CN1045666A - Commutating distribution-difference type relay-protection part - Google Patents

Abstract

One class electric power system rectification distribution-difference type protective relaying device.Be specially adapted to line protection, transformer and generator overcurrent protection, overload protection.It is characterized in that: with one or more similar or inhomogeneity original electrical parameters; through dividing synthetic or direct simple transformation; obtain one or more pairs of normally have zero or negative difference features; the intermediate variable that has the principal-employment value tag after the fault constitutes protection by " non-zero adjust magnitude comparator " with specific setting value than the width of cloth then.

Novel protected have an operating sensitivity nargin height, the reliability nargin height of not misoperation, and device circuit is simple, and three-phase comprehensively is a protection component device.

Description

Commutating distribution-difference type relay-protection part

The present invention is a class commutating distribution-difference type relay-protection part that is used for electric power system, is specially adapted to line protection, the overcurrent of transformer and generator, overload protection.

Existing distance protection, overcurrent protection principle device, its operating sensitivity nargin Km is all relative less with the reliability nargin Kk of not misoperation, along with maximum load current I _F, the max level raising (with respect to the terminal short circuit current I of protection range _D, m), its Km, Kk nargin lose guarantee easily.

The purpose of this invention is to provide a kind of circuit, technology is simple, Km is high, Kk is high protection philosophy device, use side by side with existing distance protection, overcurrent protection, overload protection principle device or replace it.

Principle of the present invention and implement as follows: with one or more similar or inhomogeneity original electrical parameters; through the synthetic or direct simple transformation of division; obtain one or more pairs of, normally have zero or negative difference feature, fault after have the intermediate variable of principal-employment value tag, constitute protection by " non-zero adjust formula magnitude comparator " than the width of cloth with specific setting value.

Disclose in No. 87107828 patent specifications by us than the form that the width of cloth constitutes protection based on " non-zero integral expression magnitude comparator "; that is: with two original electrical parameters, obtain two intermediate variables and constitute protection than the width of cloth by " non-zero is adjusted formula than width of cloth device " through synthetic conversion with amplitude and phase property.But it is not broken away from this special occasions of tractive power supply system, uses to solving the limitation of a kind of so indivedual utilizations of different-phase circuit protection.

The present invention proposes: by one or more, similar or inhomogeneity original electrical parameter; through the synthetic or direct simple transformation of division; obtain one or more pairs of, normally have zero or negative difference feature, fault after have the method for the intermediate variable of principal-employment value tag, with three-phase comprehensively be the method for a protection component device.

1. by an original electrical parameter

_CLBe split into two equal components

', ", it is characterized in that: be provided with " non-linearization circuit ", equate with guarantee both amplitudes in normal operating condition scope, and after exceeding normal range of operation, its motion components amplitude | ' | non-linear growth, the braking component amplitude | " | non-linear constant, be expressed as: K ^△ ₁| K _{E CL}| K | K _E

_CL| form.

2. by two electric parameters

_CL, _CLSynthetic be transformed to two intermediate variables, it is characterized in that: φ of relative phase shift _ZDAngle (0～90 °) synthesizes two variablees through addition with subtracting each other again, and mates the suitable balance ratio condition of adjusting, and expression formula is:

Form.

3. by two electric parameters _OL, _CLDirectly simple transformation becomes two intermediate variables, it is characterized in that: by the fiducial value condition K of selected original electrical parameter _EE _J=K _FF _JEnsure its normally have zero or negative difference feature, fault after have the principal-employment value tag, be expressed as: | K _E

_CL|, | K _F

_CL| form.

Above-mentioned K _E, K _FBe the basic transformation coefficient of voltage formation link, K △ ₁/ K

₂, K ₃/ K ₄, K _E/ K _FBalance setting ratio for coupling.

