System for a cable route, transmission system for transmitting electrical energy and method for operating the system

Description

[0001] The invention relates to a system for an electrical cable route for transmitting electrical energy, a transmission system for transmitting electrical energy, and a method for operating the system for an electrical cable route for transmitting electrical energy.

[0002] Electrical cable runs for transmitting electrical energy are known from the prior art. The cable run can consist of a single cable section or of a plurality of cable sections coupled one behind the other. The cable run can also be referred to as an electrical cable. The transmission of electrical energy over an electrical cable run can be achieved using direct current or alternating current. Very high voltages are often used to transmit electrical energy over long distances. In this case, the cable run can be designed as a high-voltage cable. The cable run often comprises an electrically conductive core, which can be formed from a large number of individual electrically conductive wires. Several layers made of different materials and / or with different functions are often arranged around the core. One of the layers can be an insulating layer.In practice, it can happen that a so-called partial discharge occurs. This partial discharge causes a sudden electrical signal that spreads from the location of the partial discharge, also known as the partial discharge point, in opposite directions along the cable run. The signal caused by the partial discharge is also known as the partial discharge signal. The partial discharge signal can be recorded using a sensor at the end of the cable run. However, it must be taken into account that the partial discharge signal is subject to attenuation and dispersion on the path between the partial discharge point and the sensor due to the physical properties of the cable run. The attenuation and dispersion depend, for example, on the frequency components of the pulse caused by the partial discharge, the structural design of the cable run, the type of installation, the temperature of the cable run and / or the age of the cable run.Furthermore, a single sensor at one end of the cable run is not sufficient. Rather, a second sensor is required at the opposite end of the cable run to calculate where the partial discharge occurred or where the partial discharge location is based on propagation times and triangulation. Due to the dependence of the attenuation and dispersion of the partial discharge signal, there are often significant deviations between the calculated partial discharge location and the actual partial discharge location. Due to the aforementioned attenuation and dispersion, it can also happen that partial discharge signals are subject to such strong dispersion and / or attenuation, in particular frequency-dependent attenuation, that they are not detected as pulse signals by the sensors and / or an evaluation device. Therefore, there is a risk that partial discharges may occur in cable runs that are not detected.If several such partial discharges occur at the same partial discharge location, this can lead to significant damage to the cable section, which must be avoided.

[0003] Document D60020050T2 exploits the properties of partial discharge pulses generated in a partial discharge source as a function of the distance they travel in the electrical system, for example, along a conductor. By deriving characteristic parameters that specify certain properties of the partial discharge pulses from measured partial discharge pulses and inserting the parameters into a previously created model, for example, experimentally, that describes the change in the characteristic parameters as a function of distance, essentially at the frequencies at which partial discharge pulses occur, it is possible to determine the distance of a partial discharge source from the measurement point with a certain degree of accuracy.

[0004] The invention is based on the object of providing a system and an associated method that allows a reliable detection of a partial discharge and a precise determination of a distance of the partial discharge location to the sensor.

[0005] According to a first aspect of the invention, the aforementioned object is achieved by a system having the features of claim 1. Thus, a system for an electrical cable route for transmitting electrical energy is provided. The system has a first sensor for detecting electrical signals from the cable route, a processor unit, a data memory, and a signal interface. The data memory stores a first set of curves comprising a plurality of first curves, each with an associated distance from the first sensor, wherein each first curve represents an impulse response of an electrical impulse, predetermined by means of a cable model of the cable route, due to a modeled partial discharge at the distance from the first sensor on the cable route associated with the respective first curve.The first sensor is configured to detect an electrical signal, referred to as the first discharge signal, caused by an actual partial discharge along the cable route. Furthermore, the first sensor is configured to directly or indirectly transmit a first measurement signal to the processor unit, wherein the first measurement signal represents the first discharge signal. Based on the first measurement signal, the processor unit is configured to determine one of the first curves of the first set of curves as the first discharge curve, which among the first curves of the first set of curves best correlates with the first discharge signal. Which of the first curves of the first set of curves best matches or correlates with the first discharge signal can be determined by applying similarity measures in the feature space, such as Euclidean distance, Mahalanobis distance, and / or cosine similarity.The processor unit is configured to determine a first sensor distance of the actual partial discharge from the first sensor based on the distance associated with the first discharge curve. The signal interface is configured to transmit an output signal representing the first sensor distance.

[0006] Investigations have shown that the partial discharge along an electrical cable route can be modeled by an electrical impulse. Furthermore, it has been found that the cable route can be modeled by a mathematical model, namely the cable model, which can be adjusted using a variety of parameters. These parameters can be set so that the model models an actual cable route. If this cable model is then used to cause a partial discharge by a modeled impulse at a partial discharge location on the modeled cable route, the same cable model can be used to determine the impulse response at one end of the cable route or at another sensor location on the cable route. The impulse response, or at least part of the impulse response, then forms a curve. The impulse response orThe curve changes when the distance between the modeled sensor location and the modeled location for the electrical pulse input changes. It is therefore possible to use the cable model to determine corresponding curves for a variety of different distances. These curves can form the first several curves, each with a corresponding distance to the first sensor, which are stored in the data memory. The first curves differ in both their frequency spectrum and their amplitude spectrum. For example, it was found that the greater the modeled distance between the partial discharge location and the sensor, the lower the frequency spectrum of the curve, and the smaller the maximum amplitude.

[0007] With regard to the system, it is therefore preferably provided that the data memory stores a first set of curves consisting of at least 10 first curves, at least 20 first curves, or at least 30 first curves. The distances to the sensor associated with the first curves can form a series of increasingly larger distances, with the distances being equidistant from one another.

[0008] When the first sensor detects an electrical signal from the cable section, it can be compared with the first set of curves to determine which curve best fits the detected signal. This curve is assigned a distance stored in the data memory. This distance then corresponds to the actual distance from the first sensor to the actual partial discharge on the electrical cable section.

[0009] It is therefore provided that the first sensor is designed to detect an electrical signal, which is referred to as a first discharge signal and is caused by an actual partial discharge on the cable section. The first sensor can also transmit a first measurement signal to the processor unit, wherein the first measurement signal represents the detected first discharge signal. The first discharge signal is usually an analog signal. The first measurement signal, however, is preferably a digital signal. This offers the advantage that no deterioration of information relating to the detected first discharge signal occurs during transmission to the processor unit. The first sensor can therefore be designed to digitize the detected first discharge signal and form the first measurement signal therefrom.

[0010] By transmitting the first measurement signal to the processor unit, the processor unit receives not only the information about the first measurement signal as such but also information about the first discharge signal represented by the first measurement signal. The processor unit can thus select the curve that best represents the detected first discharge signal from the plurality of first curves of the first set of curves. Therefore, the processor unit is configured to determine, based on the first measurement signal, one of the first curves of the plurality of first curves as the first discharge curve that best correlates with the first discharge signal among the first curves of the first set of curves. For example, the processor unit can be configured to perform an autocorrelation for each of the first curves with the first discharge curve, such that an autocorrelation value is generated by executing each of the autocorrelation functions.The first curve for which the highest autocorrelation value was determined is then the curve among the first curves in the first set of curves that best correlates with the first discharge signal. However, there are also other methods for determining the curve among the first curves in the first set of curves that best correlates with the first discharge signal. The corresponding curve is referred to as the first discharge curve.

[0011] The processor unit is preferably coupled to the data memory so that the processor unit can access the data memory. In particular, the processor unit can be configured to read the data relating to the first curves and the associated distances from the data memory. As previously explained, the processor unit is configured to determine the first discharge curve. This first discharge curve is one of the plurality of first curves stored in the data memory. A distance representing the distance of the partial discharge from the sensor is stored in the data memory for each first curve. The processor unit is therefore preferably configured to read the distance associated with the first discharge curve from the data memory.It is therefore provided that the processor unit is configured to determine a first sensor distance of the actual partial discharge from the first sensor based on the distance associated with the first discharge curve. Preferably, the first sensor distance is the distance associated with the first discharge curve.

[0012] The first set of curves was previously determined using a cable model that can be precisely adapted to the actual cable length. This allows the cable model to also account for the actual attenuation and / or dispersion for pulses caused by partial discharges. The first curves of the first set of curves preferably differ in both their frequency response and their amplitude response. This allows for particularly precise tuning of the first curve among the first curves of the first set of curves that best matches the first discharge signal. Therefore, it is primarily the amplitude response and the frequency response that influence which of the first curves is determined as the first discharge curve.In practice, it has been found that the first discharge curve among the majority of the first discharge curves can be determined so precisely that the first sensor distance associated with the first discharge curve particularly precisely indicates the actual distance of the sensor to the partial discharge location at which the partial discharge took place.

[0013] The system also has a signal interface configured to transmit an output signal representing the first sensor distance. In particular, the output signal can be sent from the signal interface. This makes the first sensor distance accessible to further components, devices, and / or systems. In particular, the system can have further modules and / or units configured to further process the first sensor distance. It is therefore also possible for the signal interface to form an integral part of the processor unit. The processor unit and the signal interface can thus be integrally formed.

