to the wide-band power amplifier (6); the measuring device (7) is connected in parallel to the high-voltage winding; and the stabilizing component (8) is fixedly mounted on the outer shell of the experimental transformer (1) to reduce the resonance frequency of the outer shell of the experimental transformer (1);

[0006] The stabilizing component (8) comprises a U-shaped support plate (801), a wing plate (802), a resonance component (803), a current amplifier (804), an electric cylinder (805) and a stabilizing disk (806); the U-shaped back of the U-shaped support plate (801) is located between the high-voltage winding and the low-voltage winding; a group of through holes are respectively provided on the left plate, the right plate and the U-shaped back of the U-shaped support plate (801); the electric cylinder (805) is fixedly installed in the through holes; the driving shaft of the electric cylinder (805) The end is fixedly connected to the stabilizing plate (806), and the stabilizing plate (806) contacts the surface of the experimental transformer (1), wherein the stabilizing plate (806) installed on one side of the U-shaped back contacts the upper surface of the experimental transformer (1), the stabilizing plate (806) installed on one side of the left plate contacts the front side of the experimental transformer (1), and the stabilizing plate (806) installed on one side of the right plate contacts the rear side of the experimental transformer (1);

[0007] In the U-shaped support plate (801), the current amplifier (804) is fixedly installed at the center of the upper surface of the U-shaped back.

[0008] A group of wing plates (802) are respectively arranged at two ends of the lower surface of the U-shaped back, the upper surface of the wing plate (802) is fixedly connected to the U-shaped support plate (801), and the lower surface of the wing plate (802) is fixedly connected to the resonance component (803);

[0009] The resonance component (803) is composed of a sound collecting cover (8031), a film (8032), a coil (8033) and a permanent magnet (8034), wherein the upper surface of the permanent magnet (8034) is fixedly connected to the lower surface of the wing plate (802), the lower surface of the permanent magnet is fixedly connected to the sound collecting cover (8031), the sound collecting cover (8031) faces the experimental transformer (1), the lower surface of the permanent magnet (8034) is provided with an annular deep groove, the wound coil (8033) is placed in the annular deep groove, so that the coil (8033) and the permanent magnet (8034) form a movable sleeve relationship, the upper part of the coil (8033) is placed in the annular deep groove, the lower part of the coil (8033) is fixedly connected to the film (8032), and the film (8032) is located at the center of the sound collecting cover (8031);

[0010] When the low-voltage winding in the experimental transformer (1) is connected to a short-circuit current, the high-voltage winding and the low-voltage winding will vibrate and drive the body shell of the experimental transformer (1) to vibrate. The sound waves generated by the vibration of the body shell cause the film (8032) to resonate, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current. The induced current is amplified to a corresponding drive current by the current amplifier (804). The drive current drives the electric cylinder (805) to extend and press against the body shell of the experimental transformer (1) through the stabilizing disk (806), thereby reducing the vibration frequency of the body shell and stabilizing it.

[0011] Preferably, the low-voltage winding has a low-voltage port, the high-voltage winding has a high-voltage port, and the wire clamp is clamped on the low-voltage port or the high-voltage port.

[0012] Preferably, the coil (8033) is electrically connected to the current amplifier (804), and the current amplifier (804) is electrically connected to each of the electric cylinders (805), so that a closed loop is formed between the coil (8033), the current amplifier (804), and the electric cylinder (805).

[0013] Preferably, the signal output frequency of the sweep signal generator 5 is between 10 Hz and 1 MHz.

[0014] Preferably, the device further comprises a sampling resistor Rc1 (501) and a sampling resistor Rc2 (502) connected in series, wherein the sampling resistor Rc1 (501) is connected in series with the sampling resistor Rc2 (502), and the sampling resistor Rc1 (501) is connected to the output end of the sweep signal generator (5) and is used to collect the excitation signal U i The sampling resistor Rc2 (502) is connected to the input end of the frequency sweep signal generator (5) and is used to collect the response signal U n , the ground terminal is located between the sampling resistor Rc1 (501) and the sampling resistor Rc2 (502).

[0015] Preferably, the experimental transformer (1) is a three-phase core structure, the high-voltage winding is evenly drawn out with fifty taps along the axial direction, and the low-voltage winding is evenly drawn out with ten taps along the axial direction.

