METHOD FOR DETERMINING THE LOCATION OF A FAULT IN AN ELECTRICAL POWER SUPPLY SYSTEM

Description

METHOD FOR DETERMINING THE LOCATION OF A FAULT IN AN ELECTRICAL POWER SUPPLY SYSTEM Description

[001] The invention relates to a method for determining the location of a fault in an electrical power supply system, wherein a respective measured electrical variable is recorded at a first measuring point and a second measuring point in the power supply system by means of a respective measuring sensor to obtain a first or a second measuring signal, wherein each measuring point is disposed in the immediate vicinity of a busbar or on a busbar and each measuring sensor is connected to a respective intelligent electronic device (IED) and indicates the total length of the conductor section of the power supply system between the first measuring point and the second measuring point or the busbars, and the measuring signals from the first measuring point and the second measuring point are examined for the presence of a progressive wave.

[002] The reliable operation of electrical power supply systems requires the rapid and reliable identification and shutdown of any faults, such as short circuits or ground faults. The causes of faults that lead to a shutdown can be, for example, lightning strikes, broken or otherwise damaged lines, faulty insulation in cable lines, or unwanted contact between overhead lines and animal or plant parts. In order to shorten the downtime induced by a fault, such faults must be located as precisely as possible to allow a maintenance team to rectify the cause of the fault, along with any resulting damage caused by the fault.

[003] In the simplest, but also most complex case, the fault is located by manual inspection. A maintenance team then removes the faulty line and examines it for visible points of Petition 870260045604, dated 05 / 14 / 2026, page 8 / 21 2 / 14 failure. It is also a known practice to use drones equipped with cameras that fly over the faulty line. The image data is transferred to a central station. However, these procedures are time-consuming and prone to failure.

[004] Therefore, a different procedure has been widely adopted, whereby the fault location on the line is demarcated by means of analysis of measured variables, for example, currents and voltages, recorded during the occurrence of the fault. For this purpose, however, several different methods are known, the accuracy of which has a significant effect on the maintenance costs of the power supply system. Therefore, great value is given to improving the accuracy of the algorithms used for fault location, in order to facilitate maintenance and, in particular, to reduce downtime induced by power supply system faults.

[005] It is known from document EP 2476002 BI that it is possible to restrict the location of the fault by determining the direction of the fault. This method is mainly used in grounded, compensated, isolated, and high-resistance power supply systems with radial structure and low degree of interlocking. For example, a wattmeter method can be used.

[006] Methods for more precise fault location use measured current or voltage signals from the fundamental waveform (50 Hz or 60 Hz signals) for fault location. In this case, methods are known that use measured values ​​from only one end of the line (unilateral fault location) or measured values ​​from both ends of the line (bilateral fault location). As a result, the fault location is usually given as the distance from the respective measurement point (in terms of percentage of the line or in km or miles).

[007] US patent 4,996,624 A describes a fault location method in which measured values ​​from only one end of the line are used. The effort required here to perform fault location is Petition 870260045604, dated 05 / 14 / 2026, page 9 / 21 3 / 14 faults is therefore low. The aforementioned fault location method is predominantly an impedance-based method, in which an impedance for the fault location is calculated from the measured current and voltage values. It is possible to reach a conclusion regarding the fault location by comparing it with the line impedance of the entire line in the fault-free case.

[008] θ US patent 5,929,642 A provides a fault location method that has greater accuracy by virtue of using measured values ​​from both ends of the line. In this case, the measured values ​​related to fault location must be combined by means of a suitable communication connection. A high degree of accuracy (measurement error of approximately 1 to 2%) in fault location is achieved using estimation methods and non-linear optimization methods.

[009] The method mentioned at the beginning is described in the US document 8,655,609 B2. A method for locating faults using bilateral progressive waves is described in this document. Although the accuracy of fault location in impedance-based fault location methods depends on the measurement accuracy of the transducers used and the condition of the system, using a fault location method according to what is known as the progressive wave principle (“progressive wave fault location”) makes it possible to achieve a high degree of independence from these variables. According to this principle, instead of the fundamental waveforms of the measured current or voltage signals, the transient signal components that occur during the fault, which take the form of what is known as “progressive waves”, are taken into account for fault location. In this case, the edges of the high-frequency progressive waves are recorded using measurements and provided with a date and time stamp.Since the propagation speed of progressive waves is approximately the speed of light, it is possible to obtain the location of the fault from it. Petition 870260045604, dated 05 / 14 / 2026, page 10 / 21 4 / 14 evaluation of the date and time stamp. The disadvantage of this method is that the exact propagation speed of the progressive waves must be specified when calculating the fault location. However, this can vary from system to system and cannot always be determined precisely.

