Data Management

DIgSILENT PowerFactory comes with a new and innovative philosophy of storing system data, system stage definitions, case data and runtime parameter. Instead of requesting the user to edit, organize and maintain hundreds of files thereby keeping most information fully redundant, PowerFactory features a powerful data manager that serves as a window to the built-in relational database.

Introducing Intelligent Data Structures

In order to minimize data redundancy, object data is split into Type and Element Data so that the same set of data can be used many times via type references. For most network objects such as cables, motors or relays, comprehensive libraries are provided allowing user access and maintenance on various levels.

Characteristics defined as vectors or matrices can be applied to perform parametric studies with discrete or continues scales. The application of characteristics allows keeping a perfect overview on data that change from case to case, such as loads, generation, set points or transformer tap position, without having the need to create and organize additional and separate cases.

System Stages and Study Cases are defined on the basis of easy-to-use mechanisms for incremental information handling which creates and maintains base cases, alternatives, expansion stages and operational scenarios. The maintenance of these variants will automatically update or delete extensions of subsequent stages. In addition, full support is given to the comparison of appropriate variants or alternatives.

The generation and editing of cases is not done by an additional 'Job-File Editor' but, instead, is included in the program itself, utilizing modern windowing techniques for all data entry and maintenance. Consequently, any modification of system data and structures is done within the program’s memory and on the database level at the same time. This technique allows the fastest possible program handling, since typical calculation sessions do not require the time consuming and tedious standard procedures like "editing - file saving", " program restart - update of data, etc".

Libraries

The user is free to define and organize his own integrated libraries for all kind of data, grids, output definitions, forms, user-written models, frames, fault sequences, DPL scripts, etc. Special importance is given for equipment types such as transformers, cables, generators, motors, conductors, tower configurations, controllers, relays or any other object support by the PowerFactory software.

PowerFactory is supporting Global Libraries and User Libraries with respective access and modification rights. Libraries can be imported and exported to many other software systems such as MS-EXCEL.

System Stage Management

In general, any network structure is organized around Grid Definitions such as the transmission systems, the distribution networks, industrial complexes, composite models or neighboring systems. Here, the user is free to organize all data according to his individual requirements.

Configuration changes within each Grid Definition are defined as System Stages – sometimes also called "Variants". They are represented in a tree structure when there are hierarchies and dependencies. Within each project, any number of System Stages may be created to represent any number of study alternatives to the base case networks. All data - equipment data, structural data and graphical information - is added or subtracted via the "incremental objects" of System Stages. This, fully non-redundant organization principle provides basic quality assurance mechanisms which are required to keep base cases and any subsequent alternatives consistent.

. To further reduce data redundancy within DIgSILENT PowerFactory, object data is split into type and element data. This means for example, that a section of "cable" from say node A to node B in a network, requires a certain data type (e.g. NACBA), and element data specific to that section, e.g. length, reduction factor, etc. This database strategy has the advantage that any updated type information will be automatically incorporated into all System Stages employing that type.

Study Case Management

Study Cases are used to define and activate certain functions and parametric alternatives of System Stages. They allow to define which grid variants, network interconnection options or system expansion stages are activated. Additionally, they are used to initialize certain sets of calculation commands such as:

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The Study Cases also save all data necessary for reproducing previously obtained results on basis of a single mouse-click.

Basic Quality Assurance Principle - No Data Redundancy

One benefit of this data structure is that large power companies have only a single database with a single set of data to manage. In case of a change in network data, updating the database only requires the database administrator to make one change and all System Stages of all applications of all network simulations are updated automatically. This feature improves quality assurance and is an attractive feature to many power companies.