CN107482600A - Yyn0 type three-phase group formulas transformer drops excitation surge current suppressing method - Google Patents
Yyn0 type three-phase group formulas transformer drops excitation surge current suppressing method Download PDFInfo
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- CN107482600A CN107482600A CN201710585514.1A CN201710585514A CN107482600A CN 107482600 A CN107482600 A CN 107482600A CN 201710585514 A CN201710585514 A CN 201710585514A CN 107482600 A CN107482600 A CN 107482600A
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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
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
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Abstract
The invention discloses a kind of Yyn0 types three-phase group formula transformer to drop excitation surge current suppressing method, and this method comprises the following steps：First, protection device is sampled and recorded to the voltage x current of transformer during transformer separating brake；Then, the three-phase voltage current waveform obtained according to sampling determines electric current blow-out order and voltage blow-out phase angle；Finally, Transformer Close order and closing phase angle are determined according to information above；When this method need to only sample Yyn0 type three-phase group formula transformer station high-voltage side bus three-phase voltage current waveform with obtain three-phase current blow-out order and voltage blow-out phase angle information, determine therefrom that switching order and switching voltage phase angle, idle-loaded switching-on excitation surge current can be suppressed, relevant parameter easily obtains, in that context it may be convenient to in Practical Project.
Description
Technical field
The invention belongs to transformer excitation flow suppression technology field, is related to a kind of Yyn0 types three based on option principle
Phase group formula transformer excitation flow suppressing method.
Background technology
Power transformer is one of nucleus equipment of power system, and whether its normal work is directly connected to power system energy
No continuously and stably to run, difficulty is big, time between overhauls(TBO) length because failure causes after damage it to overhaul for transformer, can not only influence electricity
The normal operation of Force system, or even immeasurable economic loss and social influence can be caused.Transformer zero load put into when or
When voltage recovers after Removal of external faults, because iron core magnetic flux can not be mutated, due to voltage jump, caused transient state magnetic flux can
It can cause iron core that saturation occurs, it will to produce the very big electric current of numerical value in the side of transformer voltage mutation, the electric current is referred to as
Excitation surge current.
Exciting current very little during transformer normal work, and the amplitude of excitation surge current is likely to be breached the 6~8 of rated current
Times, protective relaying maloperation on the one hand may be caused to make to make transformer put into operation unsuccessfully, winding deformation on the other hand may be made to influence to become
Depressor service life；The a large amount of harmonic components contained simultaneously in excitation surge current will pollute power network, deteriorate the quality of power supply；For simultaneously
Row operation or higher level's transformer, excitation surge current may induce and echo surge current, disturbs neighbouring operating transformer, cause transformer and
Breaker induces the consequences such as switching overvoltage, damage electric equipment because electric power is excessive impaired.Therefore must take measures to suppress
The excitation surge current of transformer, so as to reduce a variety of destructive consequences that excitation surge current is brought.
The method for suppressing transformer excitation flow at present is broadly divided into two categories below：1) it is controlled from inside.I.e. from change
The excitation principle of depressor iron core sets out, and reaches the purpose of reduction excitation surge current by changing the internal structure of transformer, such as
Change distribution of transformer primary, vice-side winding etc..But such method but the structure due to needing change transformer, this will band
Carry out the problem of other, such as whether the insulation of transformer can be made to degenerate or influence steady-state operation of transformer etc., make its development tool
There is certain limitation.2) it is controlled from outside.Some remedial measures are taken outside transformer to cut down excitation surge current,
Such as series connected resistance, low-pressure side install capacitor method, soft start method and phase selection switch technology etc. additional.Wherein first two method needs
Optional equipment is put into, adds operation expense, the third method has parameter tuning and control problem, and excitation surge current suppresses
Less effective.
Phase selection switch technology is that a kind of novel electric power apparatus for being proposed with the development of switching technique closes means,
It is effective to suppress power system operation overvoltage and shove and improve the key technology of the quality of power supply comprehensively.Phase selection switch technology
The principle for suppressing excitation surge current is that control breaker dynamic/static contact enters at the designated phase angle moment of system voltage or current waveform
Row switch closes, and makes the iron core remanent magnetism of closing moment identical with the pre- inducting flux determined by system voltage, so as to weaken excitation
Shove.Basic reason caused by the method from excitation surge current one by one lead to oversaturated angle and start with by iron core magnetic, in theory can be complete
Eliminate excitation surge current.As new main flow research direction, this method is to improving Operation of Electric Systems stability and economy meaning
It is far-reaching, and have a extensive future.
