It is now possible to describe a protection relay's characteristic curve using any user defined equation. Please refer to the ERACS manuals for full information.
To interact with the protection module the equation must include the following symbols:
TS = Time multiplier setting or Time dial setting.
M = Multiple of setting (I/Is).
As an example, the IEC Standard Inverse characteristic would be defined using the following expression:
TS * ( 0.14 / ( M^0.02 - 1 ) )
In addition to the standard arithmetic operators, +, -, *, /, the following functions are also available:
^ Power operator.
( ) Parentheses for grouping.
Abs Returns the absolute value of its argument.
Exp Returns the exponential of its argument.
Ln Returns the natural log of its argument.
Sqrt Returns the square root of its argument.
The maximum number of protection devices for the standard version of ERACS has been increased from 300 to 450.
A new feature called 'Open Data / Results Listing' has been included in the Results menu. This feature provides access to a maximum of three options dependent upon the type of study results being displayed on the network diagram. For example, if Loadflow results are being displayed then two options are available, whilst Protection results give rise to three options. Selecting one of these options will load the results / data directly into the application that has been associated with comma separated variable files (Excel or Lotus 123).
A facility to unzip archives has been included in the file menu. In addition to unzipping archives produced by ERACS this facility will also unzip regular zip files.
Power loss (PLO, 1, 1) kV volts drop (dV) and per unit volt drop (dpV) are now calculated for lines, cables and series elements.
A facility has been included which enables you to reselect a network's library. This facility is automatically started when a network is loaded and ERACS is unable to locate the library it is using. If the library is not found ERACS will enable you to select another library, which it will then check for the presence of the appropriate library keys.
It is now possible to scale your network diagram. This facility is available via the 'Scale Diagram...' option of the Edit menu. When selected you will be requested to enter X and Y scaling factors (%). These figures will be used to scale the X and Y co-ordinates of every element. Please note that this facility does not increase or reduce the size of the element symbols.
A facility has been included to enable you to check and correct your libraries and network databases for errors. In some instances this facility can also reduce the size of your network databases. To perform a health check on a network database select 'Health Check' from the Database menu. To perform a health check on a library database select 'Health Check' from the Library menu.
A Properties option has been included in the Database menu. When selected a form is displayed listing the name, location, size and contents of the database currently being used.