CN104092197B - Ultrahigh voltage alternating current transmission lines relay protecting method based on differential factor matrix - Google Patents

Abstract

The invention discloses a kind of ultrahigh voltage alternating current transmission lines relay protecting method based on differential factor matrix, relate to Relay Protection Technology in Power System field.First it measure A, B, C phase positive sequence voltage of ultrahigh voltage alternating current transmission lines one end, forward-order current, negative sequence voltage, negative-sequence current；Utilize distributed parameter model, calculate A, B, C phase forward-order current and the negative-sequence current of the ultrahigh voltage alternating current transmission lines other end, calculate A, B, C phase mixed stocker component difference current amplitude respectively, and then calculate differential factor matrix, then utilize the magnitude relationship between each element of differential factor matrix to differentiate ultrahigh voltage alternating current transmission lines fault phase.The inventive method is not affected by capacitance current, it is adaptable to any electric pressure, particularly ultrahigh voltage alternating current transmission lines；The relay protection of whole failure process after ultrahigh voltage alternating current transmission lines fault, performance is not affected by transition resistance and load current.

Description

Ultrahigh voltage alternating current transmission lines relay protecting method based on differential factor matrix

Technical field

The present invention relates to Relay Protection Technology in Power System field, concretely relate to a kind of based on differential factor matrix Ultrahigh voltage alternating current transmission lines relay protecting method.

Background technology

Built southeast Shanxi-Nanyang-Jingmen 1000kV the extra-high voltage that Article 1 is formally incorporated into the power networks in the world of China at present Transmission line of alternation current.According to " the unified strong intelligent grid research report " of State Grid Corporation of China, before 2015, China will build up Ultrahigh voltage alternating current transmission lines 3.9 ten thousand kilometers, will build up ultrahigh voltage alternating current transmission lines 4.7 ten thousand kilometers, substantially build before the year two thousand twenty Become with extra-high voltage grid as bulk transmission grid, the national grid general layout of electric network coordinations at different levels development.

Ultra-high voltage AC transmission network can be greatly improved electric energy transmission capacity, alleviates the capacity situation that China is nervous, favorably In reducing transmission losses, save Transmission Cost, energy-saving and emission-reduction, thus promote green energy resource expanding economy, China's electricity can be made again Net is more intelligent, strong, stable, reliable.Meanwhile, as electrical network bulk transmission grid, after ultrahigh voltage alternating current transmission lines breaks down, If fault can not be detected in time and correctly excise, stability of power system can be caused to be destroyed, in some instances it may even be possible to cause System crash, thus social economy can be produced and cause loss difficult to the appraisal.

Owing to not affected by system operation mode and electric network composition, and there is natural phase-selecting function, current differential protection The always main protection of various electric pressure transmission lines of electricity.In 500kV and following electric pressure transmission line of electricity, due to power transmission line Curb line capacitance current is the least, and distribution capacity is the least on the impact of current differential protection performance.But, extra-high-voltage alternating current The transmission of the voltage of transmission line of electricity, electric current has obvious wave process, and capacitance current along the line is very big, utilizes two ends current phasor The amplitude of sum is faced with current differential protection starting current greatly as the conventional current differential protection of actuating quantity, and in order to prevent from protecting Protect malfunction, improve startup setting value and protection sensitivity can be caused again not enough, govern conventional current differential protection and hand in extra-high voltage Application on stream transmission line of electricity.

Owing to being affected by load current, during high resistance ground short trouble, directly utilize the amplitude of two ends current phasor sum As actuating quantity conventional current differential protection cannot correct tripping fault phase, but by Zero sequence current differential protection as thereafter Standby protection act tripping three-phase line.Due to non-full-operating state on the impact of system stability much smaller than the feelings of three-phase tripping Condition, can be strengthened fault by Zero sequence current differential protection action tripping three-phase line This move strategy and rush grid stability Hit.Therefore, during single phase ground fault fault, if can correct tripping fault phase, retain remaining and two normally continue to run with mutually, Be conducive to strengthening the stabilization of power grids, so that electrical network is 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 differential factor matrix extra-high Pressure transmission line of alternation current relay protecting method.The inventive method physical model uses distributed parameter model, not by distribution capacity electricity The impact of stream, it is adaptable to any electric pressure, particularly ultrahigh voltage alternating current transmission lines.The inventive method is applicable to extra-high voltage and hands over The relay protection of whole failure process after stream transmission line malfunction, performance is not affected by transition resistance and load current, Especially when ultrahigh voltage alternating current transmission lines generation single-phase high-impedance, the inventive method can correct reliable recognition fault Phase, it is achieved single-phase fault jumps the relay protection function of single-phase fault circuit.

