Abstract:
A method operates a fault indicator, in particular a fault current indicator, which can detect a fault in an electrical energy transmission line, in particular a fault current in the energy transmission line. In the event of a detected fault, the fault indicator transmits a fault signal to a superordinate control center monitoring the energy transmission line. The fault indicator regularly or irregularly transmits at least one item of local weather information, which relates to the weather in the environment of the fault indicator, to the superordinate control center, directly to a central device other than the control center or indirectly to the other central device via the control center.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority, under 35 U.S.C. §119, of European application EP 16169534.1, filed May 13, 2016; the prior application is herewith incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates, inter alia, to a method for operating a fault indicator, in particular a fault current indicator, which can detect a fault in an electrical energy transmission line, in particular a fault current in the energy transmission line, and, in the event of a detected fault, transmits a fault signal to a superordinate control center monitoring the energy transmission line. 
         [0003]    It is known that fault indicators (also called fault passage indicator) can be used to detect faults in medium-voltage overhead lines, which fault indicators monitor the magnetic field of the line with inductive coupling and trigger a signal if a fault current passes through (for example in the event of a ground fault or a short circuit). The first fault indicators of this type were already being used at the end of the 1940s. Although these fault indicators were inexpensive to acquire, they locally provide only an optical signal in the event of a fault. If a fault occurs, the line course must be combed by maintenance teams during the search for the fault until the fault location has been found. In order to avoid such combing, fault indicators which are equipped with their own communication module, in particular in the form of their own gateway, and transmit their information to a central control system, referred to here as a control center below, have also been used for some years. 
         [0004]    However, the newly used fault indicators with communication capabilities are considerably more expensive, in terms of acquisition and operation, than the previously used fault indicators without communication capabilities; for this reason, fault indicators with communication capabilities are generally currently usually installed only at selected, generally poorly accessible, locations in the energy transmission network. 
       SUMMARY OF THE INVENTION 
       [0005]    The invention is based on the object of specifying a method for operating fault indicators which makes their use more attractive than before. 
         [0006]    Accordingly, the invention provides for the fault indicator to regularly or irregularly transmit at least one item of local weather information, which relates to the weather in the environment of the fault indicator, to the superordinate control center, directly to a central device other than the control center or indirectly to the other central device via the control center. 
         [0007]    An important advantage of the method according to the invention can be seen in the fact that the fault indicators are used not only to generate and forward fault signals but also to forward local weather information. The infrastructure needed to operate the fault indicators can therefore be used twice in the method according to the invention, namely to transmit the fault signals, on the one hand, and to transmit the local weather information, on the other hand. 
         [0008]    In order to be able to continue to operate the existing infrastructure with as minimal adaptation effort as possible, it is considered to be advantageous if the at least one item of local weather information is transmitted using the same communication protocol and on the same communication channel as the fault signals in the event of a fault. 
         [0009]    With regard to central further processing of the weather information, it is considered to be advantageous if the at least one item of local weather information is transmitted to a central device in the form of a central cloud system. 
         [0010]    With regard to the handling of the local weather information in the cloud, it is considered to be advantageous if the information is stored in a database of the central cloud system and/or is visualized—alone or with other weather information, in particular weather information from other sources—using visualization means of the central cloud system. 
         [0011]    In addition, it is advantageously possible to use the local weather information, alone or together with weather information from other sources, to create a weather forecast and to create a weather forecast which, with respect to the environment of the fault indicator, is locally more established, in a manner based on measured values, than a weather forecast without the additional local weather information from the fault indicator. 
         [0012]    In addition, the local weather information can be processed further during a forecast improvement method, in which a locally modified weather forecast is created on the basis of a previously created global or regional weather forecast taking into account the local weather information. 
         [0013]    The weather forecast created using the local weather information or the locally modified weather forecast can be advantageously used to control the supply of energy into an energy transmission network. For example, the local weather information can be used to control the supply of energy into that energy transmission network which is also monitored with the fault indicator for faults, in particular fault currents. 
         [0014]    Alternatively or additionally, the local weather information used to control heating systems. 
