TW201122503A - Failure locating method. - Google Patents

Abstract

A failure locating method is suitable for calculating a failure position for a transmission cable between a first transducer and a second transducer, the method comprising the following steps: (A) measuring a first reference voltage and current at the first transducer and a second reference voltage and current at the second transducer; (B) based on the total length, characteristic impedance and propagation constant of the transmission cable, obtaining a set of factors; (C) based on the reference voltages, the reference currents, and the set of factors, calculating a failure parameter satisfying that a first failure voltage is equal to a second failure voltage, wherein the first failure voltage represents the voltage where the failure position is based on the first reference voltage, and the second failure voltage represents the voltage where the failure position is based on the second reference voltage; and (D) using the failure parameter to calculate the failure position.

Description

201122503

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for extracting power lines, and more particularly to a method of fault location. [Prior Art] In the power layout, two power transformers are usually used to contact two power transformers, so the maintenance of the quality of the power lines is a prerequisite for effective power supply. When the power supply is not stable, most of the systems require that the fault location of the power transmission line be found within 3 to 5 cycles of the transmitted power signal to remove the obstacle as soon as possible. A fault location method is known in which the power line is first measured to know the voltage and current of the transmitted power signal, and then the voltage and current are separately filtered by Discrete Fourier Transform (DFT) to extract the fundamental frequency phase. The amount of phasor is finally analyzed by comparing the relative relationship between the electric dust phase 1 and the current phasor and the characteristic impedance of the power line. However, this positioning method is mainly based on the steady state phasor. However, after φ fails, the phasor calculated by DFT, in addition to the steady-state component, usually carries transient components (such as attenuating DC components), which greatly affects the accuracy of fault location. To this end, CS Yu in 2006 transform based adaptive mimic phasor estimator for distance relaying applications," IEEE Trans. Power Delivery, in order to propose an improved DFT architecture, in an attempt to remove the attenuated DC components, but the computational cost is significantly exceeded Expected 201122503 [Summary of the Invention]

At the present end, the object of the present invention is to provide a fault location method, the location required to be faulty on the transmission line within the time required by the system, and the high accuracy of the non-defective position can also effectively control the calculation cost. Therefore, the fault location method of the present invention is adapted to calculate a fault location for contacting a power line between the first power transformer and the second power transformer, and includes the following steps: (A) separately measuring the first a first reference voltage at the transformer and a first reference current and a second reference voltage at the second power transformer and a first reference current; (8) setting an initial value of a fault parameter, the fault parameter is the fault location a ratio of the distance from the second power transformer to the total length of the power line; (C) obtaining a first set of impedances based on a total length of the power line, a characteristic impedance and a propagation constant, and the fault parameter, the first The group impedance represents an equivalent circuit model of the power line between the fault location and the first power transformer; (D) utilizing the first reference voltage and the first reference power "U· and the first group The impedance obtains a first fault voltage; (E) obtaining a second set of impedances based on the total length of the power line, the characteristic impedance and the propagation constant, and the fault parameter, the second set of impedances indicating that the fault location is located First An equivalent circuit model of the power line between the transformers; (F) using the second reference voltage, the second reference current, and the second set of impedances to obtain a first fault voltage, (G) calculating the first, The difference between the second fault voltage, and using the difference to update the fault parameter, and repeating steps (C)~(G)' based on the updated fault parameter until the updated fault parameter causes the first fault and the second fault The voltage tends to approach '' and (H) to find the 201122503 fault location using the fault parameter completed by the update. - The fault location method of the present invention is adapted to calculate a fault location for contacting a power line between a first power transformer and a second power transformer, comprising the steps of: (A) separately measuring the first change a first reference voltage at the electrical device and a first reference current and a second reference voltage at the second power transformer and a second reference current; (Β) based on a total length of the power line, a characteristic impedance spear Propagating * number, obtaining a set of factors 'The set of factors represents the ratio of the equivalent impedance of the power line between the fault location and the first power transformer relative to a fault parameter, and the fault parameter is the fault a ratio of a distance from the second power transformer to a total length of the power line; (c) calculating, based on the reference power, the reference current, and the set of factors, that satisfying a first fault voltage is equal to a second fault a fault parameter of the voltage, wherein the first fault voltage is a voltage based on the first reference voltage at the fault location, and the second fault voltage is a voltage based on the second reference voltage at the fault location; and D) obtains the parameters of the fault using a fault location. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawings. Before the present invention is described in detail, it is to be noted that in the following description, similar elements are denoted by the same reference numerals. Principles and Derivations of the First Preferred Embodiment Referring to Figure 1, a two-terminal three-phase power system 100 is illustrated. 201122503 坆-Endpoint 第 refers to the first-variable transformer 1 and the second transformer 2 in two places, which will transmit three numbers with different phases by the transmission line 3 of the total length W. In order to locate the faulty location of the power line 3, in order to synchronously take the voltage and current of the power signal at the material transformer 2, it is preferably monitored in conjunction with a Global Positioning Satellite (GPS) system 200. According to the introduction of JJ Grainger and WD Stevens〇n in System Analysis, New York .. McGraw-mu, 994, it can be seen that for the power signal, the fault location F is assumed to be at the distance from the transformer 2. At dW, then the power line 3 is in the transformer [to the fault position F will form the first group impedance as shown in Figure 2, and the + fault parameter d represents the "distance of the fault location F and the transformer 2". The ratio of the total length of the transmission line, j. The first set of impedances includes a first impedance 21 (one and two second impedances Y1(d), and the value changes with the fault parameter d. The first impedance is ζι (The sentence is connected to the transformer 1 and the fault location FPb1, and each of the second impedances γι(4) is one of the bridges and the grounding point. The detailed parameters are defined as follows:

