It is a kind of merely with voltage be independent of both-end it is synchronous zero, line mould time difference radiation network therefore
Barrier localization method
Technical field
The present invention relates to it is a kind of merely with voltage be independent of both-end it is synchronous zero, line mould time difference radiation network fault location side
Method, belongs to Relay Protection Technology in Power System field.
Background technology
Fault localization is carried out after grid collapses can mitigate artificial line walking workload, shorten fault correction time, carry
Power supply reliability high, the hidden danger of reduction loss of outage and discovery presence are simultaneously acted upon as early as possible, prevent the hair again of failure
It is raw.The method of fault localization can be divided into fault analytical method and traveling wave method by range measurement principle.The core of traveling wave method is that measurement traveling wave exists
Propagation time between bus and trouble point calculates line fault distance.Travelling wave ranging generally can be divided into Single Terminal Traveling Wave Fault Location and
The class of both-end travelling wave ranging two.Single Terminal Traveling Wave Fault Location does not need GPS to realize the synchronization of data, it is not required that carries out two end datas and leads to
News, its cost is the half of both-end travelling wave ranging cost, and travelling wave ranging is carried out by single-ended method, because traveling wave is in trouble point and bus
End is repeated catadioptric, and the wavefront of reflection to the various properties on measurement end time shaft is staggered, anti-to trouble point
The demarcation of ejected wave due in brings great difficulty, and Range finding reliability is difficult to ensure that.And both-end travelling wave ranging only requires that two is female
The moment that first wavefront of line end accurate detection is reached, therefore the method is by transition resistor electric arc characteristic, circuit distribution electricity
Hold and the influence of load current is smaller, there is reliability higher for more single-ended method, but it is same with GPS to need dual ended data to communicate
Equipment during step pair, cost of investment is big.
Radiation network is used because city electric distribution system typically more, it has closed loop design, open loop operation feature, single-phase earthing
Failure probability is high, and technology and economic factor comprehensively determine that multiple-limb radial distribution networks fault location has its particularity.For
Typical radial overhead feeder distribution system, there are many feedback outlets in bus, while being connected to numerous branches and load along feeder line
Become etc., feed out circuit length great disparity, after distribution line occurs singlephase earth fault, the discontinuous node of wave impedance and load end points
Many, the traveling wave that trouble point produces is transmitted at node, and energy attenuation is stronger, and traveling wave occurs at load end points and node
Reflection, increased identification difficulty of the measurement end to trouble point back wave so that the extraction of natural frequency is more difficult, therefore seeks it
He carries out singlephase earth fault positioning in visual angle.
The content of the invention
The technical problem to be solved in the present invention be to provide it is a kind of merely with voltage be independent of both-end it is synchronous zero, line mould when
Difference radiation network fault positioning method, overcomes for multiple-limb radiation network single-ended traveling wave method trouble point back wave wave head due in mark
Fixed difficult and both-end traveling wave method operating cost problem high.
The technical scheme is that:It is a kind of merely with voltage be independent of both-end it is synchronous zero, line mould time difference radiation network
Fault Locating Method, in multiple-limb radial networks, installs traveling wave fault location device, using the letter of both sides in feeder line both sides
Breath carries out fault localization respectively;After distribution feeder occurs earth fault, because line, zero mould spread speed are different, survey is caused
It is different that the line that detects of amount end, the initial traveling wave of zero mould arrive at the moment, initial line, zero detected according to traveling wave fault location device
Mode voltage traveling wave data, are demarcated constantly using the Wavelet Modulus Maxima under the 5th yardstick, using the modular transfer time difference
Earth fault Single Ended Fault Location computing formula calculates fault distance;The comprehensive single-ended modulus propagation time difference ranging information in both sides
Carry out fault location.
Concretely comprise the following steps:
(1) according to the actual feeder line parameter of the straight match system of overhead transmission line, fault distance is set along the line, outlet, zero mould is emulated to obtain
Wave velocity and the relation of discrete fault distance point, recycle cubic spline interpolation to draw line, zero mould velocity of wave song along total track length
Line;
(2) Wavelet Modulus Maxima being utilized respectively under the 5th yardstick surveys line, zero mode voltage traveling wave that measurement end is detected to M
Component and N survey the line that measurement end detects, zero mode voltage traveling-wave component and are demarcated constantly, show that both time differences are △
tM0,1、△tN0,1;
(3) wave velocity of feeder line midpoint is chosen as initial velocity of wave iterative value, and initial event is calculated using formula of finding range
Barrier is apart from xf (0), by primary fault apart from xf (0)Substitute into line, zero mould velocity of wave curve to be iterated, when adjacent 2 points of line mould velocity of wave
v1(n)-v1(n-1)<0.0001 and adjacent 2 points of zero mould velocity of wave v0(n)-v0(n-1)<When 0.0001, terminate iteration combination and ask
The △ t for obtainingM0,1、△tN0,1, with formulaObtain respectively between both sides M, N and trouble point
Distance;If the condition of convergence cannot be met, the selection for changing abort situation iterative initial value and its corresponding initial wave velocity is straight
To restraining, convergent fault distance is finally drawn;
(4) resultant fault positioning is carried out using the fault localization information of both sides.
