CONFIGURATION MANAGEMENT
FIELD
The invention relates to configuration management of intelligent electronic devices (IED) within an electric power system. BACKGROUND
Electric power systems are complex systems having a distributed structure. The possibility to configure the system remotely is thus a necessity. The mere possibility for remote control is often, however, not enough but configurations need to be performed by plurality of people using the same or dif- ferent configuration terminals, and from different physical locations. In addition to the remote control, also the possibility for local configuration of devices needs to be provided.
Due to the various ways of configuration the devices, management of the configurations in the network are difficult to handle. It is also difficult to get a complete view of the change history of a certain device, not to speak about managing the history of the device configuration.
BRIEF DESCRIPTION
An object of the present invention is thus to provide a method and an apparatus so as to alleviate the above disadvantages. The objects of the invention are achieved by a method and an arrangement, which are characterized by what is stated in the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.
An advantage of the invention is that it is easier to achieve a proper overview of the configuration history of the network and a certain device. DRAWINGS
In the following, the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which
Figure 1 shows an embodiment of a configuration environment; Figure 2 shows an embodiment of configuration software;
Figure 3 shows an embodiment of a method. DESCRIPTION OF SOME EMBODIMENTS
The following embodiments relate to configuration of intelligent electronic devices (lED). An lED can be defined as a device used in electric power industry and including microprocessor-based controllers of power system equipment, such as circuit breakers, transformers, and capacitor banks.
Figure 1 shows one embodiment of a configuration environment. In the figure, a user 100 is about to configure an lED 120. The user uses a configuration terminal 1 10, which is connected to the lED via a communication link 1 16. The configuration apparatus 1 10 may be a stationary computer, a laptop or a mobile device, for instance. The communication link may comprise one or more connection types of an Ethernet link, dedicated data connection, Internet connection, a mobile communication link or an infrared link, for instance.
The user configures the lED, which means changing one or more operating parameters of the lED. If the lED is a protective relay, the operating parameter may be a tripping voltage, or the operate time of the relay, for instance.
Upon the configuration of the lED, one or more change records are created. In an embodiment, a change record is created of each parameter change. In another embodiment, a single change record may contain several parameter changes, or even all the changes carried out on the lED during a configuration session.
The change record may include various pieces of information. The record may contain information to identify the user/executor and the device used in the configuration, which is the computer 1 10 in Figure 1 . As part of the change record, the date and/or time of the configuration session may be recorded. The change record may also identify the lED, and changes performed in the session.
The change record(s) is/are transmitted by the lED 120 to an external database 140. The lED may initiate the transmission of the change re- cord(s) immediately after the configuration session, or even during the session. Figure 1 also shows a local memory 122 of the lED 120. The change record may temporarily be stored in the memory 122 if the transmission or the storage in the database 140 is unsuccessful. When the change record has, after a new attempt to store the record, successfully been stored in the database 140, the record may be erased from the memory 122. Storage of the change records in a central database 140 enables future utilization of the information contained in the change records. Future utilization here refers to an lED specific functionality, such as browsing of a full list of change records, browsing a delta list between two moments of time, undo- ing one or more selected changes, and rolling the configuration of the lED back to a certain moment in time. In the optimal case, a single database 140 contains the whole change history of the lED or even a whole sub-network including a plurality of lED's. Then, any authorised person seeking to configure one or more lED's can obtain services from this single database, which in- eludes the whole configuration history and the latest configuration information on the lED/network.
Figure 1 thus shows one embodiment of a configuration arrangement in which the user uses a remote network terminal connectable to the lED. The terminal may include configuration software, or it may only include a web- interface.
Alternatively, the user may use a laptop that is connectable to the lED via an infrared connection or by a connecting cable, for instance. In a still further embodiment, the user may use no terminal device at all but a user interface (keyboard and display) of the lED.
Figure 2 shows an embodiment of the software configuration of the lED. The figure shows some possible software modules and interfaces between those. It is clear that the division into software modules does not need to be the one shown but there may be implementation-dependent alternatives. It is also clear that the software modules may connect with each other in a plural- ity of ways, of which only some are shown for illustrative purposes.