Zl(d) = Zc- sinh(^(l -d)w)

Zc { 2 ) (1) where Zc is the characteristic impedance of the input, line f, and y is the propagation constant of the transmission line 3, and. 2 ex + e~x Please note that in addition to the phase difference, the three power signals transmitted by the transmission line 3 have the same absolute value of the voltage and the same absolute value of the current, so the corresponding power signals are analyzed. The circuit will include the same impedance component value. Therefore, it is sufficient to use the circuit model 201122503 of the aforementioned related one of the power signals to investigate the fault position F. Further, the first impedance Z1(d) can also be equivalent to a resistor Ri(d) connected in series with an inductor L1(d), and the second impedance Y1(d) can also be equivalent to a conductance Gl(d) connected in parallel. Capacitor Cl(d), ie: Z\{d) = R\{d)^ jQ\L\{d)

Yl(d)=Gl(d)+ jarCl(d) where M(4)= Re4Zcsinh(Hl-i/)W)]

Ll(d)=(l/ω^-Im ag [Zc sinh (y (l - )V^)]

Reai[x] represents the real part of x, and Imag[x] represents the imaginary part of x. It is worth noting that since the power signal of a general system generally falls at a frequency of 60 Hz, the angular frequency is preferably = 2π χ 60, the sampling time Δί is 1 / (60 Ν), and Ν is a positive integer. Since the influence of the capacitance Cl(d) and the inductance Ll(d) on the circuit is non-linear, this embodiment is specifically introduced in 51.

