Abstract:
A configuration for monitoring gas-filled containers includes at least one measuring device for measuring at least one parameter of the gas in the container, a communication device which is suitable for transmitting information about the gas to an evaluation device, and an energy supply device which is suitable for acquiring electrical energy from the surrounding electromagnetic radiation. In addition, a system having the configuration and a corresponding method are provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2015 206 873.0, filed Apr. 16, 2015; the prior application is herewith incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to a configuration, a system and a corresponding method for monitoring gas-filled containers. 
         [0003]    Electrical installations such as, for example, high-voltage switching installations are frequently insulated with a protective gas such as, for example, sulfur hexafluoride (SF 6 ). SF 6  is, however, damaging to the environment, and the manufacturers and operators of the electrical installations are being required to meet ever stricter regulations to avoid SF 6  losses into the atmosphere. Recent guidelines require, for example, that less than 0.5% of the SF 6  of an installation be emitted into the environment per year. Furthermore, since 2015 there has been a requirement to monitor the SF 6  pressure and the SF 6  gas density at least every 6 months and to keep a log of the chronological profile of the SF 6  pressure and of the SF 6  gas density. Those regulations apply to all installations with more than 22 kg of the protective gas. That includes virtually all high-voltage installations. 
         [0004]    At present, analog gas pressure or gas density measuring devices are frequently used to monitor the electrical installations, and those gas pressure or gas density measuring devices have to be mounted on the installation and their readings have to be taken in situ by a technician. If the gas pressure or the gas density drops below previously specified threshold values, an alarm is triggered and/or the electrical installation is switched off directly, in order to avoid faults and damage to the installation. That constitutes a problem for the reliability of an energy distribution grid because the failure of an electrical installation due to losses of protective gas cannot be predicted and either the threshold values are not undershot and the installation remains in operation or the threshold values are undershot and failure or deactivation occurs. For that reason, the logs mentioned at the beginning are required, because those recordings can be used to detect gas losses in the chronological profile, and the need for maintenance of the electrical installation with corresponding restoration of the required protective gas pressure can be anticipated on the basis of the rate of gas loss. 
         [0005]    Nevertheless, problems arise even in the case of periodic monitoring, since many relatively old electrical installations currently do not have suitable gas pressure or gas density measuring devices and would have to be expensively retrofitted. Furthermore, technicians cannot always easily reach high-voltage installations and take their readings, which makes monitoring those installations difficult and expensive. 
         [0006]    If digital measuring devices and on-line monitoring systems are used, they have to be supplied with low voltage for their energy supply. However, that can often only be made available in a technically complex fashion with a measuring transformer, and is therefore expensive, in particular if old installations are to be retrofitted with modern measuring devices. Furthermore, data processing devices have to be used which evaluate the measurement data in situ and convert, for example, gas pressure values and gas temperature values into gas density values. 
         [0007]    By way of addition, the publication “Ambient Backscatter: Wireless Communication Out of Thin Air” by Vincent Liu, et al., University of Washington, published on SIGCOMM &#39;13, Aug. 12-16, 2013, Hong Kong, China is known. In that publication, devices are described which can communicate with one another and at the same time require only surrounding electromagnetic radiation (“ambient radio frequency signals”), such as is used, for example, by television signals, for the energy supply. In that context, a technique called “ambient backscatter” is used in which the surrounding electromagnetic radiation is backscattered in a modified form by a device, in order to transmit information such as, for example, signals of a contact sensor. Since the devices do not generate any suitable electromagnetic radiation, they are particularly economical in terms of energy. A prototype reaches data transmission rates of up to 1 kbps at a distance of up to 2.5 feet between the devices. 
         [0008]    Furthermore, the website article “Battery-Less Wireless Temperature Sensors Based On Low Power UHF RFID tags”, Jun. 10, 2013 by Mikel Choperena is known (“http://www.sensorsmag.com/product/development-platform-advances-battery-free-sensors-and”), which describes sensors from the firm Farsens. Those sensors use RFID with ultrahigh frequency signals (approximately 900 MHz) and measure the temperature, pressure, air humidity, etc. A possible use mentioned is sensors for avoiding fires in electrical switching installations. The data communication range is up to 1.5 m. 