[0010] The infrastructure required for bilateral progressive wave fault location requires, on the one hand, a communication link between the measuring devices at the different measuring points and, on the other hand, the exact time synchronization of the two measuring devices. Alternatively, in addition to the two measuring devices, a central evaluation unit, which has communication links with both measuring devices, can be used in the field. For economic reasons, the complexity associated with the device currently limits the appeal of progressive wave fault location to relatively expensive high-voltage and extra-high-voltage applications. Therefore, these fault location systems are preferably used in cases where faster availability of the faulty line justifies an expensive infrastructure.

[0011] Document WO 2016 / 118584 Al describes a method for locating faults using one-sided forward waves that is based on comparing forward waves generated during a planned fault event with forward waves generated during a fault. However, for this purpose, complex comparative measurements are required to record the forward waves by measuring them in the case of a planned fault event.

[0012] The present invention will be described below, making reference to the accompanying drawing, given only by way of example, in which: Figure 1 shows a schematic diagram of an exemplary embodiment of the method according to the present invention.

[0013] The object of the invention is to provide a method of the type Petition 870260045604, dated 05 / 14 / 2026, page 11 / 21 5 / 14 mentioned at the beginning, that is, fault location according to the bilateral progressive wave principle, which is both accurate and economical.

[0014] The invention achieves this objective by virtue of the fact that, after determining the presence of a progressive wave at both measurement points with the aid of the first reflection of said progressive wave on the respective collector bar and at the fault location, a propagation time ratio factor F is calculated, which indicates the propagation time of the progressive wave from the fault location to the first measurement point in relation to the propagation time of said progressive wave from the first measurement point to the second measurement point, and by virtue of the fact that the distance X from the fault location to the first measurement point is calculated F from the product of the propagation time ratio factor and the total length ab according to X = F·^

[0015] In the context of the invention, fault location is provided by bilateral progressive waves, which does not require high-precision time synchronization between measurement points. This considerably reduces the complexity related to the device. Furthermore, in the context of the invention, the propagation speed of the progressive wave is no longer included in the determination of fault location. In the context of the invention, inaccuracies resulting from this are consequently avoided. In addition, error factors arising from the different lengths of the signal lines between the measuring sensors and their connection device are also not relevant in the context of the invention.

[0016] The method according to the invention is based on previously known methods of fault location using unilateral progressive waves. In the context of the invention, the occurrence of a progressive wave and Petition 870260045604, dated 05 / 14 / 2026, page 12 / 21 6 / 14 The reflection of the wave at the fault location is recorded at both measurement points independently of each other. The high-frequency edges of the progressive wave or the reflection of the progressive wave are recorded using measurements and provided with a date and time stamp. The reflections of the progressive wave that occur in the event of a fault first occur at the measurement point location or, more specifically, at the collector bus that is also located there. The progressive wave reflected by the collector bus returns to the fault location and is also reflected there and returns to the measurement point, where the edge of this first reflection is recorded using measurements and provided with a second date and time stamp. The arrival of the progressive wave caused by the fault in the power supply system and its first reflection, which we have just described, can be detected at both measurement points.In the context of the invention, the time periods between the recording of the progressive wave and its first reflection at both measurement points are taken into account.

[0017] In the context of the invention, “located in the immediate vicinity of a collector bar” means that the measurement point is located on the line side of the collector bar and specifically at a distance of 0.01 to 100 meters from the collector bar. The term “collector bar” is intended to represent all components on which a progressive wave can be reflected. In the context of the invention, the measurement point can also be located on the collector bar itself. In other words, the measurement is performed on the collector bar. In the case of such small distances (0.01 to 100 meters) between the measurement point and the collector bar, when determining the location of the fault, it can be assumed with good approximation that the reflection occurs practically at the measurement points.However, in the case of greater distances between the measurement points and the respective collector bar, the distance between the measurement point and the respective collector bar must be taken into account when locating faults. Petition 870260045604, dated 05 / 14 / 2026, page 13 / 21 7 / 14

[0018] The conductor section between the first measurement point and the second measurement point is advantageously in the form of a mesh-free and node-free conductor. In other words, according to this further development of the invention, a linear conductor is monitored. This simplifies the recording of progressive waves using measurements. In particular, identifying the first reflection of the progressive wave at the fault location is simplified compared to other disturbing reflections. F

[0019] Preferably, the propagation time ratio factor is formed exclusively from a time difference that is recorded at the first measurement point and a time difference that is recorded at the second measurement point. In this way, comparison of the date and time records of one measurement point with a date and time record of the second measurement point is avoided.

