CN104300514B - Stand domain ground distance protection III section self adaptation offset characteristic setting methods - Google Patents

Abstract

The present invention relates to a kind of station domain ground distance protection III section self adaptation offset characteristic setting methods, belong to protecting electrical power system and control technology field.The method includes：Sending Dai Weinan equiva lent impedances Z are calculated with 12 cycle data after starting_thev：According to sending Dai Weinan equiva lent impedances Z for calculating_thev, self adaptation to stand domain ground distance protection III sections offset characteristic adjust：According to the ground distance protection III field offset characteristics of self-adaptative adjustment, judge whether faulty, and take corresponding actions.According to sending Dai Weinan equiva lent impedances come the offset characteristic of regulated ground distance protection III sections.The present invention can overcome station domain ground distance protection III sections in susceptiveness and selective contradiction, take into account station domain ground distance protection III sections to the susceptiveness of failure and the selectivity of reply accident overload, improve the reliability of station domain ground distance protection III section actions.

Description

Stand domain ground distance protection III section self adaptation offset characteristic setting methods

Technical field

The invention belongs to protecting electrical power system and control technology field, more particularly to a kind of station for being applied to intelligent substation Domain ground distance protection III section self adaptation offset characteristic setting methods.

Background technology

Intelligent substation has richly endowed by nature at aspects such as secondary device compatibility, interoperability, data resource sharings Advantage, bring digitized change to power system.Station domain Protective strategy based on IEC61850 standards is in the ascendant, this Applicant has disclosed a kind of protection control method and first collection of Digitized transformation station equipment in patent CN101478146A Into transforming plant protecting and the multi-function device for controlling；A kind of integrated guarantor of intelligent substation is disclosed in patent CN102761106A The fast starting and phasor calculating method of shield.On the basis of based on the shared information in station domain, more protections are changed and are carried out.

Wherein, based on station domain information solving the problems, such as to protect disproportionate movement under accident overload to be one of them Research direction.Accident overload is typically caused by large disturbances such as failures, when one or more circuit of transmission cross-section is removed, is made Cause the serious overload of same section other working lines into power flow transfer, and be likely to result in overload circuit distance protection III Section disproportionate movement, is the major reason of power system cascading trip.Apart from III sections under accident overload disproportionate movement The contradiction that essential reason is distance protection III sections in susceptiveness with selectivity, especially being ground distance III sections.

The self-adapting regulation method of the carried preventing overload mis-operation by distance protection of patent CN101335450, is judged as in protection After overload, 1.5～2 times of nargin protection act characteristic of adjusting the distance is stayed to make self-adaptative adjustment according to current loads size, by mho Circle characteristic is adjusted to prism-circle composite attribute, or will move in the resistive component restraining line of polygon characteristic.The method is in list Realize on the basis of bar line information, the distance protection acting characteristic after adjustment may the tripping in failure is subsequently answered.

The content of the invention

The purpose of the present invention is to overcome station domain ground distance protection III sections in susceptiveness and selective contradiction, proposing A kind of station domain ground distance protection III section self adaptation offset characteristic setting methods, this method are used in intelligent substation, can improve The reliability of distance protection action.

A kind of station domain ground distance protection III section self adaptation offset characteristic setting methods proposed by the present invention, its feature exist In the method is comprised the following steps：

Step 1) sending Dai Weinan equiva lent impedances Z are calculated with 1-2 cycles data after starting_thev：Circular It is as follows：

When secondary side bus negative sequence voltage amplitudeDuring more than or equal to 0.5V, bus negative sequence voltage, all inlet wires are extracted Negative-sequence current sum calculates sending Dai Weinan equiva lent impedances Z_thevFor：

In formula (1),For the counted bus negative sequence voltage of k-th sampled point；Adopt for k-th for the m article inlet wire The counted negative-sequence current of sampling point, to flow out generatrix direction as positive direction, a total of M bars inlet wire of transformer station, addition can it is all enter Line negative-sequence current sumZ_thevK () is the counted sending Dai Weinan equiva lent impedances of k-th sampled point；N is every Cycle sampled point, t₀Instance sample point numbering is started for protection, Z counted to 2 cycles after starting_thevK () averaged is obtainedSending Dai Weinan equiva lent impedances Z can be obtained_thev；

