CN103217622B - Based on the distribution network fault line selection method of multiterminal voltage traveling wave - Google Patents

Abstract

The invention discloses a kind of distribution network fault line selection method based on multiterminal voltage traveling wave, belong to Relay Protection Technology in Power System field.The steps include: the transformer station in power distribution network and each basic routing line branches end installed rows ripple harvester; Utilize transformer station's bus connection switch divide-shut brake to produce travelling wave signal, the mistiming of the initial time that on calculating basic routing line, the fault traveling wave of each branches end arrives and the initial time that the fault traveling wave at substation bus bar place arrives, obtain array reference time; The mistiming of the initial time that during calculating fault, on basic routing line, the fault traveling wave of each branches end arrives and the initial time that the fault traveling wave at substation bus bar place arrives, set up array fault-time; By reference time array and fault-time array carry out least square fitting, realize the use processing of row ripple time of arrival of each collection point record, find faulty line.The present invention does not limit by fault type, has the advantage that computing is simple, route selection is reliable, practical.

Description

Based on the distribution network fault line selection method of multiterminal voltage traveling wave

Technical field

The invention belongs to Relay Protection Technology in Power System field, particularly a kind of distribution network fault line selection method based on multiterminal voltage traveling wave.

Background technology

Extensively adopt small grounding current system in China's low and medium voltage distribution network, its probability that singlephase earth fault occurs is the highest, because single-phase earth fault current is less, does not affect and powers continuously to load, and regulations stipulate can continue operation 1 ~ 2h by tape jam.But along with power distribution network development, bus feeder line increases and the use of cable in circuit year by year, short circuit capacitance electric current is increased, operate with failure for a long time and easily make failure propagation become or multipoint earthing short circuit at 2, arc grounding also can cause total system superpotential, and then damage equipment, destroys system safety operation, so must failure judgement circuit rapidly and accurately, accurately locate for further fault and provide foundation with failture evacuation.

In existing failure line selection, the route selection of many employing low current faults, but fault current is little, Earth Fault Detection difficulty.According to the difference of location design, be successively proposed the line selection apparatus remaining the principles such as method of addition based on active power method, injecting signal, wavelet analysis method, ground connection both at home and abroad.But existing various line selection apparatus is by the impact of the factors such as fault state complexity, faint, the on-the-spot electromagnetic interference (EMI) of fault current and out-of-balance current, and on-the-spot operational effect is unsatisfactory, and accuracy rate is not high.

Summary of the invention

In order to solve the above-mentioned technical matters that existing distribution network fault line selection exists, the invention provides a kind of distribution network fault line selection method based on multiterminal voltage traveling wave.The present invention is highly sensitive, speed is fast, strong robustness, do not limit by fault type and the method for operation, possesses comparatively strong fault tolerance ability, engineer applied is easy to realize, more accurately more reliable foundation can be provided for further localization of fault and failture evacuation, the service requirement with distributed power supply smart power distribution network can be met.

The present invention solves the problems of the technologies described above adopted technical scheme and comprises the following steps:

(1) transformer station in power distribution network and each basic routing line branches end installed rows ripple harvester;

(2) the bus connection switch divide-shut brake of transformer station in power distribution network is produced travelling wave signal, the initial time utilizing the capable ripple of row ripple harvester record trouble to arrive, the initial time t ' that the fault traveling wave calculating each branches end on basic routing line m arrives _mnthe initial time t ' arrived with the fault traveling wave at substation bus bar place ₀mistiming, obtain array H reference time of basic routing line m _m=(t ' _m1-t ' ₀, t ' _m2-t ' ₀..., t ' _mN-t ' ₀), m=1 ..., k, k are the sum of basic routing line, and m is basic routing line numbering, and N is the sum of each branches end row ripple harvester on basic routing line m;

(3) when power distribution network breaks down, the initial time utilizing the capable ripple of row ripple harvester record trouble to arrive, the initial time t that the fault traveling wave calculating each branches end on basic routing line m arrives _mnthe initial time t arrived with the fault traveling wave at substation bus bar place ₀mistiming, obtain array G fault-time of basic routing line m _m=(t _m1-t ₀, t _m2-t ₀..., t _mN-t ₀), m=1 ..., k, n are the numbering of each branches end row ripple harvester on basic routing line m, and N is the sum of each branches end row ripple harvester on basic routing line m;

(4) array H reference time is set up _mwith array G fault-time _mequation of linear regression G _m=A _m+ B _mh _m, calculate A according to principle of least square method _mbest estimate, if A _min [-0.3,0.3] scope, then circuit m is non-fault line, otherwise circuit m is faulty line.