         [0015]    A forecast method for forming a weather forecast on the basis of the local weather information and/or a forecast improvement method can be advantageously carried out using an artificial neural network, for example based on a multilayer perceptron model or statistical methods such as the support vector machines. 
         [0016]    If an artificial neural network is used, it is considered to be advantageous if a network having at least three layers is used, the input layer and the output layer of the layers of the network each having the same number of perceptrons. Each perceptron respectively represents in this case a variable of the weather forecast for each interval of time. 
         [0017]    During a forecast improvement method, a previously created global or regional weather forecast and the local weather data from the fault indicators can be input to the input layer, for example, by applying the corresponding weather data to the perceptrons of the input layer. The locally modified weather forecast determined by the neural network is output by means of the perceptrons of the output layer. 
         [0018]    Before the forecast method or the forecast improvement method is carried out, the artificial neural network is preferably trained with the aid of the back propagation method and measured weather data as training data. 
         [0019]    The fault indicator or at least its communication module (for example gateway) is preferably operated with solar energy obtained by use of a solar cell of the fault indicator. It is also advantageous if the respective power output of the solar cell is used as a measure of the respective solar radiation and a measured solar radiation value is generated on the basis of the respective power output. The measured solar radiation value is preferably transmitted as the at least one item of local weather information or one of the items of local weather information to the control center and/or the central device. 
         [0020]    The fault indicator can also have one or more further weather sensors, in particular a rain gage, a wind gage, a temperature sensor and/or an air pressure sensor, the sensor signals of which are transmitted as local weather information to the control center and/or the central device. 
         [0021]    Another advantageous configuration provides for the fault indicator to comprise, in addition to a communication module, in particular a gateway, which is suitable for transmitting the fault signal to the control center, an additional communication device, in particular a near field communication device. 
         [0022]    A data connection, in particular in the form of a radio connection, is preferably maintained between at least one current and/or voltage sensor of the fault indicator and the communication module of the fault indicator by means of such an additional communication device in order to transmit the measured values from the current and/or voltage sensor and/or a fault signal already formed therefrom in the sensor to the communication module or gateway for the purpose of forwarding to the control center. 
         [0023]    Alternatively or additionally, a data connection, in particular in the form of a radio connection, can be maintained between at least one external weather sensor and the communication module of the fault indicator by such an additional communication device in order to transmit weather information from the external weather sensor to the communication module or gateway for the purpose of forwarding to the control center. 
         [0024]    In other words, provision may therefore be made for the fault indicator to permanently or at least occasionally, in particular regularly or irregularly, have a communication connection to one or more external weather sensors by the communication device, for the sensor signals from the external weather sensors to be transmitted to the fault indicator via the communication connection, and for the sensor signals to then be forwarded from the communication module or gateway of the fault indicator as local weather information to the control center and/or the central device. 
         [0025]    For the purpose of monitoring an energy transmission network, in addition to the at least one fault indicator, further fault indicators are preferably operated, which further fault indicators each monitor the same electrical energy transmission line as the fault indicator or monitor a different electrical energy transmission line of the same energy transmission network which is indirectly or directly connected to the energy transmission line and, in the event of a fault, each transmit a fault signal to the superordinate control center by their communication module. Each of the fault indicators preferably respectively regularly or irregularly also transmits at least one item of local weather information, which relates to the weather in the environment of the respective fault indicator, to the control center or directly to a central device or indirectly to a central device via the control center using its communication module. The local weather information is preferably transmitted in each case using the same communication protocol and on the same communication channel as that used to transmit the fault signals. If one or more fault signals are received, the control center determines those sections of the energy transmission network which are affected by the fault on the basis of the fault signals. 
         [0026]    The local weather information from the fault indicators is preferably stored in a database of a central cloud system, and/or visualized, and/or used to create a weather forecast, and/or used to create a locally modified weather forecast, for example on the basis of a previously created global or regional weather forecast and on the basis of the local weather information provided by the fault indicators. 
         [0027]    The invention also relates to a fault indicator for detecting a fault in an electrical energy transmission line, in particular a fault current in the energy transmission line, and for transmitting a fault signal to a superordinate control center monitoring the energy transmission line in the event of a detected fault. 