When secondary side bus negative sequence voltage amplitudeDuring less than or equal to 0.5V, then sending is calculated with positive sequence Sudden Changing Rate Dai Weinan equiva lent impedances Z_thevFor：

In formula (2),For the counted bus positive sequence voltage of k-th sampled point,For kth -2N sampling The counted bus positive sequence voltage of point,For the counted bus positive sequence Sudden Changing Rate voltage of k-th sampled point, N is that every cycle is adopted Sampling point number；For the forward-order current of the m article inlet wire, k-th sampled point,For the m article inlet wire kth -2N The forward-order current of sampled point,For the counted positive sequence Sudden Changing Rate electric current of the m article inlet wire, k-th sampled point, to flow out bus Direction is positive direction, and a total of M bars inlet wire of transformer station, addition can all inlet wire forward-order current Sudden Changing Rate sums Z_thevK () is the counted sending Dai Weinan equiva lent impedances of k-th sampled point；t₀Instance sample point numbering is started for protection, it is right The counted Z of 2 cycles after starting_thevK () averaged is obtainedSending Dai Weinan equiva lent impedances can be obtained Z_thev；

Step 2) according to step 1) sending Dai Weinan equiva lent impedances Z that calculate_thev, self adaptation is to domain ground distance of standing The offset characteristic of protection III sections is adjusted：

In formula (3),For polarizing voltage, place's power-frequency voltage or positive sequence voltage can be fetched protection；To protect installation place to survey Amount phase current, Φ are separate, can use A, B, C phase；To protect installation place zero-sequence current；K₀For circuit zero-utility theory, by line Road positive sequence impedance and zero sequence impedance are tried to achieve；α is deviation ratio, can be from 0～0.5 value)；For new impedance of adjusting, with circuit Initially adjust impedance Z_setRelation be：Can use 0.7～1.0 times of Z_set, as shown in Figure 2；Wherein, broken circle is ground distance Protection III section acting characteristics, solid line circle are the ground distance protection III section active regions with self adaptation offset characteristic after adjustment Domain；

Step 3) according to step 2) the ground distance protection III field offset characteristics of self-adaptative adjustment, carry out protection calculating (tool Body method belongs to routine techniquess).

The characteristics of of the invention and beneficial effect：

The setting method is the offset characteristic protected come adjustable range based on sending Dai Weinan equiva lent impedances, main pin To domain ground distance protection III sections of standing.Wherein, sending Dai Weinan equiva lent impedances be based on station domain it is shared on the basis of, root Voltage, current data according to all inlet wires after protection is started in 1-2 cycle carries out Real-time solution and obtains.

The beneficial effect of the invention is：When system is under the big method of operation, the big load weight of trend, fault signature are more bright Aobvious, and accident overload probability of happening is high, sending end Dai Weinan equiva lent impedance now is smaller, according to the present invention carried it is adaptive Offset characteristic setting method is answered, the active region of distance protection is less, can effectively reduce standing domain ground distance protection III sections in accident The probability started under overload ensures to select sexual act；When system is under the little method of operation, trend is less, fault signature ratio Less obvious, accident overload probability of happening is not high, and sending end Dai Weinan equiva lent impedance now is than larger；Carried according to the present invention Self adaptation offset characteristic setting method, the active region of distance protection is larger, can effectively improve station domain ground distance protection III sections The sensitivity started in the case of the big resistance singlephase earth faults of Jing.This method can be adaptive to system operation mode, take into account and connect Selectivity of the ground distance protection III sections to the susceptiveness and reply accident overload of transition resistance.

Description of the drawings

Fig. 1 is the station domain ground distance protection III section self adaptation offset characteristic setting method schematic diagrams of the present invention；

Fig. 2 is the station domain performance chart of the ground distance protection III sections with self adaptation offset characteristic of the present invention.