In the above-mentioned distribution network fault line selection method based on multiterminal voltage traveling wave, described step sets up array H reference time in (4) _mwith array G fault-time _mequation of linear regression G _m=A _m+ B _mh _m, according to principle of least square method, calculate A _mthe step of best estimate be: definition h _nfor H _min n-th (t ' _mn-t ' ₀), g _nfor G _mn-th (t _mn-t ₀), calculate A as follows _m:

$A_m=\frac{\left({\mathrm{\Σh}}_n^2\right)\left({\mathrm{\Σg}}_n\right)-\left({\mathrm{\Σh}}_n\right)\left({\mathrm{\Σh}}_n{g}_n\right)}{N\left({\mathrm{\Σh}}_n^2\right)-{\left({\mathrm{\Σh}}_n\right)}^2}\→0$

If A _min [-0.3,0.3] scope, then circuit m is non-fault line, otherwise circuit m is faulty line.

Technique effect of the present invention is: when the present invention utilizes the fault of power distribution network capable ripple harvester record, row ripple temporal information carries out route selection, rapid sensitive, is easy to realize, does not limit by fault type and the method for operation; The present invention utilizes equation of linear regression and principle of least square method to form route selection criterion, and computing is simple, and accuracy rate is high, is easy to realize, and effectively can reduce the recording error disturbing and cause.

Accompanying drawing explanation

The topology diagram of power distribution network in Fig. 1 the present invention.

Fig. 2 process flow diagram of the present invention.

The failure line selection fitted figure of circuit a in Fig. 3 the present invention.

The failure line selection fitted figure of circuit b in Fig. 4 the present invention.

The failure line selection fitted figure of circuit c in Fig. 5 the present invention.

Embodiment

Embodiment

See Fig. 1, Fig. 1 for implementing power distribution network topology diagram of the present invention, the distribution network fault line selection step that the present invention is based on multiterminal voltage traveling wave is:

(1) transformer station in power distribution network as shown in Figure 1 and 3 basic routing line branches end installed rows ripple harvesters, m (m=a is numbered to 3 basic routing lines, b, c), n is numbered to basic routing line each branches end row ripple harvester, wherein each branches end row ripple harvester of basic routing line a is numbered a1, a2, a3, a4, a5, be numbered b1, b2, b3 to basic routing line b each branches end row ripple harvester, basic routing line c each branches end row ripple harvester is numbered c1, c2, c3, c4.

(2) by the bus connection switch divide-shut brake of transformer station in power distribution network to produce travelling wave signal, utilize the initial time that the capable ripple of row ripple harvester record trouble arrives, the initial time t ' that the fault traveling wave calculating basic routing line m (m=a, b, c) branches end arrives _mnthe initial time t ' arrived with the fault traveling wave at substation bus bar place ₀mistiming, obtain array H reference time of basic routing line m (m=a, b, c) _m:

H _a=(t′ _a1-t′ ₀，t′ _a2-t′ ₀，t′ _a3-t′ ₀，t′ _a4-t′ ₀，t′ _a5-t′ ₀)=(150.00，133.33，126.67，73.33，30.00)；

H _b=(t′ _b1-t′ ₀，t′ _b2-t′ ₀，t′ _b3-t′ ₀)=(90.00，43.00，16.00)；

H _c=(t′ _c1-t′ ₀，t′ _c2-t′ ₀，t′ _c3-t′ ₀，t′ _c4-t′ ₀)=(135.80，155.70，65.70，13.90)。

(3) distribution network failure occurs on basic routing line c as shown in Figure 1, the initial time utilizing the capable ripple of row ripple harvester record trouble to arrive, the initial time t ' that the fault traveling wave calculating basic routing line m (m=a, b, c) branches end arrives _mnthe initial time t ' arrived with the fault traveling wave at substation bus bar place ₀mistiming, obtain array G fault-time of basic routing line m (m=a, b, c) _m:

G _a=(t _a1-t ₀，t _a2-t ₀，t _a3-t ₀，t _a4-t ₀，t _a5-t ₀)=(150.04，133.39，126.63，73.35，30.06)；

G _b=(t _b1-t ₀，t _b2-t ₀，t _b3-t ₀)=(89.96，42.99，15.98)；

G _c=(t _c1-t ₀，t _c2-t ₀，t _c3-t ₀，t _c4-t ₀)=(57.00，76.90，-46.44，-52.63)。

(4) array H reference time is set up _mwith array G fault-time _mequation of linear regression G _m=A _m+ B _mh _m, according to principle of least square method, calculate A _mthe step of best estimate be: to power distribution network basic routing line m, definition h _nfor H _min n-th (t ' _mn-t ' ₀), g _nfor G _mn-th (t _mn-t ₀), N is the maximal value of each branches end row ripple harvester numbering n of basic routing line, calculates A _m:

For circuit a: $A_a=\frac{\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{h_n}^2\right)\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{g}_n\right)-\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{h}_n\right)\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{h}_n{g}_n\right)}{5\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{h_n}^2\right)-{\left(\underset{n=1}{\overset{5}{\mathrm{\Σ}}}{h}_n\right)}^2}=-0.1908$

For circuit b: $A_b=\frac{\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{h_n}^2\right)\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{g}_n\right)-\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{h}_n\right)\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{h}_n{g}_n\right)}{3\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{h_n}^2\right)-{\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{h}_n\right)}^2}=-0.0079$

For circuit c: $A_c=\frac{\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{h_n}^2\right)\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{g}_n\right)-\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{h}_n\right)\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{h}_n{g}_n\right)}{4\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{h_n}^2\right)-{\left(\underset{n=1}{\overset{4}{\mathrm{\Σ}}}{h}_n\right)}^2}=-83.5953$

The A of circuit c clearly can be found out by the above results _cwell beyond the scope of [-0.3,0.3]; And the A of circuit a _awith the A of circuit b _bvalue levels off to 00, obviously belongs in the scope of [-0.3,0.3]; To sum up, easily judge that circuit c is as faulty line, and circuit a and b is non-fault line.Use MATLAB to array H reference time of power distribution network basic routing line m _mwith array G fault-time _mcarry out matching, fitting result is as shown in Fig. 3, Fig. 4, Fig. 5, and the point of a circuit and b circuit meets non-fault line that linear correlation is thought, the point of c circuit does not meet linear correlation, and institute thinks faulty line.It can thus be appreciated that the distribution network fault line selection method that the present invention is based on multiterminal voltage traveling wave correctly, reliably can select faulty line.

Claims (2)

1., based on a distribution network fault line selection method for multiterminal voltage traveling wave, comprise the following steps:

(1) transformer station in power distribution network and each basic routing line branches end installed rows ripple harvester;

(2) the bus connection switch divide-shut brake of transformer station in power distribution network is produced travelling wave signal, the initial time utilizing the capable ripple of row ripple harvester record to arrive, the initial time t ' that the fault traveling wave calculating each branches end on arbitrary basic routing line m arrives _mnthe initial time t arrived with the fault traveling wave at substation bus bar place ₀' mistiming, obtain array H reference time of basic routing line m _m=(t ' _m1-t ' ₀, t ' _m2-t ' ₀... t ' _mN-t ' ₀), m=(a, b, c ...), n=(1,2 ..., N), n is the numbering of each branches end row ripple harvester on basic routing line m, and N is the sum of each branches end row ripple harvester on basic routing line m;

(3) when power distribution network breaks down, the initial time utilizing the capable ripple of row ripple harvester record trouble to arrive, the initial time t that the fault traveling wave calculating each branches end row ripple harvester n on arbitrary basic routing line m arrives _mnthe initial time t arrived with the fault traveling wave at substation bus bar place ₀mistiming, obtain array G fault-time of basic routing line m _m=(t _m1-t ₀, t _m2-t ₀..., t _mN-t ₀);

(4) array H reference time is set up _mwith array G fault-time _mequation of linear regression G _m=A _m+ B _mh _m, calculate A according to principle of least square method _mbest estimate, if A _min [-0.3,0.3] scope, then circuit m is non-fault line, otherwise circuit m is faulty line.

2. the distribution network fault line selection method based on multiterminal voltage traveling wave according to claim 1, sets up array H reference time in described step (4) _mwith array G fault-time _mequation of linear regression G _m=A _m+ B _mh _m, according to principle of least square method, calculate A _mthe step of best estimate be: definition h _nfor H _min n-th (t ' _mn-t ' ₀), g _nfor G _mn-th (t _mn-t ₀), calculate A as follows _m:

$A_m=\frac{\left(\mathrm{\Σ}{h}_n^2\right)\left(\mathrm{\Σ}{g}_n\right)-\left(\mathrm{\Σ}{h}_n\right)\left(\mathrm{\Σ}{h}_n{g}_n\right)}{N\left(\mathrm{\Σ}{h}_n^2\right)-{\left(\mathrm{\Σ}{h}_n\right)}^2}$

If A _min [-0.3,0.3] scope, then circuit m is non-fault line, otherwise circuit m is faulty line.