Method, arrangement and computer program product for a condition-based calculation of a maintenance date of a technical installation

Abstract

The condition of a technical installation is automatically monitored. A measured value of at least one component of the installation is sensed by at least one sensor device on the installation, and the at least one measured value is used, in a data processing arrangement specific to the installation, for determining a current operating state of the installation. By way of the data processing arrangement, including component-specific aging functions, a future chronological course of the operating condition is determined from the current operating condition, and a maintenance interval for the installation is adjusted on the basis of the future chronological course of the operating condition, in order to determine a next maintenance date of the installation. A corresponding arrangement and a computer program product for condition monitoring are also described.

Claims

1. A method for an automatic condition monitoring of a technical installation, the method comprising: recording, with at least one sensor device at the installation, at least one measured value of at least one component of the installation and using the at least one measured value in a data-processing arrangement, in each case specifically for the installation, for determining a current operating condition of the installation; determining, with a data processing arrangement, the current operating condition of the technical installation from a plurality of partial operating conditions, wherein individual components of the installation are each allocated to the individual partial operating conditions, and wherein the data processing arrangement brings together each of the individual partial operating conditions in a weighted manner to determine the current operating condition; determining, with the data processing arrangement, a future chronological course of the operating condition, making use of component-specific ageing functions, on a basis of the current operating condition; adjusting, with the data processing arrangement, a maintenance interval for the installation on a basis of the future chronological course of the operating condition, in order to specify a next maintenance date of the installation; wherein the installation is a transformer, a gas-insulated switchgear, or an air-insulated switchgear.

2. The method according to claim 1, which comprises continuously updating a specification of the next maintenance date based on the at least one recorded measured value.

3. The method according to claim 1, wherein the adjusting step comprises: adjusting a prespecified maintenance interval respectively for a subsequent point in time with a specified time interval from a current date, taking into account the operating condition at a subsequent point in time known from the future chronological course of the operating condition, wherein the maintenance interval determined until the subsequent point in time is a predetermined maintenance interval for a next subsequent point in time, until the maintenance interval has become so short that it coincides with a subsequent point in time or comes to lie before the subsequent point in time.

4. The method according to claim 1, which comprises determining a weighting of an individual partial operating condition on a basis of a known total fault rate for the type of the installation, by determining a relative proportion that the allocated components have in a total fault rate for the allocated components.

5. The method according to claim 4, which comprises: allocating each recorded measured value of a component to an individual partial operating condition; including each measured value in a determination of the allocated individual partial operating condition with a relative proportion in the allocated partial operating condition, by determining, for the allocated component, a relative proportion that the allocated component has in the fault rate of all the components of the individual partial operating condition.

6. The method according to claim 1, which comprises establishing which partial operating conditions correlate, and forming a quotient for each two correlating partial operating conditions, and, when the quotient falls below a lower threshold value or exceeds an upper threshold value, issuing a warning message, so that a maintenance date can be brought forward.

7. The method according to claim 1, which comprises determining a chronological course of a failure probability of the installation on a basis of the chronological course of the operating condition, and thereby taking into account a known chronological course of the failure probability of a type of the installation.

8. The method according to claim 7, which comprises determining a chronological course of a risk of failure from the chronological course of the failure probability of the installation, taking into account the consequences of a failure of the installation.

9. The method according to claim 8, wherein the consequences of the failure of the installation include costs of the failure that depend on a type of the installation and a location of the installation.

10. The method according to claim 9, which further comprises taking into account an installation performance and/or an availability of spare parts in a calculation of the failure risk.

11. The method according to claim 8, which further comprises taking into account an installation performance and/or an availability of spare parts in a calculation of the failure risk.

12. The method according to claim 1, which comprises determining a point in time for an exchange or repair of the installation by calculating a chronological course of the discounted new price of the installation and determining a minimum of the chronological course of a total of a failure risk and a discounted new price.

13. The method according to claim 1, which comprises monitoring a multiplicity of installations and in each case determining average values and/or histograms of the operating condition and/or of the failure probability and/or of the failure risk of the multiplicity of installations and of the respective chronological course.

14. A computer program product, comprising: a non-transitory computer-readable medium storing a computer-readable program code configured to cause a computer, forming a data-processing arrangement, and/or a cloud-based data processing arrangement to carry out the method according to claim 1 when the computer program product is executed on the computer and/or on the cloud-based data-processing arrangement.

15. The method according to claim 1, which comprises: performing maintenance on the installation based on the next maintenance date specified by the future chronological course of the operating condition.