[0020] According to a further development of the invention in this respect, the times are recorded at the first measurement point and are calculated according to , where ΐα2 indicates the time when the progressive wave arrives and indicates the time when the first reflection of said progressive wave arrives at the first measurement point. At the same time, the times and are recorded at the second measurement point, where is calculated according to ^b=~ ^b2 ~ ^b0 , where indicates the time when the progressive wave arrives and indicates the time when the reflection of the progressive wave arrives at the second measurement point. Also in this case, the arriving progressive wave is initially reflected at the collector bar, i.e., practically at the measurement point, and then at the fault location. In principle, a progressive wave is reflected at an arbitrary frequency between the fault location and the collector bar. The amplitude of the wave decreases constantly, but the propagation time of Petition 870260045604, dated 05 / 14 / 2026, page 14 / 21 8 / 14 from the fault location to the collector bar remains the same. However, the first reflection can be detected with sufficient accuracy. If a plurality of reflections from the fault location can be measured, these can be used within the context of the invention to verify the time differences and determined from the first reflection. This must be ensured first. It is also convenient to validate the measurements if the propagation time through the entire line is calculated from the sum of and compared with a predetermined “target value” for the propagation time through the line. Furthermore, it is possible to verify the fault location according to the invention using bilateral fault location with high-precision time synchronization.

[0021] According to a preferred variant of the method according to F of the invention, the propagation time ratio factor is calculated from p= Ata+àtbacordo com

[0022] According to a further development of the invention, the propagation time of the progressive wave from the fault location to the first measurement point is determined by the difference between the time at which the first reflection of the progressive wave reaches the first measurement point and the time after which the progressive wave reaches the first measurement point = “ ^a2—Tu. 1-) according to

[0023] According to this further development in this respect, the propagation time of said progressive wave from the first measurement point to the second measurement point is calculated from the sum of the propagation time of the progressive wave from the fault location to the first measurement point and the propagation time of the progressive wave from the fault location to the second measurement point according to tab = àta+ - tbi) tb2. , in which , and in which indicates the time Petition 870260045604, dated 05 / 14 / 2026, page 15 / 21 9 / 14 indicates the time when the reflection of the progressive wave reaches the second measurement point, and indicates the time at which the progressive wave reaches the second measurement point.

[0024] Advantageously, in the context of the invention, two LEDs are provided, which are connected to a control center arrangement by means of a communication connection, wherein the control center arrangement locates the fault location.

[0025] In contrast, the LEDs are connected to each other via a communication link, with the result that the measured values ​​can be transmitted between the LEDs. The fault location can then be calculated by one of the LEDs.

[0026] Control center arrays are individual data processing devices or groups of data processing devices that are centrally or decentrally organized and generally execute complex algorithms to observe and / or control the facility. Control center arrays typically have a human-machine interface that enables a facility operator to observe and monitor the status of the facility as a whole, observe and monitor the status of individual components of the facility, and control individual components or a plurality of components.

[0027] In the context of the invention, the control center arrangement can also be implemented by a data processing cloud. A data processing cloud should be understood in this document as an arrangement that has one or more data storage devices and one or more data processing devices, which can be designed to perform any desired data processing processes through appropriate programming. In this case, the data processing devices are generally universal data processing devices (e.g., servers) that initially do not have any specific design in Petition 870260045604, dated 05 / 14 / 2026, page 16 / 21 10 / 14 Construction and Programming Terms. The universal data processing apparatus can be upgraded to perform specific functions only through programming. If the data processing cloud has a plurality of individual components, these will be connected to each other in a manner suitable for data communication (e.g., via a communication network). Any desired data can be supplied to a data processing cloud for data storage and / or processing. The data processing cloud itself, in turn, provides other devices, for example, a computer workstation connected to the data processing cloud, with the stored data and / or the results of the data processing that has been performed. In the context of the invention, the term control center arrangement used in this document is also intended to extend to such a data processing cloud.A data processing cloud can also be provided, for example, by a single computing center or a plurality of networked computing centers. A data processing cloud is usually located spatially distant from the facility.

[0028] Intelligent electronic devices (called LEDs) are capable of independently performing tasks to automate or protect an electrical power supply system while executing specific algorithms. In this context, LEDs can be, in particular, protection and control devices, measuring devices, power quality devices, or energy meters.