Numerical Methods for Engineers, 5th Edition, McGraw-Hill, A^w 13⁄4味2(9)5 A method for describing dynamic phasors, mainly in the case of sampling time Δί, with sampling time index value k, K-Ι describes the power signal, and will particularly emphasize the transient characteristics of the inductor Ll(d) and the capacitor Cl(d), namely: the current flowing through Ll(d), and the cross-pressure change of Cl(d) 201122503 Assuming that the power signal at the measuring transformer 1 will obtain a first reference electrical calendar Vl(k) and a first reference current ii(k), then the first fault voltage vFi at the distance dW from the transformer 2 ( k,d) is: (M) = V; (8)-LU) _L1 (6) Izl(k,d)-Izl(kl,d) 2 At (3) The first fault current Izl(k,d) here represents: The result of i1(k) deducting the "current flowing to Yl(d)" can be further written as: 2 At (4) 凊> idea, for each sampling time index value k, the first reference voltage v1 (k) ) is somewhat different from the first reference current Ii(k). The fault may occur at every place of the power line 3, so the first fault voltage VF1(k'd) and the first fault current Izi(kd) may vary with d except for k. On the other hand, in the field of the invention, the general knowledge can reasonably infer: when the fault parameter is d, a second set of impedance between the transformer 2 and the fault position F will be as shown in FIG. 3, and the first included The impedance Z2(d) has a resistor R2(d) connected in series with each other and an inductor L2(d)' includes two second impedances Y2(d) respectively having a conductance G2(d) and a capacitor C2 connected in parallel. (d). Z2(4)=Zc ♦ sinh(jcW) = /?2(4) + · L2(4) F2(rf) = itanh (4) where i?2(4)= Rea/[Zc,sinh(jcW)] * 1 u —tanh fjdW\ [Zc v 2 J_ L2(d) = {\.l ωλ)·\χΆ ag [Zc · sinh(^/W)] G2(d) = Re,al 201122503 (5) Assume that the power signal at the measuring transducer 2 will get one The second reference voltage V2(k) and the second reference current 〖2(k), then the second fault voltage VF2(k,d) at "distance dW from the transformer 2" is: heart 2 (M) = (4) -Z2{d) (6)

Zc

The first fault current Iz2(k,d) represents: l2(k) deducting the result of "current flowing to Y2(d)", which can be further written as:

Iz2{k,d) = l2(k)~ Y2(d)V2^-V2^k~^· -C2(d 2 At (7) Finally, because of the GPS system 2〇〇, the power signal can be accurately measured. Synchronous voltage and current of the transformers 1, 2, so, regardless of which transient state (such as: sampling time index value k), from the transformer / or from the substation f 2 to derive the voltage level of the fault location F , will get the same value. In short, as long as you find the d that meets Vn(W)_[2(w)=〇, you can push it. At the distance dW from the transformer 2, the power line 3 has occurred. The first preferred embodiment of the present invention is applicable to the first connection of the transformer (i) built in the transformer i. The measuring module η, the wire connection - (d) the second measuring module 2 of the transformer 2, the butterfly solid modules 11, 21 - respectively measure the power signal on the power line 3, with the fault locator 5 for 201122503 As a reference for calculating the fault location, the fault locator 5 includes - the setting unit 5 ι, & ... group 52, - the first electric operation module, "3 - the second current operation module 55, - the first, the operation module 56, nose mold 55, and a damper-mode, and 57, the clamp module 58, and the impedance 3 is calculated as 59. And the module Ml 56 is coupled, and the module modulo 55, μ, The modules 53 , 56 , 58 are coupled respectively. Preferably, the current calculation module _ 59 j: the rut ^ , . 2 and the voltage calculation module 53 , 56 are rounded up to an arithmetic device 50. First Positioning ==11 Secondly, the fault of the present invention performed by the fault locator 5 preferably includes the following steps of FIG. 5: Step 7G. The first measuring module u receives the (10) system _, One step time kAi, and the first reference voltage v1(k), Vl(k_1), V1(k-2) and the first reference power are measured; Ali(k), ii(k♦ The second measurement module 21 also receives the synchronization time, and accordingly, the second reference voltages V2(k), v2(kl), v2(k_2), and the second reference current secret are detected. Step 71 The setting unit 51 sets an initial value for the fault parameter d. Step 72: The impedance calculating unit 59 is based on the length W of the power transmission line 3, the characteristic impedance Zc, and the propagation constant based on the equations (1), (2), and (5). ^ and the fault parameter d, get the first set of impedance and the first Group impedance. That is, 'determine the first impedance Zl (d), the second impedance Y1 (d), the inductance L1 (d) capacitance Cl (d) ' and the first impedance Z2 (d), the second impedance Y2 (d ), inductor L2 (d), capacitor C2 (d). 10 201122503 Step 73: computing module 52 ~ a reference voltage v1 (k), Vi (k two; equations (2) ~ (4), using the first, work (4) and the first group impedance, find the::·2) and the first reference current 1 state calculation modules 55 to 56 based on the equation = barrier voltage VF1 (M), and the two sets of impedances, find the second fault voltage Step 73 includes the following sub-steps of FIG. 6: Sub-step 7 算 The calculation 52 subtracts the steady-state and transient currents flowing to the second impedance ^(4) based on the silk patterns (7) and (4), respectively, to capture the IKk, Ιι〇Μ) 'To find the current Ιζ1(Μ) and Izl(kl,d) flowing to the first-impedance 卯.