Principle of the invention is:After distribution feeder occurs earth fault, due to the cataclysm of fault point voltage, produce
The zero line wave component propagated between the line line wave component and wire and the earth propagated between wire.Because distribution wire is short out and not
Lightning conducter is set up along meeting, line line ripple propagation loss between wire is small, zero line ripple is propagated between the earth and wire, outgoing
Road frequency dependent character is big, causes zero mould each frequency component presentation otherness, but its initial traveling wave is easy to detection, in the single-phase survey of distribution
Seek the distance-finding method using zero, the line mould time difference in the case of the difficulty.
Because line, zero mould spread speed are different, line, the initial traveling wave of zero mould that measurement end detects is caused to arrive at the moment not
Together, the earth fault Single Ended Fault Location computing formula therefore based on the modular transfer time difference is
Wherein, Δ t0,1It is zero, line mould ripple to time difference, v1、v0Respectively line, zero mould velocity of wave, Δ v1,0It is line, zero mould ripple
Speed difference.
By taking the topological structure of multiple-limb radiation network shown in Fig. 1 as an example, in order to improve range accuracy, sample frequency is chosen for herein
10MHz.Known under different faults distance there is single phase metal earth fault in system, extract line, zero of 0.5ms after failure
Mode voltage data, are demarcated constantly using the Wavelet Modulus Maxima under the 5th yardstick, line, the 1 mould discrete distance point for calculating
On velocity of wave, cubic spline interpolation is carried out thereafter and obtains as shown in Figure 2 along the line in circuit length range, zero mould velocity of wave curve.
Figure it is seen that the conversion of line during near terminal fault, zero mould velocity of wave is violent, and under other fault distances in addition to near-end its
General morphologictrend is presented dull, and line, zero mould wave velocity are no longer presented functional relation with distance, fine using cubic spline interpolation
Solve the problems, such as that range error is excessive caused by wave velocity Function Fitting, and can well faults distance and velocity of wave
Degree relation between the two.The wave velocity of feeder line midpoint is chosen as initial velocity of wave iterative value, formula is calculated using finding range
Primary fault is apart from xf (0), by primary fault apart from xf (0)Substitute into line, zero mould velocity of wave curve to be iterated, when adjacent 2 points of line
Mould velocity of wave v1(n)-v1(n-1)<0.0001 and adjacent 2 points of zero mould velocity of wave v0(n)-v0(n-1)<When 0.0001, terminate iteration
With reference to the line tried to achieve, zero mould ripple arrival time difference Δ t0,1, the distance between M sides and trouble point are obtained with formula (1).If cannot meet
The condition of convergence, then change the selection of abort situation iterative initial value and its corresponding initial wave velocity until convergence, finally draws receipts
The fault distance held back.
The beneficial effects of the invention are as follows:Because distribution line is shorter, branch is more and tree structure is presented, typically using single-ended
The mould velocity of wave of line zero difference localization method can not recognize branched line, can only calculate fault distance, and both-end distance measuring typically investment compared with
Greatly, it is difficult to realize during local communication pair.Therefore this method use distribution line backbone two ends carry out respectively one-end fault determine
Position, so as to reduce near-end range finding dead band and can further recognize branch.
Brief description of the drawings
Fig. 1 is embodiment of the present invention list outlet multiple-limb radiation network topological structure;
Fig. 2 is line, the zero mould velocity of wave obtained using cubic spline interpolation;
Fig. 3 is M side lines, zero mode voltage traveling wave and its modulus maximum.
Fig. 4 is N side lines, zero mode voltage traveling wave and its modulus maximum.
Specific embodiment
With reference to the accompanying drawings and detailed description, the invention will be further described.
It is a kind of merely with voltage be independent of both-end it is synchronous zero, line mould time difference radiation network fault positioning method, at many points
In branch radial networks, traveling wave fault location device is installed in feeder line both sides, fault localization is carried out respectively using the information of both sides;
After distribution feeder occurs earth fault, because line, zero mould spread speed are different, line, zero mould that measurement end is detected are caused
Initial traveling wave arrives at moment difference, and initial line, the zero mode voltage traveling wave data detected according to traveling wave fault location device are utilized
Wavelet Modulus Maxima under 5th yardstick is demarcated constantly, using the earth fault Single Terminal Traveling Wave Fault Location of modular transfer time difference
Method computing formula calculates fault distance;The comprehensive single-ended modulus propagation time difference ranging information in both sides carries out fault location.