The present invention solves being the technical scheme is that of its technical problem

Based on differential factor matrix ultrahigh voltage alternating current transmission lines relay protecting method, it comprises the following steps:

(1) ultrahigh voltage alternating current transmission lines A, B, C phase positive sequence voltage in m transforming plant protecting installation place is measuredA, B, C phase forward-order currentMeasure ultrahigh voltage alternating current transmission lines to become at n A, B, C phase forward-order current of protection installation place, power station

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

(3) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase positive sequence voltage of m transforming plant protecting installation placeA, B, C phase forward-order currentCalculate ultrahigh voltage alternating current transmission lines in n power transformation Stand and protect A, B, C phase forward-order current of installation place

${\stackrel{\·}{I}}_{mnA1}={\stackrel{\·}{I}}_{mA1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB1}={\stackrel{\·}{I}}_{mB1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC1}={\stackrel{\·}{I}}_{mC1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

Wherein, γ₁For ultrahigh voltage alternating current transmission lines positive sequence propagation constant；Z_c1For ultrahigh voltage alternating current transmission lines positive sequence ripple Impedance；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；Cosh (.) is hyperbolic cosine function； Sinh (.) is hyperbolic sine function；

(4) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase negative sequence voltage of m transforming plant protecting installation placeA, B, C phase negative-sequence currentCalculate ultrahigh voltage alternating current transmission lines to become at n A, B, C phase negative-sequence current of protection installation place, power station

${\stackrel{\·}{I}}_{mnA2}={\stackrel{\·}{I}}_{mA2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB1}={\stackrel{\·}{I}}_{mB2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC2}={\stackrel{\·}{I}}_{mC2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

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

(5) A, B, C phase mixed stocker component difference current amplitude is calculated:

$I_{dA}=\left|{\stackrel{\·}{I}}_{mnA1}+{\stackrel{\·}{I}}_{nA1}+{\stackrel{\·}{I}}_{mnA2}+{\stackrel{\·}{I}}_{nA2}\right|$

$I_{dB}=\left|{\stackrel{\·}{I}}_{mnB1}+{\stackrel{\·}{I}}_{nB1}+{\stackrel{\·}{I}}_{mnB2}+{\stackrel{\·}{I}}_{nB2}\right|$

$I_{dC}=\left|{\stackrel{\·}{I}}_{mnC1}+{\stackrel{\·}{I}}_{nC1}+{\stackrel{\·}{I}}_{mnC2}+{\stackrel{\·}{I}}_{nC2}\right|$

(6) differential factor matrix is calculated

(7) greatest member in differential factor matrix S is chosenThen basisChoose differential factor matrix S In elementWithSet threshold values α, utilize 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 phase is ABC phase or ACB phase or BAC phase or BCA phase or CAB phase or CBA phase.

The technical program is compared with background technology, and it has the advantage that

The inventive method physical model uses distributed parameter model, is not affected by capacitance current, it is adaptable to any Electric pressure, particularly ultrahigh voltage alternating current transmission lines.The inventive method is whole after being applicable to ultrahigh voltage alternating current transmission lines fault The relay protection of individual failure process, performance is not affected by transition resistance and load current, especially defeated when extra-high-voltage alternating current During electric line generation single-phase high-impedance, the correct reliable recognition fault phase of the inventive method energy, it is achieved single-phase fault is jumped single The relay protection function of phase fault circuit.

Accompanying drawing explanation

The invention will be further described with embodiment below in conjunction with the accompanying drawings.