In detail, the implementation of this example is: first calculate the average result of p(k) and v.1 by the steady-state unit su and enlarge Y1(4) times, and then calculate HJ Vl by the transient unit TU. (k) and νια_υ are subtracted by (4) and amplified by Cl(d) times. Then, using a snapping unit ρυ, the current “(8) is deducted from the steady-state unit and the output of the transient unit TM, and the current Izl is obtained. (k, d). Note that as time passes, the first current calculation module 52 can calculate the index values k=l, 2, 3··· in order, so not only according to Vi(k), vjk -;!), Ii(k) finds the current lzl(k,d), and can also find the current Izl(kl,d) according to ν#]), Vi(k 2), Ii(k_ 1). 732: The first voltage calculation module 53 subtracts the "steady state and transient voltage drop of the first impedance Z1(d)" based on the equations (2) and (3) 'the voltage VJk" to obtain the first fault voltage Vp. "k,d).

In detail, in this embodiment, the average result of Wk, d) and Izl(k], d) is first calculated by a steady-state unit SU 201122503 and amplified by Z1 (4) times, and then by a transient unit TU Calculate the two subtraction divided by Izl(k,d) and Izi(]M,d), and the '.σ fruit and amplify L1 (d) times, and then use a fetch unit ρυ to make the voltage v, (k) Deducting the output of the steady-state cell su and the transient cell τυ, and obtaining the electrical VF1(k,d) 〇 sub-step 733: The second current computing module 55 makes the current I2(k) based on equations (5) and (7), I/ki) deducts the "steady state and transient current flowing to the second impedance γ2 (4)" to obtain the currents MM) and IZ2 (kl, d) flowing to the first impedance Z2 (4). Sub-step 734: The second voltage calculation module 56 subtracts the "steady state and transient voltage drop of the first impedance Z2 (4)" from the voltage v2(k) based on equations (7) and (6)' to determine the second fault voltage VF2(k, d). In this example, the voltage calculation modules 52 and 55 are similar in wire form, and the implementations of the current operation modules 53 and 56 are similar. The order of execution of sub-steps 733-734 is not limited to being performed in sub-steps 731-732, and sub-steps 731-734 are preferably performed in parallel with sub-steps 731-732 in order to compete for shorter clamping times. Step 74: The setting unit 51 sets a comparison parameter to "fault parameter" plus "one approach step J", that is, d+J. Step 75. The calculation modules 52 to 53 and 55 to 56 obtain the electric power k number based on the equations (2) to (7), and obtain a first-comparison voltage Vndd+e at a distance from the transformer 2 and a first The comparison voltage Vp2(k, d+❼. Since the execution of this step is similar to the step 73, it will not be described. 12 201122503 'Step 76: The approach module 57 calculates the difference between the first and second fault voltages. /(M) 'and use the difference to update the fault parameter d, and repeat steps 73-76' based on the updated fault parameter d until the updated fault parameter d causes the first and second fault voltages to approach Therefore, a positioning parameter d.t is equal to d. That is, the approximation module 57 performs approximation according to a nonlinear function /(Μ) =. In order to find the coincidence as quickly as possible • This nonlinear function f(k,d Solution, this embodiment uses the aforementioned

