CN102721902B - Electric transmission line fault detection method based on voltage traveling wave prediction - Google Patents

Abstract

The invention belongs to the technical field of power system relay protection, and discloses an electric transmission line fault detection method based on voltage traveling wave prediction. The method comprises the following steps of: firstly, acquiring voltage and current traveling wave components at the two ends of an electric transmission line at each sampling moment in real time, and performing phase-mode transformation to obtain 0, alpha and beta mode voltage and current traveling wave components on the two end sides of the electric transmission line at each sampling moment; secondly, computing a voltage traveling wave prediction component of an electric transmission line end at a moment t; thirdly, computing a three-phase voltage traveling wave prediction component at each sampling moment according to the prediction component; and lastly, subtracting the three-phase voltage traveling wave prediction component at the end of the electric transmission line acquired in real time respectively, obtaining an absolute value, and performing setting judgment according to the absolute value. According to the method, the voltage traveling wave component at each sampling moment is not required to be evaluated through interpolation operation, so that operand is reduced, a fault detection function can be completed in a short data window of a quarter of period, and protection action speed is high; and the method is suitable for performing traveling wave protection in the entire transient fault process of electric transmission lines of various voltage classes.

Description

Based on the electric transmission line fault detection method of voltage traveling wave prediction

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to a kind of electric transmission line fault detection method based on voltage traveling wave prediction.

Background technology

Owing to not affecting by system operation mode and electric network composition and having natural phase-selecting function, current differential protection is the main protection of various electric pressure transmission line of electricity always.In 220kV and following electric pressure transmission line of electricity, because transmission line of electricity capacitance current along the line is very little, distributed capacitance is very little on the impact of current differential protection performance.But; the voltage of ultra-high/extra-high voltage transmission line of alternation current, current delivery have obvious wave process; capacitance current along the line is very large; the amplitude of the vector of two ends fundamental frequency steady-state current component is utilized to be faced with current differential protection starting current as the conventional current differential protection of actuating quantity large; and in order to prevent false protection; improving startup setting value can cause again protection sensitivity not enough, governs the application of conventional current differential protection on ultra-high/extra-high voltage transmission line of alternation current.

Traveling-wave differential protection considers the impact of distributed capacitance in protection algorism familiar models, and the impact not by transmission line of electricity distributed capacitance in traveling-wave differential protection principle, has very high performance.Application number 200910034669.1 patent of invention " is applicable to the traveling-wave differential protection method of series capacitor compensated line " and solves the impact of distributed capacitance on differential protection performance; but for the situation that the time delay of row wave traveling is non-integral multiple sampling interval; need the electric parameters obtained by interpolation arithmetic on each time point; very high to the requirement of protective device sample frequency; therefore very high to protective device hardware requirement; and each sampling time to carry out interpolation arithmetic; the required operand of protection algorism itself is large, cannot meet the requirement of protection quick-action." traveling-wave differential protection of UHV Transmission Line with Shunt Reactor " of Su Bin, Dong Xinzhou and Sun Yuan Zhang Fabiao and " traveling-wave differential protection based on wavelet transformation " of Su Bin, Dong Xinzhou and Sun Yuan Zhang Fabiao and application number 200410079501.X the patent of invention detection method of voltage zero-cross annex fault " in the traveling-wave protection " also need the electric parameters obtained by interpolation arithmetic on each time point for the situation that the time delay of row wave traveling is non-integral multiple sampling interval, there is the problem that operand is large equally; Need to carry out wavelet transformation, desired data window is large, and protection detects that fault generation required time is long.

At present; the transmission line travelling wave differential protecting method that many scholars have proposed all needs to carry out interpolation arithmetic to the situation that the time delay of row wave traveling is non-integral multiple sampling interval and asks electric parameters on its each time point; the operand of protection algorism own is large, requires high to protective device sampling hardware.Wherein part transmission line travelling wave differential protecting method even needs to carry out wavelet transformation, and desired data window is large, extends protection and the time that fault occurs detected, cannot meet the requirement of relay protection to quick-action.

Summary of the invention

The object of the invention is to the deficiency overcoming prior art existence, the electric transmission line fault detection method based on voltage traveling wave prediction that a kind of detection speed is fast, low to protective device hardware requirement, meet protection quick-action requirement is provided.