[0014] The first sensor of the system can be configured for the repeated and / or periodic detection of an electrical signal. This results in a first discharge curve and a first sensor distance being determined with each detection of an electrical signal. The processor unit can be configured accordingly for this purpose. Furthermore, the signal interface can be configured to transmit the output signal in such a way that the most current sensor distance is transmitted. The output signal can therefore periodically transmit the previously determined, first sensor distances. The periodic detection of electrical signals with the first sensor offers the advantage that the system can continuously monitor the electrical cable route.

[0015] An advantageous embodiment of the system is characterized in that the system has a second sensor for detecting electrical signals from the cable section. The data memory preferably stores a second set of curves comprising a plurality of second curves, each with an associated distance from the second sensor, wherein each second curve represents an impulse response of an electrical pulse, predetermined by means of the cable model of the cable section, caused by a modeled partial discharge at the distance from the second sensor on the cable section associated with the respective second curve. In addition, the first sensor and the second sensor can be attached to the cable section at a predetermined sensor distance from one another. The second sensor is preferably designed to detect an electrical signal, referred to as a second discharge signal, which is caused by the same, actual partial discharge on the cable section.Furthermore, the second sensor is preferably configured to directly or indirectly transmit a second measurement signal to the processor unit, which second measurement signal represents the second discharge signal. The processor unit is preferably configured to determine, based on the second measurement signal, one of the second curves from the second set of curves as the second discharge curve that best correlates with the second discharge signal among the second curves. Which of the second curves from the second set of curves best matches or correlates with the second discharge signal can be determined by applying similarity measures in the feature space, such as Euclidean distance, Mahalanobis distance, and / or cosine similarity.Furthermore, the processor unit is preferably configured to determine the first sensor distance of the actual partial discharge to the first sensor based on the predetermined sensor distance, the distance associated with the first discharge curve, and the distance associated with the second discharge curve.

[0016] In addition to the first sensor, the system therefore has a further sensor, namely the second sensor. The second sensor is also designed to detect electrical signals. The first and second sensors can be attached to the cable section at a predetermined sensor spacing. Preferably, the first sensor can be attached to a first end of the cable section and the second sensor can be attached to a second, opposite end of the cable section. If a partial discharge occurs on the cable section, this causes a pulse-like signal that is detected as an electrical signal by the two sensors. However, due in particular to the attenuation and dispersion of the electrical cable section, different electrical signals reach the two sensors.For example, if the distance from the partial discharge location to the first sensor is shorter than to the second sensor, the first discharge signal will have a larger amplitude in the high-frequency spectral component than the second discharge signal. Since the first discharge signal and the second discharge signal are often different in practice, a corresponding discharge curve can be determined for each of the two discharge signals.

[0017] It is therefore preferably provided that the data memory has stored a second set of curves consisting of a plurality of second curves, each with an associated distance from the second sensor. With regard to the second set of curves, the second curves and the associated distances, reference is made in an analogous manner to the advantageous explanations, preferred features, technical effects and / or advantages as have already been explained for the first set of curves, the first curves and the associated distances. In principle, it can therefore be provided that the data memory has stored a first set of curves and a second set of curves. The two sets of curves can be different. However, it is also possible for the first set of curves and the second set of curves to be the same. In this case, the data memory can have stored a common set of curves that forms both the first set of curves and the second set of curves.The same applies to the corresponding distances.

[0018] The second sensor can be configured analogously to the first sensor. Therefore, for the second sensor, reference is made analogously to the advantageous explanations, preferred features, technical effects, and / or advantages as explained in connection with the first sensor. However, it should be noted that the first discharge signal and the second discharge signal are caused by the same, actual partial discharge along the cable section. Due to the often different distances from the partial discharge location to the two sensors and / or due to different physical conditions, the first discharge signal usually differs from the second discharge signal.

[0019] It is therefore also preferably provided that the processor unit is configured to determine the second discharge curve from the second curve set that best correlates with the second discharge signal. Furthermore, the processor unit can be configured to read the distance associated with the second discharge curve from the data memory. The same can be provided for the first discharge curve. Thus, the first processor unit can be configured to read the distance associated with the first discharge curve from the data memory. Ideally, adding the two read-out distances results in the predetermined sensor distance between the two sensors. It follows that the first sensor distance, namely the distance between the location of the actual partial discharge on the electrical cable section (partial discharge location) and the first sensor, is determined by the distance associated with the first partial discharge curve.Likewise, the first sensor distance is also determined by subtracting the distance associated with the second discharge curve from the predetermined sensor distance. In this case, the processor unit can be configured to redundantly determine the first sensor distance based on the predetermined sensor distance, the distance associated with the first discharge curve, and the distance associated with the second discharge curve. This is because the processor unit can be designed to carry out the aforementioned mathematical steps. If the difference between the predetermined sensor distance and the distance associated with the second discharge curve does not correspond to the distance associated with the first discharge curve, the first sensor distance can be determined, for example, by averaging the aforementioned difference and the distance associated with the first discharge curve. The processor unit can be configured accordingly for this purpose.By taking into account the distances belonging to the first and second discharge curves, the first sensor distance can be determined even more precisely.

[0020] A further advantageous embodiment of the system is characterized in that the system has a first pulse feed unit for feeding at least one first electrical pulse into the cable section. The processor unit is configured to change parameters of the cable model, which represents a transmission behavior of electrical pulses over the cable section. The processor unit is further designed to control the first pulse feed unit such that electrical pulses referred to as first reference pulses are fed into the cable section by means of the first pulse feed unit, wherein the first pulse feed unit is arranged at a distance from the first sensor. The first sensor is designed to detect electrical signals referred to as first reference signals and caused by the first reference pulses.Furthermore, the first sensor is configured to directly or indirectly transmit a first test signal to the processor unit, wherein the first test signal represents the first reference signals. Furthermore, the processor unit is configured to adapt the parameters of the cable model based on the first test signal, so that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable section represented by the first reference pulses and the first reference signals.

[0021] In connection with the system, it has already been explained that the data memory can have stored a first set of curves consisting of a plurality of first curves, wherein each first curve of these first curves of the first set of curves can be predetermined using a cable model of the cable route. The cable model can, for example, be stored in the data memory of the system. Furthermore, the cable model can, for example, be loaded by the processor unit in order to execute it. The cable model can be changeable using parameters. By changing the parameters of the cable model, the modeled transmission behavior of electrical impulses over the cable route can be changed. The parameters of the cable model can, for example, be adjusted in order to model a different attenuation and / or dispersion behavior of the cable route using the cable model.The parameters can be used, for example, to cause frequency-specific attenuation and / or location-specific attenuation and / or frequency-specific dispersion and / or frequency-specific dispersion. By configuring the processor unit to modify the cable model parameters, the transmission behavior of the cable link can be adapted particularly precisely to the actual transmission behavior of the cable link. Predetermined parameters can be used for the initial use of the cable model. However, to adapt the cable model parameters to the actual transmission behavior and thus achieve precise modeling, test signals are advantageous.

[0022] The processor unit is therefore designed to control the first pulse feed unit such that electrical pulses referred to as first reference pulses are fed into the cable section by means of the first pulse feed unit. This feed preferably takes place at a distance from the first sensor. This distance of the first pulse feed unit from the first sensor can be predetermined and / or known. As previously explained, the first sensor detects electrical signals. The first sensor therefore also detects the electrical signal referred to as the first reference signal and caused by the first reference pulse. Furthermore, the first sensor is designed to transmit a test signal to the processor unit, wherein the first test signal represents the first reference signal. The first reference signal is usually an analog signal.To avoid degrading the information content, the first sensor can be configured to digitize the first reference signal to generate the first test signal. Furthermore, the first sensor is configured to transmit the first test signal to the processor unit.

[0023] Furthermore, the processor unit can be coupled to the pulse feed unit in such a way as to send a control signal to the first pulse feed unit so that the first reference pulse is fed into the cable section. The control signal can represent the first reference pulse. Alternatively or additionally, it is possible for the processor unit to at least temporarily store data representing the first reference pulse. Alternatively or additionally, it is possible for a signal to be sent from the pulse feed unit to the processor unit after the first reference pulse has been fed in, this signal representing the first reference pulse.

[0024] The injection of the first reference pulse causes the first reference signal to be detected by the first sensor. The processor unit can therefore be configured to determine the actual transmission behavior of the cable section based on the first reference pulse and the first reference signal. Since the location at which the pulse injection unit injects the first reference pulse into the cable section is known, the cable model can also be used to model a transmission behavior represented by the cable model that would occur if a pulse corresponding to the first reference pulse were injected into the cable section modeled by the cable model at the theoretically same location.Against this background, the processor unit is therefore configured to adapt the parameters of the cable model based on the first test signal such that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route represented by the first reference pulses and the first reference signals. This applies at least if, for this purpose, the cable route is modeled by the processor unit using the cable model in such a way that pulses corresponding to the first reference pulses are fed into the modeled cable route, so that auxiliary signals corresponding to the first reference signals are generated by the cable model. This is because, with these auxiliary signals and the aforementioned pulses, the transmission behavior represented by the cable model can be compared accordingly with the actual transmission behavior of the cable route.The cable model's parameters are adjusted to minimize the difference between the transmission behavior represented by the cable model and the actual transmission behavior of the cable route. This difference preferably relates to the amplitude response and / or the frequency response.

