CN104092195B - Based on Negative Sequence Differential coefficient matrix ultrahigh voltage alternating current transmission lines guard method - Google Patents

Abstract

Based on Negative Sequence Differential coefficient matrix ultrahigh voltage alternating current transmission lines guard method: model initially with distributed constant; A, B, C phase negative-sequence current of the ultrahigh voltage alternating current transmission lines other end, Negative Sequence Differential current amplitude is calculated respectively by A, B, C phase negative sequence voltage of ultrahigh voltage alternating current transmission lines one end, negative-sequence current; and then calculate Negative Sequence Differential coefficient matrix, utilize the magnitude relationship Judging fault phase line between each element of matrix.The inventive method physical model uses distributed parameter model; performance is not affected by capacitance current; it is applicable to any electric pressure; the relay protection of whole failure process after being particularly well-suited to ultrahigh voltage alternating current transmission lines fault; performance is not affected by transition resistance and load current; especially when ultrahigh voltage alternating current transmission lines generation single-phase high-impedance, the correct reliable recognition fault phase circuit of energy, it is achieved the relay protection function of uniline fault tripping single-phase fault circuit.

Description

Based on Negative Sequence Differential coefficient matrix ultrahigh voltage alternating current transmission lines guard method

Technical field

The present invention relates to Relay Protection Technology in Power System field, it is a kind of poor based on negative phase-sequence to concretely relate to Dynamic coefficient matrix ultrahigh voltage alternating current transmission lines guard method.

Background technology

Ultra-high voltage AC transmission network can be greatly improved electrical network transmission capacity, advantageously reduces transmission losses, joint Save Transmission Cost, energy-saving and emission-reduction, thus promote green energy resource expanding economy, can make again electrical network more intelligent, Strong, stable, reliable.Meanwhile, as electrical network bulk transmission grid, ultrahigh voltage alternating current transmission lines breaks down After, if fault can not be detected in time and be correctly isolated, stability of power system can be caused to be destroyed, Possibly even cause mains breakdown, thus social economy is produced and causes loss difficult to the appraisal.

Owing to not affected by power system operation mode and electric network composition, and there is natural phase-selecting function, Current differential protection is always the main protection of various electric pressure transmission line of electricity.At 500kV and following voltage In grade transmission line of electricity, owing to transmission line of electricity capacitance current along the line is the least, distribution capacity is to difference between current Dynamic Perfomance of protective relaying impact is the least.But, the transmission of the voltage of ultrahigh voltage alternating current transmission lines, electric current has Significantly wave process, capacitance current along the line is very big, utilizes the amplitude of two ends current phasor sum as action It is big that the conventional current differential protection of amount is faced with current differential protection starting current, and in order to prevent current differential False protection, improves startup setting value and differential protection sensitivity can be caused again not enough, govern conventional current poor Dynamic protection application on ultrahigh voltage alternating current transmission lines.

Owing to being affected by load current, during transmission line of electricity single-phase high-impedance, directly utilize two ends electric current The amplitude of vector as actuating quantity conventional current differential protection cannot correct tripping fault phase, but by zero Sequence current differential is protected as its standby protection act tripping three-phase line.Owing to non-full-operating state is to electricity Net the stable impact situation much smaller than three-phase tripping, by Zero sequence current differential protection action tripping three-phase line This move strategy can strengthen the fault impact to grid stability.Therefore, there is single-phase high resistant in transmission line of electricity During ground short circuit fault, if can correct tripping fault phase, retain remaining and two normally continue to run with mutually, favorably In strengthening grid stability, electrical network can be made the strongest reliably.

Summary of the invention

It is an object of the invention to the deficiency overcoming prior art to exist, it is provided that a kind of based on Negative Sequence Differential coefficient Matrix ultrahigh voltage alternating current transmission lines guard method.The inventive method physical model uses distributed parameter model, Performance is not affected by capacitance current, it is adaptable to any electric pressure, particularly extra-high-voltage alternating current The relay protection of transmission line of electricity.The inventive method is whole fault after being applicable to ultrahigh voltage alternating current transmission lines fault The relay protection of process, performance is not affected by transition resistance and load current, especially hands over when extra-high voltage During stream transmission line of electricity generation single-phase high-impedance, the correct reliable recognition fault phase of the inventive method energy, real The relay protection function of existing uniline fault tripping single-phase fault circuit.