[0016] Preferably, when the frequency sweep signal generator (5) outputs a low-frequency excitation signal to the high-voltage winding, the low-frequency equivalent test circuit is a T-type circuit in which two groups of RL circuits are connected in parallel and then connected in series with another group of RL circuits.

[0017] Preferably, when the frequency sweep signal generator (5) outputs a high-frequency excitation signal to the high-voltage winding, the medium- and high-frequency equivalent test circuit is a linear two-port network composed of n groups of RLC circuits connected in parallel, and the capacitors in the medium- and high-frequency equivalent test circuit are divided into inter-pancake capacitors and ground capacitors, the inter-pancake capacitors are all connected in parallel with equivalent resistors, and the ground capacitors are all grounded.

[0018] The present invention also provides a method for collecting transformer impedance data, the implementation subject is the aforementioned device for collecting transformer impedance data, and the method comprises the following steps:

[0019] S1, connecting the transformer to be tested to a device for collecting transformer impedance data, electrically connecting a short-circuit power supply (4) and a low-voltage winding of the transformer to be tested via a first wire group (91), electrically connecting a sweep signal generator (5) and a high-voltage winding of the transformer to be tested via a second wire group (92), and electrically connecting the high-voltage winding of the transformer to be tested to a measuring device (7);

[0020] S2, after the short-circuit power supply (4) applies a short-circuit current to the low-voltage winding, the high-voltage winding generates an induced current, and the sweep frequency signal generator (5) applies a sinusoidal sweep frequency signal to the high-voltage winding;

[0021] S3, collecting the excitation signal U through the sampling resistor Rc1 (501) i , responding to the signal U through the sampling resistor Rc2 (502) n , and calculate the swept impedance Z k (jω);

[0022] S4, drawing a swept frequency impedance curve, where the swept frequency impedance curve is used to describe the winding state of the transformer to be tested;

[0023] S5. When the low-voltage winding in the transformer (1) to be tested is connected to a short-circuit current, causing the housing to vibrate, the film (8032) of the stabilizing component (8) resonates under the influence of the sound wave, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current. The induced current is amplified by the current amplifier (804) to become a driving current. The driving current drives the electric cylinder (805) to extend in the direction of the transformer (1) to be tested, so that the stabilizing plate (806) presses against the housing, thereby stabilizing the housing.

[0024] It can be seen from the above technical solution that the transformer impedance data acquisition device provided in the embodiment of the present invention is composed of an experimental transformer (1), a short-circuit power supply (4), a swept frequency signal generator (5), a wide-band power amplifier (6), a measuring device (7) and a stabilizing component (8). The stabilizing component (8) is fixedly mounted on the housing of the experimental transformer (1). The impedance data of the transformer is acquired by the acquisition device of the present invention to understand whether the transformer winding is deformed, while reducing the resonance interference of the transformer body housing during the acquisition process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the device for collecting transformer impedance data of the present invention.

[0026] Figure 2 It is a schematic diagram of the structure of the stabilizing component of the present invention.

[0027] Figure 3 It is a schematic diagram of the cross-sectional structure of the stabilizing component of the present invention.

[0028] Figure 4 It is a schematic diagram of the cross-sectional structure of the resonance component of the present invention.

[0029] Figure 5 It is a schematic diagram of the equivalent circuit structure of the present invention.

[0030] Figure 6 It is a schematic diagram of the low-frequency equivalent circuit structure of the present invention.

[0031] Figure 7 It is a schematic diagram of the medium and high frequency equivalent circuit structure of the present invention.

[0032] Figure 8 The circuit schematic diagram of the device for collecting transformer impedance data of the present invention is shown in FIG.