[0025] By adjusting the parameters of the cable model, the cable model can therefore be particularly easily adapted to the actual conditions of the actual cable route. This applies in particular to initial commissioning. However, it is also possible for the cable model to be adjusted several times during operation by changing the parameters. In practice, for example, strong partial discharges can lead to changes in the attenuation and / or dispersion of the cable route at certain points. This attenuation and / or dispersion can change, in particular, with regard to the amplitude response or the frequency response. These changes can be taken into account by adjusting the parameters of the cable model. If a new adjustment of the parameters of the cable model is carried out using the processor unit, the processor unit can be configured to redetermine the first set of curves and / or the second set of curves.Furthermore, the processor unit can be configured to store the new, first set of curves in the data memory. The same can apply to the new, second set of curves and the distances. This, in turn, makes it possible for the first sensor distance to continue to be determined with particular precision during continuous operation, especially when the cable length is subject to changes.

[0026] The cable model parameters can influence the transmission behavior, for example, with regard to amplitude response, phase response, group delay, phase delay, relative permittivity of the cable route, and / or other properties of the cable route. This allows the cable model to be adapted particularly precisely to the actual cable route.

[0027] It has proven advantageous if the first sensor is located at one end of the cable run, and the first pulse feed unit feeds the first reference pulse at the opposite end. In this case, the first reference pulse must be transmitted through the entire cable run before a corresponding first reference signal, generated by this first reference pulse, is detected by the first sensor. This first reference signal is therefore particularly advantageous for adjusting the cable model parameters.

[0028] As previously explained, the system can preferably comprise two sensors, namely the first sensor and the second sensor. Furthermore, it is preferably provided that the first sensor is arranged at one end of the cable section and the second sensor is arranged at the opposite end of the cable section. The first reference pulse is preferably applied to this opposite end, as previously explained.

[0029] An advantageous embodiment of the system is characterized in that the system has a second pulse feed unit for feeding at least one second electrical pulse into the cable section. The processor unit is designed to control the second pulse feed unit such that electrical pulses referred to as second reference pulses are fed into the cable section by means of the second pulse feed unit, wherein the second pulse feed unit is arranged at a distance from the second sensor. The second sensor is designed to detect electrical signals referred to as second reference signals and caused by the second reference pulses. Furthermore, the second sensor is designed to directly or indirectly transmit a second test signal to the processor unit, which test signal represents the second reference signals.The processor unit is configured to adapt the parameters of the cable model based on the first test signal and the second test signal such that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable link represented by the first reference pulses and the first reference signals and / or by the second reference pulses and second reference signals.

[0030] For the second pulse feed unit, the second reference pulse, the second reference signal and the second test signal, reference is made to the previous explanations, preferred features, technical effects and / or advantages in an analogous manner as they were explained in connection with the first pulse feed unit, the first reference pulses, the first reference signals and the first test signal. It should be noted, however, that the second pulse feed unit is arranged at a distance from the second sensor. For example, the second pulse feed unit can be arranged such that the second pulse feed unit feeds the second reference pulses at the same end where the first sensor is arranged. The second sensor is preferably arranged at the opposite end of the cable section, where the first pulse feed unit preferably also feeds the first reference pulses.The reference pulses fed in by the second pulse feed unit must therefore be transmitted from the cable section to the second sensor at the opposite end, where they are recorded as second reference signals. However, during transmission, the fed-in reference pulses are subject to frequency-dependent and / or amplitude-dependent attenuation and / or dispersion.

[0031] In principle, the second test signal can be used in a similar way to the first test signal to adapt the parameters of the cable model. However, the parameters of the cable model can be adapted even more precisely if this adaptation is based on the first test signal and the second test signal. The adaptation can be carried out by the processor unit in such a way that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route represented by the first reference pulses and the first reference signals, as well as to the actual transmission behavior of the cable route represented by the second reference pulses and the second reference signals. By adapting the parameters of the cable model with corresponding precision, as explained above, the first set of curves and / or the second set of curves can be updated, which are preferably stored in the data memory.This in turn allows a particularly precise determination of the first sensor distance.

[0032] An advantageous embodiment of the system is characterized in that the first sensor and the second pulse feed unit are designed as a common, first transducer unit. The first transducer unit can be designed to be arranged and / or fastened at one end of the cable run. A further embodiment of the system is characterized in that the second sensor and the first pulse feed unit are designed as a common, second transducer unit. The second transducer unit can be designed to be arranged and / or fastened at a further end of the cable run. Thus, the first and second transducer units can be arranged and / or fastened at opposite ends of the electrical cable run.

[0033] A further advantageous embodiment of the system is characterized in that the processor unit is configured, the first and / or second pulse feed unit is designed to periodically feed in reference pulses and after each feed in of the reference pulses to adapt the parameters of the cable model.

[0034] The periodic input of reference pulses, preferably the periodic input of first reference pulses and / or the periodic input of second reference pulses, allows the cable model to be updated periodically. This also allows a periodic update of the first set of curves and / or the second set of curves. The same applies to the associated distances. The processor unit can be configured accordingly for this purpose. The periodic updating of the cable model and / or the set(s) of curves enables a particularly precise and always up-to-date detection of the first sensor distance.

[0035] A further advantageous embodiment of the system is characterized in that the first sensor is designed to periodically detect electrical signals from the cable section. The processor unit is also preferably configured to determine the associated first discharge curve each time the electrical signal detected by the first sensor forms a first discharge signal, and to determine the first sensor distance of the first sensor from the respective partial discharge based on the first discharge curve.

[0036] It can therefore preferably be provided that the first sensor distance is determined in an event-driven manner, namely whenever the electrical signal detected by the first sensor forms a first discharge signal. This allows the first sensor distance to be determined for each partial discharge detected along the cable section.

[0037] A further advantageous embodiment of the system is characterized in that the second sensor is designed to periodically detect electrical signals from the cable section. The processor unit is also preferably configured to determine the associated second discharge curve each time the electrical signal detected by the second sensor forms a second discharge signal, and to determine the first sensor distance of the respective partial discharge from the first sensor based on the predetermined sensor distance, the distance associated with the first discharge curve, and the distance associated with the second discharge curve.To determine the first sensor distance, it has already been established that, when the system comprises the first and second sensors, the first sensor distance can be determined particularly precisely if the distance associated with the first discharge curve, the distance associated with the second discharge curve, and the predetermined sensor distance between the two sensors are used. This first sensor distance can therefore also be determined in an event-driven manner, namely whenever the electrical signals detected by the first and second sensors form associated discharge signals.

[0038] A further advantageous embodiment of the system is characterized in that the processor unit is configured to determine a frequency of several actual partial discharges at the same distance from the first sensor, and wherein the output signal also represents the frequency.

[0039] By configuring the processor unit to determine the first and / or second discharge curve, it is possible for even weak partial discharges to be detected and taken into account, and for a first sensor distance to be determined for each of these. If multiple weak partial discharges occur at the same partial discharge location, and thus with the same first sensor distance from the first sensor, this can in practice result in these multiple, weak partial discharges having a similar adverse impact on the cable route as a single, particularly strong partial discharge. The frequency of multiple, actual partial discharges, each occurring at the same first sensor distance from the first sensor on the cable route, is therefore particularly relevant information in practice.The transmission of the frequency of such partial discharges by means of the output signal therefore advantageously offers the possibility of precisely monitoring the condition of the cable section.

[0040] A further advantageous embodiment of the system is characterized in that the processor unit is configured to determine at least one characteristic of several actual partial discharges at the same distance from the first sensor, and wherein the output signal also represents the determined characteristic.

[0041] The characteristic can represent a property of the partial discharges. For example, the characteristic can represent the energy of the partial discharges. However, the energy of the partial discharges can be only one of many pieces of information that can be determined from the spectral composition of the partial discharges. The processor unit can be configured to perform source-filter separation to determine the characteristic.

[0042] A further advantageous embodiment of the system is characterized in that the processor unit is configured to generate a warning signal when the frequency of the partial discharges is greater than a predetermined threshold frequency and / or when the determined characteristic of the partial discharges is greater than a predetermined threshold characteristic, and wherein the signal interface is designed to transmit the warning signal.

[0043] It was already explained above that the frequency of partial discharges occurring at the same first sensor distance from the first sensor can lead to damage to the cable section. The frequency of these partial discharges can be a measure of the damage. It is therefore advantageous to generate a warning signal if the frequency is greater than the predetermined threshold frequency. The threshold frequency can be predetermined so that the warning signal is generated in good time before the damage to the cable section becomes excessive. In a similar way, the parameter can be taken into account if the parameter is greater than a predetermined threshold parameter. In this case, too, there is a risk of damage to the cable section, so an appropriate warning signal must be generated.