The configuration software comprises a configuration interface module 224 for providing an interface towards the user desiring to configure the lED. The module 224 may first authorise the user. As an input from the user, the lED may receive logon information (user identity and password). The lED checks whether the user is authorised to change configuration settings of the lED, and either grants or rejects the configuration request of the user. If the configuration request is granted, the lED is locked such that no other user may log into the lED to change the configuration of the lED while the user's configuration session is active.
After receiving the instructions from the user, a configuration module
226 changes one or more parameters of the lED. A record creator module 228 creates one or more change records of the changes. The primary option is to transmit the record(s) immediately after the end of the configuration session, or even during the configuration session, to a database storing the records. A transmission module 230 establishes the data transfer connection via a data- base interface 232 to an external database. The module 230 also coordinates possible retransmissions if the initial transmissions are unsuccessful. The record^) may be stored in a memory 222 until they have been successfully sent to the database.
A database 240 may be located on a computer that is connected to the IED via a communication network. The connection between the IED and the database computer may be a dedicated connection, or an encrypted connection in a public network, for instance.
The database computer 240 includes an IED interface module 242 for providing an interface towards one or more lED's. A receiver module 244 is configured to handle reception of change records. The receiver module may also send the IED acknowledgements regarding successful storage of a change record, and provide a functionality to handle reception of retransmissions of the records. A storing module 246 is configured to store the records in the database. Instead of a database, the storage may be a file folder. Each change record may thus be a file to be added to the file folder.
The computer 240 may further include a service interface 248 for providing services to a service user 250. Such services may include listing of the change history of an IED. Such a listing may include all change records that have been created for an IED. Furthermore, the user may wish to undo one or more changes performed on the IED. That is, the user may select one or more change records and select the changes provided therein to be undone. Furthermore, the user may wish to rollback the configuration status of the IED to a certain status back in time. The configuration of the IED may then be rolled back to the status such that all the change records of the IED are un- done one by one. To implement the service functionality, the database computer 240 may use the interface modules 242 and 232 in the database computer and the IED, respectively.
The software functionality of Figure 2 may be provided in the IED and the database on computers comprising a processor and a memory. The software functionality may be stored in/loaded to the memory and instructions provided by the software may be executed by the processor. Figure 3 shows an embodiment of a method. At the beginning, the user starts (300) a configuration session to configure the IED. When the configuration has been successfully completed, the IED may send an acknowledgement (302) to the user device.
The IED may preliminarily store (304) one or more change records created during the configuration session. Then, the IED may transmit (306) the one or more change records to a database device. Figure 3 shows an embodiment where the transmission of the change record first fails (308). The reason may be a failure in the data connection or the database computer, for instance.
After some time, the IED makes a new attempt to transmit (310) the change record. Such retransmission attempts may be repeated by the IED periodically until the transmission is successful.
When the retransmission is successful, the one or more change re- cords are stored in/saved (312) on the database computer, which acknowledges (314) successful storage to the IED. When the IED has received an acknowledgement that the change record has been successfully stored in the database, the record may be deleted (316) from the non-volatile memory of the IED.
Figure 3 also shows a further embodiment where a service user connects to the database to retrieve information from the database and/or to start a configuration session of its own. In Figure 3, the service user connects to the database to browse (318) a change history of the IED. As a response, the database provides (320) a list of change records. The service user may then order (322) for a rollback of the IED configuration to a moment back in time. Figure 3 shows that the configuration session (rollback) is performed directly between the service user and the IED, but the database server may as well act between those. In Figure 3, the IED acknowledges (324) to the service user that the configuration has been set.
As at the beginning of the example of Figure 3, the IED is responsible for storing the change record(s) in the database as illustrated by steps save_config (326) and transmit_record (328). Upon successful saving (330) of the change records, the saving is acknowledged (332) to the IED, whereby they may be deleted (334) from the memory of the IED.
It will be evident to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The inven- tion and its embodiments are not limited to the examples described above but may vary within the scope of the claims.