CN115483665A - Voltage transformer low-frequency oscillation suppression wiring method and device applied to power distribution network - Google Patents
Voltage transformer low-frequency oscillation suppression wiring method and device applied to power distribution network Download PDFInfo
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- CN115483665A CN115483665A CN202211317487.7A CN202211317487A CN115483665A CN 115483665 A CN115483665 A CN 115483665A CN 202211317487 A CN202211317487 A CN 202211317487A CN 115483665 A CN115483665 A CN 115483665A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
- H02H7/05—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers for capacitive voltage transformers, e.g. against resonant conditions
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/005—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions
- H02H9/007—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions avoiding or damping oscillations, e.g. fenoresonance or travelling waves
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load
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Abstract
The invention discloses a low-frequency oscillation suppression wiring method and device for a voltage transformer of a power distribution network. The method is applied to a voltage transformer with double windings and V-V type wiring, wherein the voltage transformer comprises a first winding and a second winding, the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance; the method comprises the following steps: and carrying out short circuit on a first short circuit point of the first winding and a second short circuit point of the second winding of the voltage transformer, wherein the distance from the first short circuit point to the public end is a first distance of 2/3, and the distance from the second short circuit point to the public end is a second distance of 2/3. The technical scheme of the invention realizes the suppression of the low-frequency oscillation of the electromagnetic voltage transformer of the power distribution network.
Description
Technical Field
The invention relates to the technical field of voltage transformer low-frequency oscillation suppression, in particular to a voltage transformer low-frequency oscillation suppression wiring method applied to a power distribution network.
Background
The 10 kV-35 kV power distribution network in China is a system with a neutral point not directly grounded, and is divided into main neutral point grounding modes such as a neutral point ungrounded system (a network with small capacitance current), a neutral point grounded through an arc suppression coil (a network with an overhead line as a main part) and a neutral point grounded through a small resistor (a network with a cable line as a main part) according to the load characteristics, and the modes of the neutral point grounded through a small resistor connected in parallel with the arc suppression coil and the neutral point grounded through a reactance are adopted.
In a power distribution network, an electromagnetic voltage transformer (hereinafter referred to as PT) has a nonlinear characteristic, when a power grid generates certain disturbance, overvoltage or overcurrent passes through a PT high-voltage coil to reach a saturation state, excitation inductance is reduced, and when system inductance (mainly PT excitation inductance) and system capacitance parameters are matched to form a resonant circuit, ferromagnetic resonance overvoltage and overcurrent can be excited.
Along with the development of a power distribution network, the scale of a cable line is larger and larger, the length and the number of overhead lines are increased, and especially a large number of power cables with larger ground capacitance are used in a composite dense area, so that the ground capacitance of a power distribution network system is increased remarkably, at the moment, the capacitive reactance of the system is smaller, and the system and a PT inductor are difficult to form a resonance condition, namely, the matching of inductance and capacitance parameters exceeds a resonance area, but enters a low-frequency oscillation area. At this time, ferromagnetic resonance does not constitute a major contradiction, and the failure mode is qualitatively changed.
The low-frequency oscillation refers to that when a power distribution network system operates (a grounding fault line is cut off, the line is normally cut open, a single-phase grounding fault recovery process and the like), charges accumulated on a non-fault phase line capacitor are discharged through a circuit formed by PT, at the moment, an excitation source is charges accumulated on the line capacitor and is close to a direct current component, namely PT primary current is changed into quasi-direct current excitation from alternating current excitation; since the frequency ω is very low, the winding of the PT presents a low impedance and a small inductance value during charge bleeding, during which a non-linear low-frequency oscillation process will be induced in the bleed-off loop. At this time, the current passing through the primary winding and the primary fuse of the PT body is large, which brings a large operation risk to the PT fuse, even the PT body.