4. in three-phase electrical power system, when only constituting rectification distribution-difference type relaying protection component arrangement according to current parameter, its three-phase comprehensively is that three kinds of practical forms of a protection component device are:

Practical form one is characterized in that: three-phase current behind voltage formation and rectifying and wave-filtering, is formed the maximum output circuit by three diodes arranged side by side and is carried out comprehensively respectively.

Practical form two is a kind of novel three-phase current synthesizers, and schematic circuit shows and it is characterized in that as Fig. 9: single-phase iron core, the three-phase current coil ratio is: Na: Nb: Nc=n: 1.5n: 2n, secondary is by a coil N ₂Output.As establish the three-phase shortcircuit nargin K that is active in one's movements ⁽³⁾ _m=1, K then ⁽²⁾ _m, K ⁽¹⁾ _mRelative value provide as table 1-I.

Practical form three is another novel three-phase current synthesizer, and schematic circuit shows and it is characterized in that as Figure 10: three-limb core, three-phase current coil turn equate that be around in three posts respectively, secondary two coils place number of turn N ' on two side columns ₂=N " ₂Behind rectifying and wave-filtering, form the maximum output circuit by two diodes arranged side by side and carry out comprehensively respectively.Its K ⁽²⁾ _m, K ⁽¹⁾ _mRelative value provide as table 1-II.

5. in three-phase electrical power system; when foundation electric current and voltage parameter constituted rectification distribution-difference type relaying protection component arrangement, its synthetic circuit was characterised in that: forms minimum value output circuit that three diodes of maximum output circuit and another group form by one group of three diode arranged side by side and mate mutually to use and carry out comprehensively.

The present invention can also reach by following measure: the single-phase form and action condition Mathematical Modeling of commutating distribution-difference type relay-protection part is as follows.

1. universal expression formula:

〉=C _ZDK _EE _JOr C _ZDK _FF _J

2. select original electrical parameter fiducial value and satisfy K _EE _J=K _FF _J

3. select a pair of intermediate variable in the practicality at least for use and satisfy the balanced proportions condition.

Choice difference, the utilization condition difference of all tuning coefficient in to its Mathematical Modeling, can constitute the protection relay element and the device of a series of difference in functionality purposes: when dividing with the original electrical parameter, single electric parameter type, similar two electric parameter types can be arranged, two electric parameter types of inhomogeneity; When dividing, a pair of balance variable type, many to the balance variable type can be arranged with intermediate variable item number; When dividing, can there be polarized relay type, relay to trigger type, miniature intermediate relay type with execution link feature; When dividing, start type can be arranged, apart from type, single-phase utilization type, three-phase utilization type, the comprehensive type of three-phase with the purposes feature.

The present invention also can develop into a kind of simple and practical form, promptly directly puts on an auxiliary relay with the three-phase current synthesizer behind rectifying and wave-filtering and constitutes protection as carrying out link.

Mathematical Modeling of the present invention can be protected (Microcomputer Protection) to be implemented fully by numeric type, can reach equal effect.Its key depends on the Mathematical Modeling condition of implementing protection.

The present invention's advantage compared with prior art is: the reliability nargin Kk height of the nargin that is active in one's movements Km height, not misoperation; principle and device circuit are simple, three-phase can comprehensively be a protection component device, have changed safety factor Kk, resetting ratio K when design is adjusted in utilization _FNotion, improved adjust precision with simplified the adjusting setting procedure.

Several aspects of economic benefit:

Can use side by side with existing distance protection, overcurrent protection, overload protection or replace it, produce corresponding benefit.

Because Km, Kk height, device circuit are simple and reliable, all directly help reducing the probability of " malfunction " and " tripping " overstep tripping, so at the minimizing interruption duration and dwindle and have the potentiality benefit aspect the power failure scope.

Owing to can improve fuse and thermal relay and protect incomplete present situation for threephase motor provides simple and practical protective device, reduce or avoid the scaling loss motor winding, have corresponding benefit.

Describe several embodiments of the present invention in greater detail referring now to accompanying drawing 1～10.

