CN106684850B - High-tension transformer earth neutral system - Google Patents
High-tension transformer earth neutral system Download PDFInfo
- Publication number
- CN106684850B CN106684850B CN201611148478.4A CN201611148478A CN106684850B CN 106684850 B CN106684850 B CN 106684850B CN 201611148478 A CN201611148478 A CN 201611148478A CN 106684850 B CN106684850 B CN 106684850B
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- capacitor
- inductance
- series resonant
- transformer
- fault
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- 230000007935 neutral effect Effects 0.000 title claims abstract description 28
- 239000003990 capacitor Substances 0.000 claims abstract description 37
- 238000007599 discharging Methods 0.000 claims description 10
- 229910044991 metal oxide Inorganic materials 0.000 claims description 6
- 150000004706 metal oxides Chemical class 0.000 claims description 6
- 230000005611 electricity Effects 0.000 claims description 5
- 229920006395 saturated elastomer Polymers 0.000 claims 1
- 230000001052 transient effect Effects 0.000 abstract description 4
- 230000009194 climbing Effects 0.000 abstract description 3
- 230000006378 damage Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- 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
- H02H9/08—Limitation or suppression of earth fault currents, e.g. Petersen coil
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
A kind of high-tension transformer earth neutral system provided by the invention, including the series resonant equipment for being connected between the neutral point and ground by high-tension transformer, the series resonant equipment is in industrial frequency resonance state when electric system operates normally, series impedance position zero, guarantee that the neutral point of transformer has good power-frequency earthing, capacity cell in device can be avoided the transformer bias phenomenon due to caused by system dc component, when there is ground fault in system, nonlinear inductance saturation, resonant tank is detuning, capacitor can effective fault restriction phase short circuit current, to guarantee the regular event of breaker, simultaneously, nonlinear inductance can be with the climbing of fault current limiting, avoid transient current impact failure capacitor.
Description
Technical field
The present invention relates to a kind of electric network protection system more particularly to a kind of high-tension transformer earth neutral systems.
Background technique
The selection of electric system Discussion on Neutral is a global question, can with system power supply
It is closely related by property, Insulation Coordination, relay protection, communication interference, electrical safety etc..
The purpose of neutral ground is to limit short circuit current in single phase grounding, reduces external short circuit failure and rush to transformer
It hits, to reduce harm of the fault current to equipment, reduces the loss of outage to user, safeguards system reliability of operation and peace
Quan Xing.With the rapid development of extra-high voltage DC transmission system, the DC current that the earthing pole of direct current system flows into the earth will be right
Power equipment in AC electric power systems has an impact, so that flowing into direct current in transformer winding, DC magnetic bias phenomena occurs, from
And the problems such as causing main transformer harmonic wave, noise, overheat, the damage of transformer, capacitor group can be caused when serious, threatens power grid
Safe operation.Meanwhile with the continuous increase of power grid scale and capacity, the capacity of short circuit and short circuit current of electric system be not yet
It is disconnected to increase.The type selecting that excessive short circuit current not only results in breaker is difficult, and will affect stablizing for power grid and be safely operated.
Currently, neutral grounding mode mainly has Neutral Point Through Low Resistance, neutral point through small for high-tension transformer
The methods of reactance grounded, neutral-point solid ground, capacitor blocking, but the above earthing mode can not combine it is inclined to direct current
The inhibition of magnetic is with the limitation to short-circuit current: for Neutral Point Through Low Resistance mode, when there are DC components for system
When, transformer bias cannot be completely restricted；For Neutral grounding via small reactor mode, since reactance itself is perceptual member
Part constitutes resonant tank with line mutual-ground capacitor, resonance overvoltage can occur under certain condition, while not can avoid transformer
Bias；For neutral-point solid ground mode, when system is there are when DC component, transformer bias cannot be completely restricted, together
Shi Wufa limits excessive short circuit current；For neutral point capacitor blocking mode, when single-phase earth fault current is larger, transient state
Rush of current may damage capacitor.Therefore, a kind of new neutral ground method is needed, with safeguards system reliability of operation
And safety.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of high-tension transformer earth neutral systems to solve above-mentioned technology
Problem.
A kind of high-tension transformer earth neutral system provided by the invention, including for by the neutral point of high-tension transformer
The series resonant equipment connected between ground, the series resonant equipment are in industrial frequency resonance shape when electric system operates normally
State.