[0044] A further advantageous embodiment of the system is characterized in that the processor unit is configured to determine an aging state of the cable section based on the frequency of the partial discharges and / or the at least one determined characteristic of the partial discharges and / or the adapted parameters, wherein the output signal also represents the aging state.

[0045] The aging state of the cable can be determined depending on the number and / or extent of damage to the cable. The processor unit can be configured accordingly for this purpose. A high frequency of partial discharges indicates an increasing aging state. This can be determined based on the characteristic. The processor unit can also be configured to adjust the cable model parameters based on the aging state.

[0046] A further advantageous embodiment of the system is characterized in that the cable route has a plurality of cable segments that are arranged one behind the other along the cable route, wherein opposite ends of cable segments are connected to one another to form coupling points. Each cable segment is assigned a first sensor and a first set of curves for the respective first sensor, so that the system has a plurality of first sensors and a plurality of first sets of curves are stored by the data memory. The processor unit is preferably configured to determine the cable segment with the partial discharge as the identified cable segment based on the first sensor distances. The signal interface is preferably designed to provide the output signal that indicates the identified cable segment and represents the first sensor distance of the first sensor of the identified cable element from the partial discharge.

[0047] In practice, it can happen that a partial discharge occurs in one of the cable segments. However, the cable segment in which the partial discharge occurs is coupled to the other cable segments. The partial discharge therefore causes an electrical pulse that spreads across all cable segments and is therefore also detected by all of the first sensors. To prevent the mistaken assumption that a partial discharge has occurred in each of the cable segments, the cable segment with the actual partial discharge is determined as the identified cable segment based on the first sensor distances by means of the processor unit. The remaining first sensor distances are discarded. Furthermore, it is preferably provided that the output signal provided by the signal interface indicates the identified cable segment and represents the first sensor distance to the first sensor of the identified cable segment.This allows for a particularly precise and unambiguous determination of the first sensor distance and thus also a clear determination of the partial discharge location along the entire cable route. The processor unit can be configured accordingly.

[0048] According to a second aspect of the invention, the object mentioned above is achieved by a transmission system having the features of claim 15. Thus, a transmission system for transmitting electrical energy is provided, wherein the transmission system comprises a cable route and a system. The system is the system according to the first aspect of the invention and / or one of the associated advantageous embodiments. With regard to the system, reference is made to the preceding explanations, preferred features, technical effects, and / or advantages in an analogous manner to that already explained for the first aspect of the invention or one of the associated advantageous embodiments.

[0049] According to a third aspect of the invention, the object mentioned at the outset is achieved by a method having the features of claim 16. Thus, a method is provided for operating a system for an electrical cable route for transmitting electrical energy, wherein the system has a first sensor for detecting electrical signals from the cable route, a processor unit, a data memory, and a signal interface. The data memory stores a first set of curves comprising a plurality of first curves, each with an associated distance from the first sensor. Each first curve represents an impulse response, predetermined by means of a cable model of the cable route, of an electrical pulse caused by a modeled partial discharge at the distance from the first sensor on the cable route associated with the respective first curve. In addition, the method comprises the following steps a) to e): In step a), electrical energy is transmitted via the cable route.In step b), an electrical signal is detected by the first sensor, which is referred to as the first discharge signal and is caused by an actual partial discharge on the cable section. In step c), a first measurement signal representing the first discharge signal is transmitted from the first sensor to the processor unit directly or indirectly. In step d), a first curve of the first set of curves is determined, based on the first measurement signal and by means of the processor unit, as the first discharge curve that best correlates with the first discharge signal among the first curves of the first set of curves. In step e), a first sensor distance of the actual partial discharge from the first sensor is determined by means of the processor unit based on the distance associated with the first discharge curve.

[0050] The steps of the method correspond to the features of the system according to the first aspect of the invention. For the method according to the third aspect of the invention, reference is therefore made to the advantageous explanations, preferred features, technical effects, and / or advantages in an analogous manner to those already explained for the system according to the first aspect of the invention. Repetition is therefore omitted.

[0051] Furthermore, with regard to the advantageous embodiments of the method presented below, reference is made to the explanations, preferred features, technical effects, and advantages in an analogous manner to those already explained for the corresponding advantageous embodiments of the system. Here, too, analogous repetition is omitted.

[0052] An advantageous embodiment of the method is characterized in that the system has a second sensor for detecting electrical signals from the cable route, the data memory having stored a second set of curves comprising a plurality of second curves, each with an associated distance from the second sensor. Each second curve represents an impulse response, predetermined by means of the cable model of the cable route, of an electrical impulse caused by a modeled partial discharge at the distance from the second sensor on the cable route associated with the respective second curve. The first sensor and the second sensor are arranged on the cable route at a predetermined sensor distance from one another. In addition, the method comprises the further following steps d.1) to d.3): In step d.1) An electrical signal is detected by the second sensor, which is referred to as the second discharge signal and is caused by the same, actual partial discharge on the cable section. In step d.2), a second measurement signal is transmitted from the second sensor to the processor unit directly or indirectly, representing the second discharge signal. In step d.3), a second curve from the second set of curves is determined, based on the second measurement signal and by means of the processor unit, as the second discharge curve that best correlates with the second discharge signal among the second curves of the second set of curves. The first sensor distance is additionally determined in step e) by means of the processor unit based on the distance associated with the second discharge curve.

[0053] A further advantageous embodiment of the method is characterized in that the system has a first pulse feed unit for feeding at least one first electrical pulse into the cable section. The processor unit is configured to change parameters of the cable model that represents a transmission behavior of electrical pulses over the cable section. The first pulse feed unit is arranged at a distance from the first sensor. Furthermore, the method has the following additional steps f) to i): In step f), the first pulse feed unit is controlled by the processor unit so that electrical pulses referred to as first reference pulses are fed into the cable section by means of the first pulse feed unit. In step g), electrical signals referred to as first reference signals, each of which was caused by one of the first reference pulses, are detected by means of the first sensor.In step h), first test signals are transmitted directly or indirectly from the first sensor to the processor unit, each of which represents one of the first reference signals. In step i), the parameters of the cable model are adjusted by the processor unit based on the at least one first test signal, so that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable section represented by the first reference pulses and the first reference signals.

[0054] A further advantageous embodiment of the method is characterized in that the system has a second pulse feed unit for feeding at least one second electrical pulse into the cable section, wherein the second pulse feed unit is arranged at a distance from the second sensor. Furthermore, the method has the following further steps j) to l): In step j), the second pulse feed unit is controlled by means of the processor unit so that electrical pulses referred to as second reference pulses are fed into the cable section by means of the second pulse feed unit. In step k), an electrical signal is detected by means of the second sensor, which is referred to as the second reference signal and is caused by the second reference pulses. In step l), a second test signal representing the second reference signal is transmitted directly or indirectly from the second sensor to the processor unit.Furthermore, in step j), the parameters of the cable model are adapted by means of the processor unit based on the first test signal and the second test signal such that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable section represented by the first reference pulses and the second reference signals and / or by the second reference pulses and second reference signals.

[0055] A further advantageous embodiment of the method is characterized in that the method comprises the further, following step m): In step m), an output signal is transmitted by means of the signal interface, which represents the first sensor distance.

[0056] A further advantageous embodiment of the method is characterized in that the group of method steps a) to e) are carried out once or repeatedly.

[0057] A further advantageous embodiment of the method is characterized in that steps g) to j) or steps g) to m) are carried out once, periodically, after or before each execution of the group of method steps a) to e).

[0058] A further advantageous embodiment of the method is characterized in that the first and / or second set of curves is calculated with the cable model updated by the adapted parameters by means of the processor unit and stored in the data memory, preferably after each adaptation of the parameters of the cable model.

[0059] Further features, advantages, and possible applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. In the figures, the same reference numerals refer to the same or similar objects. Fig. 1 shows a first advantageous embodiment of the system in a schematic representation. Fig. 2 shows several curves of a common set of curves. Fig. 3 shows a further advantageous embodiment of the system in a schematic representation. Fig. 4 shows a further advantageous embodiment of the system in a schematic representation. Fig. 5 shows a further advantageous embodiment of the system in a schematic representation. Figs. 6 to 8 each show advantageous flow diagrams for the method.

[0060] In the Figure 1 An advantageous embodiment of the system 2 is schematically illustrated. The system 2 comprises a first sensor 6, a processor unit 8, a data memory 10, and a signal interface 12. The first sensor 6 is designed to detect an electrical signal from the cable section 4. Therefore, the system 2 also serves for an electrical cable section 4 used to transmit electrical energy.

[0061] In principle, the first sensor 6 can be designed as a single sensor 6 or as an integral part of another device. For example, in practice, high-frequency transducers are often attached to the ends of the cable run, and the first sensor 6 can be part of such a high-frequency transducer.