The method is to select optimal switching-on phase angle applied to the key for suppressing transformer during no-load closing excitation surge current,
Include the grasp to transformer core remanent magnetism information and the cooperation of alternate switching order.For Yyn0 type three-phase group formula transformers
For, its basic structure is that three single-phase transformers form, and iron core is mainly by silicon steel sheet stack into former vice-side winding is star-like
Knot and vice-side winding neutral ground.Because each phase magnetic flux closes along respective magnetic circuit, therefore its magnetic circuit system is independently of each other, in electricity
Source frequency and the timing of umber of turn one, each phase iron core magnetic flux are determined by winding applied voltage and (are ignored coil resistance and leakage magnetic flux).
Therefore each phase iron core remanent magnetism information can be grasped by three-phase voltage during monitoring separating brake, determines therefrom that optimal closing phase angle.This
Invention takes into full account the influence of the factors such as blow-out characteristic, transformer iron-core structure and the winding connection way of breaker, gives
One kind is directed to Yyn0 type three-phase group formula transformer phase selection methods, and this method can be very good to suppress transformer during no-load closing production
Raw excitation surge current.
The content of the invention
In order to solve the above-mentioned problems of the prior art, the present invention provides a kind of Yyn0 types three-phase group formula transformer air-drop
Excitation surge current suppressing method, this method need to only sample three-phase voltage current waveform during Yyn0 type three-phase group formula transformer separating brakes,
Record each phase current blow-out order and voltage blow-out phase angle, you can determine therefrom that phase selection closes order and switching voltage phase angle, phase
Related parameter easily obtains, in that context it may be convenient to in Practical Project.
In order to achieve the above object, the present invention adopts the following technical scheme that：
Yyn0 type three-phase group formulas transformer drops excitation surge current suppressing method, comprises the following steps：
Step 1：During Yyn0 type three-phase group formula transformer separating brakes, signal pickup assembly is by transformer to Yyn0 type three-phases
The three-phase voltage current waveform of group formula transformer is sampled and recorded；
Step 2：The three-phase current waveform obtained according to step 1 sampling, determine three-phase blow-out order and blow-out time；Its
Middle blow-out order includes first disconnected phase and the last two-phase of blow-out simultaneously, the first disconnected phase for mutually referring to disconnect first, i.e., when certain phase
Electric current be reduced to zero first and keep constant, then phase of breaking headed by the phase, the last two-phase refers to that prime minister simultaneously switches off after disconnecting
Two-phase；
Step 3：Blow-out order according to obtained by step 2, the three-phase voltage waveform obtained with reference to step 1 sampling, record are first
Disconnected phase blowout voltage phase angleAnd last two-phase blow-out phase angleIt is describedUsing the disconnected phase voltage positive zero crossings of head as
Reference point, i.e., when the disconnected phases of head are in voltage positive zero crossing blow-out,
Step 4：Blow-out order according to obtained by step 2 determines Yyn0 type three-phase group formulas Transformer Close order, i.e., first
Last two-phase is closed a floodgate simultaneously, switching voltage phase angle isIt is delayed after 2~3 cycles to the disconnected phase combined floodgates of head, switching voltage phase
Angle is
Determination blow-out order and blow-out time in the step 2, comprise the following steps：
Step 1：It is determined that first disconnected phase and prime minister's blow-out moment td1；
The disconnected phases mutually as disconnected first of head, according to breaker zero crossing blow-out order, when the electric current of certain phase drops first
Be zero and keep it is constant i.e. headed by break phase, the moment is prime minister's blow-out moment td1；
Step 2：It is determined that last two-phase blow-out moment td2；
Yyn0 type three-phase group formulas transformer primary side is the wye connection of isolated neutral, remaining two-phase after first disconnected phase blow-out
Loop each other, size of current equal direction is on the contrary, its electric current of event while zero passage, and the blow-out moment is identical, according to current recording waveform
Obtain last two-phase blow-out moment td2。
The first disconnected phase blowout voltage phase angle of determination in the step 3And last two-phase blow-out phase angleIncluding following step
Suddenly：
Step 1：First disconnected phase voltage positive zero crossing moment t is determined according to voltage recording waveform0；
Step 2：With t0Moment is reference point, calculates first disconnected phase blowout voltage phase angle and is
Step 3：Calculating last two-phase blowout voltage phase angle is
Compared to the prior art compared with the present invention possesses following advantage：
1st, relevant parameter easily obtains.I.e. all parameters of excitation surge current suppressing method can be obtained by direct measurement.