[0029] In the context of the invention, a communication connection means both wired connection lines and wireless radio connections.

[0030] Other convenient configurations and advantages of the invention are the subject of the description of exemplary embodiments of the invention that follows with reference to the figure of the drawing, in which the figure schematically shows an exemplary embodiment of the method according to Petition 870260045604, dated 05 / 14 / 2026, p. 17 / 21 11 / 14 the invention.

[0031] The figure shows an exemplary embodiment of the method according to the invention. In the example shown, the electrical power supply system is designed as a linear, meshless, and nodeless line 1, which has a three-phase design. In other words, line 1 comprises three individual phase conductors. This is not shown in the figure. Conductor 1 extends from a first collector bus 2 to a second collector bus 3. Furthermore, two measuring points a and b can be seen, wherein measuring point a is located in the immediate vicinity of collector bus 2 and measuring point b is located in the immediate vicinity of collector bus 3. In the exemplary embodiment shown, the distance between the respective measuring point and the collector bus is five meters. Measuring sensor 4a is located at measuring point a, and measuring sensor 4b is located at measuring point b. Both measuring sensors are voltage transformers.In the context of the invention, however, current transformers or small-signal transformers, for example, a Rogowski coil, can also be used.

[0032] Each measuring sensor 4a, 4b is connected to the measuring device input of an intelligent electronic device (IED) 5a or 5b. In the exemplary embodiment shown, the LEDs 5a, 5b are protection devices.

[0033] The measurement signals generated on the output side by the measuring sensors are provided to the protection devices 5a or 5b. Each protection device 5a and 5b collects samples of the analog measurement signals to obtain sample values, wherein the sample values ​​are then digitized by an analog-to-digital converter to obtain measured values.

[0034] The figure also indicates that there is a short circuit at fault location 7 on line 1. The short circuit itself is indicated by a jagged arrow. Petition 870260045604, dated 05 / 14 / 2026, pages 18 / 21 12 / 14 6. Progressive waves 8a and 8b occur at fault location 7 due to the short circuit, where progressive wave 8a travels from fault location 7 to measurement point a and progressive wave 8b travels from fault location 7 to measurement point b. These progressive waves 8a and 8b are what we call transient signal components, which are high-frequency.

[0035] Below line 1 and protection devices 5a, 5b, two time lines ta and tb can be seen in the figure, which are intended to indicate the time record of the respective protection devices 5a and 5b. Protection devices 5a and 5b have an internal clock or timing unit to measure time, with the aid of which a date and time record can be generated. The clocks of protection devices 5a and 5b are not synchronized with each other. In the figure, the time record of the clock of protection device 5a is indicated by time line ta and the time record of the clock of protection device 5b is indicated by time line tb.

[0036] If the progressive wave 8a reaches the measurement point a, its The high-frequency edge will be provided with the date and time stamp. In other words, the time measures the arrival of the progressive wave 8a at the measurement point a. This is shown schematically with an arrow, whose tip touches the timeline at . The reflection of the progressive wave on collector bar 2 provides another arrow, whose tip is on the dashed line that runs parallel to the timelines ta and tb and is positioned between them in the figure. At the fault location 7, which is symbolized by the dashed line in the figure, a renewed reflection of the progressive wave 8a occurs, which can then be detected again at measurement point a as the first reflection. The moment when the first reflection of the progressive wave is recorded at measurement point ΐα2 a is indicated by on the timeline ta.

[0037] On the other side of line 1, on side b, a corresponding procedure follows. The arrival of the progressive wave 8b at measurement point b is Petition 870260045604, dated 05 / 14 / 2026, pp. 19 / 21 13 / 14 provided with the date and time stamp. The progressive wave 8b is then reflected again at collector bar 3 in the direction of fault location 7, resulting in a renewed reflection at fault location 7. The arrival of the progressive wave, which is reflected at fault location 7, at measurement point b is provided with the date and time stamp.

[0038] Protection devices 5a and 5b are each connected to a control center arrangement 10 by means of a communication link 9, with the help of which the aforementioned date and time records of the progressive waves 8a and 8b and their first reflections are transmitted to the control center arrangement 10. In the exemplary embodiment shown, the communication link 9 is a wireless radio link. The control center arrangement 10 is now able to locate the short circuit, i.e., determine or reduce the distance of the fault location from the measurement point a.