[0033] The accompanying drawings are marked as follows: 1. experimental transformer; 2. port; 3. wire clamp; 4. short-circuit power supply; 5. swept frequency signal generator; 501. sampling resistor Rc1; 502. sampling resistor Rc2; 6. wide-band power amplifier; 7. measuring device; 8. stabilizing component; 801. support plate; 802. wing plate; 803. resonance component; 8031. sound collecting cover; 8032. film; 8033. coil; 8034. permanent magnet; 804. current amplifier; 805. electric cylinder; 806. stabilizing disk; 91. first wire group; 92. second wire group. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. In addition, the forms of the various structures recorded in the following embodiments are only examples. The device for collecting transformer impedance data and the method for collecting transformer impedance data involved in the present invention are not limited to the various structures recorded in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0035] Reference Figure 1-Figure 4 As shown, the present invention provides a device for collecting transformer impedance data, comprising an experimental transformer (1), a short-circuit power supply (4), a sweep signal generator (5), a wide-band power amplifier (6), a measuring device (7) and a stabilizing component (8); wherein the short-circuit power supply (4) short-circuits the low-voltage winding of the experimental transformer (1) through a first wire group (91) with a wire clamp (3), the sweep signal generator (5) is electrically connected to the high-voltage winding through a second wire group (92) with a wire clamp (3) to form a loop, the sweep signal generator (5) is electrically connected to the wide-band power amplifier (6), the measuring device (7) is connected in parallel to the high-voltage winding, and the stabilizing component (8) is fixedly mounted on the housing of the experimental transformer (1) to reduce the resonant frequency of the housing of the experimental transformer (1).

[0036] like Figure 1 As shown, the low-voltage winding has a low-voltage port, the high-voltage winding has a high-voltage port, the shape of port 2 is shown in the figure, and the wire clamp 3 cooperates with port 2 and is clamped on the low-voltage port or the high-voltage port.

[0037] like Figure 5-8 As shown, the frequency sweep signal generator 5 is electrically connected to a sampling resistor Rc1, and the frequency sweep signal generator 5 is electrically connected to a sampling resistor Rc2. The sampling resistor Rc1 and the sampling resistor Rc2 are connected in series and then connected in parallel with the high-voltage winding end of the experimental transformer 1. The grounding end is located between the sampling resistor Rc1 (501) and the sampling resistor Rc2 (502). In this embodiment, the sampling resistor Rc1 and the sampling resistor Rc2 are used to obtain the excitation signal U i and the response signal U n The short-circuit power supply 4 applies a short-circuit current to the low-voltage winding area of ​​the experimental transformer 1, resulting in an induced current in the high-voltage winding area of ​​the experimental transformer 1. Since the sweep signal generator 5 applies a sinusoidal sweep signal to the high-voltage winding area of ​​the experimental transformer 1, the sampling resistor Rc1 and the sampling resistor Rc2 can be used to obtain the excitation signal U under the induced current. i and the response signal U n , and the impedance of the experimental transformer 1 can be obtained by calculation.

[0038] The experimental transformer (1) is a three-phase core structure, with a capacity of 50kVA and a voltage ratio of 10kV / 380V. The high-voltage and low-voltage windings are led out through bushings at the ends, and fifty taps are evenly drawn out of the high-voltage winding along the axial direction, and ten taps are evenly drawn out of the low-voltage winding along the axial direction. In this embodiment, the structural design of the experimental transformer 1 is to facilitate parallel or series connection of capacitors, inductors, and short-circuit inter-cake winding, so as to simulate various types, degrees, and locations of faults. The setting of the taps only needs to be briefly explained, so in Figure 1 Not fully drawn.

[0039] In this embodiment, the swept frequency signal generator 5 and the wide-band power amplifier 6 are connected in series. Their function is to use the wide-band power amplifier 6 to amplify the sinusoidal swept frequency signal emitted by the swept frequency signal generator 5, and then apply it to the high-voltage winding end of the experimental transformer 1. The signal output frequency of the swept frequency signal generator 5 is set between 10Hz and 1MHz, and there is no specific limitation on the equipment models of the swept frequency signal generator 5 and the wide-band power amplifier 6.

[0040] The stabilizing component (8) comprises a U-shaped support plate (801), a wing plate (802), a resonance component (803), a current amplifier (804), an electric cylinder (805) and a stabilizing disk (806); the U-shaped back of the U-shaped support plate (801) is located between the high-voltage winding and the low-voltage winding; a group of through holes are respectively provided on the left side plate, the right side plate and the U-shaped back of the U-shaped support plate (801); the electric cylinder (805) is fixedly installed in the through holes; the end of the driving shaft of the electric cylinder (805) is fixedly connected to the stabilizing disk (806); the stabilizing disk (806) contacts the surface of the experimental transformer (1); wherein the stabilizing disk (806) installed on one side of the U-shaped back contacts the upper surface of the experimental transformer (1); the stabilizing disk (806) installed on one side of the left side plate contacts the front side of the experimental transformer (1); and the stabilizing disk (806) installed on one side of the right side plate contacts the rear side of the experimental transformer (1);