Technical purpose of the present invention is realized by following technological means:

Based on the electric transmission line fault detection method of voltage traveling wave prediction, its main points are, comprise the steps:

(1) a kind of row wave datum analytical equipment is provided, it includes data acquisition module, data computing module, data judge output module, above-mentioned modules sequentially connects, wherein data acquisition module is connected with a data storage device, the data terminal of this data storage device and data computing model calling, data judge that output module is connected with a base modules, the capable ripple setting valve of storage voltage in this base modules, data judge that output module is connected with host computer by communication system;

(2) data acquisition module Real-time Collection transmission line of electricity both end sides---the voltage of each sampling instant in m side and n side, current traveling wave component respectively, and send data computing module to;

(3) after data computing module receives sampled data, first carry out phase-model transformation calculating: respectively by the voltage of each for transmission line of electricity two ends sampling instant, current traveling wave component by phase-model transformation obtain each sampling instant in transmission line of electricity two ends 0, α, β mode voltage, current traveling wave component, and be stored in data storage device;

(4) secondly, computing electric power line m side t 0, α, β mode voltage row ripple anticipation component: according to 0 of moment circuit n side, the circuit n side of α, β mould current traveling wave component and t 0, α, β mode voltage traveling-wave component carry out transformation calculations obtain circuit m side t 0, α, β mode voltage row ripple anticipation component;

(5) same, computing electric power line n side t 0, α, β mode voltage row ripple anticipation component: according to 0 of moment circuit m side, the circuit m side of α, β mould current traveling wave component and t 0, α, β mode voltage traveling-wave component carry out transformation calculations obtain circuit n side t 0, α, β mode voltage row ripple anticipation component;

(6) by 0 of the circuit m side t of acquisition, α, β mode voltage row ripple anticipation component carries out phase mould inverse transformation, thus obtains the capable ripple anticipation component of three-phase voltage of each sampling instant of transmission line of electricity m transforming plant protecting installation place;

(7) by obtain circuit n side t 0, α, β mode voltage row ripple anticipation component carries out phase mould inverse transformation, thus obtains the capable ripple anticipation component of three-phase voltage of each sampling instant of transmission line of electricity n transforming plant protecting installation place;

(8) data computing module extracts the voltage traveling wave component of circuit m each sampling instant of side in data storage device, and subtract each other with the capable ripple anticipation component of the three-phase voltage of each sampling instant of circuit m transforming plant protecting installation place, obtain the absolute value of difference, and send data to and judge output module;

(9) data computing module extracts the voltage traveling wave component of circuit n each sampling instant of side in data storage device, and subtract each other with the capable ripple anticipation component of the three-phase voltage of each sampling instant of circuit n transforming plant protecting installation place, obtain the absolute value of difference, and send data to and judge output module;

(10) data judge that output module receives above-mentioned calculated difference absolute value, and make the following judgment according to the setting valve stored in base modules: if the absolute value of a certain phase voltage row ripple difference is greater than setting valve, then the judgement information of outlet line fault; Otherwise the then judgement information normally run of outlet line, the judgement information exported sends host computer to by communication system.

The present invention compared with prior art, has following positive achievement:

The inventive method is without the need to asking the voltage traveling wave component in its each moment by interpolation arithmetic; decrease the operand that traveling-wave protection algorithm itself is required; fault detection capability can be completed in the short-data windows in 1/4 cycle; protection act speed is fast, is applicable to the traveling-wave protection of the whole transient fault process of the transmission line of electricity of various electric pressure.

Accompanying drawing explanation

Figure 1 shows that the framed structure schematic diagram of row wave datum analytical equipment of the present invention.

Embodiment

Embodiment is provided to be expressed in further detail technical scheme of the present invention for a certain transmission line of electricity below.

A kind of row wave datum analytical equipment is provided, it includes data acquisition module, data computing module, data judge output module, above-mentioned modules sequentially connects, wherein data acquisition module is connected with a data storage device, the data terminal of this data storage device and data computing model calling, data judge that output module is connected with a base modules, the capable ripple setting valve of storage voltage in this base modules, and data judge that output module is connected with host computer by communication system;

First, data collecting module collected transmission line of electricity is at the three-phase voltage traveling-wave component u of each sampling instant of m transforming plant protecting installation place _mA(t), u _mB(t), u _mC(t), three-phase current traveling-wave component i _mA(t), i _mB(t), i _mC(t); And gather the three-phase voltage traveling-wave component u of transmission line of electricity in each sampling instant of n transforming plant protecting installation place _nA(t), u _nB(t), u _nC(t), three-phase current traveling-wave component i _nA(t), i _nB(t), i _nC(t), and be stored in data storage device.