         [0009]    A similar system is also described in the operating instructions “STANDALONE SOFTWARE USER GUIDE; UG-STANDALONESW-V03” from Farsens of April 2014. Software is described therein with which sensor data of the sensor “ANDY100” can be processed. Such a sensor is known from the product brochure “EPC C1 G2 COMPLIANT BATTERYLESS SENSOR/ACTUATOR DEVELOPMENT PLATFORM POWERED BY ANDY100 PB-MEDUSA-V01” by Farsens from September 2014. 
       SUMMARY OF THE INVENTION 
       [0010]    It is accordingly an object of the invention to provide a configuration, a system and a method for monitoring gas-filled containers, which overcome the hereinafore-mentioned disadvantages of the heretofore-known configurations, systems and methods of this general type and with which monitoring can be carried out automatically and simply without the need to make available an additional connection to an energy supply grid for supplying energy to the configuration. 
         [0011]    With the foregoing and other objects in view there is provided, in accordance with the invention, a configuration for monitoring gas-filled containers, comprising at least one measuring device for measuring at least one parameter of the gas in the container, a communication device which is suitable for transmitting information about the gas to an evaluation device, and an energy supply device which is suitable for acquiring electrical energy from the surrounding electromagnetic radiation. 
         [0012]    This is an advantage because costs and expenditure on maintenance for making available a connection to an energy supply grid are avoided. In particular, it is not necessary to generate a voltage which is suitable for the voltage supply of the configuration according to the invention by using a measuring transformer, for example from the high voltage which is at a gas-insulated electrical installation. Possible sources of the electromagnetic radiation are TV signals, radio signals or communication networks such as 3G, 4G, etc. which are available with almost total area coverage in many countries. Electromagnetic radiation near to high-voltage lines can also be used. 
         [0013]    In this context it is generally advantageous to use measuring devices with a comparatively low energy demand such as are known, for example, from the RFID sensors from Farsens as mentioned in the introduction. 
         [0014]    The information about the gas can include the measured parameters and/or other information, for example if further processing of the measured parameters takes place directly in the configuration. 
         [0015]    In one preferred embodiment of the configuration according to the invention, an additional source of electromagnetic radiation is used to generate more electrical energy by using the energy supply device. A WIFI, TV, radio or light source can be used as the additional source. In this context, continuous irradiation can take place or chronologically short radiation pulses can be used. It is an advantage of this additional, cableless energy supply that only one additional source of electromagnetic radiation has to be made available with little expenditure at the place of use, for example a switching installation with a plurality of containers, which source can, where appropriate, be supplied itself by solar energy if no energy supply grid connection is available. The evaluation device can also be configured as an additional source, in which case the device then not only receives measurement data but also emits energy. 
         [0016]    In a further preferred embodiment of the configuration according to the invention, the at least one measuring device includes a gas pressure measuring device. This is advantageous because the pressure of the gas in the container permits conclusions to be drawn about the leakproofness of the container. 
         [0017]    In a further preferred embodiment of the configuration according to the invention, the at least one measuring device includes a temperature measuring device. This is advantageous because knowledge of the temperature in conjunction with the pressure of the gas in the container permits conclusions to be drawn about the density of the gas. 
         [0018]    In a further preferred embodiment of the configuration according to the invention, the communication device is suitable for establishing a radio link to the evaluation device. This is advantageous because radio links can be used simply, cost-effectively and flexibly. 
         [0019]    In a further preferred embodiment of the configuration according to the invention, the communication device is suitable for establishing a radio link to adjacent configurations. This is advantageous because in this way a communication network can be formed when there is, for example, a plurality of installations to be monitored. In this context, a single evaluation device can be provided jointly for all, or for some, of the users of the network. 
         [0020]    In a further preferred embodiment of the configuration according to the invention, the energy supply device is suitable for using electromagnetic radiation in the radio frequency band and/or in the frequency band for TV signals and/or in the frequency band for mobile radio for the acquisition of energy. This is an advantage because energy supply is secured with virtually total area coverage in the radio frequency band with TV signals and/or radio signals and/or mobile radio such as, for example, 3G or 4G. 
         [0021]    In a further preferred embodiment of the configuration according to the invention, the energy supply device is suitable for using light by using solar cells for the acquisition of energy. This is advantageous because the acquisition of energy by using solar cells has been tested and proven for a long time and is reliable. 
         [0022]    In a further preferred embodiment of the configuration according to the invention, an energy accumulator is provided for buffering the electrical energy which is generated by the energy supply device. This is an advantage because in this way a significantly higher quantity of energy can be generated with very low continuous generation of energy, and that quantity permits parameters of the gas to be measured periodically once a day for example. 