[0041] In the U-shaped support plate (801), a current amplifier (804) is fixedly installed in the center of the upper surface of the U-shaped back, and a group of wing plates (802) are respectively arranged at the two ends of the lower surface of the U-shaped back, the upper surface of the wing plate (802) is fixedly connected to the U-shaped support plate (801), and the lower surface of the wing plate (802) is fixedly connected to the resonance component (803); the resonance component (803) is composed of a sound collecting cover (8031), a film (8032), a coil (8033) and a permanent magnet (8034), wherein the upper surface of the permanent magnet (8034) is connected to the lower surface of the wing plate (802). The lower surface of the permanent magnet (8034) is fixedly connected to the sound collecting cover (8031), the sound collecting cover (8031) faces the experimental transformer (1), the lower surface of the permanent magnet (8034) is provided with an annular deep groove, the wound coil (8033) is placed in the annular deep groove, so that a movable sleeve connection is formed between the coil (8033) and the permanent magnet (8034), the upper part of the coil (8033) is placed in the annular deep groove, the lower part of the coil (8033) is fixedly connected to the film (8032), and the film (8032) is located at the center of the sound collecting cover (8031);

[0042] When the low-voltage winding in the experimental transformer (1) is connected to a short-circuit current, the high-voltage winding and the low-voltage winding will vibrate and drive the body shell of the experimental transformer (1) to vibrate. The sound waves generated by the vibration of the body shell cause the film (8032) to resonate, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current. The induced current is amplified to a corresponding drive current through the current amplifier (804). The drive current drives the electric cylinder (805) to extend and press against the body shell of the experimental transformer (1) through the stabilizing plate (806), thereby reducing the vibration frequency of the body shell and stabilizing it, thereby achieving its adaptive anti-vibration effect.

[0043] During measurement, when the sweep signal generator (5) outputs a low-frequency excitation signal to the high-voltage winding, Figure 6 As shown, the low-frequency equivalent test circuit is a T-type circuit in which two groups of RL circuits are connected in parallel and then in series with another group of RL circuits. Through the low-frequency equivalent test circuit, the excitation resistance, excitation reactance and excitation impedance of the experimental transformer 1 can be obtained.

[0044] When the sweep signal generator (5) outputs a high-frequency excitation signal to the high-voltage winding, Figure 7 As shown, the medium and high frequency equivalent test circuit is a linear two-port network composed of n groups of RLC circuits in parallel. The capacitors in the medium and high frequency equivalent test circuit are divided into inter-pane capacitors and ground capacitors. The inter-pane capacitors are all connected in parallel with the equivalent resistors, and the ground capacitors are all grounded.

[0045] The working principle of the present invention is as follows: when the device for collecting transformer impedance data is working, the output end of the short-circuit power supply 4 is connected to the low-voltage winding of the transformer to be tested by using the wire clamp 3, and then the output end of the sweep signal generator 5 is electrically connected to the high-voltage winding end of the transformer to be tested by using the wide-band power amplifier 6, and at the same time, the high-voltage winding end of the transformer to be tested is electrically connected to the measuring device 7. At this time, the short-circuit power supply 4 will apply a short-circuit current to the low-voltage winding end of the transformer, resulting in an induced current at the high-voltage winding end of the transformer. The high-voltage winding end of the transformer is electrically connected with a sampling resistor Rc1 and a sampling resistor Rc2 at the same time. Since a sinusoidal sweep signal is applied to the high-voltage winding end of the transformer through the sweep signal generator 5, the impedance of the transformer to be tested can be calculated using the sampling resistor Rc1 and the sampling resistor Rc2, and the calculation formula is:

[0046]

[0047] Since the resistance of the sampling resistor Rc1 and the sampling resistor Rc2 in the test system is generally 50 ohms, the calculation of the transformer's swept impedance can be simplified to:

[0048]

[0049] The equivalent circuit of this detection method can be divided into two types, one is a low-frequency equivalent test circuit, and the other is a medium- and high-frequency equivalent test circuit. Figure 6 It can be seen that the swept frequency impedance method test circuit is completely equivalent to the short-circuit impedance method in the low frequency band. Therefore, the value of the swept frequency impedance curve at 50 Hz can be used as the short-circuit impedance value to determine the transformer winding state. If it is to be compared with the transformer nameplate value, the swept frequency impedance value at 50 Hz needs to be normalized. For a single-phase transformer, its short-circuit impedance percentage Z ke for:

[0050]

[0051] In the formula, Z k is the swept impedance value at 50Hz / Ω, I e and U e They are the rated current / A and voltage / V of the transformer respectively. For a three-phase transformer, the conversion between phase voltage and line voltage must also be considered, so the calculation method is:

[0052]

[0053] Depend on Figure 4It can be seen that if the transformer distributed parameters in the circuit change, the swept-frequency impedance value will inevitably change. Therefore, the swept-frequency impedance curve is similar to the frequency response curve and can describe the state of the transformer winding. In summary, when using the swept-frequency impedance method for testing, the transformer can be regarded as an equivalent circuit composed of components such as resistance, inductance and capacitance. Once the winding is deformed, the values ​​of the above circuit components will change, and eventually cause the swept-frequency impedance value to change. Therefore, the swept-frequency impedance method can effectively detect transformer winding deformation defects. Since the swept-frequency impedance curve is based on the above equivalent circuit Figure 6 and Figure 7 Therefore, the swept-frequency impedance curve can be identified, and the circuit component parameter values ​​in the equivalent circuit can be deduced based on this, and the transformer winding deformation can be intelligently detected according to the change of the component parameter values.

[0054] The present invention also provides a method for collecting transformer impedance data, the implementation subject is the aforementioned device for collecting transformer impedance data, and the method comprises the following steps:

[0055] S1, connecting the transformer to be tested to a device for collecting transformer impedance data, electrically connecting a short-circuit power supply (4) and a low-voltage winding of the transformer to be tested via a first wire group (91), electrically connecting a sweep signal generator (5) and a high-voltage winding of the transformer to be tested via a second wire group (92), and electrically connecting the high-voltage winding of the transformer to be tested and a measuring device (7);

[0056] S2, after the short-circuit power supply (4) applies a short-circuit current to the low-voltage winding, the high-voltage winding generates an induced current, and the sweep frequency signal generator (5) applies a sinusoidal sweep frequency signal to the high-voltage winding;

[0057] S3, collect the excitation signal U through the sampling resistor Rc1 (501) i , responds to the signal U through the sampling resistor Rc2 (502) n , and calculate the swept impedance Z k (jω);

[0058] S4. Draw a swept frequency impedance curve, where the swept frequency impedance curve is used to describe the winding state of the transformer to be tested;

[0059] S5. When the medium and low voltage windings of the transformer (1) to be tested are connected to a short-circuit current, causing the housing to vibrate, the film (8032) of the stabilizing component (8) resonates under the influence of the sound wave, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current, which is amplified by the current amplifier (804) to become a driving current. The driving current drives the electric cylinder (805) to extend in the direction of the transformer (1) to be tested, so that the stabilizing plate (806) abuts against the housing, thereby stabilizing the housing, thereby achieving its adaptive anti-vibration effect.

[0060] The present invention has the following beneficial effects:

[0061] 1. Short-circuit the low-voltage winding of the transformer, and apply a sinusoidal sweep frequency signal to the high-voltage winding end of the transformer through a sweep frequency signal generator. The equivalent circuit composed of the sampling resistors Rc1 and Rc2 can effectively identify the swept frequency impedance curve, and the circuit component parameter values ​​in the equivalent circuit can be deduced based on this, and the transformer winding deformation can be intelligently detected according to the changes in the component parameter values. The above detection device cleverly combines the short-circuit reactance analysis method with the frequency response analysis method, and does not require the use of heavy test equipment and large-capacity test power supply.

[0062] 2. The present invention is provided with a short-circuit power supply, a swept-frequency signal generator, and a wide-band power amplifier. When the device for collecting transformer impedance data is used, the transformer can be regarded as an equivalent circuit composed of components such as resistance, inductance and capacitance through the two equivalent circuits shown in Figure 1 and Figure 2. Once the winding is deformed, the values ​​of the above circuit components will change, and ultimately cause the swept-frequency impedance value to change. Therefore, the swept-frequency impedance method can effectively detect transformer winding deformation defects.