         [0028]    With respect to such a fault indicator, the invention provides for the fault indicator to be configured in such a manner that it regularly or irregularly transmits at least one item of local weather information, which relates to the weather in the environment of the fault indicator, to the superordinate control center, directly to a central device other than the control center or indirectly to the central device via the control center using a communication module. 
         [0029]    With respect to the advantages of the fault indicator according to the invention, reference is made to the above statements in connection with the method according to the invention. 
         [0030]    With regard to the configuration of the fault indicator, it is considered to be advantageous if the fault indicator has one or more weather sensors, the sensor signals of which are transmitted as local weather information to the control center and/or the central device. 
         [0031]    Alternatively or additionally, the fault indicator can be configured in such a manner that it can permanently or occasionally have a communication connection to one or more external weather sensors and forwards received sensor signals from the external weather sensors to the control center and/or the central device as local weather information using its communication module. 
         [0032]    The invention also relates to a monitoring device for monitoring an energy transmission network, having a multiplicity of fault indicators which monitor electrical energy transmission lines of an energy transmission network and, in the event of a fault, each transmit a fault signal to a superordinate control center of the monitoring device using a communication module. 
         [0033]    With regard to the configuration of the monitoring device, the invention provides for the fault indicators to be configured as explained above. 
         [0034]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0035]    Although the invention is illustrated and described herein as embodied in a method for operating a fault indicator, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0036]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0037]      FIG. 1  is an illustration showing an exemplary embodiment of a monitoring device which can be used to monitor an energy transmission network according to the invention; 
           [0038]      FIG. 2  is an illustration showing an exemplary embodiment of a fault indicator which can be used in the monitoring device according to  FIG. 1 ; 
           [0039]      FIG. 3  is an illustration showing another exemplary embodiment of the fault indicator which can be used in the monitoring device according to  FIG. 1 ; 
           [0040]      FIG. 4  is an illustration showing an exemplary embodiment of a central cloud system which can be connected to the monitoring device according to  FIG. 1 ; and 
           [0041]      FIG. 5  is an illustration showing an exemplary embodiment of a neural network which can be used to create a weather forecast or to locally improve or make a global or regional weather forecast more precise. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    In the figures, the same reference symbols are always used for identical or comparable components for the sake of clarity. 
         [0043]    Referring now to the figures of the drawings in detail and first, particularly to  FIG. 1  thereof, there is shown a monitoring device  10  which is used to monitor an energy transmission network  20 . The energy transmission network  20  is formed by a multiplicity of energy transmission lines  21  which are connected to one another. 
         [0044]    The monitoring device  10  contains a multiplicity of fault indicators  100  which are each assigned to one of the energy transmission lines  21  and are each connected to a control center  110  of the monitoring device  10 . In the event of a fault, those fault indicators  100  which detect a fault generate a fault signal F and transmit it to the control center  110 . The control center  110  can locate the fault location inside the energy transmission network  20  on the basis of the incoming fault signals F and can separate the faulty section of the energy transmission network  20  from the remaining energy transmission network  20  possibly by disconnecting individual energy transmission lines  21 . 
         [0045]    The fault indicators  100  are also configured in such a manner that they permanently or at least occasionally, be it regularly or irregularly, generate local weather information W and transmit it to the control center  110 . The local weather information W is preferably transmitted by the fault indicators  100  in exactly the same manner as the fault signals F in the event of a fault, that is to say preferably on the same communication channel and using the same communication protocol as the fault signals F. 
         [0046]    The local weather information W is preferably transmitted in the form of measured values or measured value signals, for example measured temperature values, measured pressure values, measured precipitation values, measured wind values, etc. 
         [0047]    In the exemplary embodiment according to  FIG. 1 , the control center  110  forwards the weather information W to a central device in the form of a central cloud system  30 . The local weather information W can be stored in the central cloud system  30  and/or can be visualized using visualization means of the central cloud system  30 . It is also possible to create a weather forecast in the central cloud system  30  on the basis of the local weather information W or to locally refine an already created global or regional weather forecast on the basis of the local weather information W or to make it more precise. 