In order to solve above-mentioned technical problem, the invention provides and hand over based on Negative Sequence Differential coefficient matrix extra-high voltage Stream line protection method, it is characterised in that comprise the following steps:

(1) ultrahigh voltage alternating current transmission lines A, B, C phase negative voltage in m transforming plant protecting installation place is measuredA, B, C phase negative-sequence currentMeasure extra-high-voltage alternating current Transmission line of electricity is at A, B, C phase negative-sequence current of n transforming plant protecting installation place

(2) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase negative voltage of m transforming plant protecting installation placeA, B, C phase negative-sequence currentCalculate extra-high-voltage alternating current Transmission line of electricity is at A, B, C phase negative-sequence current of n transforming plant protecting installation place

${\stackrel{\·}{I}}_{\mathrm{mnA}2}={\stackrel{\·}{I}}_{\mathrm{mA}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mA}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnB}2}={\stackrel{\·}{I}}_{\mathrm{mB}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mB}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnC}2}={\stackrel{\·}{I}}_{\mathrm{mC}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mC}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

Wherein, γ₂For ultrahigh voltage alternating current transmission lines negative phase-sequence propagation constant；Z_c2For ultrahigh voltage alternating current transmission lines Negative phase-sequence natural impedance；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；cosh(.) For hyperbolic cosine function；Sinh (.) is hyperbolic sine function；

(3) calculate $I_{\mathrm{dA}2}=|{\stackrel{\·}{I}}_{\mathrm{mnA}2}+{\stackrel{\·}{I}}_{\mathrm{nA}2}|,I_{\mathrm{dB}2}=|{\stackrel{\·}{I}}_{\mathrm{mnB}2}+{\stackrel{\·}{I}}_{\mathrm{nB}2}|,I_{\mathrm{dC}2}=|{\stackrel{\·}{I}}_{\mathrm{mnC}2}+{\stackrel{\·}{I}}_{\mathrm{nC}2}|,$ Calculate negative phase-sequence Differential factor matrix $S=\left[\begin{array}{ccc}1& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dB}2}}& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dA}2}}& 1& \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dA}2}}& \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dB}2}}& 1\end{array}\right];$

(4) greatest member in Negative Sequence Differential coefficient matrix S is chosenThen basisChoose Element in Negative Sequence Differential coefficient matrix SSet threshold values α, utilize following relay to protect Protect criterion failure judgement phase line:

If i () meets S_ij> α and S_ik> α, then judge that i phase line is fault phase circuit；

(ii) if meeting S_ij> α and S_kj> α, then judge that ik phase line is fault phase circuit；

(iii) if meeting α > S_ij> 1, then judge that ijk phase line is fault phase circuit；Wherein, ijk=ABC, ACB, BAC, BCA, CAB, CBA phase.

The feature of the present invention and technological achievement:

The inventive method physical model uses distributed parameter model, and performance is not by the shadow of capacitance current Ring, it is adaptable to the relay protection of any electric pressure, particularly ultrahigh voltage alternating current transmission lines.Side of the present invention Method is the relay protection of whole failure process after being applicable to ultrahigh voltage alternating current transmission lines fault, and performance is not subject to , especially there is the event of single-phase high resistance ground when ultrahigh voltage alternating current transmission lines in transition resistance and the impact of load current During barrier, the correct reliable recognition fault phase of the inventive method energy, it is achieved uniline fault tripping single-phase fault line The relay protection function on road.

Accompanying drawing explanation

Fig. 1 is the ultrahigh voltage alternating current transmission lines fault schematic diagram of application the inventive method.

Detailed description of the invention

Below according to Figure of description, technical scheme is expressed in further detail.