16. An arrangement for an automatic condition monitoring of an electrical installation, the arrangement comprising: at least one sensor device disposed at the electrical installation and configured to acquire at least one measured value of at least one component of the installation; and a data processing arrangement connected to receive from said at least one sensor device the at least one measured value and configured to use, in each case specifically for the installation, the at least one measured value for determining a current operating condition of the installation; said data processing arrangement being configured to determine the current operating condition of the technical installation from a plurality of partial operating conditions, wherein individual components of the installation are each allocated to the individual partial operating conditions, and said data processing arrangement is configured to bring together each of the individual partial operating conditions in a weighted manner to determine the current operating condition; said data processing arrangement being configured to determine a future chronological course of the operating condition making use of component-specific ageing functions on a basis of the current operating condition, and to adjust a maintenance interval for the installation on a basis of the future chronological course of the operating condition, in order to specify a next maintenance date of the installation; wherein the installation is a transformer, a gas-insulated switchgear, or an air-insulated switchgear.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) For the sake of a better explanation of the invention below

(2) The FIGURE shows a schematic representation of an exemplary embodiment of the arrangement according to the invention.

DESCRIPTION OF THE INVENTION

(3) The arrangement 1 according to the invention comprises a technical installation 2 whose condition is automatically monitored. The installation 2 is a gas-insulated switchgear with a rated voltage of 400 kV.

(4) The installation 2 comprises a plurality of components 21, 22, 23.

(5) The component 21 is an insulation system, and is monitored by two sensor devices 3, 4, where sensor device 3 monitors the shield gas density, and sensor device 4 monitors the gas humidity.

(6) The component 22 is a drive mechanism, and is monitored by two sensor devices 5, 6, where sensor device 5 monitors the opening time of the contacts of the switchgear, and sensor device 6 monitors the closing time of the contacts of the switchgear.

(7) The component 23 are the elements that are responsible for the breaking capacity of the switchgear. Two sensor devices 7, 8 are used, wherein sensor device 7 monitors the rated current, and sensor device 8 monitors the switching power (in i.sup.2*t).

(8) By means of the communication connections 41, the measured values recorded by the sensor devices 3-8 are transmitted to a data-processing arrangement 9. The communication connections 41 can here be radio connections, conventional wired connections, connections via the Internet, or connections that transfer the data over a power network.

(9) In an alternative embodiment, the recorded measured values can also first be collected in an intermediate evaluation apparatus (not illustrated).

(10) The data-processing arrangement 9 uses the measured values in each case specifically for the installation, in order to determine an operating condition of the installation.

(11) For this purpose the measured values that have been recorded by the sensor devices 5-8 are allocated to the components that said sensor devices monitor. The components of the installation are in turn allocated to four partial operating conditions 10-13.

(12) The component 23 is allocated to the partial operating condition 10, which comprises the components of the insulation system (IS), wherein the partial operating condition 10 is entered into the determination of the operating condition with 50.7%.

(13) The component 22 is allocated to the partial operating condition 11, which comprises the components of the drive mechanism (DM), wherein the partial operating condition 11 is entered into the determination of the operating condition with 23.4%.

(14) The component 21 is allocated to the partial operating condition 12, which comprises the components of the breaking capacity (BC), wherein the partial operating condition 12 is entered into the determination of the operating condition with 12.3%.

(15) The partial operating condition 13 comprises other factors (OF), and is entered into the determination of the operating condition with 13.6%. The sensor device 39 measures a measured value that is not yet allocated to any of the main components 21, 22, 23 of the installation. In addition to this, further factors such as age of the components, maintenance compliance, inspection compliance, inspection results and maintenance results are included in the partial operating condition 13, where these are obtained from a data memory 43 by means of a data transmission connection 41. The data memory 43 can be manually filled by a user. Alternatively, the data memory 41 can be filled by obtaining data from a system for the planning and execution of maintenance, repairs and replacement of installations.

(16) As the next steps according to the invention, the measured data obtained from the sensor devices 3-8, and the empirical data obtained from the data memory 43, are used in order to age the determined measured data using component-specific aping functions. Both the current and the future operating conditions can be determined in this way. Examples for the use of aping functions are illustrated in steps 14 to 17.