Suppress Yyn0 type three-phase group formulas transformer air-drop excitation surge current method 2. being closed compared to traditional phase selection, take into full account
The influence of iron core remanent magnetism, excitation surge current inhibition are more preferable.
Brief description of the drawings
Fig. 1 is Yyn0 type three-phase group formula transformer connection group schematic diagrames.
Fig. 2 is the overall plan figure of the inventive method.
Fig. 3 is simulation model figure.
Voltage oscillogram when Fig. 4 is the separating brake that emulation obtains.
Current waveform figure when Fig. 5 is the separating brake that emulation obtains.
Voltage oscillogram when Fig. 6 is phase selection.
Current waveform figure when Fig. 7 is phase selection.
Embodiment
The present invention is described in detail with reference to the accompanying drawings and detailed description：
It is as shown in Figure 1 Yyn0 type three-phase group formula transformer connection group schematic diagrames, if A phases supply voltage is uA(t)=
UmSin (ω t+ α), UmIt is primary side winding voltage peak, ω is voltage angular frequency, and α is supply voltage initial phase angle, during definable
The voltage phase angle at quarter is
It is to A phase transformer first winding row loop-voltage equations：
Wherein：uNFor neutral point voltage, R is transformer primary circuit equivalent resistance, and i is transformer primary circuit electric current, N1
It is the primary side winding number of turn, φAIt is transformer core magnetic flux；Due to transformer primary circuit equivalent resistance R very littles, often can be neglected not
Meter, and u during three-phase symmetrical operationN=0, then have
I.e.：
Both sides integrate：
Fig. 2 is the overall plan figure of the inventive method, in figure：XLLine impedance is represented, TV represents voltage transformer, TA tables
Show current transformer, QK represents three-phase breaker.Carry out sub-switching operation to three-phase breaker QK, signal pickup assembly by TA and
TV gathers three-phase voltage current waveform.Yyn0 type three-phase group formula transformers are gathered by current transformer TA and voltage transformer TV
Primary side winding voltage x current information during separating brake, primary side three-phase current is big during normal operation in three-phase symmetrical system for the transformer
It is small equal, phase mutual deviation 120°, the nature disjunction in current over-zero due to each phase breaker, therefore the three-phase separating brake moment is non-synchronous.
Assume that A phases disconnect first after breaker open operation, blowout voltage phase angle isConvolution (1) and formula (5) understand that its iron core remanent magnetism is
Due to the wye connection that Yyn0 type three-phase group formulas transformer primary side is isolated neutral, after A phase blow-outs, B, C two
Mutually loop each other, then primary side loop equation have：
Wherein uB=Umsin(ωt+α-120°),uC=UmSin (+120 ° of ω t+ α), same negligible resistance R, then formula (7)
Abbreviation obtains：
Both sides integrate：
Due to B, C two-phase loop each other, then its blow-out moment is identical.Assuming that blowout voltage phase angle isBringing formula (9) into can
Obtaining B, C two-phase remanent magnetism has：
Switching order and switching voltage phase angle are determined according to above remanent magnetism information, due to Yyn0 type three-phase group formula transformer primaries
Side isolated neutral, the no current loop if being closed a floodgate to a wherein phase, therefore wherein two-phase is closed a floodgate first.It is of the invention first
First last blow-out two-phase (B, C) close a floodgate simultaneously, shown in the same formula of closing circuit equation (7), then B, the C determined by supply voltage
The pre- inducting flux of phase iron core is：
In order that the moment iron core magnetic flux that closes a floodgate is directly entered steady-state operation, then require to control the moment iron core remanent magnetism and premonition
Answer magnetic flux identical, i.e.,
φ'B(t1)-φ'C(t1)=ΦrB-ΦrC (12)
Wherein, t1For the optimal closing time of B, C；
Convolution (11) has with formula (12)
Have
Therefore the last two-phase blowout voltage phase angle of selection is its closing phase angle.
