Operation of a trailing cable

Abstract

In a method for operating a cable (1), the cable (1) has a sensor (2) for detecting a use of the cable (1), wherein sensor signals (3) are stored, wherein a characteristic for the cable (1) is produced by means of the sensor signals (3), wherein a plurality of characteristics are determined at different times, wherein the characteristics are evaluated together. This method can be used in a system having a cable (1), more particularly a trailing cable, for electrical energy supply, wherein the trailing cable has a sensor (2) in the cable (1).

Description

[0001] Description

[0002] Operation of a tow cable

[0003] The invention relates to a method for operating a cable, in particular a trailing cable.

[0004] Operation involves monitoring, fault prediction, and operational optimization of the trailing cable. The trailing cable is primarily used for HV / LV power supplies. HV stands for high voltage. LV stands for low voltage. Trailing cables are regularly used in moving applications. Moving applications can be found, for example, in cranes, particularly in port facilities, in mining, or in waste dumps.

[0005] One of the most common causes of failure in moving applications, particularly those with an on-board high-voltage power supply provided by a coiled cable, is cable damage caused by unfavorable mechanical stress, particularly triggered by incorrect cable routing and / or inappropriate operation of the application. An application failure can occur due to mechanical stress on a cable, which leads to electrical damage. The stress reflects the use of the cable. An application failure could be, for example, the failure of a crane, a belt conveyor, an excavator such as a lignite excavator, etc. An application failure can therefore mean the failure of a technical system or a partial failure of a technical system. The mechanical stress on a cable, an electrical cable, can be monitored and measured.This also monitors or measures the cable's usage. The load is a particular measure of usage. For example, a cable, i.e., an electrical cable, may include an optical fiber. The mechanical load can be measured using this optical fiber integrated into the cable. One object of the invention is to advantageously use information about the load on the cable, in particular the electrical cable, for the operation of the cable, where the cable is, in particular, a trailing cable.

[0006] A solution to the problem arises from a method according to claim 1 and a device according to claim 9. Further embodiments arise, for example, from claims 2 to 8

[0007] In a method for operating a cable, the cable has a sensor for detecting use, in particular a load, of the cable, sensor signals being stored, the sensor signals yielding a characteristic for the cable, operating data being used to evaluate the sensor signals, the operating data relating in particular to past and / or future data which depend in particular on the torque and / or speed of a cable drum. Data which depend on the torque and / or speed of a cable drum are, for example, the speed of movement of the cable, the tension on or in the cable, but also the torque and / or speed of the cable drum itself. The cable can be wound up or unwound using the cable drum.

[0008] In one embodiment of the method, a stress on the cable is predicted. This prediction is based in particular on current cable data, which in particular takes into account any stress the cable has already been subjected to, as well as on data for future use of the cable, depending on the planned application. Thus, the prediction, which represents a simulation of the future, takes into account in particular future winding processes and / or future speeds for the winding process and / or future torques of the cable drum and / or future tensile forces on the cable. If it turns out during the simulation, for example, that the simulated service life of the cable is shorter than the planned service life, an earlier replacement of the cable can be planned and / or the stress on the cable can be reduced.Reduced stress on the cable can be achieved, for example, by reducing the number of winding processes and / or by reducing the speed at which the cable is wound or unwound.

[0009] In one embodiment of the method, a large number of characteristics are determined at different times, and the characteristics are evaluated together. A sensor should also be understood here as an element of a sensor. A sensor element is, for example, an optical fiber. In this case, a light source and / or a semiconductor for detecting light can also be regarded as belonging to the sensor. The characteristic is in particular a piece of data or a data set. The characteristic therefore relates to the use or load of the cable. The sensor has, for example, a fiber optic cable. With the help of the sensor, for example, a twisting, bending, stretching and / or compression of the cable can be determined. These are circumstances which relate to the use of the cable. In particular, the location of a twisting, bending, stretching and / or compression of the cable can also be determined.The location refers to a position on the cable. For example, 3 meters or 58 meters from the beginning or end of the cable.

[0010] So with a cable it is not just possible to measure the mechanical stress on the cable, with a warning light illuminating if a limit is exceeded. By saving the characteristics of a cable at different times, a trend / development of the cable's integrity can be determined. It is even possible to predict further stress on the cable and therefore, for example, its wear or failure if future use is simulated. This means that you can, for example, specify the number of operating cycles of a system with the monitored cable and calculate what effect this has on the cable. This not only enables condition monitoring of the cable, but also a prediction. This helps with the predictive maintenance approach. This is achieved in particular by using a correlation between the data about the cable and the application in which the cable is used.This allows predictive properties, or predictions, to be made about the cable. These properties can be obtained particularly well with a cable that has an integrated optical fiber. This allows the mechanical stresses of a HV cable to be measured. The measurement of mechanical stress on optical fibers, for example, is based on a changing wavelength of the reference wavelength of the measurement signal.

[0011] By evaluating the characteristics, various functionalities can be achieved, such as:

[0012] • Early detection of incorrect cable loading, which may cause or cause damage later,

[0013] • Recognizing a connection between the operation of an application or a production behavior and the cable used in it,

[0014] • Optimization of application operation to avoid cable damage,

[0015] • Detecting an application error based on the mechanical measurement and / or

[0016] • A determination of the remaining service life of the cable based on the operating data of the application and the load data of the cable.

[0017] The characteristic is a kind of fingerprint of the cable. This allows a wide variety of functionalities to be generated.