The improved secant method mentioned in the book MeMM5 is implemented. According to this method, the approximation module 57 includes a calculation unit 572 and a determination unit 573, and the step 76 includes the following sub-steps of FIG. 7: Sub-step 761: the calculation unit 572 calculates the fault voltages νρι(_, VF2(k, d) the difference is obtained by approximating the pre-signal/heart, and calculating the comparison voltage VF1 (k'd+ ^), Vp2 (k, d + force difference to obtain - comparison signal + A, and then by secant method The proposed equation (8) is obtained by approximating the post-lu parameter dNEW. δ (8) f(k,d + S)-f(k,d) a sub-step 762: the judging unit 573 compares whether n and Left is the error tolerance value, and divination represents the absolute value of χ. If the result of the determination is no, then sub-step 763 is performed; if true, then sub-step 764 is reached. Sub-step 763: Judgement unit 573 compares "executed Whether the number of sub-steps 761 is equal to - the count tolerance (four). If yes, the sub-step collapse 13 201122503 is performed, and if not, the next fault parameter d is set to this dNEw, and jumps back to step 73. Sub-step 764: setting The unit 51 sets the positioning parameter tpt to the post-approximation parameter cInew, thus achieving the purpose of approaching the module 57. Step 77 The positioning module 58 ends the process of the fault location method by multiplying the positioning parameter dDpt by the total length W' of the power line and the position of the power line that is "distant from the transformer 2" as the location where the fault occurred. In contrast, conventional techniques always attempt to ignore or remove transient components such as attenuating DC components. The computing modules 52, 53, 55, and 56 of this example are retained by dynamic phasor description. The transient components caused by the capacitors c1(d), C2(d) and the inductors L1(d), L2(d), so the function of the approximation module 57 is /(M) = ^(compared to the prior art). U)_W (4) ==〇 can more closely express the actual circuit situation, so that the fault location accuracy is greatly improved. In addition, the dynamic phasor description of the operation modules 52, 53, 55, 56 is simply 'plus approximation The module 57 adopts a relatively simple modified secant method, so the circuit implementation cost is far superior to the conventional technology. Moreover, in the sub-step 763, the 'judging unit 573 will add the repeated sub-steps.

Li II can effectively ensure that the fault locator 5 of this example can find the fault location of the power line 3 in the required time within the system and the required time. 14 201122503 Introduction and Derivation of the Principles of the Second Preferred Embodiment In general, transmission lines of less than 80 km (km) are called short-range transmission lines, 80 to 250 km are called medium-range, and more than 250 km are called long-range. Basically, the first preferred embodiment is applicable to any short, medium, and long-range power transmission line. In order to provide a more economical and rapid practice, the second preferred embodiment further discloses a fault locator and method dedicated to short- and medium-range transmission lines. The aforementioned corpse ower - in the book, has proved: when using one

For medium-range transmission lines, sinh(x) will approximate X, and tanh(;c) will also approximate X. Therefore, the first impedance Z2(d) and the second impedance Y2(d) may approach the equation (9), and the equation (9) further interprets Z2(d) as d times the "one first impedance factor ZE". And interpret Y2(d) as d times the "one second impedance factor YE". Among them, each factor exhibits a complex number type due to the nonlinear characteristic of the corresponding element, and has a real part and an imaginary part.

Z2(d) = Zc sinh(^iW) ^ZcjdW = dZE Y2{d)·

Zc •tanh 2 J 2Zc

dYE (9)

Therefore, the inductance L2(d) and the capacitance C2(d) can be organized into the equation (10), and the equation (10) further interprets L2(d) as d times the "one inductance factor LE", and C2(d) ) is interpreted as d times the "one capacitance factor CE". L2(d 卜丄.Imag[Zc. =also £ ωι C2(rf) = ]mag

TdW ~2Zc dCc (10) and so on, can find the inductance Ll (d) is equivalent to "inductance factor Le (1-d) times, capacitance Cl (d) is equivalent to "capacitance factor CE" (1-d ) times.

Ll(rf)« — · lmag[Zc γ{\ -d)w]= {ld)LE ωι 15 201122503 201122503 (11) r(\-d)w ~Tic~ Further these equivalent elements Zl(d) , Ll (d), Yl (d), Cl (d), Z2 (d), L2 (d), Y2 (d), C2 (4) substitution, will sort out a quadratic polynomial (12) with a variable d, And its solution is as in (13).