In a power distribution network, PT has three types, namely Y-Y type wiring (star three windings), V-V type wiring (two windings are connected between three phases) and V type wiring (a single winding is connected between two phases). For the occasions needing to measure three-phase voltage, a Y-Y type wiring type is selected; when the device is used for indicating and taking energy of a voltmeter and the like, interphase connection PT with few coils, such as V-V connection (two coils for displaying three-phase voltage) and V-type connection (one coil for taking energy), is selected to obtain better technical and economic indexes.
When the ground capacitance of a 10 kV-35 kV power distribution network is large, the power distribution network is separated from a resonance region with the cooperation of PT inductance parameters and enters a low-frequency oscillation region, when the system operates (a ground fault circuit is cut off, a circuit is normally cut, a single-phase ground fault recovery process and the like), charges accumulated by the circuit capacitance are discharged through a circuit formed by PT, and due to the fact that an excitation source is close to a direct-current component, the frequency omega is low, a PT winding presents low impedance and small inductance, a nonlinear low-frequency oscillation process is caused in the discharge circuit, the current of the PT winding is increased, and the problems that PT (including V-V type wiring PT and V type wiring PT) outgoing line PT fuses of an interphase wiring type and even body faults are frequent are solved. According to operation statistics, the fuse burnout fault on the primary side of the PT during operation is concentrated on inter-phase connection PT (V-V type connection PT and V type connection PT).
Because of different forming mechanisms, the common mature harmonic elimination measures lack pertinence to the suppression of low-frequency oscillation, and therefore, in actual operation, fusing of a PT fuse, burning loss of a body and even explosion faults still frequently occur; even if the non-fault phase voltage is effectively clamped after the neutral point grounding mode optimization (such as grounding through a small resistor) of the power distribution network, the PT fuse fusing caused by low-frequency oscillation is still common, and even the PT body fault is common.
Disclosure of Invention
The invention provides a low-frequency oscillation suppression wiring method of a voltage transformer applied to a power distribution network, which can prevent ferromagnetic resonance and simultaneously suppress low-frequency oscillation of an electromagnetic voltage transformer of the power distribution network so as to ensure safe operation of a PT fuse and a body winding under the low-frequency oscillation.
An embodiment of the invention provides a voltage transformer low-frequency oscillation suppression wiring method applied to a power distribution network, which comprises the following steps of:
the voltage transformer is applied to V-V type wiring of double windings and comprises a first winding and a second winding, wherein the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance; the method comprises the following steps:
and carrying out short circuit on a first short circuit point of the first winding and a second short circuit point of the second winding of the voltage transformer, wherein the distance from the first short circuit point to the public end is a first distance of 2/3, and the distance from the second short circuit point to the public end is a second distance of 2/3.
Further, the connection point of the first winding and the first end is a first connection point, the connection point of the first winding and the common end is a second connection point, and the ratio of the winding length from the first short point to the first connection point to the winding length from the first short point to the second connection point is 1:2;
the connection point of the second winding and the public end is a third connection point, the connection point of the second winding and the second end is a fourth connection point, and the ratio of the winding length from the second short point to the third connection point to the winding length from the second short point to the fourth connection point is 2:1.
furthermore, a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
Further, the resistance value ranges of the first damping resistor and the second damping resistor are 60k Ω -120 k Ω.
The invention provides a low-frequency oscillation suppression device of a voltage transformer applied to a power distribution network, which is applied to a voltage transformer of a V-V type wiring with double windings, wherein the voltage transformer comprises a first winding and a second winding, the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance;
the device comprises a short-circuit line used for connecting the first winding and the second winding, wherein the connection point of the short-circuit line and the first winding is a first short-circuit point, the connection point of the short-circuit line and the second winding is a second short-circuit point, the distance from the first short-circuit point to the public end is a 2/3 first distance, and the distance from the second short-circuit point to the public end is a 2/3 second distance.
