Results Reporting
How to see and analyse calculation results
Introduction
PowerFactory offers a diverse range of calculation functions, from load flow and short-circuit analysis through to many optional, specialist modules, such as Protection or RMS Simulation. But however good the calculations are, it is also important to users that they have the best tools to access and analyse those results efficiently. Sometimes an overview is needed; on other occasions it will be necessary to look closely at every detail. That’s why PowerFactory allows access to calculation results in a number of different ways:
| Output window | Shows the progress of the calculation, any errors and warnings, and in some cases a summary of the key results. |
|---|---|
| Diagram colouring | Offers a visual overview of calculation outcomes. |
| Diagram results boxes | Enable the user to look at precise calculation results in any specific part of the network. |
| Network Model Manager | For every active network element, all relevant results can be seen, in a spreadsheet format. |
| Plots | Many different types of plot, such as time-series, R-X, eigenvalue, vector plots. . . |
| Tabular reports | Flexible reports with filtering options, enabling the user to look at all results and easily find the main items of interest. |
| PDF reports | Easy-to-read presentation of results. Reports can also be exported from PowerFactory and shared with colleagues and clients. |
| User-defined reports | Options for users to access the raw results and generate their own customised reports. |
In this paper, we present a number of different examples, to show how selected options might be employed, according to the task at hand. Other reporting options are also of course available in each case.
Example 1: Load Flow Analysis
Calculation purpose and typical reporting options
Load flow analysis is fundamental to the modelling and assessment of a network and underpins many other calculation functions. When a load flow calculation
is run in PowerFactory, the results are held in memory and can immediately be viewed graphically and in the Network Model Manager without the need to run a report.
Output window
The Output Window is an essential source of information, as it shows the progress of the calculation, with a level of detail that can be selected by the user. Importantly, it shows any warnings or errors. In general, the information in the Output Window can be filtered and searched, or copied to be used outside PowerFactory.
Diagram colouring
The default diagram colouring for load flow calculations gives a quick overview of the state of the network, highlighting any problems such as circuit overloading or voltages outside limits. The colour selection and thresholds are of course fully configurable. A heat-map option can be used to enhance the colouring.
Diagram results boxes
To see what is really going on in the network in detail, it can be useful to see power flows, currents etc. in a particular part of the network. The results boxes show calculation results for the various elements of the network, and are configurable in terms of content and format. Users can also create their own results boxes to show detailed or summary results.
Network Model Manager
The Network Model Manager enables the user to see attribute details and calculation results for each class of network element in the model. The information is presented in a tabular format, with sorting and filtering options. As well as standard tabs, a Flexible data page allows users to select exactly what they want to see. Data can also be copied and pasted into external tools such as MS Excel.
The ways of accessing calculation results that have been shown in this example for the load flow calculation are widely applicable PowerFactory, with many options for adapting them according to the analysis being carried out.
In the following examples, two other results reporting options are also explored: plots, which are an essential visualisation tool, and reports, which come in tabular or text format according to the requirements of the particular calculation function.
Example 2: Contingency Analysis
Calculation purpose and typical reporting options
Contingency Analysis, also referred to as n-1, is a load-flow assessment of the effect of fault outages on a network. As with many other calculation functions, the quantity of result variables and the fact that multiple results are recorded for each network element means that the results are held not in memory but in a results file.
Output Window
In the Output Window, the user can see the progress of the calculation, with options to show convergence details. Additional information such as remedial action scheme triggering (if used) will be provided.
Diagram colouring
Results shown on the diagram will just be those of the last-executed load flow, but the colouring indicates the worst limit violations out of all the contingencies.
Tabular reports
For functions such contingency analysis, which potentially generate a great deal of calculation output, tabular reports are the main tool for assessing the results. As well as summary report options, there are a range of different inbuilt reports that allow the user to easily assess the outcome of the contingency analysis. The reports include options to look at specific contingencies and specific time-phases, if used, and colouring to allow quick visual assessments.
Example 3: Time-Domain Simulations
Calculation purpose and typical reporting options
RMS and EMT simulations are used to assess the dynamic stability of a network, and look in detail at the transient effects of system disturbances. A typical case would be the use of an RMS simulation to study the dynamic response of the network when a short-circuit event occurs. The information in the output window is important, because events in the simulation are reported, together with any relevant warnings, but the main tool is the use of plots, which access the results in the results file and allow variables of interest to be seen over the simulation time period.
Output Window
The progess of the simulation is shown in the output window, with information about simulation events, modelling warnings and other details being shown; the user has options to control how much information is displayed.
Plots
Plots are essential for the evaluation of any simulation. As part of the simulation set-up, the user can select which element variables should be recorded, and then easily configure plots to show the results, once the simulation has run.
Of course, this is just one example; other calculations such as EMT Simulations, Quasi-Dynamic Simulations and Unit Commitment and Dispatch Optimisation also make use of time-based plots.
Example 4: Protection Functions
Calculation purpose and typical reporting options
The Time-Overcurrent Protection and Distance Protection modules functions in PowerFactory offer a great range of different features to support the protection engineer or system planner, including the Protection Coordination and Protection Audit. For some types of assessment, the diagrammatic information may be the most important output, but in other cases it is the detailed tabular output of results that is required.
Plots
Diagrams or plots are essential for the evaluation of protection schemes, as is evidenced by the number of different plot types available in PowerFactory:
- Time-distance
- Time-overcurrent
- Short-circuit sweep
- Relay operational limits
- R-X
- Phase comparison differential
- Current comparison differential
- Curve-input
Tabular reports
Tabular reports are used to output the results of PowerFactory functions such as the Protection Audit or the Protection Coordination assistant. These reports don’t just present results in a table; they include features such as options for further analysis or the transfer of calculated settings back to the protection devices.
Example 5: Connection Request Assessment
Calculation purpose and typical reporting options
Connection Request Assessment function in PowerFactory is just one of many calculation functions that make use of PDF reports for presenting results. The function assesses potential connections against industry guidelines and the reports show results such as voltage changes, flicker and harmonics, as well as an evaluation of the acceptability of the proposed connection.
PDF reports
Once a Connection Request Assessment calculation has been executed, it is very straightforward to execute the report command, which will by default generate the PDF report in the inbuilt PDF viewer within PowerFactory. The reports are structured in such a way as to provide all the necessary calculation outputs together with a clear assessment outcome. The advantage of this type of reporting is that it can simply be exported from PowerFactory and forwarded to managers or clients without any further work, although there are also options for exporting in other formats such as MS Word, to enable further editing outside PowerFactory. The reporting framework enables users to introduce some customisation, such as the inclusion of company logos and suitable headers and footers.
User-defined reports
Although all the options described above give a great deal of flexibility in results reporting, we recognise that sometimes customers have some very specific requirements regarding how results are presented to the user. It is therefore possible for users to have their own customised reports, and two different approaches are possible.
Customised reporting scripts
Most calculation functions produce results files, and these are readily accessible. Scripts written in Python or DPL (the DIgSILENT scripting language) can be used to access the data in the results files and report it in ASCII or tabular format. Such scripts can be written by users themselves or commissioned from DIgSILENT.
Report Designer
The PDF reports described above can also be modified or written from scratch by users. This is done via the Report Designer, which makes use of third-party software that has been integrated into PowerFactory.
Executive Summary
PowerFactory’s many calculation functions are complemented by a range of different options for reviewing and assessing the results, ranging from results boxes that are readily viewed in a network diagram to sophisticated and customised reports. In this paper, we have presented some examples of typical applications and shown how the users can easily find the information that they need.
All reporting functions described in this paper are part of the PowerFactory Base Package.