[0062] The electrical cable section 4 can also be designed and / or referred to as an electrical cable. The electrical cable section 4 often has an electrically conductive core, for example made of copper, and insulation that encloses the core. If an electrical signal is transmitted via the conductive core, the first sensor 6 can be designed, for example, for contactless detection of the electrical signal. However, it is alternatively also possible for the sensor 6 to have electrical contact with the electrically conductive core of the cable section 4, so that the first sensor 6 is designed to detect electrical signals from the cable section 4 via this electrical contact.

[0063] The first sensor 6 is preferably coupled to the processor unit 8 via a signal connection 58. The processor unit 8 can in turn be coupled to the data memory 10 via a further signal connection 60 in order to read data from the data memory 10 or to store data on the data memory 10. Furthermore, it is preferably provided that the processor unit 8 is connected to the signal interface 12 via a further signal connection 62. The signal interface 12 serves to transmit an output signal U. The processor unit 8 can, for example, control the signal interface 12 via the further signal line 62 in order to send the output signal U. The signal interface 12 can form an integral part of the processor unit 8. Thus, the processor unit 8 and the signal interface 12 can form a common unit. It is also possible for the data memory 10 to be assigned to this common unit.In other words, a common unit can be provided which comprises the processor unit 8, the data memory 10 and the signal interface 12.

[0064] During the transmission of electrical energy via a cable section 4, a partial discharge 22 may occur, particularly if the electrical energy is transmitted with a particularly high electrical voltage. The partial discharge 22 may occur at a partial discharge location T. The partial discharge 22 causes a pulse 20 that extends in the axial direction L of the cable section 4 in opposite directions. If the partial discharge location T is located at a first sensor distance E from the first sensor 6, a certain propagation time is required until the pulse 20 reaches the first sensor 6 from the partial discharge location T. However, the use of propagation time to determine the partial discharge location T has proven to be error-prone in practice. The pulse 20 caused by the partial discharge 22 is shown purely as an example in the Figure 2The amplitude A of the pulse 20 is numbered one. Due to the physical properties of the cable section 4, the pulse 20 is subject to location-dependent and / or frequency-dependent attenuation and / or dispersion. Depending on the first sensor distance E between the partial discharge location T and the first sensor 6, the signal shape changes as shown in Figure 2 is shown schematically.

[0065] If it is assumed purely as an example that the length of the cable section 4 is approximately 800 m, the change in the pulse 20 is dependent on the distance covered or on the first sensor distance E in the Figure 2 If the partial discharge T occurs, for example, at a first sensor distance E of 100 m from the first sensor 6, the first sensor 6 will be able to detect an electrical signal which corresponds at least in the form of the curve 16 shown in the Figure 2at the first sensor distance E of 100 m. If the partial discharge 22 occurs at a partial discharge location T that is further away, for example 200 m from the first sensor 6, the first sensor distance E is 200 m. In this case, the sensor 6 will be able to detect an electrical signal that corresponds to the curve 16 at the first sensor distance E of 200 m. In other words, the electrical signal detected in this case will, except for a proportional factor, have the shape that the curve 16 has at the first sensor distance E of 200 m. The further curves 16 from Figure 2 result from partial discharges 22 with a first sensor distance E of 300 m, 400 m or 500 m.

[0066] From the Figure 2it can be seen that the curves 16 differ in their frequency response as well as in their amplitude response depending on the first sensor distance E. Therefore, the first sensor distance E can also be determined independently of the propagation time of the first pulse 20 based on the curve shape of the signal measured by the first sensor 6. To make this possible, the data memory 10 stores a first set of curves 14 comprising a plurality of first curves 16, each with an associated distance to the first sensor 6, wherein each first curve 16 represents an impulse response of an electrical pulse 20, predetermined by means of a cable model of the cable section 4, by a modeled partial discharge 22 at a distance from the first sensor 6 on the cable section 4 that is associated with the respective first curve 16.

[0067] The use of a cable model of the cable section 4 offers the advantage that the cable section 4 does not have to be partially destroyed by partial discharges 22 in order to obtain the information about the first curves 16. Rather, the cable model can be used to generate a pulse 20 at any location on the modeled cable section 4, and the same cable model can be used to determine the first curve 16 that would be measured at the respective distance of the pulse acting on the modeled cable section 4 from the location of the first sensor 6. By varying the distance to the location of the sensor 6, a plurality of first curves 16 can be predetermined using the cable model. The processor unit 8 can be configured for this purpose. These first curves 16 together form the first set of curves 14. This set of curves 14 is stored in the data memory 10.In this case, data representing the first set of curves 14 or the first curves 16 can actually be stored in the data memory 10. The same applies to the corresponding distances.

[0068] The first curves 16 of the first set of curves 14 can then be compared with an electrical signal from the first sensor 6, which is arranged on the actual cable section 4 for detecting the electrical signals. This allows the curve 16 to be determined which best correlates or matches the electrical signal actually detected by the first sensor 6. Furthermore, an associated distance is stored in the data memory 10 for each first curve 16. Thus, if one of the curves 16 has been determined as the first discharge curve 26, which, among the first curves 16 of the first set of curves 14, best correlates with the discharge signal 24 actually detected by the sensor 6, the distance associated with the first discharge curve 26, for example, the first sensor distance E of 300 m, can be determined using the first curves 16 and associated distances stored in the data memory 10.

[0069] For system 2, it is therefore provided that the first sensor 6 is designed to detect an electrical signal, which is referred to as a first discharge signal 24 and is caused by an actual partial discharge 22 on the cable section 4. However, this first discharge signal 24 is usually an analog signal. The first sensor 6 is therefore preferably designed to digitize the first discharge signal 24 in order to determine a first measurement signal M based thereon, which represents the first discharge signal 24. The first sensor 6 can then transmit the first measurement signal M, for example, via the signal connection 58, to the processor unit 8. The signal connection can be designed as a wired signal connection 58 or as a wireless signal connection 58.However, it is also possible that there is an optical signal connection between the first sensor 6 and the processor unit 8, via which the first measurement signal M can be transmitted from the first sensor 6 to the processor unit 8.

[0070] The processor unit 8 is configured, based on the first measurement signal M, to determine one of the first curves 16 of the first set of curves 14 as the first discharge curve 26 that best matches the first discharge signal 24 among the first curves 16 of the first set of curves 14. Which of the first curves 16 best matches the first discharge signal 24 can be determined based on the cross-correlation between the first discharge signal 24 and the respective first curve 16. The first curve 16 that produces the greatest correlation value can be understood as best matching the first discharge signal 24. The corresponding first curve 16 then forms the first discharge curve 26. An associated distance to this first discharge curve 26 is stored in the data memory 10.The processor unit 8 is coupled to the data memory 10 via the signal connection 60, so that the processor unit 8 can read the corresponding distance to the first discharge curve 26 from the data memory 10. The processor unit 8 is therefore configured to determine a first sensor distance E of the actual partial discharge 22 from the first sensor 6 based on the distance associated with the first discharge curve 26. In the simplest case, the first sensor distance E corresponds to the distance associated with the first discharge curve 26, which is stored in the data memory 10. In the example shown in . Figure 1 and Figure 2 In the case shown, the distance to the first discharge curve 26 stored in the data memory 10 is 300 m. Therefore, in this case, the first sensor distance E can be determined as 300 m.

[0071] To provide this information about the first sensor distance E of 300 m, the system 2 has the signal interface 12, which is designed to transmit an output signal U representing the first sensor distance E. This allows the information about the first sensor distance E to be made available to other components, devices, and / or modules of the system 2.

[0072] In the Figure 3 A further advantageous embodiment of the system 2 is shown schematically. With regard to the system 2 from the Figure 3 will refer to the previous explanations of the system Figure 1 in an analogous manner. However, System 2 shows Figure 3a further sensor 28, namely the second sensor 28. The first and second sensors 6, 28 can be arranged and / or attached at opposite ends 42, 44 of the cable section 4. The second sensor 28 is preferably designed analogously to the first sensor 6. With regard to the second sensor 28, reference is therefore made to the advantageous explanations, preferred features, technical effects, and / or advantages as already explained above for the first sensor 6.

[0073] The second sensor 28 is preferably coupled to the processor unit 8 via a further signal connection 64, so that a second measurement signal N can be transmitted from the second sensor 28 to the processor unit 8.