Specific embodiment

A kind of intelligent substation station domain proposed by the present invention combines accompanying drawing and reality apart from back-up protection self-adaptive sites method Apply example detailed description as follows：

The station domain ground distance protection III section self adaptation offset characteristic setting method flow processs of the present invention are as shown in figure 1, the party Method is comprised the following steps：

Step 1) sending Dai Weinan equiva lent impedances Z are calculated with 1-2 cycles data after starting_thev：Circular It is as follows：

When secondary side bus negative sequence voltage amplitudeDuring more than or equal to 0.5V, bus negative sequence voltage, all inlet wires are extracted Negative-sequence current sum calculates sending Dai Weinan equiva lent impedances Z_thevFor：

In formula (1),For the counted bus negative sequence voltage of k-th sampled point；Adopt for k-th for the m article inlet wire The counted negative-sequence current of sampling point, to flow out generatrix direction as positive direction, a total of M bars inlet wire of transformer station, addition can it is all enter Line negative-sequence current sumZ_thevK () is the counted sending Dai Weinan equiva lent impedances of k-th sampled point；N is every Cycle sampled point, t₀Instance sample point numbering is started for protection, Z counted to 2 cycles after starting_thevK () averaged is obtainedSending Dai Weinan equiva lent impedances Z can be obtained_thev；

When secondary side bus negative sequence voltage amplitudeDuring less than or equal to 0.5V, then sending is calculated with positive sequence Sudden Changing Rate Dai Weinan equiva lent impedances Z_thevFor：

In formula (2),For the counted bus positive sequence voltage of k-th sampled point,For kth -2N sampling The counted bus positive sequence voltage of point,For the counted bus positive sequence Sudden Changing Rate voltage of k-th sampled point, N is that every cycle is adopted Sampling point number；For the forward-order current of the m article inlet wire, k-th sampled point, I_m1(k-2N) adopt for the m article inlet wire kth -2N The forward-order current of sampling point,For the counted positive sequence Sudden Changing Rate electric current of the m article inlet wire, k-th sampled point, to flow out bus side To for positive direction, a total of M bars inlet wire of transformer station, addition can all inlet wire forward-order current Sudden Changing Rate sums Z_thevK () is the counted sending Dai Weinan equiva lent impedances of k-th sampled point；t₀Instance sample point numbering is started for protection, it is right The counted Z of 2 cycles after starting_thevK () averaged is obtainedSending Dai Weinan equiva lent impedances can be obtained Z_thev；

Step 2) according to step 1) sending Dai Weinan equiva lent impedances Z that calculate_thev, self adaptation is to domain ground distance of standing The offset characteristic of protection III sections is adjusted：

In formula (3),For polarizing voltage, place's power-frequency voltage or positive sequence voltage can be fetched protection；To protect installation place to survey Amount phase current, Φ are separate, can use A, B, C phase；To protect installation place zero-sequence current；K₀For circuit zero-utility theory, by Circuit positive sequence impedance and zero sequence impedance are tried to achieve；α is deviation ratio, can be from 0～0.5 value；For new impedance of adjusting, with line Road is initially adjusted impedance Z_setRelation be：Can use 0.7～1.0 times of Z_set, as shown in Figure 2；Wherein, broken circle for ground connection away from From protection III section acting characteristics, solid line circle is the ground distance protection III section active regions with self adaptation offset characteristic after adjustment Domain；

Step 3) according to step 2) the ground distance protection III field offset characteristics of self-adaptative adjustment, carry out protection calculating (tool Body method belongs to routine techniquess).

On the basis of station domain information is shared, voltage, the current information of a plurality of circuit is known in domain of standing apart from back-up protection.When After protection is started, before ground distance III sections protection processing routine is carried out, adjusted according to sending Dai Weinan equiva lent impedances The offset characteristic of distance protection.

Under the little method of operation of system that accident overload does not result in the starting of distance protection III sections, this method can be appropriate Improve susceptiveness of the protection to transition resistance；The big operation of system of distance protection III sections starting is likely to result in accident overload Under mode, emphasis ensures the selection sexual act of protection, i.e., be failure to actuate under accident overload as far as possible.The method is common based on station domain Information realization is enjoyed, therefore intelligent substation station domain is particularly adapted to apart from back-up protection.