         [0023]    In a further preferred embodiment of the configuration according to the invention, the evaluation device is suitable for calculating the density of the gas from the measured parameters of the gas pressure and temperature. This is advantageous because in this way further processing and evaluation of the measured parameters can take place centrally in the evaluation device, and no separate computing capacity has to be provided in each individual configuration. This saves energy during operation, as a result of which the energy supply device can be given a smaller configuration. Furthermore, costs can be saved. The measured parameters are transmitted to the evaluation device with the communication device. 
         [0024]    In a further preferred embodiment of the configuration according to the invention, a computer device is provided which is suitable for calculating the density of the gas from the measured parameters of the gas pressure and temperature. This is advantageous because in this way the measured parameters can be further processed and evaluated locally in the configuration. The calculated gas density is transmitted to the evaluation device with the communication device. This is advantageous because in this way all the required functionality for determining the gas density is provided in the configuration, and the evaluation device merely requires an interface for receiving the gas density. 
         [0025]    In a further preferred embodiment of the configuration according to the invention, the at least one measuring device is assigned to a connecting apparatus which is suitable for connecting to a container. This is advantageous because as a result there is no need for an additional opening to be made into an existing container, but instead, for example, a gas filling apparatus of a gas-insulated switching installation can be used to implement automatic monitoring of the gas in the container. 
         [0026]    In addition, the invention has the object of making available a system for monitoring gas-filled containers with which monitoring can be carried out automatically and simply without an additional connection to an energy supply grid for supplying energy to the configuration having to be made available. 
         [0027]    With the objects of the invention in view, there is also provided a system for monitoring gas-filled containers, the system comprising a configuration according to the invention and a gas-filled container. 
         [0028]    According to the invention, the container may be an electrical installation being filled with a protective gas. The protective gas may include sulfur hexafluoride. The configuration may be configured for retrofitting a container to its existing gas filling apparatus. In this context, the same advantages as described at the beginning for the configuration according to the invention arise correspondingly for the system according to the invention and its embodiments. 
         [0029]    In addition, the invention has the object of making available a method for monitoring gas-filled containers with which monitoring can be carried out automatically and simply without an additional connection to an energy supply grid for supplying energy to the configuration having to be made available. 
         [0030]    With the objects of the invention in view, there is concomitantly provided a method for monitoring gas-filled containers, comprising acquiring electrical energy from electromagnetic radiation surrounding a gas-filled container for supplying energy to at least one measuring device and one communication device, using the at least one measuring device to measure at least one parameter of the gas in the container, and using the communication device to transmit information about the gas to an evaluation device. 
         [0031]    According to a preferred and advantageous embodiment, the method further includes using the at least one measuring device to measure pressure and temperature parameters of the gas, and calculating a density of the gas from the measured parameters. In this context, the method according to the invention and its embodiments correspondingly result in the same respective advantages as described for the configuration according to the invention in the introduction. 
         [0032]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0033]    Although the invention is illustrated and described herein as embodied in a configuration, a system and a method for monitoring gas-filled containers, 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. 
         [0034]    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 
         [0035]      FIG. 1  is a diagrammatic, perspective view illustrating an application example of the system according to the invention; 
           [0036]      FIG. 2  is a perspective view of a known closure device for a gas filling device for a container; 
           [0037]      FIG. 3  is a longitudinal-sectional view of an exemplary embodiment of a system according to the invention; and 
           [0038]      FIG. 4  is a block diagram of an exemplary embodiment of a configuration according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]    Referring now to the figures of the drawings in detail and first, particularly, to  FIG. 1  thereof, there is seen a diagrammatic illustration of a switching installation  1 . Three containers  2 ,  3 ,  4 , which in this case are gas-insulated, high-voltage switching installations that are filled with the protective gas SF 6 , each have an analog measuring device  5 ,  6 ,  7  which indicates the gas density. In this context the arrows in the measuring devices  5 ,  6 ,  7  indicate the display of the gas density on an analog scale. 
         [0040]    Each of the containers  2 ,  3 ,  4  has, on its gas filling device, a configuration  8 ,  10 ,  12  according to the invention which utilizes the surrounding electromagnetic radiation  19  of a radiation source  18 , which is a TV transmission mast or tower, for acquiring energy. 