[0074] If a partial discharge 22 occurs on the cable section 4, the resulting pulse 20 is detected as an electrical signal at the first sensor 6 and as a further electrical signal at the sensor 28. However, the two detected electrical signals are different because the first sensor distance E does not correspond to the second sensor distance F. Due to the different distances E, F, different attenuation and / or dispersion occur, so that a first discharge signal 24 is detected by the first sensor 6 and a second discharge signal is detected by the second sensor 28. If the total length of the cable section 4 is, for example, 800 m, the first discharge signal 24 can be transmitted to the processor unit 8 via the first measurement signal M. Based on the first discharge signal 24, the first processor unit 8 can read out a distance E of 300 m associated with the corresponding first curve 16 from the data memory 10.A further set of curves, namely a second set of curves comprising a plurality of second curves, each with an associated distance from the second sensor 28, can be stored in the data memory 10, wherein each second curve represents an impulse response, predetermined by means of the cable model of the cable section 4, of an electrical pulse caused by a modeled partial discharge at the distance from the second sensor 28 on the cable section 4 associated with the respective second curve. After the second measurement signal N, which represents the second discharge signal, has been transmitted to the processor unit 8, the processor unit 8 can determine one of the second curves of the second set of curves as the second discharge curve which, among the second curves, best matches the second discharge signal. This second curve, referred to as the second discharge curve, is stored in the data memory 10 together with an associated distance.The processor unit 8 can therefore read the corresponding distance from the data memory 10. The processor unit 8 is preferably configured for this purpose. The corresponding second sensor distance F can be, for example, 500 m. If the two sensors 6, 28 are arranged at a sensor distance S of 800 m, the previously determined sensor distances, namely the first sensor distance E of 300 m and the second sensor distance F of 500 m, correspond to the sensor distance S between the two sensors 6, 28 of 800 m. The processor unit 8 is therefore preferably configured to determine the first sensor distance E of the actual partial discharge 22 from the first sensor 6 based on the predetermined sensor distance S (800 m), the distance associated with the first discharge curve 26 (300 m), and the distance associated with the second discharge curve (500 m). In the previously explained example, the first sensor distance E can be determined as redundant.However, if the distances E and F do not add up to the sensor distance S, the distance can be determined by averaging the distance corresponding to the first discharge curve and the difference between the sensor distance and the distance corresponding to the second discharge curve. This allows the first sensor distance E to be determined particularly precisely. The first sensor distance E and the known location of the first sensor 6 also simultaneously determine the partial discharge location T.

[0075] In the Figure 4 A further advantageous embodiment of the system 2 is shown. The system 2 corresponds at least essentially to the Figure 4 System 2 explained. The corresponding explanations are therefore referred to analogously. System 2 from Figure 4further comprises a first pulse feed unit 32. This can be formed jointly with the second sensor 28. The first pulse feed unit 32 and the second sensor 28 can thus form a common unit.

[0076] In principle, the parameters of the cable model can be predetermined. For example, the parameters of the cable model can be predetermined in such a way that the cable model can use these parameters to determine first and / or second sets of curves for a large number of identical cable routes 4. In practice, however, the cable routes exhibit small to large differences from one another. The same parameter set for a cable model for a large number of cable routes therefore often only allows for suboptimal modeling. In order to achieve a better adaptation of the parameters to the respective cable route and thus better modeling of the cable route by the cable model, it is preferably provided that the parameters of the cable model are adapted to the actual properties of the respective cable route 4. This can be done when the cable route is operated for the first time.However, it is also possible, alternatively or additionally, for the cable model parameters to be adjusted periodically or depending on specific events. By repeatedly adjusting the cable model parameters during operation, the adjusted cable model parameters can ensure better modeling of cable section 4, which may also be subject to certain changes during operation. For example, if a severe partial discharge has occurred on cable section 4, resulting in a change in the attenuation and / or dispersion properties of cable section 4, this can be better represented by adjusting the cable model parameters.

[0077] It is therefore preferably provided that the system has the first pulse feed unit 32, which is designed to feed at least one first electrical pulse into the cable section 4. The processor unit 8 is designed to control the first pulse feed unit 32 such that electrical pulses, referred to as first reference pulses 38, are fed into the cable section 4 by means of the first pulse feed unit 32. The first pulse feed unit 32 is arranged at a distance from the first sensor 6. Preferably, the first sensor 6 is arranged at the first end 42 of the cable section 4, whereas the first pulse feed unit 32 is arranged at the opposite end 44 of the cable section 4. This ensures that the first reference pulses 38 fed into the cable section 4 must pass through the entire cable section 4 before they can be detected as electrical signals by the first sensor 6.The first sensor 6 is therefore designed to detect electrical signals, which are referred to as first reference signals and are caused by the first reference pulses 38. If a first reference pulse 38 is fed into the cable section 4 by the first pulse feed unit 32, this first reference pulse 38 is subject to the attenuation and / or dispersion caused by the cable section 4. The first reference signal detected by the first sensor 6 is therefore caused by the first reference pulse. In particular, the first reference signal can be the first reference pulse 38 attenuated by the cable section 4. The first reference signal is usually an analog signal. The first sensor 6 is therefore preferably designed to digitize each first reference signal.In addition, the first sensor 6 is designed to transmit a first test signal O to the processor unit 8 via the signal connection 58, wherein the first test signal O represents the first reference signals.

[0078] Preferably, the processor unit 8 is coupled to the first pulse feed unit 32 via the control line 66 in order to control the first pulse feed unit 32. Therefore, the first reference pulse 38 is also known to the processor unit 8. If the second sensor 28 and the first pulse feed unit 32 form a common unit, the first reference pulse 38 can be detected by the second sensor 28 for monitoring purposes and a corresponding signal can be transmitted to the processor unit 8 via the signal line 64. This also makes the first reference pulse 38 known to the processor unit 8. Via the first test signal O from the first sensor 6 to the processor unit 8, the processor unit 8 also knows the at least one first reference signal. The transmission behavior of the cable section 4 can therefore be determined in the usual way from a first reference pulse 38 fed into the cable section 4 and an associated first reference signal.The processor unit 8 can be configured accordingly for this purpose. The same transmission behavior should, in principle, be possible with the cable model. However, when the cable section 4 is put into operation for the first time and / or due to changes to the cable section 4, it may be necessary to adjust the parameters of the cable model so that the transmission behavior for the cable section 4 represented by the cable model and the actual transmission behavior of the cable section 4, which can be determined from a first reference pulse and an associated first reference signal, match.

[0079] Therefore, the processor unit 4 is configured to adapt the parameters of the cable model based on the first test signal O, so that the transmission behavior for the cable section 4 represented by the cable model corresponds to the actual transmission behavior of the cable section 4 represented by the first reference pulses and the first reference signals.

[0080] The system 2 can also have a second pulse feed unit 40, which is also designed to feed electrical pulses into the cable section 4. The second pulse feed unit 40 can feed corresponding second reference pulses into the cable section 4, so that a second reference signal can be detected by the first sensor 6. The second pulse feed unit 40 can be used and operated together with the first sensor 6 in a similar manner to that previously explained for the first pulse feed unit 32 and the second sensor 28. For example, it is possible for both pulse feed units 32, 40 to feed reference pulses into the cable section 4 in parallel, with a time delay, or alternately, and for corresponding reference signals to be detected by the sensors 6, 28. The reference pulses and reference signals can then be used to better determine the actual transmission behavior of the cable section 4.

[0081] The second pulse supply unit 40 can also be designed jointly with the first sensor 6. They can thus form a common unit.

[0082] In the Figure 5 A further advantageous embodiment of the system 2 is shown. With regard to the processor unit 8, the data memory 10, and the signal interface 12, reference is made analogously to the previous explanations. However, the system 2 is adapted for a cable route 4 having a plurality of cable segments 46 arranged one behind the other along the cable route 4, wherein the opposite ends 44, 42 of the cable segments 46 are connected to one another to form coupling points 48. The coupling points 48 are designed such that electrical energy can be transmitted from cable segment 46 to cable segment 46 via the coupling point 48.

[0083] For each cable segment 46, the same configurations of the system 2 can be provided as previously described in connection with the Figures 1 to 4 have already been explained. Therefore, for each cable segment 46, reference is made analogously to the previous explanations, preferred features, effects, and advantages as explained in connection with system 2 and cable segment 4. Analogous repetitions are therefore omitted.

[0084] Each cable segment 46 is assigned a first sensor 6, which is preferably connected to the processor unit 8 via an associated signal line 58. Furthermore, each first sensor 6 is assigned a first set of curves, which is stored in the data memory 10. The system 2 thus has a plurality of first sensors 6 and a plurality of first sets of curves 14. With reference to the preceding explanations, the processor unit 8 is configured to determine the first sensor distance E from an actual partial discharge 22 for each first sensor 6.

[0085] If, for example, a partial discharge 22 occurs in one of the cable segments 46, this triggers a pulse 20 which, due to the coupling points 48 between the cable segments 46, spreads across all cable segments 46. This can fundamentally result in the first sensors 6 of the cable segments 46 each detecting a first discharge signal which is caused by the same partial discharge 22, but which only occurred in one of the cable segments 46. The processor unit 8 is therefore configured to identify the cable segment 46 with the actual partial discharge 22 as the identified cable segment 54 based on the first sensor distances E. In other words, the processor unit 8 can first determine a respective associated discharge curve and the resulting first sensor distance E based on the first discharge signals. Thus, an associated first sensor distance E can be determined for each cable segment 46.Based on these multiple first sensor distances E, the processor unit 8 can then determine one of the cable segments 46 as the identified cable segment 54 at which the partial discharge 22 actually occurred. The first sensor distance E assigned to this cable segment 46 then also forms the actual first sensor distance E, which can be represented by the output signal U. The output signal U can additionally indicate the identified cable segment 46. Thus, it is preferably provided that the signal interface 12 is configured to provide the output signal U that indicates the identified cable segment 54 and represents the first sensor distance E of the first sensor 6 of the identified cable segment 54 with the actual partial discharge 22.

