CN1753267A - Adaptive impedance relay - Google Patents

Abstract

This invention relates to an earth faulty distance protection technology of high voltage transmission line, which is an adaptive earth direction impedance relay taking the residual voltage Uo at the faulty protection installation place as the polarized volume, which not only has the strong ability of bearing the transient impedance, but also has the advantage of protecting residual component.

Description

A kind of adaptive impedance relay

Technical field

The present invention relates to ultra-high-tension power transmission line earth fault distance protection technology.

Background technology

Modal fault is a single-phase earthing in the ultra-high-tension power transmission line, and how the transition resistance that allows when how to improve earth fault in the protection zone guarantees that clear and definite directivity is the major issue of ground connection directional impedance relay.Tripping occurs or surmount the malfunction phenomenon because the existence of transition resistance, traditional earthing distance relay are influenced by it can.The used polarizing voltage of earthing distance relay adopts memory voltage  more at present _[0]Or the positive sequence voltage  after the fault ₁ , the action of this type of relay has clear and definite directivity, but the transition resistance that allows during single-phase earthing in the district is very little.New type line frequency variable quantity impedance relay, the ability of its tolerance transition resistance is also very limited.Zero sequence Reactance Relay has good adaptive characteristic to transition resistance, but moves non-directional.For making the impedance ground relay that very strong anti-transition resistance ability can be arranged, again directivity can be arranged, need impedance ground relay with quadrilateral characteristics or composite attribute, increased the complexity that relay is realized like this, also just reduced reliability.

Summary of the invention

The technical problem to be solved in the present invention is; defective at the prior art existence; propose a kind of adaptive impedance relay, it has good adaptivity to earth resistance, the problem of anti-transition resistance ability when having impedance relay to the protection zone internal fault now to overcome.

Technical solution of the present invention is that described adaptive impedance relay is: with the residual voltage U of protection installation place after the fault ₀For amount of polarization constitutes the adaptive earthing directional impedance relay.

Below the present invention made further specify.

Adaptive earthing directional impedance relay of the present invention has the good adaptivity of earth resistance, and its adaptive characteristic is analyzed as follows:

With both-end electric power system shown in Figure 1 is example, is located at the K point single-phase earthing (is example with the A phase fault) through transition resistance has taken place, and rated current positive direction such as Fig. 1 show, during fault each fault amount as shown in Figure 2,  _KAFor the voltage of fault phase A phase short circuit place, be an amount that changes with the variation of fault point transition resistance, its variation track is seen Fig. 2;  _OPABe A phase operating voltage, ${\stackrel{\·}{U}}_{\mathrm{OPA}}={\stackrel{\·}{U}}_A-({\stackrel{\·}{I}}_A+K3{\stackrel{\·}{I}}_0)Z_{\mathrm{set}},$ Promptly adjust the impedance end voltage (in the formula,  _ABe protection installation place A phase voltage,

For flowing through the A phase current and the zero-sequence current of protection installation place).As can be seen from Fig. 2, if with  _KABe on trip boundary (dynamic action border), and be active region by shade one side, then during the internal fault of protection zone,  _OPAAlways at active region, during the protection external area error,  _OPAAlways at non-active region, Bao Hu operating characteristics just is not subjected to the influence of fault point transition resistance like this.But measure less than  in the protection installation place _KA, therefore to seek an energy from motion tracking  _KAAnd the amount that can measure.

Accident analysis is protected the residual voltage  of installation place as can be known _MOShort-circuit voltage  with the fault point _KAIdentical variation track is arranged, has during A phase ground connection:

${\stackrel{\·}{U}}_{\mathrm{KA}}=(1-\frac{Z_{\mathrm{\Σ}1}+Z_{\mathrm{\Σ}2}+Z_{\mathrm{\Σ}0}}{3R_g+Z_{\mathrm{\Σ}1}+Z_{\mathrm{\Σ}2}+Z_{\mathrm{\Σ}0}}){\stackrel{\·}{U}}_{\mathrm{KA}\left[0\right]}$

${\stackrel{\·}{U}}_0=\frac{-C_0{Z}_{M0}}{3R_g+Z_{\mathrm{\Σ}1}+Z_{\mathrm{\Σ}2}+Z_{\mathrm{\Σ}0}}{\stackrel{\·}{U}}_{\mathrm{KA}\left[0\right]}$

 when Fig. 3 shows A phase ground connection ₀With  _KAThe end points variation track, when Rg=0～∞ changes,  _KAThe end points track change  counterclockwise along circular arc 1 ₀The end points track change counterclockwise along circular arc 2.Among Fig. 3:

${\mathrm{\θ}}_K=\arg \mathrm{ta}\frac{3R_g+R_{\mathrm{\Σ}1}+R_{\mathrm{\Σ}2}+R_{\mathrm{\Σ}0}}{X_{\mathrm{\Σ}1}+X_{\mathrm{\Σ}2}+X_{\mathrm{\Σ}0}}$

${\mathrm{\θ}}_A=\arg \mathrm{tg}\frac{3R_8+R_{\mathrm{\Σ}1}+R_{\mathrm{\Σ}2}+R_{\mathrm{\Σ}0}}{X_{\mathrm{\Σ}1}+X_{\mathrm{\Σ}2}+X_{\mathrm{\Σ}0}}$

R _g=0 o'clock, ${\mathrm{\θ}}_{K\left[0\right]}={\mathrm{\θ}}_{A\left[0\right]}=\arg \mathrm{tg}\frac{R_{\mathrm{\Σ}1}+R_{\mathrm{\Σ}2}+R_{\mathrm{\Σ}0}}{X_{\mathrm{\Σ}1}+X_{\mathrm{\Σ}2}+X_{\mathrm{\Σ}0}}$

R _gDuring=∞, θ _K[∞]=θ _A[∞]=90 °, when Rg changes, $\frac{{\mathrm{d\θ}}_K}{{\mathrm{dR}}_g}=\frac{{\mathrm{d\θ}}_A}{{\mathrm{dR}}_g},$ Therefore,  ₀Trip boundary and  after the deflection-90 ° _KATrip boundary identical.And,  ₀With  _KAThe above-mentioned relation influence that not be positioned at by relay to send electric side or be subjected to electric side, be not subjected to the influence of load current yet.So the residual voltage phase place of available protection installation place replaces the false voltage of fault point, constitute the adaptive impedance relay of residual voltage polarization.Compare with the impedance ground relay that is made of other polarizing voltage, this relay not only has very strong tolerance transition resistance ability, but also has the advantage of zero-sequence component protection, is the very good adaptive impedance relay of combination property.The MATLAB simulation analysis is the result prove, this relay has good operating characteristics, on the supertension line of 500KV earth resistance had very strong adaptive ability.

As known from the above, the present invention is a kind of adaptive impedance relay, and its characteristic compared with the prior art has:

When (1) in protection range earth fault taking place, the impedance ground relay of residual voltage polarization has very strong anti-transition resistance ability, and this is that other polarizing voltage relay is incomparable;

(2) when earth fault takes place in the protection exit, the relay of residual voltage polarization has the highest operating sensitivity, does not promptly have voltage action " dead band ", has solved " dead band " problem of conventional impedance ground relay;

(3) actuating of relay has clear and definite directivity, and this is that the relay of zero sequence reactance characteristic is not available;

(4) no matter relay is provided in a side of and send electric side and be subjected to the electric side can both correct operation;

(5) during nearly protection range end fault, the operating characteristics of the impedance ground relay of residual voltage polarization can be subjected to the influence of transition resistance, and is subjected to the ability of electric side tolerance transition resistance not enough.But can find out in the table from behind; if with the zero sequence polarizing voltage to the suitable phase shift of leading direction; then both can reinforcing relay in the adaptive ability of protection range end to transition resistance, the sensitivity of the actuating of relay in the time of further improving the protection range internal fault again.

Description of drawings

Fig. 1 is a both-end electric power system diagram;

Voltage phasor-diagram when Fig. 2 is A phase ground connection;

Voltage phasor-diagram when Fig. 3 is A phase ground connection.

Embodiment

Carry out simulation calculation when adopting MATLAB software to the 500KV supertension line A phase ground connection of a long 300Km, wherein transmission line adopts distributed parameter model.System wiring as shown in Figure 1, simulation system parameters is as follows:

System parameters: Z _M=Z _N=5.74+j14.1 Ω

Line parameter circuit value: r ₁=0.02083 Ω/km, l ₁=0.8984mH/km, c ₁=0.0129MF/km

r ₀＝0.1148Ω/km， l ₀＝2.2886mH/km，c ₀＝0.00523MF/km。60 ° of circuit both sides electrical source voltage phase differences, the district of adjusting is 85% of total track length.