The first winding is connected with the first end through a first short circuit point, the first winding is connected with the first end through a second short circuit point, and the first short circuit point meets the following proportional characteristics:
the ratio between the winding length of the first shorting contact to the first connection point and the winding length of the first shorting contact to the second connection point is 1:2;
the second winding is connected with the common end through a second short circuit point, and the second short circuit point meets the following proportional characteristics:
the ratio between the winding length of the second shorting point to the third connection point and the winding length of the second shorting point to the fourth connection point is 2:1.
furthermore, a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
Further, the resistance value ranges of the first damping resistor and the second damping resistor are 60k Ω -120 k Ω.
The embodiment of the invention has the following beneficial effects:
the invention provides a voltage transformer low-frequency oscillation suppression wiring method and device applied to a power distribution network, wherein short circuit is carried out on a first short circuit point of a first winding and a second short circuit point of a second winding of the voltage transformer, the distance from the first short circuit point to a public end is a first distance of 2/3, and the distance from the second short circuit point to the public end is a second distance of 2/3. The method realizes the aim of increasing the damping of a residual charge discharge loop on the line capacitor in a targeted manner and inhibiting PT low-frequency oscillation, achieves the aim of inhibiting the low-frequency oscillation of the electromagnetic voltage transformer of the power distribution network while preventing ferromagnetic resonance, and ensures the safe operation of the PT fuse and the body winding under the low-frequency oscillation. Therefore, the invention achieves the purpose of inhibiting the low-frequency oscillation of the electromagnetic voltage transformer of the power distribution network by increasing the impedance of the charge leakage loop on the line capacitor of the power distribution network, realizes the judgment and inhibition of the low-frequency nonlinear oscillation of the PT, and distinguishes the ferromagnetic resonance and the low-frequency oscillation of the PT. Different suppression methods are adopted for different system overvoltage, pertinence is strong, fusing and burning accidents of PT fuses can be effectively reduced, and safety of a power distribution network power system is improved.
Drawings
Fig. 1 is a schematic flow chart of a low-frequency oscillation suppression wiring method of a voltage transformer applied to a power distribution network according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a short-circuit of a winding in a voltage transformer of the low-frequency oscillation suppression wiring method for a voltage transformer applied to a power distribution network according to an embodiment of the present invention;
FIG. 3 is an equivalent circuit schematic of the winding shorting circuit of FIG. 2 according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a V-V type connection voltage transformer without short circuit when a power distribution network provided by an embodiment of the invention operates normally;
fig. 5 is a schematic diagram of an equivalent low-frequency oscillating circuit of a V-V type wiring voltage transformer without short circuit after a fault line is cut off in a power distribution network according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a PT excitation curve of a low-frequency oscillation suppression wiring method of a voltage transformer applied to a power distribution network according to an embodiment of the present invention;
fig. 7 (a) is a schematic circuit diagram of a V-V type connection voltage transformer with short circuit after a fault line is cut off in a power distribution network according to a voltage transformer low-frequency oscillation suppression connection method applied to the power distribution network provided by an embodiment of the present invention;
fig. 7 (b) is a schematic diagram of an equivalent low-frequency oscillation circuit of a V-V type connection voltage transformer with a short circuit after a fault line is cut off in a power distribution network according to the voltage transformer low-frequency oscillation suppression connection method applied to the power distribution network provided by the embodiment of the invention.
Detailed Description
The technical solutions in the present invention will be described clearly and completely with reference to the drawings in the present invention, and it should be apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a low-frequency oscillation suppression wiring method for a voltage transformer applied to a power distribution network, where the low-frequency oscillation suppression wiring method is applied to a voltage transformer of a V-V type wiring with two windings, the voltage transformer includes a first winding and a second winding, the first winding is disposed between a first end and a common end, and a distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance; the method comprises the following steps:
step S101: and carrying out short circuit on a first short circuit point of the first winding and a second short circuit point of the second winding of the voltage transformer, wherein the distance from the first short circuit point to the public end is a first distance of 2/3, and the distance from the second short circuit point to the public end is a second distance of 2/3.
