CN216252170U - Transformer direct current magnetic biasing isolating device with high reliability - Google Patents
Transformer direct current magnetic biasing isolating device with high reliability Download PDFInfo
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- CN216252170U CN216252170U CN202121621078.7U CN202121621078U CN216252170U CN 216252170 U CN216252170 U CN 216252170U CN 202121621078 U CN202121621078 U CN 202121621078U CN 216252170 U CN216252170 U CN 216252170U
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Abstract
The utility model discloses a high-reliability transformer direct-current magnetic biasing isolation device, which comprises a PLC (programmable logic controller), a transformer, a current detection module, a zinc oxide arrester FR, an online monitoring device for performing performance test on the zinc oxide arrester FR, a capacitor C, a switch K1, a switch K2, a switch K4 and a capacitor protection circuit, wherein one end of the switch K1 and one end of the switch K2 are both connected with a neutral point of a transformer winding, the other end of the switch K1 is connected with one end of the switch K4 and one end of the capacitor C, the other end of the switch K4 is respectively connected with the online monitoring device and one end of the zinc oxide arrester FR, and the other end of the capacitor C, the other end of the online monitoring device, the other end of the zinc oxide arrester FR and the other end of the switch K2 are all grounded through the current detection module; the utility model has the advantages that: the reliability is strong.
Description
Technical Field
The utility model relates to the technical field of transformers, in particular to a high-reliability transformer direct-current magnetic biasing isolation device.
Background
When the ultrahigh voltage direct current transmission line is in monopolar or bipolar unbalanced operation, direct current flows through a transformer winding of a transformer substation or a booster station and flows into the ground through a neutral point, so that the working magnetization curve of a transformer iron core is deviated, and the phenomenon is direct current magnetic biasing. The direct current magnetic biasing phenomenon can cause the vibration, noise and loss increase of the transformer, the temperature rise, even the relay protection does not move, and the tripping of the unit is caused.
The traditional blocking device usually adopts an FR zinc oxide arrester and an isolating switch to protect the capacitor, the FR zinc oxide arrester has quick action time, but is easy to age and has low reliability when the humidity and salinity in the air of coastal areas are high. For example, chinese patent publication No. CN207801468U discloses a self-protecting dc bias grounding system for a high-voltage FU, which includes a dc capacitor C, a disconnecting switch G1, an energy-absorbing fuse FU, a discharge damper RL, a high-speed eddy current switch K0, and a non-linear resistor FR; the inlet wire end of the isolating switch G1 is connected with a neutral point A of the transformer, and the outlet wire end of the isolating switch G1 is respectively connected with the inlet wire end of the energy-absorbing fuse FU, the inlet wire end of the discharge damper RL and the inlet wire end of the nonlinear resistor FR; the outlet end of the energy-absorbing fuse FU is connected with the inlet end of the direct current capacitor C, the outlet end of the discharge damper RL is connected with the inlet end of the high-speed eddy current switch K0, and the outlet end of the nonlinear resistor FR is grounded with the outlet end of the high-speed eddy current switch K0 and the outlet end of the direct current capacitor C respectively. The utility model has the advantages of higher safety, higher DC blocking efficiency, stable and reliable operation, long service life and the like, and can ensure the safe and reliable operation of the neutral point of the transformer. In the patent, the non-linear resistor FR is easy to age when the humidity and salinity in air in coastal areas are large, and the reliability is not strong, so that the reliability of the self-protection direct current magnetic bias grounding system of the high-voltage FU provided by the patent is not strong.
SUMMERY OF THE UTILITY MODEL
The technical problem to be solved by the utility model is that the reliability of the transformer direct-current magnetic biasing isolation device in the prior art is not strong.