After data computing module receives sampled data, first carry out phase-model transformation calculating: the three-phase voltage traveling-wave component of each sampling instant of m transforming plant protecting installation place, three-phase current traveling-wave component are converted to 0, α, β line wave component u _m0(t), u _{m α}(t), u _{m β}(t) and i _m0(t), i _{m α}(t), i _{m β}(t):

$\left[\begin{array}{c}{i}_{m0}\left(t\right)\\ i_{\mathrm{m\α}}\left(t\right)\\ i_{\mathrm{m\β}}\left(t\right)\end{array}\right]={\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]}^{-1}\left[\begin{array}{c}{i}_{\mathrm{mA}}\left(t\right)\\ i_{\mathrm{mB}}\left(t\right)\\ i_{\mathrm{mC}}\left(t\right)\end{array}\right]$

$\left[\begin{array}{c}{u}_{m0}\left(t\right)\\ u_{\mathrm{m\α}\left(t\right)}\\ u_{\mathrm{m\β}}\left(t\right)\end{array}\right]={\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]}^{-1}\left[\begin{array}{c}{u}_{\mathrm{mA}}\left(t\right)\\ u_{\mathrm{mB}}\left(t\right)\\ u_{\mathrm{mC}}\left(t\right)\end{array}\right]$

The three-phase voltage traveling-wave component of each sampling instant of n transforming plant protecting installation place, three-phase current traveling-wave component are converted to 0, α, β line wave component u _n0(t), u _{n α}(t), u _{n β}(t) and i _n0(t), i _{n α}(t), i _{n β}(t):

$\left[\begin{array}{c}{i}_{n0}\left(t\right)\\ i_{\mathrm{n\α}}\left(t\right)\\ i_{\mathrm{n\β}}\left(t\right)\end{array}\right]={\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]}^{-1}\left[\begin{array}{c}{i}_{\mathrm{nA}}\left(t\right)\\ i_{\mathrm{nB}}\left(t\right)\\ i_{\mathrm{nC}}\left(t\right)\end{array}\right]$

$\left[\begin{array}{c}{u}_{n0}\left(t\right)\\ u_{\mathrm{n\α}\left(t\right)}\\ u_{\mathrm{n\β}}\left(t\right)\end{array}\right]={\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]}^{-1}\left[\begin{array}{c}{u}_{\mathrm{nA}}\left(t\right)\\ u_{\mathrm{nB}}\left(t\right)\\ u_{\mathrm{nC}}\left(t\right)\end{array}\right]$

Computing electric power line m side t 0, α, β mode voltage row ripple anticipation component: utilize circuit n side respectively 0 of moment, the t of α, β mould current traveling wave component and circuit n side 0, the prediction of α, β mode voltage traveling-wave component obtain t m transforming plant protecting installation place 0, α, β mode voltage row ripple anticipation component:

$u_{m0}^{\′}\left(t\right)=u_{n0}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{c0}})+i_{n0}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{c0}})Z_{c0}$

$u_{\mathrm{m\α}}^{\′}\left(t\right)=u_{\mathrm{n\α}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})+i_{\mathrm{n\α}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})Z_{\mathrm{c\α}}$

$u_{\mathrm{m\β}}^{\′}\left(t\right)=u_{\mathrm{n\β}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})+i_{\mathrm{n\β}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})Z_{\mathrm{c\β}}$

Wherein, l is transmission line length; T is the cycle length of fundamental component; Z _c0, Z _{c α}, Z _{c β}be respectively 0 of transmission line of electricity, the characteristic impedance of α, β traveling-wave component; v _c0, v _{c α}, v _{c β}be respectively 0 of transmission line of electricity, the velocity of propagation of α, β traveling-wave component.

Utilize circuit m side respectively 0 of moment, the t of α, β mould current traveling wave component and circuit m side 0, the prediction of α, β mode voltage traveling-wave component obtain t n transforming plant protecting installation place 0, α, β mode voltage row ripple anticipation component:

$u_{n0}^{\′}\left(t\right)=u_{m0}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{c0}})+i_{m0}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{c0}})Z_{c0}$

$u_{\mathrm{n\α}}^{\′}\left(t\right)=u_{\mathrm{m\α}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})+i_{\mathrm{m\α}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})Z_{\mathrm{c\α}}$

$u_{\mathrm{n\β}}^{\′}\left(t\right)=u_{\mathrm{m\β}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})+i_{\mathrm{m\β}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})Z_{\mathrm{c\β}}$

Wherein, l is transmission line length; T is the cycle length of fundamental component; Z _c0, Z _{c α}, Z _{c β}be respectively 0 of transmission line of electricity, the characteristic impedance of α, β traveling-wave component; v _c0, v _{c α}, v _{c β}be respectively 0 of transmission line of electricity, the velocity of propagation of α, β traveling-wave component.