[0039] To determine the location of fault 7, that is, the distance X from the location of fault 7 to the measuring point a, a propagation time ratio factor F is calculated in the context of the invention by means of the control center arrangement 10. This factor F corresponds to the ratio between the propagation time of the progressive wave 8a, from the location of fault 7 to the measuring point a, and the propagation time of a corresponding progressive wave along the entire line 1, from the measuring point a to the measuring point b. This distance is called Lab.

[0040] According to the invention, the propagation time of the progressive wave 8a from the fault location 7 to the first measurement point a is determined by the difference between the time t, when the first reflection of the progressive wave arrives and the time t, when the progressive wave arrives at the first measurement point in each case according to The propagation time of a progressive wave corresponding to the first Petition 870260045604, dated 05 / 14 / 2026, page 20 / 21 The time between measurement point a and the second measurement point b, indicated by t^b, can be calculated from the sum of the propagation time of the progressive wave 8a from fault location 7 to the first measurement point a, indicated by t^b, and the propagation time of the progressive wave 8b from fault location 7 to the second measurement point b (t^b), according to t^b = (t^a + t^b) / 2, where t^b is calculated. The ratio factor is calculated. The propagation time F can therefore be calculated according to W _ X is the distance from the measurement point to the result, according to Δία j àtaA-átbabe X = FLab=

Claims

CLAIMS 1. Method for determining the location of a fault (7) in an electrical power supply system (1), wherein a. a respective measured electrical variable is recorded at a first measuring point (a) and a second measuring point (b) in the power supply system (1) by means of a respective measuring sensor (4a, 4b) to obtain a first or second measuring signal, wherein each measuring point is disposed in the immediate vicinity of a busbar or on a busbar and each measuring sensor (4a, 4b) is connected to a respective intelligent electronic device IED (5a, 5b) and indicates the total length of the conductor section of the power supply system between the first measuring point (a) and the second measuring point (b) or the busbars, b.the measurement signals from the first measurement point (a) and the second measurement point (b) are examined for the presence of a progressive wave (8a, 8b); characterized in that c. after determining the presence of a progressive wave (8a, 8b) at both measurement points with the aid of the chronologically first reflection of said progressive wave on the respective collector bar (a or b) and then at the fault location (7), a propagation time ratio factor is calculated, which indicates the propagation time of the progressive wave (8a) from the fault location (7) to the first measurement point (a) in relation to the propagation time of said progressive wave (8a, 8b) from the first measurement point (a) to the second measurement point (b), and X d. the distance of the fault location (7) from the first measurement point (a) is calculated from the product of the propagation time ratio factor and the total length ab according to Petition 870250082904, dated 09 / 15 / 2025, page 25 / 29 2 / 3.

2. Method according to claim 1, characterized by the fact that the propagation time ratio factor is formed exclusively from a time difference that is recorded at the first measurement point (a) and a time difference that is recorded at the second measurement point (b).

3. Method according to claim 2, characterized in that the times al and are recorded at the first measurement point Δΐα = τα1^ ΐα1 (a) and is calculated according to , where indicates the time when the progressive wave (8a) arrives and indicates the time when the first reflection of said progressive wave (8a) arrives, and in that the times £^2 ^b and are recorded at the second measurement point (b) and is ^b = ~Üb2~ ^bl) Tbl calculated according to , where indicates the time at ^b2 that the progressive wave (8b) arrives and indicates the time when the first reflection of the progressive wave (8b) arrives at the second measurement point (b).

4. Method according to claim 3, characterized in that the propagation time ratio factor is calculated according to P = with 5. Method according to any of the preceding claims, characterized in that the propagation time of the progressive wave (8a) from the fault location (7) to the first measurement point (a) is determined from the difference between the time at which the first reflection of the progressive wave arrives and the time at which the progressive wave arrives at the first measurement point according to 6. Method according to claim 5, characterized in that the propagation time of the progressive wave (8b) from the first measurement point (a) to the second measurement point (b) is calculated from the sum of the propagation time of the progressive wave (8a) from the fault location (7) to the first measurement point (a) and the propagation time of the progressive wave (8b) from the fault location (7) to the second measurement point &tbTab = = - [tb2 ~tbl) (b) according to , where , and where indicates the time at which the first reflection of the progressive wave reaches the second measurement point and indicates the time at which the progressive wave reaches the second measurement point.

7. Method according to any of the preceding claims, characterized in that the two LEDs (5a, 5b) are connected to a control center arrangement (10) by means of a communication link (9), wherein the control center arrangement (10) locates the fault location.

8. Method according to any of the preceding claims, characterized in that the two LEDs (5a, 5b) have a clock, wherein the clocks are not synchronized with each other.

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