After being closed a floodgate to B, C phase, due to the symmetry of tri-phase iron core structure, three equivalent excitation impedance phases during iron core unsaturation
Together, then it is identical into B, C winding partial pressure during steady-state operation, have
I.e.
Bring formula (2) into and understand that the pre- inducting flux of A phase windings is
Make φ 'A(t2)=φrA, i.e.,
The optimal closing phase angle of A phases, which can then be obtained, is
Because three-phase system has a symmetry, thus break headed by B, C phase phase when, head it is disconnected mutually and another two-phase flux change rule with
The above situation is identical, therefore switching order and the selection of switching voltage phase angle follow mentioned above principle.
Embodiment
Fig. 3 is the simulation model built, and transformer is three-phase two-simulation transformer group in this simulation model, and rated voltage is
345/289kV, rated capacity 1209MVA, rated no-load current are about 2A., by Fig. 3 I, V gather transformer primary side around
Group electric current and voltage waveform, controlling switch are not cut-off voltage waveform at inphase angle, observe primary side winding current waveform.
Respectively as shown in Figure 4 and Figure 5, three-phase current blow-out order is the current-voltage waveform at separating brake moment as shown in Figure 4
A-B (C), compares figure 5 understand that first disconnected phase (A phases) blowout voltage phase angle isLast two-phase blowout voltage phase angle is
Therefore can determine that the Three-Phase Transformer switching order is B (C)-A, B, C phase can be obtained by bringing formula (14) and (17) into respectively
Optimal switching voltage phase angle is β1=108 °, the optimal switching voltage phase angle of A phases is β1=123.5 °.Closed according to above-mentioned closing phase angle
Voltage current waveform difference during lock is as shown in Figure 6 and Figure 7, it can be seen that period three phase current magnitude of closing a floodgate is empty close to stable state
Electric current is carried, excitation surge current is totally constrained.
Above-described embodiment, the purpose of the present invention, technical scheme and beneficial effect are carried out further
Describe in detail, should be understood that the embodiment that the foregoing is only the present invention, be not intended to limit the present invention
Protection domain, within the spirit and principles of the invention, any modification, equivalent substitution and improvements done etc., all should include
Within protection scope of the present invention.
Claims (3)
1.Yyn0 type three-phase group formulas transformer drops excitation surge current suppressing method, it is characterised in that comprises the following steps：
Step 1：During Yyn0 type three-phase group formula transformer separating brakes, signal pickup assembly is by transformer to Yyn0 type three-phase group formulas
The three-phase voltage current waveform of transformer is sampled and recorded；
Step 2：The three-phase current waveform obtained according to step 1 sampling, determine three-phase blow-out order and blow-out time；Wherein put out
Arc order includes first disconnected phase and the last two-phase of blow-out simultaneously, the first disconnected phase for mutually referring to disconnect first, the i.e. electricity when certain phase
Stream is reduced to zero and keeps constant first, then phase of breaking headed by the phase, the last two-phase refers to the two-phase that prime minister simultaneously switches off after disconnecting；
Step 3：Blow-out order according to obtained by step 2, the three-phase voltage waveform obtained with reference to step 1 sampling, it is determined that first disconnected phase
Blowout voltage phase angleAnd last two-phase blow-out phase angleIt is describedUsing the disconnected phase voltage positive zero crossings of head as reference
Point, i.e., when the disconnected phases of head are in voltage positive zero crossing blow-out,
Step 4：Blow-out order according to obtained by step 2 determines Yyn0 type three-phase group formulas Transformer Close order, i.e., first to end
Two-phase is closed a floodgate simultaneously, and switching voltage phase angle isIt is delayed after 2~3 cycles and is to the disconnected phase combined floodgates of head, switching voltage phase angle