Axd2+Bxd + C = 0 (12) d __8±do 2 4AC 2A (13) The dynamic phasor description is also introduced. The coefficients A, B, and C of the polynomial are as follows: 2 ΔεΥε JYMrvi(k^) V2(k)-V2(k-1)\ l Δί At J^£^£ + ceZ£) g_^i_£W+/z2 EW+/d_£(fc-1)+ 2^Ak)+v^ki) 2 EE £ (k -1) + [z2^)-~^e ^ At ------- A/ Δί 味)-味-1) Δί i^E^E ^ ^Ε^ε) Δί

Le 16 201122503 J^lLJt±ZE, £(.-i)l + 普普^ Δί ε and heart-£(the illusion represents: when indexing the value of the factor YE, CE into the formula (4) U represents: When the index value k is indexed, the factors Ye and CE are substituted into the result of equation (7). In addition, since all the factors are of the complex type, it is expected that the coefficients of the coefficients A, B, c and the solution of the equation (10) d" will be a complex number. ^ By using the k-like solution quadratic equation method, the obtained d can be directly used as the positioning parameter d τ-number dopt without the iteration like the first preferred embodiment. Operation, so the flute-spot timing--the example can more effectively shorten the faulty position factor 4, A, B, c* but related to the voltage Vi(k VKk) at two sampling time The voltage change is also related to the current /d five (9),: 2_£ (the illusion of the two sampling times - j only so this example can also achieve the purpose of aptly depicting the circuit transient characteristics. Second preferred embodiment The second preferred embodiment of the implementation manner 6 is applicable to the module 11 and is connected to the inside of the module. The fault locator of the present invention is coupled to the built-in variable. The first measurement module 21β fault locator 6 built in the transformer 2 includes a factor generating unit 6!, a first current computing module 62, and a second current computing module 63. A second preferred embodiment of the fault location method of the present invention performed by a coefficient generating unit 64, a solving unit 65 and a positioning module 66, and the fault locator 6 comprises the following steps of FIG. 9: Step 80: First The measurement module u receives the synchronization time k^ transmitted from the GPS system, and measures the first reference voltages v〆1), v1(k-2) and the first reference currents Ii(k), ri(4). The other two quantities: the modulo ... receive the synchronization time, and according to the measurement: v2 ((four) - υ, ν · 2) and the second reference current _, qing ^ step 8!: the factor generating unit 61 generates an impedance factor ΖΕ, The second yang Dingba smashed the first - Γ. The anti-factor Υ ε, the inductance factor le, and the capacitance due to early CE. The production method is .·· E 畀罨 因子 factor multiplied by the characteristic resistance and then divided by twice the power transmission line The propagation constant m is the total length w multiplied by the anti-Zc, and the first impedance factor is obtained; the propagation constant of the transmission line is special, and the second is obtained. :: The imaginary part of the second factor ZE is divided by the angular frequency to obtain the second impedance factor γ capacitance factor CE. The virtual 卩 is divided by the angular frequency to get 18 201122503 - Step 82: A current calculation module 62 generates a first factor current Izl E(k) by using the equations (4) to adjust the first reference current ijk, Kk-i, respectively, by the terms Ye and CE. Izl E(kl). In detail, the implementation of this example is: first calculate the average result of \^(1〇 and VJk-1) by a steady-state unit su and amplify 丫]£倍, and then calculate by a transient unit TU VKk)* VJk-1) Divide the two subtractions by the result of & and amplify (^ times, then use a snapping unit pu to subtract the steady state unit SU and the output of the transient unit TU from the current 11(]〇 And obtain the first factor current Φ Izl-E(k) and calculate in a similar manner from Vi(kl), VKk-2) and IKk-l)

Izi_E(k-l). Step 83. The second current operation module 63 generates a second factor electrical implementation similar to step 82 by adjusting the second reference current sanding by using the sub-Ye and the CE, respectively, based on the equation (7). It is preferably performed in parallel with step 82.