The utility model solves the technical problems through the following technical means: a high-reliability transformer direct-current magnetic biasing isolation device comprises a PLC (programmable logic controller), a transformer, a current detection module, a zinc oxide arrester FR, an online monitoring device for performing performance test on the zinc oxide arrester FR, a capacitor C, a switch K1, a switch K2, a switch K4 and a capacitor protection circuit, wherein one end of the switch K1 and one end of the switch K2 are connected with a neutral point of a transformer winding, the other end of the switch K1 is connected with one end of a switch K4 and one end of the capacitor C, the other end of the switch K4 is respectively connected with the online monitoring device and one end of the zinc oxide arrester FR, and the other end of the capacitor C, the other end of the online monitoring device, the other end of the zinc oxide arrester FR and the other end of the switch K2 are all grounded through the current detection module; the IO control end of the PLC is respectively connected with the control ends of the switch K4, the switch K1 and the switch K2, and the sampling port of the PLC is connected with the online monitoring device; the other end of the switch K1 is connected with the current detection module through a capacitance protection circuit, and the capacitance protection circuit is connected with the PLC.
The utility model adopts an online monitoring device to monitor the zinc oxide arrester FR in real time, if the performance is good, namely the performance meets the preset requirement, the zinc oxide arrester FR is put into use to perform overvoltage protection on the capacitor C, if the aging of the zinc oxide arrester is monitored to be serious, namely the performance does not meet the preset requirement, a loop where the zinc oxide arrester FR is positioned is disconnected, and a capacitor protection circuit is adopted to protect the capacitor, thereby solving the problem of poor reliability caused by the easy aging of the zinc oxide arrester FR when the humidity and salinity in the air of coastal areas are high.
Further, the capacitance protection circuit comprises a switch K3, one end of the switch K3 is connected with the other end of the switch K1, the other end of the switch K3 is grounded through the current detection module, and the control end of the switch K3 is connected with an IO control end of the PLC controller.
Furthermore, the capacitance protection circuit further comprises a thyristor, the source of the thyristor is connected with the other end of the switch K1, the drain of the thyristor is grounded through the current detection module, and the gate of the thyristor is connected with the other IO control end of the PLC controller.
Furthermore, the current detection module is a current transformer.
Further, at least one current transformer is installed on a connecting line between the drain of the thyristor, the other end of the capacitor, the other end of the on-line monitoring device, the other end of the zinc oxide arrester FR, the other end of the switch K3, and the other end of the switch K2 and the ground terminal.
Furthermore, the online monitoring device is a zinc oxide arrester tester.
Further, the model of the zinc oxide lightning arrester tester is YTC 620D.
The utility model has the advantages that:
(1) the utility model adopts an online monitoring device to monitor the zinc oxide arrester FR in real time, if the performance is good, namely the performance meets the preset requirement, the zinc oxide arrester FR is put into use to perform overvoltage protection on the capacitor C, if the aging of the zinc oxide arrester is monitored to be serious, namely the performance does not meet the preset requirement, a loop where the zinc oxide arrester FR is positioned is disconnected, and a capacitor protection circuit is adopted to protect the capacitor, thereby solving the problem of poor reliability caused by the easy aging of the zinc oxide arrester FR when the humidity and salinity in the air of coastal areas are high.
(2) If the single-phase short circuit occurs to the transformer, the current detection module detects that the alternating current is larger than a second current threshold value, if the switch K4 is closed, the zinc oxide arrester acts firstly to discharge current, and the switch K3 is closed to protect the capacitor; if the switch K4 is disconnected, the thyristor acts to discharge current firstly, the switch K3 is closed, the capacitor is protected, the advantages of quick acting time of the zinc oxide arrester FR and strong reliability of the thyristor are integrated, the reliability of the circuit is further improved, and the reliability of capacitor protection is enhanced.