Further, the series resonant equipment includes one end and the high pressure transformation of inductance L1 and capacitor C1, the inductance L1
The neutral point of device is electrically connected, and the other end of inductance L1 is grounded by capacitor C1.
Further, the inductance L1 is nonlinear inductance, and is worked when electric system operates normally in linear zone.
Further, the series resonant equipment further includes discharging gap, and one end of the discharging gap is connected to inductance L1
Points of common connection between capacitor C1, other end ground connection.
Further, the series resonant equipment further includes metal oxide arrester, the metal oxide arrester with
The both ends of discharging gap connect to form parallel-connection structure.
Beneficial effects of the present invention: high-tension transformer earth neutral system of the invention can guarantee in transformer
Property point be grounded with good industrial frequency resonance, when, there are when DC component, capacitor can obstruct DC current in electric system, have
Effect avoid high-tension transformer occur bias phenomenon, when there is singlephase earth fault in system, can to failure phase short circuit current into
Row effectively limitation, to guarantee the regular event of breaker, nonlinear inductance can avoid capacitor with limiting short-circuit current climbing
By transient current impact failure, meanwhile, capacitor both ends parallel connection gaps and arrester are damaged prevented also from capacitor because of overvoltage；This
Inventive structure is simple, and rationally, and power electronics dispatch control system is not present in design, reduces because power electronic equipment failure is made
At equipment malfunction or tripping possibility, reduce fault current to the person and equipment safety harm, avoid fault point electric arc mistake
Voltage is to apparatus insulated damage, safeguards system reliability of operation and safety.
Detailed description of the invention
The invention will be further described with reference to the accompanying drawings and examples:
Fig. 1 is circuit diagram of the invention.
Specific embodiment
Fig. 1 is circuit diagram of the invention, as shown, a kind of high-tension transformer neutral ground provided by the invention
System, including the series resonant equipment for being connected between the neutral point and ground by high-tension transformer, the series resonant equipment
It is in industrial frequency resonance state when electric system operates normally, can guarantee that there is the neutral point of transformer good power frequency to connect
Ground, and can be avoided the transformer bias phenomenon due to caused by DC component, so that transformer formation is effectively protected, and
And when singlephase earth fault occurs in system, failure phase short circuit current can effectively be limited, to guarantee breaker
Regular event.
In the present embodiment, the series resonant equipment includes inductance L1 and capacitor C1, one end of the inductance L1 and high pressure
The neutral point of transformer is electrically connected, and the other end of inductance L1 is grounded by capacitor C1, wherein the inductance L1 is non-linear electricity
Sense, when electric system operates normally, nonlinear inductance L1 work is in linear zone, the series resonance of inductance L1 and capacitor C1 composition
For loop works in resonant state, the power frequency series impedance of series resonant tank is zero, guarantees the power-frequency earthing of transformer neutral point.
When, there are when DC component, due to the effect of capacitor C1, DC current is separated by capacitor C1 in system, it can be to prevent
Transformer formation is effectively protected in only high-tension transformer bias phenomenon due to caused by DC component；
When there is ground fault in electric system, at this point, fault current flows into the earth through nonlinear inductance L1 and capacitor C1,
Nonlinear inductance L1 can effectively fault current limiting climbing, avoid transient current impact failure capacitor C1.
And when ground fault occurs, the fault current for flowing through nonlinear inductance L1 increases, and nonlinear inductance L1 is gradually
The resonant state of saturation, nonlinear inductance L1 and capacitor C1 terminate, and capacitor C1 access system, capacitor C1 being capable of effective fault restriction
The breaker of the short circuit current of phase, guarantee normally trips.
In the present embodiment, the series resonant equipment further includes discharging gap, and one end of the discharging gap is connected to electricity
Feel the points of common connection between L1 and capacitor C1, the other end is grounded, when there is short trouble, inductance L1 and the public company of capacitor C1
The voltage-to-ground of contact increases, and after reaching the breakdown voltage in gap, gap discharge, capacitor C1 is short-circuited, and can prevent electricity
Press impact failure capacitor C1；Further, in order to enhance the protective effect to capacitor C1, the series resonant equipment further includes gold
Belong to Oxide Arrester (English abbreviation MOA), the metal oxide arrester connected with the both ends of discharging gap to be formed it is in parallel
Structure effectively ensures the safety of capacitor C1 by the cooperating of discharging gap and metal oxide arrester, extends capacitor C1
Service life；Through this embodiment, it can avoid being drawn by DC current in system under the premise of not influencing transformer normal operation
The transformer bias risen also can reduce system earth short circuit current, guarantee normal operation of circuit breaker.