[0086] From the Figures 1 , 3 , 4 and 5A transmission system 56 can also be seen. The transmission system 56 comprises system 2. This is illustrated in various embodiments in the aforementioned figures. The transmission system 56 also comprises the cable section 4 as such. Therefore, for the transmission system 56, reference is made analogously to the preceding explanations, preferred features, effects, and advantages.

[0087] In the Figure 6 A flowchart for an advantageous embodiment of the method for operating system 2 is shown. The method comprises the following steps: a) Transmitting electrical energy via the cable section 4; b) Detecting an electrical signal by means of the first sensor 6, which is referred to as the first discharge signal 24 and is caused by an actual partial discharge 22 on the cable section 4; c) Directly or indirectly transmitting a first measurement signal M, which represents the first discharge signal 24, from the first sensor 6 to the processor unit 8; d) Determining a first curve 16 of the first set of curves 14 as the first discharge curve 26 that best matches the first discharge signal 24 among the first curves 16 of the first set of curves 14, based on the first measurement signal M and by means of the processor unit 8; and e) Determining a first sensor distance E of the actual partial discharge 22 to the first sensor 6 based on the distance associated with the first discharge curve 26 by means of the processor unit 8.

[0088] With regard to the method, reference is made to the previous explanations, preferred features, effects and / or advantages as they apply to System 2 of the Figures 1 - 5 already explained, are referred to analogously. Therefore, a repetition is omitted.

[0089] It should be noted, however, that process steps a) to e) can be carried out in the order mentioned.

[0090] If the procedure is carried out with a System 2, as for example in the Figure 3 As shown, the following additional steps d.1) to d.3) can be carried out between steps d) and e). A corresponding flow chart is shown in Figure 7 shown schematically. The additional steps can be summarized as follows: d.1) Detecting an electrical signal by means of the second sensor 28, which is referred to as the second discharge signal and is caused by the same, actual partial discharge 22 on the cable section 4; d.2) Directly or indirectly transmitting a second measurement signal N, which represents the second discharge signal, from the second sensor 28 to the processor unit 8; d.3) Determining a second curve of the second set of curves as the second discharge curve that best matches the second discharge signal among the second curves of the second set of curves, based on the second measurement signal, by means of the processor unit 8.

[0091] It is also preferably provided that the first sensor distance E in step e) is additionally determined by means of the processor unit 8 based on the distance associated with the second discharge curve.

[0092] In the Figure 8A further embodiment of the method is shown in a schematic representation of a flow chart. According to this embodiment of the method, the method comprises, in addition to the steps described in connection with Figure 7 explained, also the following steps: f) Controlling the first pulse feed unit 32 by means of the processor unit 8 so that electrical pulses, referred to as first reference pulses 38, are fed into the cable section 4 by means of the first pulse feed unit 32; g) Detecting first signals, referred to as first reference signals, which are each caused by one of the first reference pulses 38, by means of the first sensor 6; h) Directly or indirectly transmitting first test signals O, each representing one of the first reference signals, from the first sensor 6 to the processor unit 8; i) Adjusting the parameters of the cable model 4 by means of the processor unit 8 and based on the at least one first test signal O, so that the transmission behavior represented by the cable model 4 corresponds to the actual transmission behavior of the cable section 4 represented by the first reference pulses 38 and the first reference signals.

[0093] In addition, any of the measures previously taken in connection with the Figures 6 to 8 The methods explained above comprise the additional step m), which is shown purely by way of example in the flow chart of the Figure 8 is shown. The method preferably also comprises the following step: m) transmitting an output signal U, which represents the first sensor distance E, by means of the signal interface 12.

[0094] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features described with reference to one of the above embodiments can also be used in combination with other features of other embodiments described above. Reference signs in the claims are not to be considered as limitations. LIST OF REFERENCE SYMBOLS

[0095] AAmplitude First measurement signal Nsecond measurement signal Ofirst test signal Psecond test signal Efirst sensor distance Fsecond sensor distance Ssensor distance Tpartial discharge location Uoutput signal LAxial direction 2System 4Cable section 6first sensor 8Processor unit 10Data memory 12Signal interface 14First curve set 16First curve 20Pulse 22Partial discharge 24First discharge signal 26First discharge curve 28Second sensor 32First pulse injection unit 38First reference pulse 40Second pulse injection unit 42First end 44Second end 46Cable segment 48Coupling point 54Identified cable segment 56Transmission system 58Signal connection 60Signal connection 62Signal connection 64Signal connection 66Control line 68Control line

Claims

1. System (2) for an electrical cable route (4) for the transmission of electrical energy, the system (2) having a first sensor (6) for detecting electrical signals from the cable section (4), a processor unit (8), a data memory (10), and a signal interface (12), the data memory (10) having stored a first set of curves (14) comprising a plurality of first curves (16), each with an associated distance from the first sensor (6), each first curve (16) representing an impulse response, predetermined by means of a cable model of the cable route (4), of an electrical impulse (20) by a modeled partial discharge (22) at the distance from the first sensor (6) on the cable route (4) associated with the respective first curve (16), wherein the first sensor (6) is designed to detect an electrical signal, which is referred to as a first discharge signal (24) and is caused by an actual partial discharge (22) on the cable section (4), and is designed to transmit a first measurement signal M, which represents the first discharge signal (24), directly or indirectly to the processor unit (8), wherein the processor unit (8) is configured to determine, based on the first measurement signal M, one of the first curves (16) of the first set of curves (14) as the first discharge curve (26) which, among the first curves (16) of the first set of curves (14), correlates best with the first discharge signal (24), wherein the processor unit (8) is configured to determine a first sensor distance E of the actual partial discharge (22) to the first sensor (6) based on the distance associated with the first discharge curve (26), and wherein the signal interface (12) is designed to transmit an output signal U which represents the first sensor distance E.

2. System (2) according to the preceding claim, characterized in that the system (2) has a second sensor (28) for detecting electrical signals from the cable section (4), the data memory (10) having stored a second set of curves comprising a plurality of second curves, each with an associated distance from the second sensor (28), each second curve representing an impulse response, predetermined by means of the cable model of the cable route (4), of an electrical impulse (20) by a modeled partial discharge (22) at the distance from the second sensor (28) on the cable route (4) associated with the respective second curve, wherein the first sensor (6) and the second sensor (28) can be attached to the cable section (4) at a predetermined sensor spacing from one another, wherein the second sensor (28) is designed to detect an electrical signal, which is referred to as a second discharge signal and is caused by the same, actual partial discharge (22) on the cable section (4), and is designed to transmit a second measurement signal N, which represents the second discharge signal, directly or indirectly to the processor unit (8), wherein the processor unit (8) is configured to determine, based on the second measurement signal N, one of the second curves of the second set of curves as the second discharge curve that best correlates with the second discharge signal among the second curves, and wherein the processor unit (8) is configured to determine the first sensor distance E of the actual partial discharge (22) to the first sensor (6) based on the predetermined sensor distance, the distance associated with the first discharge curve (26) and the distance associated with the second discharge curve.

3. System (2) according to one of the preceding claims, characterized in that the system (2) has a first pulse feed unit (32) for feeding at least a first electrical pulse (20) into the cable section (4), wherein the processor unit (8) is configured to change parameters of the cable model representing a transmission behavior of electrical pulses (20) over the cable route (4), wherein the processor unit (8) is designed to control the first pulse feed unit (32), so that electrical pulses (20) designated as first reference pulses (38) are fed into the cable section (4) by means of the first pulse feed unit (32), wherein the first pulse feed unit (32) is arranged at a distance from the first sensor (6), wherein the first sensor (6) is adapted to detect electrical signals, referred to as first reference signals, caused by the first reference pulses (38) and is adapted to directly or indirectly transmit a first test signal O, representing the first reference signals, to the processor unit (8), and wherein the processor unit (8) is configured to adjust the parameters of the cable model based on the first test signal O, so that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route (4) represented by the first reference pulses (38) and the first reference signals.

4. System (2) according to claim 3 in combination with claim 2, characterized in that the system (2) has a second pulse feed unit (40) for feeding at least a second electrical pulse (20) into the cable section (4), wherein the processor unit (8) is designed to control the second pulse feed unit (40), so that electrical pulses (20) designated as second reference pulses are fed into the cable section (4) by means of the second pulse feed unit (40), wherein the second pulse feed unit (40) is arranged at a distance from the second sensor (28), wherein the second sensor (28) is adapted to detect electrical signals, referred to as second reference signals, caused by the second reference pulses, and is adapted to directly or indirectly transmit a second test signal P representing the second reference signals to the processor unit (8), and wherein the processor unit (8) is configured to adjust the parameters of the cable model based on the first test signal O and the second test signal P, so that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route (4) represented by the first reference pulses (38) and the first reference signals and / or by the second reference pulses and second reference signals.