Drawings
Fig. 1 is a schematic diagram of a high-reliability dc magnetic bias isolation device for a transformer according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all 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, a high-reliability transformer dc magnetic biasing isolation device includes a PLC controller 1, a transformer 2, a current detection module 3, a zinc oxide arrester FR, an online monitoring device 4 for performing a performance test on the zinc oxide arrester FR, a capacitor C, a switch K1, a switch K2, a switch K4, and a capacitor protection circuit, where the online monitoring device 4 is a zinc oxide arrester tester. The model of the zinc oxide arrester tester is YTC 620D. One end of the switch K1 and one end of the switch K2 are both connected with a neutral point of a winding of the transformer 2, the other end of the switch K1 is connected with one end of the switch K4 and one end of the capacitor C, the other end of the switch K4 is respectively connected with the online monitoring device 4 and one end of the zinc oxide arrester FR, and the other end of the capacitor C, the other end of the online monitoring device 4, the other end of the zinc oxide arrester FR and the other end of the switch K2 are all grounded through the current detection module 3; the IO control end of the PLC controller 1 is respectively connected with the control ends of the switch K4, the switch K1 and the switch K2, and the sampling port of the PLC controller 1 is connected with the online monitoring device 4; the other end of the switch K1 is connected with the current detection module 3 through a capacitance protection circuit, and the capacitance protection circuit is connected with the PLC controller 1.
With reference to fig. 1, the capacitor protection circuit includes a switch K3, one end of the switch K3 is connected to the other end of the switch K1, the other end of the switch K3 is grounded through the current detection module 3, and a control terminal of the switch K3 is connected to an IO control terminal of the PLC controller 1.
With continued reference to fig. 1, the capacitance protection circuit further includes a thyristor 5, a source of the thyristor 5 is connected to the other end of the switch K1, a drain of the thyristor 5 is grounded through the current detection module 3, and a gate of the thyristor 5 is connected to the other IO control end of the PLC controller 1.
In this embodiment, the current detection module 3 is a current transformer. And at least one current transformer is arranged on the connecting lines among the drain electrode of the thyristor 5, the other end of the capacitor, the other end of the online monitoring device 4, the other end of the zinc oxide arrester FR, the other end of the switch K3, the other end of the switch K2 and the grounding end.
The working method of the high-reliability direct-current magnetic biasing isolation device of the transformer 2 provided by the utility model comprises the following steps: when the transformer 2 normally operates, the switch K2 is closed, the neutral point of the winding of the transformer 2 is directly grounded, the current detection module 3 detects the neutral point-to-ground current in real time, when the transformer 2 generates direct current magnetic biasing, and the current detection module 3 detects that the direct current flowing through the neutral point reaches a first current threshold value set by the PLC controller 1, the PLC controller 1 outputs a signal to control the switch K2 to be switched off, the switch K1 is closed, the neutral point of the winding of the transformer 2 is grounded through the capacitor C, and the capacitor C is connected with alternating current resistance direct current to isolate the direct current in the transformer 2; the online monitoring device 4 monitors the state of the zinc oxide arrester FR in real time, and if the online monitoring device 4 tests that the performance of the zinc oxide arrester FR meets the preset requirement, the PLC controller 1 controls the switch K4 to be closed; if the online monitoring device 4 tests that the FR performance of the zinc oxide arrester does not meet the preset requirement, the PLC controller 1 controls the switch K4 to be switched off and the capacitor protection circuit to be switched on.
If the transformer 2 is in a single-phase short circuit, when the current detection module 3 detects that the alternating current is larger than a second current threshold value set by the PLC 1, if the switch K4 is in a closed state, the zinc oxide arrester FR acts firstly to drain, the switch K3 is closed later to protect the capacitor C, if the switch K4 is in an open state, the thyristor 5 acts firstly to drain, and the switch K3 is closed later to protect the capacitor C; when the direct current flowing through the current detection module 3 is smaller than the third current threshold set by the PLC controller 1, the switch K1 is opened, the switch K3 is opened, the switch K2 is closed, and the neutral point of the winding of the transformer 2 is restored to be directly grounded. It should be noted that the present invention only protects the hardware architecture, and does not protect the program control logic and the internal program and logic of the PLC controller 1.