Fig. 1 is the ultrahigh voltage alternating current transmission lines fault schematic diagram of application the inventive method.

Based on Negative Sequence Differential coefficient matrix ultrahigh voltage alternating current transmission lines guard method, comprise the following steps:

(1) ultrahigh voltage alternating current transmission lines is at m side transformer station and the fundamental frequency of transforming plant protecting installation place, n side Electric parameters is respectively by synchronous phasor measurement unit (the phase measurement being arranged on transformer station both this Unit, PMU) measure obtain.Synchronous phasor measurement unit measures ultrahigh voltage alternating current transmission lines in m transformer station A, B, C phase negative voltage of protection installation placeA, B, C phase negative-sequence current Measure ultrahigh voltage alternating current transmission lines A, B, C phase negative-sequence current in n transforming plant protecting installation place ${\stackrel{\·}{I}}_{\mathrm{nB}2},{\stackrel{\·}{I}}_{\mathrm{nC}2}.$

The measurement data of synchronous phasor measurement unit is defeated to extra-high-voltage alternating current through fibre optic data transmission channel transfer Electric line protective relaying device, ultrahigh voltage alternating current transmission lines protective relaying device is by application the inventive method Complete ultrahigh voltage alternating current transmission lines relay protection function:

(2) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase negative voltage of m transforming plant protecting installation placeA, B, C phase negative-sequence currentCalculate ultra-high voltage AC transmission line Road is at A, B, C phase negative-sequence current of n transforming plant protecting installation place

${\stackrel{\·}{I}}_{\mathrm{mnA}2}={\stackrel{\·}{I}}_{\mathrm{mA}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mA}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnB}2}={\stackrel{\·}{I}}_{\mathrm{mB}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mB}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnC}2}={\stackrel{\·}{I}}_{\mathrm{mC}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mC}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

Wherein, γ₂For ultrahigh voltage alternating current transmission lines negative phase-sequence propagation constant；Z_c2For ultrahigh voltage alternating current transmission lines Negative phase-sequence natural impedance；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；cosh(.) For hyperbolic cosine function；Sinh (.) is hyperbolic sine function.

(3) calculate $I_{\mathrm{dA}2}=|{\stackrel{\·}{I}}_{\mathrm{mnA}2}+{\stackrel{\·}{I}}_{\mathrm{nA}2}|,I_{\mathrm{dB}2}=|{\stackrel{\·}{I}}_{\mathrm{mnB}2}+{\stackrel{\·}{I}}_{\mathrm{nB}2}|,I_{\mathrm{dC}2}=|{\stackrel{\·}{I}}_{\mathrm{mnC}2}+{\stackrel{\·}{I}}_{\mathrm{nC}2}|.$

And then calculate Negative Sequence Differential coefficient matrix $S=\left[\begin{array}{ccc}1& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dB}2}}& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dA}2}}& 1& \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dA}2}}& \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dB}2}}& 1\end{array}\right].$

(4) greatest member in Negative Sequence Differential coefficient matrix S is chosenThen basisChoose Element in Negative Sequence Differential coefficient matrix SWithSet threshold values α, utilize following relay to protect Protect criterion failure judgement phase line:

If i () meets S_ij> α and S_ik> α, then judge that i phase line is fault phase circuit；

(ii) if meeting S_ij> α and S_kj> α, then judge that ik phase line is fault phase circuit；

(iii) if meeting α > S_ij> 1, then judge that ijk phase line is fault phase circuit；Wherein, ijk=ABC, ACB, BAC, BCA, CAB, CBA phase.

The inventive method physical model uses distributed parameter model, and performance is not by the shadow of capacitance current Ring, it is adaptable to the relay protection of any electric pressure, particularly ultrahigh voltage alternating current transmission lines.Side of the present invention Method is the relay protection of whole failure process after being applicable to ultrahigh voltage alternating current transmission lines fault, and performance is not subject to , especially there is the event of single-phase high resistance ground when ultrahigh voltage alternating current transmission lines in transition resistance and the impact of load current During barrier, the correct reliable recognition fault phase of the inventive method energy, it is achieved uniline fault tripping single-phase fault line The relay protection function on road.