         [0048]      FIG. 2  shows an exemplary embodiment of a fault current indicator which can be used as a fault indicator  100  in the transmission device  10  according to  FIG. 1 . The fault current indicator contains current sensors  100  which can be used to measure the current through the energy transmission line  21  according to  FIG. 1  which is monitored by the fault current indicator; faults, for example ground faults or short circuits in particular, can be detected on the basis of the measurement results and a fault signal F can be generated if necessary. 
         [0049]    The current sensors  100  of the fault current indicator are connected to the fault indicator&#39;s own communication module in the form of a gateway  102  which makes it possible to transmit the fault signal F to the control center  110  according to  FIG. 1 , for example in a wired manner or by radio. 
         [0050]    For the power supply, the fault current indicator according to  FIG. 2  is equipped with a solar cell  103 . The respective power output of the solar cell  103  is used by the fault current indicator as a measure of the respective solar radiation and a measured solar radiation value is generated on the basis of the respective power output of the solar cell  103  and is transmitted as local weather information W to the control center  110  according to  FIG. 1 . The solar cell  103  is therefore used twice, namely as a generator and as a weather sensor. 
         [0051]    The fault current indicator is also equipped with a multiplicity of further weather sensors, of which a rain gage  104 , a temperature sensor  105 , an air pressure sensor  106  and a wind gage  107  are illustrated, by way of example, in  FIG. 2 . The sensor signals of these weather sensors are transmitted as local weather information W to the control center  110  according to  FIG. 1 . 
         [0052]    In the exemplary embodiment according to  FIG. 2 , the fault current indicator is therefore itself equipped with weather sensors, the sensor signals of which are forwarded as local weather information W. 
         [0053]      FIG. 3  shows another exemplary embodiment of a fault current indicator which can be used as a fault indicator  100  in the energy transmission network  20  according to  FIG. 1 . In the case of the fault current indicator, current sensors  101  fastened to a mast  500  and the gateway  102  are arranged at a distance from one another and communicate with one another via a near field communication connection, for example Zigbee or the like. The sensor data from the current sensors  101  are transmitted, via the near field communication connection, to the gateway  102  which, in the event of a fault, transmits a fault signal F to the control center  110  according to  FIG. 1 . The sensor data from the current sensors  101  can be evaluated in the sensor or gateway for the purpose of detecting faults and generating fault signals. 
         [0054]    In order to operate the near field communication connection, the fault current indicator has an additional communication device  510 , here in the form of a near field communication device. 
         [0055]    The gateway  102  is also connected, via a near field communication connection, to an external weather station  50  from which the gateway  102  receives external local weather data W. The external local weather data W are forwarded from the gateway  102  to the control center  110  according to  FIG. 1 . 
         [0056]    In the exemplary embodiment according to  FIG. 3 , the gateway  102  of the fault current indicator therefore has a dual interface function since it forms both an interface to the current sensors  101  and an interface to the external weather station  50 . 
         [0057]      FIG. 4  shows an exemplary embodiment of a central cloud system  30  more specifically in detail. The central cloud system  30  has a cloud  31  to which the local weather information W from the fault indicators  100  according to  FIG. 1  is supplied. 
         [0058]    In the cloud, the central cloud system  30  preferably provides a database  32  for storing the local weather information W, visualization means  33  for visualizing the local weather information W, forecast means  34  for creating a weather forecast using the local weather information W and forecast adaptation means  35  for locally improving a regional or global weather forecast. 
         [0059]    The database  32  can make it possible, for example, for third parties to access the local weather information via suitable interfaces so that said third parties can externally evaluate the data. For example, a weather forecast can be externally created or a created regional or global weather forecast can be externally refined using the local weather information W. 
         [0060]    The visualization means  33  enable a geographically oriented representation of the weather information, for example. The positions of the fault indicators can be displayed on a map, for example. Windows in which the local weather information is presented can be opened by clicking on the positions. 