Fig. 1 is the three-phase electrical power system rectification distribution-difference type protection component principle of device block diagram of first embodiment of the invention.

Fig. 2 is the key link circuit theory diagrams of Fig. 1 embodiment.

Fig. 3 is Fig. 1 embodiment key link circuit characteristic figure.

Fig. 4 is the three-phase electrical power system rectification distribution-difference type protection component principle of device block diagram of second and third two embodiment of the present invention.

Fig. 5 is the circuit theory diagrams of Fig. 4 embodiment key link.

Fig. 6 is third embodiment of the invention behavioral illustrations figure.

Fig. 7 be first embodiment of the invention implement the comprehensive functional-block diagram of three-phase by means of the three-phase current synthesizer.

Fig. 8 simplifies the functional-block diagram of form for first embodiment of the invention.

Fig. 9 is one of the three-phase current synthesizer of a Fig. 7 circuit diagram.

Figure 10 is two circuit diagrams of the three-phase current synthesizer of Fig. 7.

Referring now to Fig. 1～3 explanations first embodiment of the present invention.

The single-phase form relational expression of its operation condition is as follows:

K ^△ ₁｜K _{i CL}｜-K

｜K _i

_CL｜≥C _ZDK _iI _j

Selected K ₁=K ₂=1(linear zone), I _J=I _Fmax, C _ZD=0.1～1, be " start type " protection component device.

Among Fig. 1: (1) voltage forms adjust amplitude comparing element, (6) of link, (2) rectifying and wave-filtering link, (3) three-phase summation loop, (4) non-linearization processing link, (5) non-zero and carries out link.

Wherein (1), (2) link are conventional typical circuit, are omitted.(3), (4), (5), (6) link circuit theory illustrate as Fig. 2.

Three-phase summation loop (3) includes: diode D ₁～D ₃, form the maximum output circuit;

Non-linearization link (4) includes: by R ₂With voltage stabilizing didoe WY ₁Form the non-linearize processing circuit of action circuit, by R ₄With voltage stabilizing didoe WY ₂Form and suppress loop non-linearization processing circuit;

Non-zero adjust amplitude comparing element (5) with carry out (6) jointly by resistance R ₁, R ₃With double winding polarized relay JHJ _I, JHJ _IIForm.

Under normal operation, three-phase current all is being equal to or less than I _FmaxScope in, so SR among Fig. 2 _ISR _IIAt R ₂, R ₄(R _JHJ＜＜R ₄) on pressure drop all do not reach voltage-stabiliser tube WY ₁, WY ₂Reverse breakdown voltage U _WBecause R ₁=R ₃, R ₂=R ₄So SC _I=SC _II, JHJ _IWith JHJ _IIIn synthetic excitation be 0, so JHJ reliably be failure to actuate, its

$K_K=\frac{{\mathrm{<figure-callout\; id="0"\; label="C\; ZD"\; filenames="891012702\_DRIMG3.png"\; state="\{\{state\}\}">C</figure-callout>}}_{\mathrm{ZD}}}{0}\mathrm{\to \infty \; 。}$

When the protected system fault that is short-circuited, establish Ia=I _D＞I _Fmax, D among Fig. 2 then ₁Conducting makes SR _I, SR _IIIncrease at R ₂, R ₄On pressure drop surpass U simultaneously _W, WY ₁, WY ₂All reverse breakdown presents non-linearization variation, SC for former linear change _I↑, SC _II↓, synthetic excitation meets and exceeds setting value C among the JHJ _ZDAfter, then send trip signal by JHJ.Fig. 3 provides non-linearization link output characteristics figure.

Because C _ZDThat can adjust is very little, so its action sensitivity performance significantly improves than existing overcurrent protection.

Referring now to Fig. 4, Fig. 5 second embodiment of the present invention is described, the single-phase form relational expression of its operation condition is as follows:

〉=C _ZDK _uU _JOr C _ZDK _iI _J

Selected K ₃=1, K ₄=2, φ _ZD=90 °, I _J=I _Fmax, U _J=U _FminC _ZD=0.2～0.8, be " start type " protection component device.