(17) The calculation of an exponentially increasing aping function is performed, for example, for the measured value of the closing time, which is monitored by sensor device 6, as follows: according to the manufacturer, the service life of the component is 50 years (parameter L); also according to the manufacturer's data, the minimum closing time is 34 ms (OT.sub.t), and the maximum (permissible) closing time is 38 ms (OT.sub.t+L). The environmental condition factor for the aping process is deemed to be negligible when the installation is in climate-controlled rooms (parameter B=1); for installations that are not in climate-controlled conditions, a parameter B>1 is selected, in order to take the increased aping resulting, for example, from increased air humidity or temperature, into account. According to the equation
OT.sub.t+L=OT.sub.t*(1+B*C).sup.T
a value of about 0.002 results for the exponential factor C. According to the above equation, the future chronological course of the closing time as from the current date can be calculated. In a comparable manner, exponentially falling, linearly increasing and constant aping functions can be determined on the basis of known manufacturer's data.

(18) For example, the following measured values for a 400 kV GIS switchgear can be aged in accordance with an exponentially falling aping function: gas purity, gas dew point.

(19) For example, the following measured values for a 400 kV GIS switchgear can be aged in accordance with an exponentially increasing aping function: closing time, opening time, current of an open coil, current of a closed coil, compression motor current for a spring, switching capacity.

(20) For example, the following measured values for a 400 kV GIS switchgear can be aged in accordance with a linearly rising aping function: number of breaking faults, part discharge, running time of the motor for a spring drive, number of operations of the installation, number of faults when closing, load current, aping parameter of the installation.

(21) For example, the following measured values for a 400 kV GIS switchgear are aged or held constant by means of a constant aping function: inspection compliance, maintenance compliance, maintenance results.

(22) Step 14 shows an application of an exponentially falling aping function to a measured value P.sub.1 for a component, so that the current measured value 15 deteriorates exponentially, starting from the present point in time t.sub.1 and measured value P.sub.2. The gas dew point, for example, deteriorates exponentially.

(23) In a similar manner, step 15 shows the effect of a linear aping function on a measured value P.sub.3, starting from the current measured value 18 at the measuring point t.sub.1, P.sub.4; step 16 shows the effect of an exponentially increasing aping function on a measured value P.sub.5 starting from the current measured value 19 at measuring point t.sub.1, P.sub.6.

(24) Step 17 shows the effect of a constant aping function (the operating condition remains the same over time) on a measured value P.sub.7, starting from the current measured value 20 at measurement point T.sub.1, P.sub.8.

(25) In a similar way, all the recorded measured values are aged starting from the day they are recorded, in order to obtain a course of an operating condition for the respective partial operating condition 10-13 (not shown).

(26) The partial operating conditions are, as indicated above, brought together in a weighted manner, and yield a chronological course of the operating condition of the entire installation 2, as is illustrated in step 24.

(27) The operating condition H deteriorates from the commissioning t.sub.0 of the installation, from a value of zero up to a value of 10 at the end of operation of the installation t.sub.E. At the current point in time t.sub.1, an operating condition H.sub.1 results with a value of 4.5, which is indicated by the point 25 on the operating condition curve.

(28) There is, furthermore, a dependency of an expected maintenance interval M (measured in years, a) on the operating condition, as is illustrated schematically in the FIG. 45. As the operating condition of an installation becomes poorer, the maintenance interval is set shorter. In the example illustrated, an installation that is in mint condition with an operating condition value of 0 has a maintenance interval of 2 years; starting from an operating condition of 4, this becomes shorter, until, at an operating condition of 7, a maintenance interval of 1 year is reached. At the current operating condition of 4.5, step 24 thus yields a current maintenance interval of M.sub.x, which is about 1.83 years.

(29) It must, however, be borne in mind that it is not simply possible to set a maintenance date that is 1.83 years following the previous maintenance. This would fail to consider the fact that in the time from now until the maintenance date, the operating condition would continue to deteriorate as a result of the aping of the installation, and the maintenance interval would accordingly also have to be shortened. Without a corrective calculation, the maintenance date would thus regularly be set too far into the future, and there would be a risk of a failure or fault in the installation.

(30) For this reason, a comparison is made in step 26 between the course of the maintenance interval 27 adjusted to the respective operating condition, which continuously falls, and a linear time line 28 which represents the months following the current date. The next maintenance date t.sub.M, indicated by point 29, is specified for the place where the two curves meet.

(31) The specified maintenance date t.sub.M, the current operating condition H1 and the future chronological course of the operating condition are transmitted by means of a further communication connection 41 to a display apparatus, where they are presented for reading by a user.

(32) In a development of the system, it is also possible to transmit the specified maintenance date t.sub.M to a system for planning maintenance work. Taking employee work plans, geographical information on routes and installation sites, as well as, if relevant, weather forecasts into account, this system can then plan a suitable trip for maintaining, repairing or replacing these and other installations with specified maintenance dates that are chronologically close to each other, and make it available for a user.