The circuit m side t just obtained 0, α, β mode voltage row ripple anticipation component u ' _m0(t), u ' _{m α}(t), u ' _{m β}t () row ripple anticipation component carries out the three-phase voltage capable ripple anticipation component u ' that phase mould inverse transformation obtains each sampling instant of m transforming plant protecting installation place _mA(t), u ' _mB(t), u ' _mC(t):

$\left[\begin{array}{c}{u}_{\mathrm{mA}}^{\′}\left(t\right)\\ u_{\mathrm{mB}}^{\′}\left(t\right)\\ u_{\mathrm{mC}}^{\′}\left(t\right)\end{array}\right]=\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]\left[\begin{array}{c}{u}_{m0}^{\′}\left(t\right)\\ u_{\mathrm{m\α}}^{\′}\left(t\right)\\ u_{\mathrm{m\β}}^{\′}\left(t\right)\end{array}\right]$

By obtain circuit n side t 0, α, β mode voltage row ripple anticipation component u ' _m0(t), u ' _{m α}(t), u ' _{m β}t () row ripple anticipation component carries out the three-phase voltage capable ripple anticipation component u ' that phase mould inverse transformation obtains each sampling instant of n transforming plant protecting installation place _nA(t), u ' _nB(t), u ' _nC(t):

$\left[\begin{array}{c}{u}_{\mathrm{nA}}^{\′}\left(t\right)\\ u_{\mathrm{nB}}^{\′}\left(t\right)\\ u_{\mathrm{nC}}^{\′}\left(t\right)\end{array}\right]=\left[\begin{array}{ccc}1& 1& 1\\ 1& -2& 0\\ 1& 1& -1\end{array}\right]\left[\begin{array}{c}{u}_{n0}^{\′}\left(t\right)\\ u_{\mathrm{n\α}}^{\′}\left(t\right)\\ u_{\mathrm{n\β}}^{\′}\left(t\right)\end{array}\right]$

Sampled by m transforming plant protecting installation place and obtain the three-phase voltage traveling-wave component u of each sampling instant _mA(t), u _mB(t), u _mC(t) and the three-phase voltage traveling-wave component u ' predicting each sampling instant obtained _mA(t), u ' _mB(t), u ' _mCt () takes absolute value after subtracting each other, and send data to and judge output module.

Sampled by n transforming plant protecting installation place and obtain the three-phase voltage traveling-wave component u of each sampling instant _nA(t), u _nB(t), u _nC(t) and the three-phase voltage traveling-wave component u ' predicting each sampling instant obtained _nA(t), u ' _nB(t), u ' _nCt () takes absolute value after subtracting each other, and send data to and judge output module.

Data judge that output module receives above-mentioned calculated difference absolute value, and make the following judgment according to the setting valve stored in base modules: if the absolute value of a certain phase voltage row ripple difference is greater than setting valve, then the judgement information of outlet line fault; Otherwise the then judgement information normally run of outlet line, the judgement information exported sends host computer to by communication system.

The foregoing is only preferred embodiment of the present invention; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses, the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1., based on the electric transmission line fault detection method of voltage traveling wave prediction, it is characterized in that, comprise following sequential steps:

(1) a kind of row wave datum analytical equipment is provided, it includes data acquisition module, data computing module, data judge output module, above-mentioned modules sequentially connects, wherein data acquisition module is connected with a data storage device, the data terminal of this data storage device and data computing model calling, data judge that output module is connected with a base modules, the capable ripple setting valve of storage voltage in this base modules, data judge that output module is connected with host computer by communication system;

(2) data acquisition module Real-time Collection transmission line of electricity both end sides---the voltage of each sampling instant in m side and n side, current traveling wave component respectively, and send data computing module to;

(3) after data computing module receives sampled data, first carry out phase-model transformation calculating: respectively by the voltage of each for transmission line of electricity two ends sampling instant, current traveling wave component by phase-model transformation obtain each sampling instant in transmission line of electricity two ends 0, α, β mode voltage, current traveling wave component, and be stored in data storage device;