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

Detailed description of the invention

Fig. 1 is the ultrahigh voltage alternating current transmission lines fault schematic diagram of application the inventive method.Ultrahigh voltage alternating current transmission lines Fundamental frequency electric parameters in m side transformer station and transforming plant protecting installation place, n side is respectively by the locking phase being arranged on transformer station both this Phasor measurement unit (phase measurement unit, PMU) is measured and is obtained.Synchronous phasor measurement unit measures extra-high-voltage alternating current Transmission line of electricity is at A, B, C phase positive sequence voltage of m transforming plant protecting installation placeA, B, C phase forward-order currentMeasure ultrahigh voltage alternating current transmission lines A, B, C phase forward-order current in n transforming plant protecting installation place

Synchronous phasor measurement unit is measured ultrahigh voltage alternating current transmission lines A, B, C phase in m transforming plant protecting installation place and is born Sequence voltageA, B, C phase negative-sequence currentMeasure ultra-high voltage AC transmission line Road is at A, B, C phase negative-sequence current of n transforming plant protecting installation place

Measurement data sends ultrahigh voltage alternating current transmission lines protection device, ultra-high voltage AC transmission to through optic fibre data channel Line protective devices complete relay protection function by application the inventive method:

Utilize ultrahigh voltage alternating current transmission lines at A, B, C phase positive sequence voltage of m transforming plant protecting installation place A, B, C phase forward-order currentCalculate ultrahigh voltage alternating current transmission lines at n transforming plant protecting A, B, C phase forward-order current of installation place

${\stackrel{\·}{I}}_{mnA1}={\stackrel{\·}{I}}_{mA1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB1}={\stackrel{\·}{I}}_{mB1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC1}={\stackrel{\·}{I}}_{mC1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

Wherein, γ₁For ultrahigh voltage alternating current transmission lines positive sequence propagation constant；Z_c1For ultrahigh voltage alternating current transmission lines positive sequence ripple Impedance；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；Cosh (.) is hyperbolic cosine function； Sinh (.) is hyperbolic sine function.

Utilize ultrahigh voltage alternating current transmission lines at A, B, C phase negative sequence voltage of m transforming plant protecting installation place A, B, C phase negative-sequence currentCalculate ultrahigh voltage alternating current transmission lines at n transforming plant protecting A, B, C phase negative-sequence current of installation place

${\stackrel{\·}{I}}_{mnA2}={\stackrel{\·}{I}}_{mA1}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB2}={\stackrel{\·}{I}}_{mB2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC2}={\stackrel{\·}{I}}_{mC2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

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

Calculating A, B, C phase mixed stocker component difference current amplitude:

$I_{dA}=\left|{\stackrel{\·}{I}}_{mnA1}+{\stackrel{\·}{I}}_{nA1}+{\stackrel{\·}{I}}_{mnA2}+{\stackrel{\·}{I}}_{nA2}\right|$

$I_{dB}=\left|{\stackrel{\·}{I}}_{mnB1}+{\stackrel{\·}{I}}_{nB1}+{\stackrel{\·}{I}}_{mnB2}+{\stackrel{\·}{I}}_{nB2}\right|$

$I_{dC}=\left|{\stackrel{\·}{I}}_{mnC1}+{\stackrel{\·}{I}}_{nC1}+{\stackrel{\·}{I}}_{mnC2}+{\stackrel{\·}{I}}_{nC2}\right|$

Calculate differential factor matrix

Choose the greatest member in differential factor matrix SThen basisChoose in differential factor matrix S ElementWithSet threshold values α, utilize 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 phase is ABC phase or ACB phase or BAC phase or BCA phase or CAB phase or CBA phase.

The inventive method physical model uses distributed parameter model, is not affected by capacitance current, it is adaptable to any Electric pressure, particularly supertension/ultrahigh voltage alternating current transmission lines.The inventive method is applicable to ultrahigh voltage alternating current transmission lines event Relay protection in barrier ripple time two weeks after, performance is not affected by transition resistance and load current, especially works as extra-high voltage When there is single-phase high-impedance in transmission line of alternation current, the correct reliable recognition fault phase of the inventive method energy, it is achieved single-phase event Barrier jumps the relay protection function of single-phase fault circuit.