         [0041]    The configurations  8 ,  10 ,  12  transmit the measured parameters of the gas, in this case the temperature and the gas pressure, to an evaluation device  17  over radio links  9 ,  11 ,  13  such as, for example, W-LAN. The digital transmission of the data is indicated by an arrow  14  and a signal  101101001 . 
         [0042]    The evaluation device  17  has an antenna  16  for receiving and/or transmitting radio signals  15  and is configured to calculate the density of the gas from the measured parameters of the gas pressure and temperature. Therefore, the rate at which gas loss occurs within the container can be determined precisely by using the chronological profile of a plurality of measurements. In addition to the radiation source  18  or even instead of the radiation source  18 , the evaluation device  17  can, by using its transmission function, make available electromagnetic radiation for the energy supply of the energy supply devices of the configurations. 
         [0043]    The evaluation device  17  in this example is disposed close to the individual containers, but it could also be disposed at any desired location throughout the world given corresponding wider-ranging communication devices such as, for example, an Internet link. 
         [0044]    It is an advantage of the system according to the invention that a power supply or an energy grid connection for the configurations  8 ,  10 ,  12  does not have to be specially configured on any of the containers. 
         [0045]    Instead, an existing container can be retrofitted with the configuration  8 ,  10 ,  12  according to the invention on its gas filling device which is usually already present. 
         [0046]      FIG. 2  shows a known closure device  21  for a gas filling device  20  of a container, wherein the gas filling device  20  has a rear side  22  and a front side  23  with a valve. If the configuration according to the invention is to be used instead of the closure device  21  shown in order to retrofit an existing container, the configuration according to the invention must be suitable for use with the gas filling device  20 . 
         [0047]      FIG. 3  is a diagrammatic illustration of an exemplary embodiment of a system  30  according to the invention. A container which is filled with the protective gas SF 6  is located in a region  31 . 
         [0048]    A customary gas filling device  20  is attached to the container in a region  32 . The gas filling device  20  has a base  34  with a recess  35  in which a chamber  37  and a through-opening  36  are located. The chamber  37  and through-opening  36  form a fluid-conducting connection to the container and therefore contain the gas. The chamber is open toward the left-hand side. 
         [0049]    A configuration according to the invention, which is shown in a region  33 , has not yet been completely fitted (in the direction of an arrow) onto the gas filling device  20  for the sake of better clarity. The configuration has a sleeve  38  and a bushing  39  with sealing devices (indicated by circles). A central part  40  is located at a base of the bushing  39 . 
         [0050]    If the configuration is completely fitted onto the gas filling device  20 , the sleeve  38  engages around the left-hand part of the base  34 , and the bushing  39  encloses the recess  35 , with the result that the chamber  37  bears against the central part  40 . In this way, the gas SF 6  is present at the central part of the configuration during the operation of the system. 
         [0051]    The central part  40  of the configuration has a gas pressure measuring device and a temperature measuring device with which the gas pressure and temperature of the SF 6  can be determined. 
         [0052]    In one development of the configuration, a computer device for controlling the configuration and processing the measured parameters, as well as an energy accumulator, can additionally be provided in the central part. 
         [0053]    The central part  40  is adjoined by an outer part  43  which, on one hand, has an energy supply device  41  that is suitable for acquiring electrical energy from the surrounding electromagnetic radiation. On the other hand, the outer part  43  has a communication device  42  which is suitable for transmitting the measured parameters to an evaluation device. 
         [0054]      FIG. 4  shows an exemplary embodiment of a configuration according to the invention with an energy supply device  50  which is suitable for acquiring electrical energy from the surrounding electromagnetic radiation. In this context, a first energy acquisition device  51  is used to acquire electrical energy from surrounding radio waves such as, for example, TV signals and/or radio signals and/or a second energy acquisition device  52  is used to acquire electrical energy from light. 
         [0055]    The acquired electrical energy is buffered in an energy accumulator  53  and used when necessary, for example periodically once per day, in order to determine the gas pressure and temperature by using a measuring device  54  and to transmit these to a computer device  55 . The computer device  55  processes the measured parameters and can calculate the density of the protective gas in the container from the gas pressure and the temperature by using a calculation rule which is adapted to the protective gas SF 6 . 
         [0056]    Finally, the calculated density value and, if appropriate, the measured parameters are transmitted by radio through a communication device  56  with an antenna  57  for further processing. In this context, the communication device  56  is also supplied by the energy accumulator  53 .