The calculation is initiated as a normal distribution calculation.

After tracing the network, select the tab Load values and select the radio button Load pattern curves which is found under the section Load type in order to activate the tab Load profile.

 

Set the conditions for the load profile calculation.

 

 

Define time interval for the calculation

Use the calender and the drop down lists to set start and end time for the calculations. In the example above, 24 hours will be calculated the whole day 01-05.

Make sure to check the start time and the end time hence a mistake can generate a very large result if you have selected to save the result for every hour. E.g. a monthly calculation can generate approximately 700 load calculations, if you choose to save data for individual nodes and conductors, it will be very large volume very fast. There are no problems with performing time series over a long time but it should be done with an extra thought.

 

Run a calculation for actual date and time (now)

You need to have a manually entered temperature. See section C.

 

Temperatures

Two alternatives is possible:

1.Select a Temperature set. The temperature set needs to have temperatures for all the days that are included in the calculation. A possible year for the temperature set is not used during the calculation. It is only used when loading hour values. It is hence possible to use a temperatur set from 2010 and use it for a calculation during 2011 etc. The radio button Used set needs to be selected.

2.Manually entered temperature. Enter a temperature in the text field and select the radio button Use indicated value.

 

Wind

This alternative is only used if there are generators with specified wind profile data.

Two alternatives is possible:

1.Select a Wind set. The wind set needs to contain the wind data for the whole calculated time interval. The radio button Used set needs to be selected.

2.Manually entered wind and a possible spread. Enter Mean (m/s) and possible Deviation (m/s). The radio button Use indicated value needs to be selected.

 

Edge probability

The edge possibility or confidence degree is a statistical term that is defined according to the following:

If the probability is set to 99%, it means that for each individual hour, the probability is that the power does not exceed the upper limit curve of 99%.

If the radio button save summary curve (F) is selected, the summarized curve in the feeding point will be saved in the database and you will obtain a excel result. The curves are also presented graphically in another window.

Note! That excel needs to have a decimal point = '.' (point) set. This is done via the control panel and national settings (Regional and Language Options > Customize .. > Decimal symbol).

 

Perform load flow calculation at max or min hour at the feeding point

If desired, you can request a complete load calculation for either a maximum hour or a minimum hour automatically when forecasting a time series. After a forecast calculation over all requested hours, the maximum time and minimum time will be identified in the feeding point. The max-min hour can then be used to make a complete distribution calculation for this hour. Both the fault current calculation and the load flow calculation are performed in the usual order.

 

 

Save the result from all the hours for specific object types and result terms

It is possible to save results for specific objects for all the hours in the prognosis.

The alternatives that are available:

•Save voltage for all nodes and hours.

•Save current for all conductors and hours.

•Save relative load for all conductors and hours.

•Save transformer loads for all transformers and hours.

Press the button Calculate in order to start the prognosis.

 

Run load calculations for hour with highest and lowest load in the feeding point

It is possible to perform a complete load calculation for either highest hour or lowest hour automatically when prognosing a time set. After a prognosis calculation for all the requested hours, the highest or lowest hour is identified in the feeding point. The highest and lowest hour can be used to perform a complete distribution calculation for that hour. Both fault analysis and load flow calculations are performed as usual.