[0063] 3. The present invention is provided with a stabilizing component. When the winding in the experimental transformer is connected to a short-circuit current, the winding will vibrate, causing the outer casing of the body to vibrate as well. The sound waves generated by the vibration cause the film to resonate, thereby driving the coil to cut the magnetic flux lines on the permanent magnet, thereby causing the coil to generate an induced current. The current is amplified by the current amplifier to drive the electric cylinder and use the stabilizing plate to support the outer casing of the experimental transformer to stabilize it. The driving effect of the electric cylinder depends entirely on the vibration frequency of the outer casing of the experimental transformer, thereby achieving its adaptive anti-vibration effect.

[0064] 4. When the loading voltage frequency is high, the winding of the experimental transformer can be set as a linear two-port network composed of a series of distributed parameters such as inductance, capacitance and resistance. The capacitance in the equivalent circuit of the experimental transformer is divided into inter-pancake capacitance and ground capacitance. The equivalent inter-pancake capacitance of the experimental transformer is connected in parallel with the equivalent resistance, and the equivalent ground capacitance of the experimental transformer is grounded. When the transformer winding in the experimental transformer is deformed, it will cause the values ​​of the above circuit elements to change, and ultimately cause the change of the swept frequency impedance value. Therefore, in theory, the swept frequency impedance method can effectively detect transformer winding deformation defects.

[0065] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0066] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0067] Finally: The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for collecting transformer impedance data, characterized in that: The invention comprises an experimental transformer (1), a short-circuit power supply (4), a sweep signal generator (5), a wide-band power amplifier (6), a measuring device (7) and a stabilizing component (8); wherein the short-circuit power supply (4) short-circuits the low-voltage winding of the experimental transformer (1) through a first wire group (91) with a wire clamp (3); the sweep signal generator (5) is electrically connected to the high-voltage winding through a second wire group (92) with a wire clamp (3) to form a loop; the sweep signal generator (5) is electrically connected to the wide-band power amplifier (6); the measuring device (7) is connected in parallel to the high-voltage winding; and the stabilizing component (8) is fixedly mounted on the outer shell of the experimental transformer (1) to reduce the resonance frequency of the outer shell of the experimental transformer (1); The stabilizing component (8) comprises a U-shaped support plate (801), a wing plate (802), a resonance component (803), a current amplifier (804), an electric cylinder (805) and a stabilizing disk (806); the U-shaped back of the U-shaped support plate (801) is located between the high-voltage winding and the low-voltage winding; a group of through holes are respectively provided on the left plate, the right plate and the U-shaped back of the U-shaped support plate (801); the electric cylinder (805) is fixedly installed in the through holes; the driving shaft of the electric cylinder (805) The end is fixedly connected to the stabilizing plate (806), and the stabilizing plate (806) contacts the surface of the experimental transformer (1), wherein the stabilizing plate (806) installed on one side of the U-shaped back contacts the upper surface of the experimental transformer (1), the stabilizing plate (806) installed on one side of the left plate contacts the front side of the experimental transformer (1), and the stabilizing plate (806) installed on one side of the right plate contacts the rear side of the experimental transformer (1); In the U-shaped support plate (801), the current amplifier (804) is fixedly installed at the center of the upper surface of the U-shaped back. A group of wing plates (802) are respectively arranged at two ends of the lower surface of the U-shaped back, the upper surface of the wing plate (802) is fixedly connected to the U-shaped support plate (801), and the lower surface of the wing plate (802) is fixedly connected to the resonance component (803); The resonance component (803) is composed of a sound collecting cover (8031), a film (8032), a coil (8033) and a permanent magnet (8034), wherein the upper surface of the permanent magnet (8034) is fixedly connected to the lower surface of the wing plate (802), the lower surface of the permanent magnet is fixedly connected to the sound collecting cover (8031), the sound collecting cover (8031) faces the experimental transformer (1), the lower surface of the permanent magnet (8034) is provided with an annular deep groove, the wound coil (8033) is placed in the annular deep groove, so that the coil (8033) and the permanent magnet (8034) form a movable sleeve relationship, the upper part of the coil (8033) is placed in the annular deep groove, the lower part of the coil (8033) is fixedly connected to the film (8032), and the film (8032) is located at the center of the sound collecting cover (8031); When the low-voltage winding in the experimental transformer (1) is connected to a short-circuit current, the high-voltage winding and the low-voltage winding will vibrate and drive the body shell of the experimental transformer (1) to vibrate. The sound waves generated by the vibration of the body shell cause the film (8032) to resonate, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current. The induced current is amplified to a corresponding drive current by the current amplifier (804). The drive current drives the electric cylinder (805) to extend and press against the body shell of the experimental transformer (1) through the stabilizing disk (806), thereby reducing the vibration frequency of the body shell and stabilizing it.