(4) secondly, computing electric power line m side t 0, α, β mode voltage row ripple anticipation component: according to 0 of moment circuit n side, the circuit n side of α, β mould current traveling wave component and t 0, α, β mode voltage traveling-wave component carry out transformation calculations obtain circuit m side t 0, α, β mode voltage row ripple anticipation component u ' _m0(t), u ' _{m α}(t), u ' _{m β}(t), specific as follows:

$u_{m0}^{\′}\left(t\right)=u_{n0}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{c0}})+i_{n0}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{c0}})Z_{c0}$

$u_{\mathrm{m\α}}^{\′}\left(t\right)=u_{\mathrm{n\α}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})+i_{\mathrm{n\α}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})Z_{\mathrm{c\α}}$

$u_{\mathrm{m\β}}^{\′}\left(t\right)=u_{\mathrm{n\β}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})+i_{\mathrm{n\β}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})Z_{\mathrm{c\β}}$

Wherein, l is transmission line length; T is the cycle length of fundamental component; Z _c0, Z _{c α}, Z _{c β}be respectively 0 of transmission line of electricity, the characteristic impedance of α, β traveling-wave component; ν _c0, ν _{c α}, ν _{c β}be respectively 0 of transmission line of electricity, the velocity of propagation of α, β traveling-wave component; u _n0(t), u _{n α}(t), u _{n β}(t) be respectively the circuit n side of t 0, α, β mode voltage traveling-wave component; be respectively moment circuit n side 0, α, β mould current traveling wave component;

(5) same, computing electric power line n side t 0, α, β mode voltage row ripple anticipation component: according to 0 of moment circuit m side, the circuit m side of α, β mould current traveling wave component and t 0, α, β mode voltage traveling-wave component carry out transformation calculations obtain circuit n side t 0, α, β mode voltage row ripple anticipation component u ' _n0(t), u ' _{n α}(t), u ' _{n β}(t), specific as follows:

$u_{n0}^{\′}\left(t\right)=u_{m0}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{c0}})+i_{m0}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{c0}})Z_{c0}$

$u_{\mathrm{n\α}}^{\′}\left(t\right)=u_{\mathrm{m\α}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})+i_{\mathrm{m\α}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\α}}})Z_{\mathrm{c\α}}$

$u_{\mathrm{n\β}}^{\′}\left(t\right)=u_{\mathrm{m\β}}\left(t\right)\cos (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})+i_{\mathrm{m\β}}(t-\frac{T}{4})\sin (100\mathrm{\π}*\frac{l}{v_{\mathrm{c\β}}})Z_{\mathrm{c\β}}$

Wherein, l is transmission line length; T is the cycle length of fundamental component; Z _c0, Z _{c α}, Z _{c β}be respectively 0 of transmission line of electricity, the characteristic impedance of α, β traveling-wave component; ν _c0, ν _{c α}, ν _{c β}be respectively 0 of transmission line of electricity, the velocity of propagation of α, β traveling-wave component; u _m0(t), u _{m α}(t), u _{m β}(t) be respectively the circuit m side of t 0, α, β mode voltage traveling-wave component; be respectively moment circuit m side 0, α, β mould current traveling wave component;

(6) by 0 of the circuit m side t of acquisition, α, β mode voltage row ripple anticipation component carries out phase mould inverse transformation, thus obtains the capable ripple anticipation component of three-phase voltage of each sampling instant of transmission line of electricity m transforming plant protecting installation place;

(7) by obtain circuit n side t 0, α, β mode voltage row ripple anticipation component carries out phase mould inverse transformation, thus obtains the capable ripple anticipation component of three-phase voltage of each sampling instant of transmission line of electricity n transforming plant protecting installation place;

(8) data computing module extracts the voltage traveling wave component of circuit m each sampling instant of side in data storage device, and subtract each other with the capable ripple anticipation component of the three-phase voltage of each sampling instant of circuit m transforming plant protecting installation place, obtain the absolute value of difference, and send data to and judge output module;

(9) data computing module extracts the voltage traveling wave component of circuit n each sampling instant of side in data storage device, and subtract each other with the capable ripple anticipation component of the three-phase voltage of each sampling instant of circuit n transforming plant protecting installation place, obtain the absolute value of difference, and send data to and judge output module;

(10) data judge that output module receives the absolute value of above-mentioned difference, and make the following judgment according to the setting valve stored in base modules: if the absolute value of a certain phase voltage row ripple difference is greater than setting valve, then the judgement information of outlet line fault; Otherwise the then judgement information normally run of outlet line, the judgement information exported sends host computer to by communication system.