The above, only present pre-ferred embodiments, therefore the scope that the present invention implements can not be limited according to this, i.e. depend on The equivalence change that the scope of the claims of the present invention and description are made with modify, all should still belong in the range of the present invention contains.

Claims (1)

1. ultrahigh voltage alternating current transmission lines relay protecting method based on differential factor matrix, it is characterised in that: include following step Rapid:

(1) ultrahigh voltage alternating current transmission lines A, B, C phase positive sequence voltage in m transforming plant protecting installation place is measured A, B, C phase forward-order currentMeasure the ultrahigh voltage alternating current transmission lines A in n transforming plant protecting installation place, B, C phase forward-order current

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

(3) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase positive sequence voltage of m transforming plant protecting installation placeA, B, C phase forward-order currentCalculate ultrahigh voltage alternating current transmission lines to become at n A, B, C phase forward-order current of protection installation place, power station

${\stackrel{\·}{I}}_{mnA1}={\stackrel{\·}{I}}_{mA1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB1}={\stackrel{\·}{I}}_{mB1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC1}={\stackrel{\·}{I}}_{mC1}\cosh \left({\mathrm{\γ}}_1{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC1}}{Z_{c1}}\sinh \left({\mathrm{\γ}}_1{l}_{mn}\right)$

Wherein, γ₁For ultrahigh voltage alternating current transmission lines positive sequence propagation constant；Z_c1For ultrahigh voltage alternating current transmission lines positive sequence wave resistance Anti-；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；Cosh (.) is hyperbolic cosine function； Sinh (.) is hyperbolic sine function；

(4) utilize ultrahigh voltage alternating current transmission lines at A, B, C phase negative sequence voltage of m transforming plant protecting installation placeA, B, C phase negative-sequence currentCalculate ultrahigh voltage alternating current transmission lines to become at n A, B, C phase negative-sequence current of protection installation place, power station

${\stackrel{\·}{I}}_{mnA2}={\stackrel{\·}{I}}_{mA2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mA2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnB2}={\stackrel{\·}{I}}_{mB2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mB2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

${\stackrel{\·}{I}}_{mnC2}={\stackrel{\·}{I}}_{mC2}\cosh \left({\mathrm{\γ}}_2{l}_{mn}\right)-\frac{{\stackrel{\·}{U}}_{mC2}}{Z_{c2}}\sinh \left({\mathrm{\γ}}_2{l}_{mn}\right)$

Wherein, γ₂For ultrahigh voltage alternating current transmission lines negative phase-sequence propagation constant；Z_c2For ultrahigh voltage alternating current transmission lines negative phase-sequence wave resistance Anti-；l_mnFor the ultrahigh voltage alternating current transmission lines length between m transformer station and n transformer station；Cosh (.) is hyperbolic cosine function； Sinh (.) is hyperbolic sine function；

(5) A, B, C phase mixed stocker component difference current amplitude is calculated:

$I_{dA}=|{\stackrel{\·}{I}}_{mnA1}+{\stackrel{\·}{I}}_{nA1}+{\stackrel{\·}{I}}_{mnA2}+{\stackrel{\·}{I}}_{nA2}|$

$I_{dB}=|{\stackrel{\·}{I}}_{mnB1}+{\stackrel{\·}{I}}_{nB1}+{\stackrel{\·}{I}}_{mnB2}+{\stackrel{\·}{I}}_{nB2}|$

$I_{dC}=|{\stackrel{\·}{I}}_{mnC1}+{\stackrel{\·}{I}}_{nC1}+{\stackrel{\·}{I}}_{mnC2}+{\stackrel{\·}{I}}_{nC2}|$

(6) differential factor matrix is calculated

(7) greatest member in differential factor matrix S is chosenThen basisChoose in differential factor matrix S ElementWithSet threshold values α, utilize 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 phase is ABC phase or ACB phase or BAC phase or BCA phase or CAB phase or CBA phase.