Among Fig. 4: (1) voltage forms link, (2) rectifying and wave-filtering link, (3) three-phase summation loop, (4) nonzero setting breadth comparison device, (5) execution link.

Wherein (1), (2) link all belong to conventional typical circuit, are omitted.(3), (4), (5) link three part circuit theory diagrams are as Fig. 5.

Three-phase summation loop (3) includes: D ₁～D ₆Six diodes, its D ₁～D ₃Form the maximum output circuit, D ₄～D ₆Form minimum value output circuit;

The non-zero setting ratio width of cloth (4) with carry out link (5) jointly by resistance R ₁～R ₄, C ₁, C ₂, polarized relay JHJ forms.

Under normal operation, φ _F≤ φ _Fmax(for example 35 °～40 °), I _F≤ I _Fmax, the operation condition relational expression has 0 or the negative difference feature, suitable movement arm side voltage U in Fig. 5 _IBe equal to or less than and suppress arm side voltage U _IISo, diode D ₄～D ₅End, JHJ is not subjected to electricity, reliably is failure to actuate, its

$K_K=\frac{{\mathrm{<figure-callout\; id="0"\; label="C\; ZD"\; filenames="891012702\_DRIMG3.png"\; state="\{\{state\}\}">C</figure-callout>}}_{\mathrm{ZD}}}{0}\mathrm{\to \infty \; 。}$

After protected system was short-circuited fault, establishing short-circuit-type was D ⁽²⁾ _AB, φ _D＞φ _F(φ for example _D=65～70 °), then wiring is (I among Fig. 4 _a-I _b) with

_AbThis branch road |

_I|＞| _II|, promptly can have among Fig. 5: U _{I .1}→ D ₁→ JHJ → D ₄→ U _{II, 1}, forming path, the JHJ winding is sent trip signal after being subjected to electricity to meet and exceed its setting value.

As the above-mentioned situation of adjusting, at I _D.min≈ I _F.maxCondition under, its operating sensitivity nargin K _mCan reach 1.5～5.

Referring now to Fig. 4～Fig. 6 the 3rd embodiment of the present invention is described, the single-phase form relational expression of its operation condition is as follows:

| K _i

_CL|-| K _{u CL}| 〉=C _ZDK _iI _JOr C _ZDK _uU _J

Selected I _J=I _{D, m, max}U _J=U _{D, m, max}, C _ZD=0.1～0.2, be " apart from type " protection component device.

Be with the difference of second embodiment: (1) link form is different, and the former is the synthetic conversion form of relative phase shift, is direct simple transformation form here; The utilization condition of adjusting difference.Other circuit form and second embodiment do not have substantial difference in principle.

Under normal operation, I _F＜I _{D, m, max}, U _F＞U _{D, m, max}So its operation condition relational expression has the negative difference feature, promptly in Fig. 5, quite suppress arm side voltage U _IIGreater than movement arm side voltage U I, so D ₄～D ₆Reliably end, JHJ is not subjected to electricity, is failure to actuate reliably, its

$K_K=\frac{{\mathrm{<figure-callout\; id="0"\; label="C\; ZD"\; filenames="891012702\_DRIMG3.png"\; state="\{\{state\}\}">C</figure-callout>}}_{\mathrm{ZD}}}{0}\mathrm{\to \infty \; 。}$

After protected system was short-circuited fault, the system of setting up departments was at maximum operational mode, and short trouble occurs in Fig. 6 l＜l _MaxScope in.Fault type is D ⁽²⁾ _AB, then among Fig. 4 wiring be (

_a-

_b) with _AbThis branch road |

_I|＞|

_II| and surpassed setting value, can have in the corresponding diagram 5: U _{I .1}→ D ₁→ JHJ → D ₄→ U _{II .1}, forming path, trip signal is sent in the JHJ action.