5. System (2) according to claim 3, characterized in that the first sensor (6) and the second pulse feed unit (40) are designed as a common, first transducer unit.

6. System (2) according to the preceding claim, characterized in that the second sensor (28) and the first pulse feed unit (32) are designed as a common, second transducer unit.

7. System (2) according to any one of the preceding claims 3 to 6, characterized in that the processor unit (8) is configured to periodically feed the first and / or second pulse feed unit (32, 40) for feeding reference pulses and after each feeding of the reference pulses for adjusting the parameters of the cable model.

8. System (2) according to one of the preceding claims, characterized in that the first sensor (6) is designed to periodically detect electrical signals of the cable section (4), and the processor unit (8) is configured to determine the associated first discharge curve (26) in each case when the electrical signal detected by the first sensor (6) forms a first discharge signal (24), and to determine the first sensor distance E of the first sensor (6) to the respective partial discharge (22) based on the first discharge curve (26).

9. System (2) according to the preceding claim in combination with claim 2, characterized in that the second sensor (28) is designed to periodically detect electrical signals of the cable section (4), and the processor unit (8) is configured to determine the associated second discharge curve in each case when the electrical signal detected by the second sensor (28) forms a second discharge signal, to determine the associated second discharge curve and to determine the first sensor distance E of the respective partial discharge (22) to the first sensor (6) based on the predetermined sensor distance, the distance associated with the first discharge curve (26) and the distance associated with the second discharge curve.

10. The system (2) according to any one of the preceding claims 8 to 9, characterized in that the processor unit (8) is configured to determine a frequency of a plurality of actual partial discharges (22) at the same distance from the first sensor (6), and wherein the output signal U further represents the frequency.

11. System (2) according to any one of the preceding claims 8 to 10, characterized in that the processor unit (8) is configured to determine at least one characteristic of a plurality of actual partial discharges (22) at the same distance from the first sensor (6), and wherein the output signal U further represents the determined characteristic.

12. System (2) according to one of the preceding claims 9 to 11, characterized in that the processor unit (8) is configured to generate a warning signal if the frequency of the partial discharges (22) is greater than a predetermined threshold frequency and / or if the determined characteristic variable of the partial discharges (22) is greater than a predetermined threshold characteristic variable, and wherein the signal interface (12) is designed to transmit the warning signal.

13. System (2) according to one of the preceding claims 9 to 11, characterized in that the processor unit (8) is configured to determine an aging state of the cable section (4) based on the frequency of the partial discharges (22) and / or the at least one determined characteristic of the partial discharges (22) and / or the adjusted parameters, wherein the output signal U further represents the aging state.

14. System (2) according to one of the preceding claims, characterized in that the cable section (4) has a plurality of cable segments (46) which are arranged one behind the other along the cable section (4), wherein opposite ends of cable segments (46) are connected to one another at the end face in order to form coupling points (48), wherein each cable segment (46) is associated with a first sensor (6) and a first set of curves (14) for the respective first sensor (6), so that the system (2) comprises a plurality of first sensors (6) and a plurality of first sets of curves (14) are stored by the data memory (10), wherein the processor unit (8) is configured to determine for each first sensor (6) the first sensor distance E of the actual partial discharge (22) to the respective first sensor (6), wherein the processor unit (8) is configured to determine the cable segment (46) with the partial discharge (22) as the identified cable segment (46) based on the first sensor distances E, and wherein the signal interface (12) is designed to provide the output signal U which indicates the identified cable segment (46) and represents the first sensor distance E of the first sensor (6) of the identified cable element (46) from the partial discharge (22).

15. Transmission system (56) for transmitting electrical energy, comprising: a cable section (4), and a system (2) according to one of the preceding claims.

16. Method for operating a system (2) for an electrical cable route (4) for transmitting electrical energy, the system (4) having a first sensor (6) for detecting electrical signals of the cable route (4), a processor unit (8), a data memory (10) and a signal interface (12), the data memory (10) having stored a first set of curves (14) comprising a plurality of first curves (16) each with an associated distance from the first sensor (6), wherein each first curve (16) represents an impulse response of an electrical impulse (20) predetermined by means of a cable model of the cable route (4) by a modeled partial discharge (22) at the distance from the first sensor (6) on the cable route (4) associated with the respective first curve (16), and wherein the method comprises the following steps: a) Transmission of electrical energy via the cable route (4), b) Detection of an electrical signal, which is referred to as a first discharge signal (24) and is caused by an actual partial discharge (22) on the cable section (4), by means of the first sensor (6), c) Direct or indirect transmission of a first measurement signal M, which represents the first discharge signal (24), from the first sensor (6) to the processor unit (8), d) determining a first curve (16) of the first curve set (14) as the first discharge curve (26) which, among the first curves (16) of the first curve set (14), best correlates with the first discharge signal (24), based on the first measurement signal M and by means of the processor unit (8), and e) Determining a first sensor distance E of the actual partial discharge (22) to the first sensor (6) based on the distance associated with the first discharge curve (26) by means of the processor unit (8).

17. Method according to the preceding claim, characterized in that the system (2) has a second sensor (6) for detecting electrical signals of the cable route (4), the data memory (10) having stored a second set of curves comprising a plurality of second curves, each with an associated distance from the second sensor (28), wherein each second curve represents an impulse response of an electrical impulse (20) predetermined by means of the cable model of the cable section (4) by a modeled partial discharge (22) at the distance associated with the respective second curve from the second sensor (28) on the cable section (4), wherein the first sensor (6) and the second sensor (28) are arranged at a predetermined sensor distance from one another on the cable section (4), and wherein the method comprises the further following steps: d.1) Detection of an electrical signal, referred to as the second discharge signal, which is caused by the same actual partial discharge (22) on the cable section (4), by means of the second sensor, d.2) directly or indirectly transmitting a second measurement signal N, representing the second discharge signal, from the second sensor (28) to the processor unit (8), and d.3) determining a second curve of the second curve set as the second discharge curve that best correlates with the second discharge signal among the second curves of the second curve set, based on the second measurement signal N and by means of the processor unit (8), and wherein the first sensor distance E in step e) is additionally determined based on the distance associated with the second discharge curve by means of the processor unit (8).

18. Method according to any one of the preceding claims 16 to 17, characterized in that the system (2) comprises a first pulse injection unit (32) for injecting at least a first electrical pulse (20) into the cable path (4), wherein the processor unit (8) is configured to change parameters of the cable model representing a transmission behaviour of electrical pulses (20) over the cable path (4), wherein the first pulse injection unit (32) is arranged spaced apart from the first sensor (6), and wherein the method comprises the further following steps: f) Controlling the first pulse feed unit (32) by means of the processor unit (8), so that electrical pulses (20) designated as first reference pulses (38) are fed into the cable section (4) by means of the first pulse feed unit (32), g) Detection of electrical signals, referred to as first reference signals, each caused by one of the first reference pulses (38), by means of the first sensor (6), h) Directly or indirectly transmitting first test signals O, each representing one of the first reference signals, from the first sensor (6) to the processor unit (8), and i) adapting the parameters of the cable model by means of the processor unit (8) and based on the at least one first test signal O, so that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route (4) represented by the first reference pulses (38) and the first reference signals.

19. Method according to the preceding claim, characterized in that the system (2) has a second pulse feed unit (40) for feeding at least one second electrical pulse (20) into the cable section (4), the second pulse feed unit (40) being arranged at a distance from the second sensor (28), and the method having the further following steps: j) Controlling the second pulse feed unit (40) by means of the processor unit (8), so that electrical pulses (20) designated as second reference pulses are fed into the cable section (4) by means of the second pulse feed unit (40), k) detecting an electrical signal, referred to as a second reference signal, caused by the second reference pulses by means of the second sensor (28), and l) Direct or indirect transmission of a second test signal P, which represents the second reference signal, from the second sensor (28) to the processor unit (8), wherein the parameters of the cable model are adapted in step i) by means of the processor unit (8) based on the first test signal O and the second test signal P in such a way that the transmission behavior represented by the cable model corresponds to the actual transmission behavior of the cable route (4) represented by the first reference pulses (38) and the second reference signals and / or by the second reference pulses and second reference signals.

20. Method according to any one of the preceding claims 16 to 19, characterized in that the method comprises the further following step: m) Transmission of an output signal U, which represents the first sensor distance E, by means of the signal interface (12).

21. Method according to one of the preceding claims 16 to 20, characterized in that the group of method steps a) to e) are carried out once or repeatedly.

22. Method according to one of the preceding claims 19 to 21, characterized in that steps g) to j) or steps g) to m) are carried out once, periodically or before each execution of the group of method steps a) to e).

23. Method according to one of the preceding claims 19 to 22, characterized in that the first and / or second set of curves (14) is calculated with the cable model updated by the adjusted parameters by means of the processor unit (8) and stored in the data memory (10), preferably after each adjustment of the parameters of the cable model.