Claims (1)

1. a kind of station domain ground distance protection III section self adaptation offset characteristic setting methods, it is characterised in that the method include with Lower step：

Step 1) sending Dai Weinan equiva lent impedances Z are calculated with 1-2 cycles data after starting_thev：Circular is as follows：

When secondary side bus negative sequence voltage amplitudeDuring more than or equal to 0.5V, bus negative sequence voltage, all inlet wire negative phase-sequences electricity are extracted Stream sum calculates sending Dai Weinan equiva lent impedances Z_thevFor：

$\left\{\begin{array}{c}{Z}_{thev}\left(k\right)=\frac{{\stackrel{\·}{U}}_2\left(k\right)}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{m2}\left(k\right)}\\ Z_{thev}=\stackrel{\‾}{Z_{thev}\left(k\right)},k=t_0+1,t_0+2,\mathrm{....},t_0+2N\end{array}\right.---\left(1\right)$

In formula (1),For the counted bus negative sequence voltage of k-th sampled point；For the m article inlet wire, k-th sampled point Counted negative-sequence current, to flow out generatrix direction as positive direction, a total of M bars inlet wire of transformer station is added to obtain all inlet wire negative phase-sequences Electric current sumZ_thevK () is the counted sending Dai Weinan equiva lent impedances of k-th sampled point；N is that every cycle is adopted Sampling point, t₀Instance sample point numbering is started for protection, Z counted to 2 cycles after starting_thevK () averaged is obtainedObtain final product sending Dai Weinan equiva lent impedances Z_thev；

When secondary side bus negative sequence voltage amplitudeDuring less than or equal to 0.5V, then sending is calculated with positive sequence Sudden Changing Rate and wear dimension Southern equiva lent impedance Z_thevFor：

$\left\{\begin{array}{c}\mathrm{\Δ}{\stackrel{\·}{U}}_1\left(k\right)=|{\stackrel{\·}{U}}_1\left(k\right)-{\stackrel{\·}{U}}_1\left(k-2N\right)|\\ \mathrm{\Δ}{\stackrel{\·}{I}}_{m1}\left(k\right)=|{\stackrel{\·}{I}}_{m1}\left(k\right)-{\stackrel{\·}{I}}_{m1}\left(k-2N\right)|\\ Z_{thev}\left(k\right)=\frac{\mathrm{\Δ}{\stackrel{\·}{U}}_1\left(k\right)}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\mathrm{\Δ}{\stackrel{\·}{I}}_{m1}\left(k\right)}\\ Z_{thev}=\stackrel{\‾}{Z_{thev}\left(k\right)},k=t_0+1,t_0+2,\mathrm{....},t_0+2N\end{array}\right.---\left(2\right)$

In formula (2),For the counted bus positive sequence voltage of k-th sampled point,Count for kth -2N sampling The bus positive sequence voltage for obtaining,For the counted bus positive sequence Sudden Changing Rate voltage of k-th sampled point, N is every cycle sampled point Number；For the forward-order current of the m article inlet wire, k-th sampled point,For the m article inlet wire kth -2N sampling The forward-order current of point,For the counted positive sequence Sudden Changing Rate electric current of the m article inlet wire, k-th sampled point, to flow out generatrix direction For positive direction, a total of M bars inlet wire of transformer station, all inlet wire forward-order current Sudden Changing Rate sums are added to obtainZ_thev(k) For the counted sending Dai Weinan equiva lent impedances of k-th sampled point；t₀Instance sample point numbering is started for protection, after starting The counted Z of 2 cycles_thevK () averaged is obtainedObtain final product sending Dai Weinan equiva lent impedances Z_thev；

Step 2) according to step 1) sending Dai Weinan equiva lent impedances Z that calculate_thev, self adaptation is to domain ground distance protection of standing The offset characteristic of III sections is adjusted：

In formula (3),For polarizing voltage, place's power-frequency voltage or positive sequence voltage are fetched protection；To protect installation place measurement mutually electricity Stream, Φ are separate, take A, B, C phase；To protect installation place zero-sequence current；K₀For circuit zero-utility theory, hindered by circuit positive sequence Anti- and zero sequence impedance is tried to achieve；α is deviation ratio, from 0～0.5 value；Z′_setFor new impedance of adjusting, initially adjust resistance with circuit Anti- Z_setRelation be：Z′_setTake 0.7～1.0 times of Z_set；

Step 3) according to step 2) the ground distance protection III field offset characteristics of self-adaptative adjustment, carry out protection calculating.