Step 84. The coefficient generating unit 64 combines all the factors obtained by the step 8i according to the reference voltages % υ, v2(k), V2(4) and the factor currents wk), Μ-e(6)), ^(8), Wk-i)' On the basis of (:4), 'generate three coefficient letters representing the remaining a, b, and c respectively. Step 85: Solve the army & A _ Calculate the two branches with one real: (4) Step out the imaginary part to approach :. The possible solutions of the real two and - imaginary parts, and the possible solutions of the - imaginary part, to make the actual part as a positioning parameter 19 201122503. Step 86: The positioning module 66 uses the position of the power line 3 "distance from the transformer 2 <~ w away" as the position where the failure occurs. The possible solution of the imaginary part approaching 〇 is chosen because: "distance ~.W" used to describe the fault location F must be a real number, so the parameter dopt is imaginary. The P month is preferably 〇, and the second preferred embodiment is such that the approximation is the exit point ′ so that the imaginary part is selected to be closer to the 。. In the above-mentioned embodiment, the computing modules 52-53, 55-56, and 62-63 introduce a dynamic phasor description mode, so that the approximating module and the solving unit 65 can retain the transient components. Under the condition, the positioning parameter is calculated, and the positioning accuracy is better than that of the well-known, and the circuit of (4) is also simpler than the DFT, so the object of the present invention can be achieved. However, the above is only the preferred embodiment of the present invention. However, the scope of the present invention is not limited by the scope of the present invention, and the simple equivalent changes and modifications made by the present invention are still within the scope of the present invention. Figure 1 is a schematic diagram showing the failure of the power line between the two transformers; Figure 2 is a block diagram showing the equivalent circuit between the first transformer and the fault location; Figure 3 is a circuit diagram showing the fault location and Second transformer, etc.

20 201122503 effect circuit; FIG. 4 is a block diagram embodiment; FIG. 5 is a flow chart preferred embodiment; FIG. 6 is a flow chart illustrating the first of the fault locator of the present invention, illustrating the fault location method of the present invention. Describe the flow of finding the fault voltage; FIG. 7 is a flow chart illustrating the execution steps of the approach module;

Figure 8 is a block diagram embodiment; and Figure 9 is a flow chart preferred embodiment. The second description of the fault locator of the present invention illustrates the first preferred method of the fault locating method of the present invention.

21 201122503 [Explanation of main component symbols] 100 · ...... Three-phase power system SU........ Steady-state unit 200 · ...... Global Positioning Satellite System TU........ State Unit 1 ' 2 ••... Transformer PU........ Capture Unit 11.........The first measurement module Cl(d), C2(d) Capacitor 21·.· ......Second measurement module Gl(d), G2(d) Conductance 3 ........ ...... Transmission line Ll(d), L2(d) Inductance 5, 6 ••... Fault locator Rl(d) , R2 (d) Resistor 50.··... Computing device Yl(d), Y2(d) Second impedance 51.··· Zl(d), Z2(d) First impedance 52 ' 62 ·. First The current calculation modules 70 to 77········································ 56··. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The second embodiment of the implementation 58 '6 6 · positioning module step 59 ... ... impedance calculation unit 61 · ·. 64. · unit. Coefficient generating unit ...... 65 ... ...... solving unit

Claims (1)