As an example, the connection point of the first winding and the first end is a first connection point, the connection point of the first winding and the common end is a second connection point, and the ratio between the winding length of the first short point to the first connection point and the winding length of the first short point to the second connection point is 1:2;
the connection point of the second winding and the public end is a third connection point, the connection point of the second winding and the second end is a fourth connection point, and the ratio of the winding length from the second short point to the third connection point to the winding length from the second short point to the fourth connection point is 2:1.
step S102: and a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
As one example, as shown in FIG. 2, the winding structure of the V-V connection PT is not changed, and the winding structure of the interphase double winding PT of the V-V connection and the winding structure of the AB interphase double winding PT are separated from the A phase
And the BC-phase winding, the C-phase
And connecting short wires. On the premise of not changing the existing winding structure of the PT windings of the V-V type connection, for the interphase double winding PT of the V-V type connection and for the winding between the AB phases, the A phase is separated from the A phase
And the BC-phase winding, the C-phase
And the resistors R are respectively connected. When the line is not in fault, the PT winding is in a linear region, and the suppression measures have no influence on the line and the PT which normally run. When the outgoing line fault of the power distribution network is removed, the non-fault phase circuit is discharged with capacitance charge to ground, the PT winding flows through large current, a winding excitation curve enters a nonlinear area, the outgoing line on the PT is subjected to low-frequency nonlinear oscillation, when no inhibiting measure is taken, the overcurrent amplitude caused by the low-frequency oscillation is large, the PT is heated by the large current, and then the fuse wire burning or even PT burning accident easily occurs.
The equivalent circuit diagram shown in fig. 3 can be obtained by performing equivalent transformation on fig. 2, and it can be seen that PT after short circuit can be equivalent to Y-type, and the inductance values of the windings in the phases after equivalent are all the same as the inductance of the original inter-phase PT winding
Meanwhile, the connected damping resistor does not change the existing V-V type PT winding junctionThe structure is equivalent to changing the connection mode of the PT, and the accessed damping resistor shares the line voltage applied to the original PT high-voltage winding during single-phase earth fault, so that the electric charge required to be released after the fault is eliminated is reduced, and the impact of capacitance current after the fault is recovered on the PT is reduced.
The circuit diagram of the voltage transformer without the short-circuit wiring method in normal operation is shown in fig. 4, the excitation curve of the PT winding is in a linear region in normal operation, the inductance value is large, no PT fault occurs, and the PT excitation curve is shown in fig. 6. Fig. 5 shows an inter-phase V-V wiring type PT equivalent low-frequency oscillation circuit without short circuit after the fault line is cut off, at this time, since the electric charge stored after the fault occurs in the earth capacitance of the non-fault phase line is redistributed after the fault occurs, when a large current flows through the PT winding, the magnetic saturation phenomenon occurs in the core of the PT winding, the excitation curve enters a nonlinear region, the inductance value of the PT winding exhibits a nonlinear characteristic, the earth capacitance of the line and the primary inductance of the electromagnetic voltage transformer form a zero-sequence oscillation loop, the oscillation frequency of the zero-sequence oscillation loop is determined by the earth capacitance of the line and the PT inductance, that is, ultra-low frequency saturation overcurrent is generated, and the PT generates low-frequency nonlinear oscillation.