2. described Yyn0 type three-phase group formulas transformer air-drop excitation surge current suppressing method according to claim 1, it is special
Sign is, determination blow-out order and blow-out time in the step 2, comprises the following steps：
Step 1：It is determined that first disconnected phase and prime minister's blow-out moment td1；
The disconnected phases mutually as disconnected first of head, according to breaker zero crossing blow-out order, when the electric current of certain phase is reduced to zero first
And keep it is constant i.e. headed by break phase, the moment is prime minister's blow-out moment td1；
Step 2：It is determined that last two-phase blow-out moment td2；
Yyn0 type three-phase group formulas transformer primary side is the wye connection of isolated neutral, and remaining two-phase is each other after the disconnected phase blow-outs of head
Loop, for size of current equal direction on the contrary, its electric current of event while zero passage, the blow-out moment is identical, is obtained according to current recording waveform
Last two-phase blow-out moment td2。
3. described Yyn0 type three-phase group formulas transformer air-drop excitation surge current suppressing method according to claim 1, it is special
Sign is, the first disconnected phase blowout voltage phase angle of the determination in the step 3And last two-phase blow-out phase angleIncluding following step
Suddenly：
Step 1：First disconnected phase voltage positive zero crossing moment t is determined according to voltage recording waveform0；
Step 2：With t0Moment is reference point, calculates first disconnected phase blowout voltage phase angle and is
Step 3：Calculating last two-phase blowout voltage phase angle is
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108226770A (en) * | 2017-12-20 | 2018-06-29 | 中国南方电网有限责任公司超高压输电公司天生桥局 | A kind of circuit breaker failure diagnostic method |
| CN108767826A (en) * | 2018-06-14 | 2018-11-06 | 西安交通大学 | Do not demagnetize converter power transformer air-drop excitation surge current suppressing method after straight resistance experiment |
| CN114237075A (en) * | 2021-12-17 | 2022-03-25 | 福州大学 | Electromagnetic switch closing control method capable of intelligently identifying load |
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| CN104037730A (en) * | 2013-03-04 | 2014-09-10 | 艾默生网络能源有限公司 | Apparatus and method for inhibiting transformer zero load closing inrush currents |
| CN104459578A (en) * | 2014-12-02 | 2015-03-25 | 西安交通大学 | Residual magnetism estimation method for Yyn0-type three-phase combined transformer non-fault tripping |
| EP3157114A1 (en) * | 2014-06-11 | 2017-04-19 | Indra Sistemas, S.A. | Method for reducing the inrush current of an inductive load |
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2017
- 2017-07-18 CN CN201710585514.1A patent/CN107482600B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104037730A (en) * | 2013-03-04 | 2014-09-10 | 艾默生网络能源有限公司 | Apparatus and method for inhibiting transformer zero load closing inrush currents |
| EP3157114A1 (en) * | 2014-06-11 | 2017-04-19 | Indra Sistemas, S.A. | Method for reducing the inrush current of an inductive load |
| CN104459578A (en) * | 2014-12-02 | 2015-03-25 | 西安交通大学 | Residual magnetism estimation method for Yyn0-type three-phase combined transformer non-fault tripping |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108226770A (en) * | 2017-12-20 | 2018-06-29 | 中国南方电网有限责任公司超高压输电公司天生桥局 | A kind of circuit breaker failure diagnostic method |
| CN108767826A (en) * | 2018-06-14 | 2018-11-06 | 西安交通大学 | Do not demagnetize converter power transformer air-drop excitation surge current suppressing method after straight resistance experiment |
| CN108767826B (en) * | 2018-06-14 | 2019-07-12 | 西安交通大学 | Do not demagnetize converter power transformer air-drop excitation surge current suppressing method after straight resistance test |
| CN114237075A (en) * | 2021-12-17 | 2022-03-25 | 福州大学 | Electromagnetic switch closing control method capable of intelligently identifying load |
| CN114237075B (en) * | 2021-12-17 | 2024-03-29 | 福州大学 | Electromagnetic switch closing control method for intelligently identifying load |
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