Concretely comprise the following steps:
(1) according to the actual feeder line parameter of the straight match system of overhead transmission line, fault distance is set along the line, outlet, zero mould is emulated to obtain
Wave velocity and the relation of discrete fault distance point, recycle cubic spline interpolation to draw line, zero mould velocity of wave song along total track length
Line;
(2) Wavelet Modulus Maxima being utilized respectively under the 5th yardstick surveys line, zero mode voltage traveling wave that measurement end is detected to M
Component and N survey the line that measurement end detects, zero mode voltage traveling-wave component and are demarcated constantly, show that both time differences are △
tM0,1、△tN0,1;
(3) wave velocity of feeder line midpoint is chosen as initial velocity of wave iterative value, and initial event is calculated using formula of finding range
Barrier is apart from xf (0), by primary fault apart from xf (0)Substitute into line, zero mould velocity of wave curve to be iterated, when adjacent 2 points of line mould velocity of wave
v1(n)-v1(n-1)<0.0001 and adjacent 2 points of zero mould velocity of wave v0(n)-v0(n-1)<When 0.0001, terminate iteration combination and ask
The △ t for obtainingM0,1、△tN0,1, with formulaObtain respectively between both sides M, N and trouble point
Distance;If the condition of convergence cannot be met, the selection for changing abort situation iterative initial value and its corresponding initial wave velocity is straight
To restraining, convergent fault distance is finally drawn;
(4) resultant fault positioning is carried out using the fault localization information of both sides.
For single outlet multiple-limb radiation network as shown in Figure 1, the G in the power network is infinitely great power supply;T is main transformation
Device, no-load voltage ratio is 110kV/35kV, and connection set is YN/d11, and measurement end is M ends, wherein basic routing line MB=20km, BC=
15km, CN=15km, branch BF=10km, CE=10km, one group of traveling wave fault location device is installed in M and N-terminal respectively.
Embodiment 1:It is now assumed that there is single-phase earthing metallic fault apart from M ends 25km basic routing lines, the initial phase angle of failure is
90 °, emulation sample frequency is 10MHz, line, zero that the Wavelet Modulus Maxima being utilized respectively under the 5th yardstick is detected to measurement end
Line wave component is demarcated constantly, is obtained the measurement of M, N two end line, zero mode voltage traveling wave and its modulus maximum and is demarcated such as Fig. 3 institutes
Show.Show that M side lines, zero mould ripple to time difference are △ tM=0.0086ms, N side line, zero mould ripple to time difference are △ tN=
0.0084ms, chooses the wave velocity of feeder line midpoint as initial velocity of wave iterative value, using formula of finding rangePrimary fault is calculated apart from xf (0), by primary fault apart from xf (0)Substitute into line, zero mould
Velocity of wave curve is iterated, as adjacent 2 points of line mould velocity of wave v1(n)-v1(n-1)<0.0001 and adjacent 2 points of zero mould velocity of wave
v0(n)-v0(n-1)<When 0.0001, terminate iteration and combine the △ t for trying to achieveM0,1、△tN0,1, with range finding formula calculate failure away from
It is 24.72km from M-f, N-f is 24.26km, comprehensive both sides fault distance information, it is apart from M at backbone to provide abort situation
End 24.5km.
Embodiment 2:It is now assumed that there is single-phase earthing metallic fault apart from the circuit of M ends 25km branches 1, the initial phase angle of failure is
50 °, fault resistance is 20 Ω, and emulation sample frequency is 10MHz, is utilized respectively the Wavelet Modulus Maxima pair under the 5th yardstick
Line that measurement end is detected, zero line wave component are demarcated constantly, obtain the measurement of M, N two end line, zero mode voltage traveling wave and its
Modulus maximum is demarcated.Show that M sides and N side lines, zero mould ripple to time difference are △ tMWith △ tN, choose the wave velocity of feeder line midpoint
As initial velocity of wave iterative value, using formula of finding rangePrimary fault is calculated apart from xf (0), by primary fault apart from xf (0)Substitute into line, zero mould velocity of wave curve to be iterated, as adjacent 2 points of line mould velocity of wave v1(n)-v1
(n-1)<0.0001 and adjacent 2 points of zero mould velocity of wave v0(n)-v0(n-1)<When 0.0001, terminate iteration and combine the △ for trying to achieve
tM0,1、△tN0,1, it is 24.79km to calculate fault distance M-f with range finding formula point, and N-f is 36.41km, comprehensive both sides failure away from
From information, it is apart from M ends 24.5km at branch line 1 to provide abort situation.
Specific embodiment of the invention is explained in detail above in conjunction with accompanying drawing, but the present invention be not limited to it is above-mentioned
Implementation method, in the ken that those of ordinary skill in the art possess, can also be before present inventive concept not be departed from
Put that various changes can be made.