As shown in fig. 7 (a), fig. 7 (a) is a circuit diagram of a V-V type connection voltage transformer using the short-circuit connection method of the present invention (i.e. adopting the low-frequency oscillation suppression measure of the present invention), and at this time, the circuit can be equivalent to the equivalent circuit shown in fig. 7 (b), and it can be obtained that, compared with the case of not adopting the low-frequency oscillation suppression measure of the present invention, the impedance in the circuit of discharging the capacitance to ground charge in the circuit of discharging the capacitance to ground is increased to the original one
(i.e., from ω L to ω L
) The amplitude of the current flowing on the PT winding number during low-frequency oscillation can be effectively reduced, the line voltage added on the original PT high-voltage winding during single-phase earth fault is shared due to the connected damping resistor, and the electric charge required to be released after the fault is eliminated is reduced by a method of not changing the PT type, so that the fault is reducedThe impact of the capacitor current after the barrier recovery to PT is reduced, thereby reducing the influence of overcurrent on PT, and avoiding the phenomenon of PT fuse fusing and even PT burnout. Therefore, the connected damping resistor shares the line voltage applied to the original PT high-voltage winding during single-phase earth fault, the electric charge required to be released after the fault is eliminated is reduced by a method of not changing the PT type, the impact of capacitance current after fault recovery on PT is reduced, the impedance in a loop is increased, the amplitude of inrush current is restrained, the current flowing through the PT winding in the low-frequency oscillation process is lower than the rated current (0.5A) of a fuse and has margin, and the occurrence of PT accidents is reduced.
Aiming at the problem of low-frequency oscillation caused by the obvious increase of the capacitance of the system to the ground in the development of a 10 kV-35 kV power distribution network, the invention specifically inhibits the PT low-frequency oscillation by increasing the damping of a residual charge discharge loop on a line capacitor based on the mechanism of the low-frequency oscillation, achieves the aim of inhibiting the low-frequency oscillation of an electromagnetic voltage transformer of the power distribution network while preventing ferromagnetic resonance, and realizes the safe operation of the PT fuse and a body winding under the low-frequency oscillation. The invention achieves the purpose of inhibiting the low-frequency oscillation of the electromagnetic voltage transformer of the power distribution network by increasing the impedance of the charge leakage loop on the line capacitor of the power distribution network, realizes the judgment and inhibition of the PT low-frequency nonlinear oscillation, and distinguishes the ferromagnetic resonance and the low-frequency oscillation of the PT. Different suppression methods are adopted for different system overvoltage, pertinence is strong, fusing and burning accidents of PT fuses can be effectively reduced, and safety of a power distribution network power system is improved.
On the basis of the embodiment of the invention, the invention correspondingly provides an embodiment of a low-frequency oscillation suppression wiring device of the voltage transformer applied to the power distribution network;
the invention provides a low-frequency oscillation suppression wiring device of a voltage transformer applied to a power distribution network, which is applied to a voltage transformer with double-winding V-V type wiring and comprises a first winding and a second winding, wherein the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance;
as shown in fig. 2, the apparatus includes a shorting line for connecting the first winding and the second winding, a connection point of the shorting line and the first winding is a first shorting point, a connection point of the shorting line and the second winding is a second shorting point, a distance from the first shorting point to the common terminal is a first distance of 2/3, and a distance from the second shorting point to the common terminal is a second distance of 2/3.
As an embodiment, a connection point of the first winding and the first end is a first connection point, a connection point of the first winding and the common end is a second connection point, and the first short-circuit point satisfies the following proportional characteristics:
the ratio between the winding length of the first shorting contact to the first connection point and the winding length of the first shorting contact to the second connection point is 1:2;
the second winding is connected with the common end through a second short circuit point, and the second short circuit point meets the following proportional characteristics:
the ratio between the winding length of the second shorting point to the third connection point and the winding length of the second shorting point to the fourth connection point is 2:1.
according to one embodiment, a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
As one embodiment, the resistance values of the first damping resistor and the second damping resistor are in the range of 60k omega-120 k omega.
For convenience and simplicity of description, the embodiments of the apparatus of the present invention include all the embodiments of the aforementioned low-frequency oscillation suppression wiring method for a voltage transformer applied to a power distribution network, and are not described herein again.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
It will be understood by those skilled in the art that all or part of the processes of the above embodiments may be implemented by hardware related to instructions of a computer program, and the computer program may be stored in a computer readable storage medium, and when executed, may include the processes of the above embodiments. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.