Simulation calculation content: simultaneously to residual voltage polarization ( ₀) and memory voltage polarization ( commonly used at present _A[0]), positive sequence voltage polarization ( _A1), the operating voltage SPA sudden phase anomalies (is  _OP[0]The operating characteristics of impedance ground relay polarization) is carried out the phase bit emulator, calculates

Phase place.Relay is located at respectively and send electric side and be subjected to electric side; the fault point is chosen for protection outlet in the other direction, positive direction outlet, the terminal 240KM of nearly protection range place; 4 points in the outside 300KM place of protection range, transition resistance change to 300 Ω (step-length is 10 Ω) from 0, and the operating characteristics of relay is

Simulation calculation the results are shown in Table 1 and table 2 (come into plain view for making data, only listed the pairing emulated data of transition resistance when certain actuating of relay characteristic is changed in the table.Subordinate list

Table 1, send electric side:

(1) positive direction exit A phase ground connection

R g	u 0	u a1	u a[0]	u [op]
					0 80 90 100 110 150 200 300	-134.95 -134.95 -132.59 -130.45 -128.49 -122.22 -116.8 -116.8	-93.716 -93.716 -88.471 -83.786 -79.589 -66.53 -55.712 -55.712	-101.67 -101.67 -96.453 -91.713 -87.403 -73.624 -61.823 -61.823	-94.243 -94.243 -89.023 -84.283 -79.973 -66.194 -54.393 -54.393

(2) the terminal A phase ground connection (240KM place) of nearly protection range

R g	u 0	u a1	u a[0]	u [op]
					0 10 20 30 40 50 100 200 300	-134.53 -100.1 -92.401 -89.181 -87.424 -86.319 -83.991 -82.765 -82.347	-149.45 -109.23 -95.979 -87.526 -80.908 -75.338 -56.219 -38.496 -30.721	-147.07 -107.86 -95.559 -87.965 -82.091 -77.144 -59.61 -41.841 -33.446	-139.64 -100.43 -88.129 -80.535 -74.661 -69.714 -52.18 -34.411 -26.016

(3) export A phase ground connection in the other direction

R g	u 0	u a1	u a[0]	u [op]
					0 100 200 300	-27.512 -74.857 -83.083 -86.26	-28.152 -28.197 -21.99 -19.163	-28.447 -36.124 -28.101 -23.77	-21.017 -28.694 -20.671 -16.34

(4) the outside A phase ground connection (300KM place) of protection range

R g	u 0	u a1	u a[0]	u [op]
					0 100 200 300	-27.512 -74.857 -83.083 -86.26	-28.152 -28.197 -21.99 -19.163	-28.447 -36.124 -28.101 -23.77	-21.017 -28.694 -20.671 -16.34

Table 2, be subjected to electric side:

(1) positive direction exit A phase ground connection

R g	u 0	u a1	u a[0]	u [op]
					0 90 100 110 120 140 200 280 290 300	171.12 -137.86 -132.66 -127.86 -123.49 -115.98 -100.98 -90.684 -89.812 -89.002	170.48 -93.743 -85.996 -78.958 -72.596 -61.712 -39.883 -24.48 -23.147 -21.904	155.36 -116.55 -108.75 -101.59 -95.081 -83.829 -60.817 -44.159 -42.699 -41.334	162.79 -109.12 -101.32 -94.164 -87.651 -76.399 -53.387 -36.729 -35.269 -33.904

(2) the terminal A phase ground connection (240KM place) of nearly protection range

R g	u 0	u a1	u a[0]	u [op]
					0 10 20 30 50 100 200 300	-165.54 -102.17 -91.706 -87.917 -84.804 -82.432 -81.237 -80.837	-151.84 -82.815 -67.019 -58.268 -46.44 -28.615 -12.194 -23.012	-169.16 -101 -85.939 -77.776 -66.704 -49.127 -31.388 -15.582	-161.73 -93.571 -78.509 -70.346 -59.274 -41.697 -23.958 -21.03

(3) export A phase ground connection in the other direction

R g	u 0	u a1	u a[0]	u [op]
					0 100 200 300	35.232 -42.175 -55.155 -59.539	34.591 4.4841 5.9376 7.5586	19.474 -18.265 -14.996 -11.872	26.904 -10.835 -7.5658 -4.4416

(4) the outside A phase ground connection (300KM place) of protection range

R g	u 0	u a1	u a[0]	u [op]
					0 100 200 300	-43.005 -80.075 -81.789 -82.28	-25.741 -22.846 -7.4564 -1.5324	-43.565 -43.565 -26.435 -19.417	-36.135 -36.135 -19.005 -11.987

Claims (1)

1, a kind of adaptive impedance relay is characterized in that, with the residual voltage U of protection installation place after the fault _oFor amount of polarization constitutes this adaptive earthing directional impedance relay.

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