[0018] In one embodiment of the method, the characteristics of the cable relate to at least 80% of the length of the cable. The characteristics can also relate to the entire length of the cable. For example, a fingerprint of the cable, which relates to the measurement signal of the sensor, can be recorded over the entire length of the cable. The recording takes place, for example, at set intervals (e.g. every minute, every hour, every day, every month, etc.) and / or in certain operating states (e.g. the cable is at rest, the cable is in motion, the cable is wound up, the cable is unwound, etc.). For example, the fingerprint, i.e. the characteristics, of the cable can change over the first 3 months after commissioning due to the mechanical load of winding and unwinding.The development of the fingerprint (especially the development of the characteristics) can be simulated and / or predicted from the outset, so that a statement about the condition of the cable is possible from day one. For the simulation or prediction, the number of winding and unwinding movements of the cable on a cable drum is taken into account. In this way, the expected future application (i.e. the application, use or utilization), i.e. the expected future operation, is taken into account when predicting cable data (e.g. wear and tear, durability, etc.). These described functionalities can of course be used not only after 3 months from commissioning, but also at other periods of time, even of varying lengths. For example, it can be determined whether a cable failure is to be expected by the next expected maintenance interval and with an expected specified usage / application.This occurs with a certain probability. For example, it can be determined whether a change in usage (e.g., slower winding or unwinding) can delay the expected failure (and, in particular, for how long).

[0019] In one embodiment of the method, a characteristic is simulated, whereby the simulation depends on a specifiable, expected use of the cable. Measurement data from the sensor or variables derived from it are used as input variables for the simulation. These include, for example, load, time, step sequence and asset data. Asset data is data from the system in which the cable is used. Asset data can also be referred to as operating data. Application data is also operating data. Asset data includes, for example, mechanical variables such as cable drum diameter, number of cable layers, mechanical cable data, and application operating data such as direction of movement and speed of the asset (system or plant object), torque and / or speed of the cable drum. The application data is correlated, for example, with cable stress values ​​(these are represented by the characteristics) in order to detect any dependencies.

[0020] In one version of the method, cable wear is predicted, making it easier to plan maintenance intervals.

[0021] In one embodiment of the method, a cable anomaly is detected. This allows, for example, the location of a cable failure to be identified early on. To extend the cable's service life, the cable can be protected in the future, for example, at the location where the anomaly was detected. For example, the cable can be moved more slowly (e.g., wound up or unwound) at certain positions.

[0022] In one embodiment of the method, an algorithm can be used to detect anomalies early on. Furthermore, by aggregating the anomalies or stress load as a function of intensity and frequency, a remaining service life can be simulated, which represents a function of the previous operating characteristics, e.g., from day 1 of operation, or from the maintenance or repair.

[0023] In one embodiment of the method, operating data, which is particularly application-specific, is also used to evaluate the characteristics. The additional correlation with the operating data reveals, for example, optimal operating conditions and allows for production optimization. Early anomaly detection enables passive intervention (e.g., informing the operator about excessive production speed). Early anomaly detection thus allows situations that would lead to a failure to be identified early on, allowing the operator to adapt operations in a timely manner.

[0024] In one embodiment of the method, incorporation or use of application data, e.g., torque or cable position, enables linking the condition potentially causing cable damage with potentially problematic operating data and geographical localization of the fault and the fault situation. This goes beyond a pure condition monitoring solution, which can only look into the past but cannot detect a fault early on.

[0025] In one version of the process, a statement about the cable's condition is placed in the context of the application's operation, making it easier to determine the cause and potentially eliminating the need for additional on-site observation. Even visually invisible faults can be detected. Automatic detection and / or notification to the operator, along with recommendations for action, are now also possible.

[0026] In a system with a cable, in particular a trailing cable, for supplying electrical energy, the trailing cable has a sensor in the cable, wherein sensor signals can be evaluated, wherein an evaluation device is provided for carrying out a method of the type described.

[0027] In the following, the invention is illustrated and explained in more detail by way of example with reference to figures.

[0028] FIG 1 a system with a trailing cable and

[0029] FIG 2 a cable . The illustration according to Figure 1 shows a system 5. The system

[0030] 5 is an industrial installation, such as a crane or a lignite excavator or the like. The installation 5 has a cable drum 6 with a trailing cable 1. The cable 1 has a sensor, which is shown in Figure 2. The sensor generates sensor signals 3, which are transmitted to an evaluation device 4.

[0031] The illustration in Figure 2 shows a cable 1 having electrical conductors 7, 7', and 7'. The cable 1 has an optical fiber 2 as a sensor or sensor element (element of a sensor). Such a cable 1 can be monitored using one of the described methods.

Claims

Patent claims 1. Method for operating a cable (1) , wherein the cable (1) has a sensor (2) for detecting use of the cable (1), wherein sensor signals (3) are stored, wherein a characteristic for the cable (1) is obtained by means of the sensor signals (3), wherein operating data are used to evaluate the sensor signals (3), wherein the operating data relate in particular to past and / or future data which depend in particular on the torque and / or speed of a cable drum.

2. The method of claim 1, wherein a stress on the cable is predicted.

3. Method according to claim 1 or 2, wherein a plurality of characteristics are determined at different times, wherein the characteristics are evaluated together.

4. Method according to any one of claims 1 to 3, wherein the characteristic relates to at least 80% of the length of the cable (1).

5. Method according to one of claims 1 to 4, wherein a characteristic is simulated, the simulation depending on a predefinable expected use of the cable (1).

6. Method according to any one of claims 1 to 5, wherein wear of the cable (1) is predicted.

7. Method according to any one of claims 1 to 6, wherein an anomaly of the cable (1) is detected.

8. Method according to any one of claims 1 to 7, wherein operational data which are application-specific are used for evaluation.

9. System (5) with a cable (1) , in particular a trailing cable (1) , for electrical power supply, wherein the trailing cable has a sensor (2) in the cable (1), wherein sensor signals (3) can be evaluated, wherein an evaluation device (4) is provided for carrying out a method according to one of claims 1 to 8.

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