Through the technical scheme, the online monitoring device 4 is adopted to monitor the zinc oxide arrester FR in real time, if the performance is good, the zinc oxide arrester is put into use to perform overvoltage protection on the capacitor, if the aging of the zinc oxide arrester is monitored to be serious, a zinc oxide loop is disconnected, the thyristor 5 and the isolating switch are adopted to protect the capacitor, the advantages of quick action time of the zinc oxide arrester FR and strong reliability of the thyristor 5 are integrated, and the reliability of capacitor protection is enhanced.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (7)
1. A high-reliability transformer direct-current magnetic biasing isolation device is characterized by comprising a PLC (programmable logic controller), a transformer, a current detection module, a zinc oxide arrester FR, an online monitoring device for performing performance test on the zinc oxide arrester FR, a capacitor C, a switch K1, a switch K2, a switch K4 and a capacitor protection circuit, wherein one end of the switch K1 and one end of the switch K2 are connected with a neutral point of a transformer winding, the other end of the switch K1 is connected with one end of the switch K4 and one end of the capacitor C, the other end of the switch K4 is respectively connected with the online monitoring device and one end of the zinc oxide arrester FR, and the other end of the capacitor C, the other end of the online monitoring device, the other end of the zinc oxide arrester FR and the other end of the switch K2 are all grounded through the current detection module; the IO control end of the PLC is respectively connected with the control ends of the switch K4, the switch K1 and the switch K2, and the sampling port of the PLC is connected with the online monitoring device; the other end of the switch K1 is connected with one end of a capacitor protection circuit, the other end of the capacitor protection circuit is connected with a current detection module, and the capacitor protection circuit is connected with a PLC controller.
2. The high-reliability transformer direct-current bias isolation device according to claim 1, wherein the capacitance protection circuit comprises a switch K3, one end of the switch K3 is connected with the other end of the switch K1, the other end of the switch K3 is grounded through the current detection module, and a control terminal of the switch K3 is connected with an IO control terminal of the PLC controller.
3. The high-reliability transformer direct-current magnetic bias isolation device according to claim 1, wherein the capacitance protection circuit further comprises a thyristor, a source of the thyristor is connected with the other end of the switch K1, a drain of the thyristor is grounded through the current detection module, and a gate of the thyristor is connected with the other IO control end of the PLC controller.
4. The high-reliability direct-current magnetic bias isolation device for the transformer as claimed in claim 1, wherein the current detection module is a current transformer.
5. The high-reliability direct-current magnetic bias isolation device for the transformer is characterized in that at least one current transformer is arranged on a connecting line between the other end of the capacitor, the other end of the online monitoring device, the other end of the zinc oxide lightning arrester FR, the other end of the capacitor protection circuit and the other end of the switch K2 and the ground terminal.
6. The high-reliability direct-current magnetic bias isolation device for the transformer as claimed in claim 1, wherein the online monitoring device is a zinc oxide lightning arrester tester.
7. The high-reliability transformer direct-current magnetic bias isolating device of claim 6, wherein the model of the zinc oxide lightning arrester tester is YTC 620D.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121621078.7U CN216252170U (en) | 2021-07-15 | 2021-07-15 | Transformer direct current magnetic biasing isolating device with high reliability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121621078.7U CN216252170U (en) | 2021-07-15 | 2021-07-15 | Transformer direct current magnetic biasing isolating device with high reliability |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216252170U true CN216252170U (en) | 2022-04-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121621078.7U Active CN216252170U (en) | 2021-07-15 | 2021-07-15 | Transformer direct current magnetic biasing isolating device with high reliability |
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| Country | Link |
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| CN (1) | CN216252170U (en) |
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2021
- 2021-07-15 CN CN202121621078.7U patent/CN216252170U/en active Active
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