The foregoing is only the preferred embodiment of the present invention, but protection scope of the present invention is not limited to This, any those familiar with the art, in the technical scope that the invention discloses, can readily occur in Change or replacement, all should contain within protection scope of the present invention.

Claims (1)

1., based on Negative Sequence Differential coefficient matrix ultrahigh voltage alternating current transmission lines guard method, its feature exists In, comprise the following steps:

(1) ultrahigh voltage alternating current transmission lines A, B, C phase in m transforming plant protecting installation place is measured Negative voltageA, B, C phase negative-sequence currentSurvey Amount ultrahigh voltage alternating current transmission lines A, B, C phase negative-sequence current in n transforming plant protecting installation place ${\stackrel{\·}{I}}_{\mathrm{nB}2},{\stackrel{\·}{I}}_{\mathrm{nC}2};$

(2) utilize ultrahigh voltage alternating current transmission lines in A, B, C phase of m transforming plant protecting installation place Negative voltageA, B, C phase negative-sequence currentCalculate Ultrahigh voltage alternating current transmission lines is at A, B, C phase negative-sequence current of n transforming plant protecting installation place ${\stackrel{\·}{I}}_{\mathrm{mnB}2},{\stackrel{\·}{I}}_{\mathrm{mnC}2}:$

${\stackrel{\·}{I}}_{\mathrm{mnA}2}={\stackrel{\·}{I}}_{\mathrm{mA}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mA}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnB}2}={\stackrel{\·}{I}}_{\mathrm{mB}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mB}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

${\stackrel{\·}{I}}_{\mathrm{mnC}2}={\stackrel{\·}{I}}_{\mathrm{mC}2}\cosh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)-\frac{{\stackrel{\·}{U}}_{\mathrm{mC}2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{\mathrm{mn}}\right)$

Wherein, γ₂For ultrahigh voltage alternating current transmission lines negative phase-sequence propagation constant；Z_c2Defeated for extra-high-voltage alternating current Electric line negative phase-sequence natural impedance；l_mnFor the ultra-high voltage AC transmission line between m transformer station and n transformer station Road length；Cosh (.) is hyperbolic cosine function；Sinh (.) is hyperbolic sine function；

(3) calculate $I_{\mathrm{dA}2}=|{\stackrel{\·}{I}}_{\mathrm{mnA}2}+{\stackrel{\·}{I}}_{\mathrm{nA}2}|,I_{\mathrm{dB}2}=|{\stackrel{\·}{I}}_{\mathrm{mnB}2}+{\stackrel{\·}{I}}_{\mathrm{nB}2}|,I_{\mathrm{dC}2}=|{\stackrel{\·}{I}}_{\mathrm{mnC}2}+{\stackrel{\·}{I}}_{\mathrm{nC}2}|,$ Calculate Negative Sequence Differential coefficient matrix $S=\left[\begin{array}{ccc}1& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dB}2}}& \frac{I_{\mathrm{dA}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dA}2}}& 1& \frac{I_{\mathrm{dB}2}}{I_{\mathrm{dC}2}}\\ \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dA}2}}& \frac{I_{\mathrm{dC}2}}{I_{\mathrm{dB}2}}& 1\end{array}\right];$

(4) greatest member in Negative Sequence Differential coefficient matrix S is chosenThen basis Choose the element in Negative Sequence Differential coefficient matrix SWithSet threshold values α, profit With following relay protection criterion failure judgement phase line:

If i () meets S_ij> α and S_ik> α, then judge that i phase line is fault phase circuit；

(ii) if meeting S_ij> α and S_kj> α, then judge that ik phase line is fault phase circuit；

(iii) if meeting α > S_ij> 1, then judge that ijk phase line is fault phase circuit；Wherein, Ijk=ABC, ACB, BAC, BCA, CAB, CBA phase.