         [0061]      FIG. 5  shows an exemplary embodiment of a neural network  200  which can be used to implement the forecast means  34  or the forecast adaptation means  35  according to  FIG. 4 . 
         [0062]    In the exemplary embodiment according to  FIG. 5 , the neural network  200  contains three layers  201 ,  202  and  203 . The input layer  201  and the output layer  203  of the neural network  200  preferably each have the same number of perceptrons P. Each perceptron P of the input layer  201  represents a variable of a global or regional weather forecast which has already been created for each interval of time. The output layer  203  or the perceptrons P of the output layer  203  is/are used to output the local weather forecast determined by the neural network  200  or to output the weather forecast locally adapted or locally modified by the neural network  200 . 
         [0063]    In the illustration according to  FIG. 5 , it is assumed, for example, for an interval of time that measured temperature values T forecast as part of a weather forecast created in another manner, wind speeds WG forecast as part of a weather forecast created in another manner, wind direction indications WR forecast as part of a weather forecast created in another manner, solar radiation values SE forecast as part of a weather forecast created in another manner are supplied to the input layer  201 . The corresponding forecast values in the form of forecast measured temperature values or forecast measured temperature values T′ adapted by local weather information, forecast wind speeds or forecast wind speeds WG′ adapted by local weather information, forecast wind direction indications or forecast wind direction indications WR′ adapted by means of local weather information and forecast solar radiation values or forecast solar radiation values SE′ adapted by means of local weather information are output at the output layer  203 . 
         [0064]    The neural network  200  is preferably trained with the aid of the back propagation method and on the basis of measured weather data as training data. 
         [0065]    In summary, the basic concept of the exemplary embodiments according to  FIGS. 1 to 5  is that of using fault indicators, in particular fault current indicators, to record weather data in order to be able to provide cloud-based services using this information. These services may include, inter alia, the forwarding of the measured local weather data to weather services and the calculation of local weather forecasts. 
         [0066]    Potential customers for the measured weather data may be national or private weather services, for example. The latter currently themselves still operate a complicated network of weather stations which must be provided with their own communication technology and accordingly must also be maintained. 
         [0067]    In addition to the acquired local weather data, improved local weather forecasts can also be offered as services. Possible customers for these services are, for example, the operators of electrical distribution networks who take weather data into account in the operational management of their networks. These forecasts may be relevant, in particular, when it is necessary to intervene in the operation of the systems in a controlling manner on account of a lack of network capacities. 
         [0068]    In addition, the operators of virtual power plants, whose portfolio contains regenerative decentralized production systems, may also be interested in an improved local weather forecast. 
         [0069]    Another target group for the improved local weather forecasts mentioned above may also be the operators of heating systems. Heating systems are currently generally controlled on the basis of the current outside temperature in each case. A more pleasant indoor climate and lower heating costs can be achieved, however, if the heating power is controlled not only on the basis of the current outside temperature in each case but also on the basis of a locally accurate temperature forecast. It is also possible to control the heating power solely on the basis of a locally accurate temperature forecast, thus making it possible to dispense with individual outside temperature sensors. 
         [0070]    In summary, the technical and economic benefit of fault indicators can be considerably improved by additionally generating and/or forwarding local weather information. 
         [0071]    Although the invention was described and illustrated more specifically in detail by means of preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention. 
         [0072]    The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:
     10  Monitoring device     20  Energy transmission network     21  Energy transmission lines     30  Cloud system, central device     31  Cloud     32  Database     33  Visualization means     34  Forecast means     35  Forecast adaptation means     50  Weather station     100  Fault indicators, current sensors     101  Current sensors     102  Gateway, communication module     103  Solar cell     104  Rain gage     105  Temperature sensor     106  Air pressure sensor     107  Wind gage     110  Control center     200  Network     201  Layer     202  Layer     203  Layer     500  Mast     510  Additional communication device   F Fault signal   P Perceptrons   SE Solar radiation values   SE′ Solar radiation values   T Measured temperature values   T′ Measured temperature values   W Weather information   WG Wind speeds   WG′ Wind speeds   WR Wind direction indications   WR′ Wind direction indications