Claims (8)
1. The voltage transformer low-frequency oscillation suppression wiring method applied to the power distribution network is characterized by comprising a first winding and a second winding, wherein the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance; the method comprises the following steps:
and carrying out short circuit on a first short circuit point of the first winding and a second short circuit point of the second winding of the voltage transformer, wherein the distance from the first short circuit point to the public end is a first distance of 2/3, and the distance from the second short circuit point to the public end is a second distance of 2/3.
2. The voltage transformer low-frequency oscillation suppression wiring method applied to the power distribution network, according to claim 1, wherein a connection point of the first winding and the first end is a first connection point, a connection point of the first winding and the common end is a second connection point, and a ratio between a winding length from the first short point to the first connection point and a winding length from the first short point to the second connection point is 1:2;
the connection point of the second winding and the public end is a third connection point, the connection point of the second winding and the second end is a fourth connection point, and the ratio of the winding length from the second short point to the third connection point to the winding length from the second short point to the fourth connection point is 2:1.
3. the voltage transformer low-frequency oscillation suppression wiring method applied to the power distribution network according to claim 2, wherein a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
4. The voltage transformer low-frequency oscillation suppression wiring method applied to the power distribution network, according to claim 3, wherein the resistance values of the first damping resistor and the second damping resistor are in a range of 60k Ω -120 k Ω.
5. The voltage transformer low-frequency oscillation suppression device is applied to a voltage transformer of a double-winding V-V type wiring, and is characterized in that the voltage transformer comprises a first winding and a second winding, the first winding is arranged between a first end and a common end, and the distance between the first end and the common end is a first distance; the second winding is arranged between a second end and the common end, and the distance between the second end and the common end is a second distance;
the device comprises a short-circuit line used for connecting the first winding and the second winding, wherein the connection point of the short-circuit line and the first winding is a first short-circuit point, the connection point of the short-circuit line and the second winding is a second short-circuit point, the distance from the first short-circuit point to the public end is a 2/3 first distance, and the distance from the second short-circuit point to the public end is a 2/3 second distance.
6. The voltage transformer low-frequency oscillation suppression wiring device applied to the power distribution network, according to claim 5, wherein a connection point of the first winding and the first end is a first connection point, a connection point of the first winding and the common end is a second connection point, and the first short-circuit point meets the following proportional characteristics:
the ratio between the winding length of the first shorting contact to the first connection point and the winding length of the first shorting contact to the second connection point is 1:2;
the second winding is connected with the common end through a second short circuit point, and the second short circuit point meets the following proportional characteristics:
the ratio between the winding length of the second shorting point to the third connection point and the winding length of the second shorting point to the fourth connection point is 2:1.
7. the voltage transformer low-frequency oscillation suppression wiring device applied to the power distribution network according to claim 6, wherein a first damping resistor is connected to the first short-circuit point, and a second damping resistor is connected to the second short-circuit point.
8. The voltage transformer low-frequency oscillation suppression wiring device applied to the power distribution network according to claim 7, wherein the resistance values of the first damping resistor and the second damping resistor are in the range of 60k Ω -120 k Ω.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211317487.7A CN115483665A (en) | 2022-10-26 | 2022-10-26 | Voltage transformer low-frequency oscillation suppression wiring method and device applied to power distribution network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211317487.7A CN115483665A (en) | 2022-10-26 | 2022-10-26 | Voltage transformer low-frequency oscillation suppression wiring method and device applied to power distribution network |
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| Publication Number | Publication Date |
|---|---|
| CN115483665A true CN115483665A (en) | 2022-12-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211317487.7A Pending CN115483665A (en) | 2022-10-26 | 2022-10-26 | Voltage transformer low-frequency oscillation suppression wiring method and device applied to power distribution network |
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| Country | Link |
|---|---|
| CN (1) | CN115483665A (en) |
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2022
- 2022-10-26 CN CN202211317487.7A patent/CN115483665A/en active Pending
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