As under system's minimum operational mode, the short trouble of same-type takes place, in the corresponding diagram 6, when the short circuit distance at l＜l _MinIn the scope, with above-mentioned course of action, the protection would trip.L as seen from Figure 6 _Min＜l _Max, but l _Min≈ l _MaxThe stability of its protection range usually can be more than 70～80%.

Referring now to Fig. 7, Fig. 9, Figure 10, Fig. 1 illustrates the 4th embodiment of the present invention, among Fig. 7: (1) three-phase current synthesizer, (2) rectifying and wave-filtering, (3) non-linear processing, (4) non-zero setting ratio width of cloth, (5) carry out link.Be with the difference of first embodiment: the effect of (3) three-phase summation loop changes by (1) three-phase current synthesizer among Fig. 7 and replaces among former Fig. 1.

Three-phase current synthesizer (1) shows two kinds of practical forms as Fig. 9, Figure 10.Other is identical with first embodiment.

Referring now to Fig. 8, Fig. 7 the 5th embodiment of the present invention is described.(1) three-phase current synthesizer among Fig. 8, (2) rectifying and wave-filtering, (3) carry out link.It is a kind of simplification evolving morphology of the 4th embodiment that the 5th embodiment belongs to, and its (3) are carried out link and adopted auxiliary relay, and protection has simple and practical advantage to threephase motor.

The present invention is not limited to the foregoing description, and for example the stack of the Mathematical Modeling of first and second embodiment can form the start type protection component device with two pairs of balance intermediate variables; System uses easily at single phase power supply.Protection component for single-phase form; In tractive power supply system, by synthetic a pair of intermediate variable, the formation different-phase circuit protection component arrangement of being transformed to of two feeder current parameters.

Table 1 three-phase current synthesizer relative sensitivity table

Claims (6)

1, a class is used for the rectification distribution-difference type protective device of electric power system; it is characterized in that: with one or more, similar or inhomogeneity original electrical parameter; through division, synthetic or direct simple transformation; obtain one or more pairs of, normally have zero or negative difference feature, fault after have the intermediate variable of principal-employment value tag, constitute protection by " non-zero adjust formula magnitude comparator " than the width of cloth then with specific setting value.

2, protective relaying device according to claim 1 is characterized in that, has following single-phase form and action condition Mathematical Modeling general formula:

〉=C _ZDK _EE _JOr C _ZDK _FF _J

K wherein _EE _J=K _FF _J

In practicality, select a pair of intermediate variable at least for use, and satisfy the balance ratio condition of adjusting by tuning coefficient.

3, according to the protective relaying device of claim 2; when being used for three-phase system; it is characterized in that: forming the maximum output circuit side by side by one group of three diode, or be complementary with three diodes of another group minimum value output circuit of forming arranged side by side, is a protection component device with comprehensive three-phase.

4, according to the protective relaying device of claim 2; when being used for three-phase system, realize that by a kind of three-phase current synthesizer three-phase current comprehensively is a protection component device, is characterized in that: single-phase iron core; the three-phase current coil ratio is n: 1.5n: 2n, and secondary is by a coil N ₂Output.

5, according to the protective relaying device of claim 2; when being used for three-phase system; realize that by a kind of three-phase current synthesizer three-phase current comprehensively is a protection component device; it is characterized in that: the three-phase three-column iron core; the three-phase current coil turn equates to be around in respectively three posts; the coil of two equal turn numbers of secondary is around in two side columns respectively and the rectifying and wave-filtering of respectively hanging oneself, and forms the maximum output circuit by two diodes arranged side by side again and realizes comprehensive.

6, according to the protective relaying device of claim 2, can develop into a kind of simple and practical form, it is characterized in that: use the three-phase current synthesizer, behind rectifying and wave-filtering, directly put on an auxiliary relay and constitute protection as carrying out link.

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