201122503 - VII. Patent application scope: -〗 A fault location method is suitable for calculating a fault location for contacting a power transmission line between a first transformer and a second transformer, comprising the following steps: (A) Measure a first reference voltage at the first transformer and a first reference current and a second reference voltage and a second reference current at the second power transformer; (B) setting a fault parameter An initial value, the fault parameter is a ratio of the position of the fault to the second transformer to the total length of the power line; (C) based on a total length of the power line, a characteristic impedance and a propagation constant, and the fault parameter Obtaining a first set of impedances, the first set of impedances representing an equivalent circuit model of the power line between the fault location and the first power transformer; (D) utilizing the first reference voltage and the first a first fault voltage is obtained by the reference current and the first set of impedances; (E) obtaining a second set of impedances based on the total length of the power line, the characteristic impedance and the propagation constant #, and the fault parameter, The two sets of impedances represent an equivalent circuit model of the power line between the fault location and the second power transformer; (F) using the second reference voltage, the second reference current, and the second set of impedances to obtain a first (2) calculating a difference between the first and second fault voltages, and using the difference to update the fault parameter, and repeating the step (Cb (G) based on the updated fault parameter until after the update The fault parameter causes the voltage of the first, 23, 201122503 to approach; and (H) finds the fault location by using the fault parameter completed by the update. 2. The fault location method according to the scope of claim patent, wherein The first set of impedances includes - a first impedance between the fault location and the (four)-transformer and - a first impedance across the first transformer and the ground, and the second impedance has a _ capacitance; And step (9) is to subtract the current flowing to the second impedance by the first reference current to determine a current flowing through the first impedance, thereby obtaining the first fault voltage, wherein the current flowing to the second impedance includes Have a cross of this capacitor 3. The fault locating method according to the scope of the patent application, wherein the first set of impedances comprises a first impedance and a crossover between the fault location and the first transformer a second impedance between the first transformer and the ground, and the first impedance has an inductance; and the step (D) is to subtract the voltage drop of the first impedance from the first reference voltage to obtain the first fault voltage The voltage drop of the first impedance includes a change in current flowing through the inductor. 4. The fault location method according to claim 1, wherein the step (D) further utilizes a first group of related comparison parameters. Impedance, obtaining a comparison voltage, and step (F) further obtaining a second comparison electric dust by using a first set of impedances associated with the comparison parameter; and (G) calculating a difference between the first and second fault voltages, And calculating a difference between the first and second comparison voltages to approximate an approximate parameter. 24 201122503 5. According to the fault location method described in item 4 of the patent scope, wherein the difference between the parameter after the approximation and the fault parameter is not less than an error tolerance value, and the parameter is regarded as the next fault parameter after the approximation Steps (C) to (G) are repeated; when the difference between the parameter and the fault parameter is less than the error tolerance value, the fault parameter is updated with the approximated parameter. 6. The fault locating method according to claim 1, wherein the step (4) measures the first reference voltage and the second reference voltage at a current sampling time, a previous sampling time, and a first two sampling times. And steps (D) and (F) are respectively calculating the first fault voltage and the second fault voltage according to the reference values of the three sampling times. 7. The fault location method of claim 1, wherein the fault parameter is multiplied by the total length of the wire to obtain a distance from the fault location to the second transformer. 8. A fault location method, which is suitable for the - fault line, and the fault location, including the following steps: U 3 Μ next (!) Detecting a first reference voltage and a reference current at the first power transformer and a second reference voltage and a first reference current at the second power transformer; (8) based on a total length, a characteristic impedance, and a number of the power line 'Brake to a set of factors, this New Zealand early ± 7 詨 first - _. @,, and the factor table v is the ratio of the equivalent impedance of the power line between the fault location and the 5&quot; relative to a fault 25 201122503 parameter and the fault parameter is the fault location and the second transformer The distance to the total length of the power line; (c) calculating, based on the reference voltage, the reference current, and the set of factors, a fault parameter that satisfies a first fault voltage equal to a second fault voltage, wherein the a fault voltage refers to a voltage based on the first reference voltage at the fault location, the second fault voltage refers to a voltage based on the second reference voltage at the fault location; and (D) using the fault parameter to find the fault position. 9. The fault locating method according to item 8 of the patent application scope, wherein the step (C) is a function representing the first fault voltage equalization, and calculating a plurality of _ real parts and _ imaginary parts respectively = Solution, and take out the possible solution that the imaginary part is close to zero, so that the real part is regarded as the fault parameter. 10. The fault location method according to claim 9, wherein the function according to step (C) is related to a voltage change of the first reference voltage at two sampling times, and is related to the second reference. The voltage changes in voltage over two sampling times. 11. The fault location method of claim 9, wherein the set of factors comprises a first impedance factor and a second impedance factor and - the second impedance factor has a capacitance factor, and step (C) comprises : a step: a reference current and the reference current, and (c-1) adjusting the first first factor current by using the first reference voltage, the first first impedance factor, and the capacitance factor; 201122503 a reference current and the first reference current, and (c-2) using the second reference voltage, the second impedance factor, and the capacitance factor to adjust the current to obtain a second factor; and (c-3 The function is used to calculate the early parameter, and the function is controlled by the factor currents. 12. The fault locating method according to claim </ RTI> wherein the function according to the step (C) is controlled by the change of the first factor current in two sampling times, and is controlled by the first The two-factor current changes over two sampling times. 13. The fault location method according to claim 8, wherein the step (A) measures the first reference voltage and the second reference at a current sampling time, a previous sampling time, and a first two sampling times. Voltage; and step (C) is to calculate the fault parameter based on the reference voltages of the three sampling times. 14. The fault location method according to claim 8, wherein the step (D) is to multiply the fault parameter by the total θ of the power line to the distance of the fault location from the second power transformer. 27