2. A device for collecting transformer impedance data according to claim 1, characterized in that: The low voltage winding is provided with a low voltage port, the high voltage winding is provided with a high voltage port, and the wire clamp is clamped on the low voltage port or the high voltage port.

3. A transformer impedance data collection device according to claim 2, characterized in that: The coil (8033) is electrically connected to the current amplifier (804), and the current amplifier (804) is electrically connected to each of the electric cylinders (805), so that a closed loop is formed among the coil (8033), the current amplifier (804) and the electric cylinder (805).

4. A device for collecting transformer impedance data according to claim 3, characterized in that: The signal output frequency of the sweep signal generator (5) is between 10 Hz and 1 MHz.

5. A transformer impedance data collection device according to claim 4, characterized in that: The device also includes a sampling resistor Rc1 (501) and a sampling resistor Rc2 (502) connected in series, wherein the sampling resistor Rc1 (501) is connected in series with the sampling resistor Rc2 (502), and the sampling resistor Rc1 (501) is connected to the output end of the sweep signal generator (5) and is used to collect the excitation signal U i The sampling resistor Rc2 (502) is connected to the input end of the frequency sweep signal generator (5) and is used to collect the response signal U n , the ground terminal is located between the sampling resistor Rc1 (501) and the sampling resistor Rc2 (502).

6. A transformer impedance data collection device according to claim 5, characterized in that: The experimental transformer (1) is a three-phase core structure, and the high-voltage winding is evenly drawn out with fifty taps along the axial direction. The low voltage winding is evenly drawn out into ten taps along the axial direction.

7. A transformer impedance data collection device according to claim 6, characterized in that: When the frequency sweep signal generator (5) outputs a low-frequency excitation signal to the high-voltage winding, the low-frequency equivalent test circuit is a T-type circuit in which two groups of RL circuits are connected in parallel and then connected in series with another group of RL circuits.

8. The device for collecting transformer impedance data according to claim 6, characterized in that: When the frequency sweep signal generator (5) outputs a high-frequency excitation signal to the high-voltage winding, the medium- and high-frequency equivalent test circuit is a linear two-port network composed of n groups of RLC circuits connected in parallel, and the capacitors in the medium- and high-frequency equivalent test circuit are divided into inter-pancake capacitors and ground capacitors, the inter-pancake capacitors are all connected in parallel with equivalent resistors, and the ground capacitors are all grounded.

9. A method for collecting transformer impedance data, characterized in that: The implementation subject is the device for collecting transformer impedance data according to any one of claims 5 to 8, comprising the following steps: S1, connecting the experimental transformer to a device for collecting transformer impedance data, electrically connecting a short-circuit power supply (4) and a low-voltage winding of the experimental transformer through a first wire group (91), electrically connecting a sweep signal generator (5) and a high-voltage winding of the experimental transformer through a second wire group (92), and electrically connecting the high-voltage winding of the experimental transformer and a measuring device (7); S2, after the short-circuit power supply (4) applies a short-circuit current to the low-voltage winding, the high-voltage winding generates an induced current, and the sweep frequency signal generator (5) applies a sinusoidal sweep frequency signal to the high-voltage winding; S3, collect the excitation signal U through the sampling resistor Rc1 (501) i , the response signal U is collected through the sampling resistor Rc2 (502) n , and calculate the swept impedance Z k (jω); S4, drawing a swept frequency impedance curve, wherein the swept frequency impedance curve is used to describe the winding state of the experimental transformer; S5. When the low-voltage winding in the experimental transformer is connected to a short-circuit current, causing the body shell to vibrate, the film (8032) of the stabilizing component (8) resonates under the influence of sound waves, driving the coil (8033) to cut the magnetic flux lines on the permanent magnet (8034), thereby causing the coil (8033) to generate an induced current. The induced current is amplified by the current amplifier (804) to become a driving current. The driving current drives the electric cylinder (805) to extend in the direction of the experimental transformer, causing the stabilizing disk (806) to press against the body shell, thereby stabilizing the body shell.

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