Finally, it is stated that the above examples are only used to illustrate the technical scheme of the present invention and are not limiting, although referring to compared with
Good embodiment describes the invention in detail, those skilled in the art should understand that, it can be to skill of the invention
Art scheme is modified or replaced equivalently, and without departing from the objective and range of technical solution of the present invention, should all be covered at this
In the scope of the claims of invention.
Claims (1)
1. a kind of high-tension transformer earth neutral system, it is characterised in that: including for by the neutral point of high-tension transformer with
The series resonant equipment connected between ground, the series resonant equipment are in industrial frequency resonance shape when electric system operates normally
State；
The series resonant equipment includes one end of inductance L1 and capacitor C1, the inductance L1 and the neutral point electricity of high-tension transformer
Gas connection, the other end of inductance L1 are grounded by capacitor C1；
The inductance L1 is nonlinear inductance, and is worked in working condition in linear zone；
The series resonant equipment further includes discharging gap, and one end of the discharging gap is connected between inductance L1 and capacitor C1
Points of common connection, the other end ground connection；
The series resonant equipment further includes metal oxide arrester, and the two of the metal oxide arrester and discharging gap
End connection forms parallel-connection structure；
When, there are when DC component, DC current is separated by capacitor C1 in system；
When there is ground fault in electric system；Fault current flows into the earth through nonlinear inductance L1 and capacitor C1；It is connecing
When earth fault, the fault current for flowing through nonlinear inductance L1 increases, and nonlinear inductance L1 is gradually saturated, nonlinear inductance L1 and electricity
The resonant state for holding C1 terminates, capacitor C1 access system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611148478.4A CN106684850B (en) | 2016-12-13 | 2016-12-13 | High-tension transformer earth neutral system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611148478.4A CN106684850B (en) | 2016-12-13 | 2016-12-13 | High-tension transformer earth neutral system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106684850A CN106684850A (en) | 2017-05-17 |
| CN106684850B true CN106684850B (en) | 2019-08-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611148478.4A Active CN106684850B (en) | 2016-12-13 | 2016-12-13 | High-tension transformer earth neutral system |
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| Country | Link |
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| CN (1) | CN106684850B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110212490A (en) * | 2018-07-11 | 2019-09-06 | 梅桂华 | A kind of transformer neutral point power frequency coupling grounding device |
| CN113396517A (en) * | 2018-09-28 | 2021-09-14 | 科技持有有限责任公司 | Power grid protection by transformer neutral point blocking system and triggering phase loss |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101944719A (en) * | 2010-08-20 | 2011-01-12 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Detection system and detection method of capacitance sleeve pipe and current transformer |
| CN202748409U (en) * | 2012-09-13 | 2013-02-20 | 安徽省电力公司淮南供电公司 | Line power frequency parameter measuring apparatus capable of eliminating power frequency interference |
| US8487635B1 (en) * | 2010-12-08 | 2013-07-16 | Dev Paul | System and method for determining system charging current |
| CN103278737A (en) * | 2013-04-25 | 2013-09-04 | 河北兆联电气设备科技有限公司 | Direct-current self-injection type small-current grounding and route selecting system and method |
| CN206226010U (en) * | 2016-12-13 | 2017-06-06 | 国家电网公司 | Transformer neutral point protection system to earth |
-
2016
- 2016-12-13 CN CN201611148478.4A patent/CN106684850B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101944719A (en) * | 2010-08-20 | 2011-01-12 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Detection system and detection method of capacitance sleeve pipe and current transformer |
| US8487635B1 (en) * | 2010-12-08 | 2013-07-16 | Dev Paul | System and method for determining system charging current |
| CN202748409U (en) * | 2012-09-13 | 2013-02-20 | 安徽省电力公司淮南供电公司 | Line power frequency parameter measuring apparatus capable of eliminating power frequency interference |
| CN103278737A (en) * | 2013-04-25 | 2013-09-04 | 河北兆联电气设备科技有限公司 | Direct-current self-injection type small-current grounding and route selecting system and method |
| CN206226010U (en) * | 2016-12-13 | 2017-06-06 | 国家电网公司 | Transformer neutral point protection system to earth |
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| Publication number | Publication date |
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| CN106684850A (en) | 2017-05-17 |
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