Due to the potential volume of data (Y and Z matrices can be up to 20 x 20), the data must be read into the line constants program through a formatted data file. The format is quite simple, as illustrated below for a 3-conductor (3 x 3) system:
|
Z: 0.137373233E+02,0.781467701E+02 0.110862970E+02,0.284027971E+02 0.102135204E+02,0.245775174E+02 0.110862970E+02,0.284027971E+02 0.155742208E+02,0.769993646E+02 0.110862970E+02,0.284027971E+02 0.102135204E+02,0.245775174E+02 0.110862970E+02,0.284027971E+02 0.137373233E+02,0.781467701E+02 Y: 0.107533374E-05,0.291619617E-03 0.450510123E-07,-.388110105E-04 0.442004979E-07,-.181654100E-04 0.450510123E-07,-.388110105E-04 0.108870661E-05,0.306977378E-03 0.450510123E-07,-.388110105E-04 0.442004979E-07,-.181654100E-04 0.450510123E-07,-.388110105E-04 0.107533374E-05,0.291619617E-03
|
The following rules should be considered:
The data file cannot contain commented text.
The data must be in COMPLEX format where real and imaginary parts are separated by a comma, such that: M + jN = M,N
The 'Y:' and 'Z:' headers indicate that the data following is for the respective matrix
The data must appear in order of left-to-right, top-to-bottom. For example the impedance data above is ordered as follows:
|
Z: Z1,1 Z1,2 Z1,3 Z2,1 Z2,2 Z2,3 Z3,1 Z3,2 Z3,3 |
Overhead line or cable models can be constructed directly from a user defined, external ZY data file. This method can be used to model transmission lines based on data generated from external software for any arbitrary shape configuration. This option can be enabled by selecting Y,Z Direct Entry (Multiple Frequencies) in the Manual Data Entry component. The external data file must be formatted as follows (as illustrated below for a 3-conductor (3 x 3) system at two frequencies). Note that text marked in grey is descriptive only and should not appear in the actual file!
|
! This is my file generated by an external program. 2 ! Number of Frequency samples (see notes below) 3 ! Number of conductors 60.0 ! First frequency (F1) [Hz] 0.137373233E+02 ! Z(1,1) Real 0.781467701E+02 ! Z(1,1) Imaginary 0.107533374E-05 ! Y(1,1) Real 0.291619617E-03 ! Y(1,1) Imaginary 0.110862970E+02 ! Z(1,2) Real 0.284027971E+02 ! Z(1,2) Imaginary 0.450510123E-07 ! Y(1,2) Real -.388110105E-04 ! Y(1,2) Imaginary 0.102135204E+02 ! Z(1,3) Real 0.245775174E+02 ! Z(1,3) Imaginary 0.442004979E-07 ! Y(1,3) Real -.181654100E-04 ! Y(1,3) Imaginary 0.110862970E+02 ! Z(2,1) Real 0.284027971E+02 ! Z(2,1) Imaginary 0.450510123E-07 ! Y(2,1) Real -.388110105E-04 ! Y(2,1) Imaginary 0.155742208E+02 ! Z(2,2) Real 0.769993646E+02 ! Z(2,2) Imaginary 0.108870661E-05 ! Y(2,2) Real 0.306977378E-03 ! Y(2,2) Imaginary 0.110862970E+02 ! Z(2,3) Real 0.284027971E+02 ! Z(2,3) Imaginary 0.450510123E-07 ! Y(2,3) Real -.388110105E-04 ! Y(2,3) Imaginary 0.102135204E+02 ! Z(3,1) Real 0.245775174E+02 ! Z(3,1) Imaginary 0.442004979E-07 ! Y(3,1) Real -.181654100E-04 ! Y(3,1) Imaginary 0.110862970E+02 ! Z(3,2) Real 0.284027971E+02 ! Z(3,2) Imaginary 0.450510123E-07 ! Y(3,2) Real -.388110105E-04 ! Y(3,2) Imaginary 0.137373233E+02 ! Z(3,3) Real 0.781467701E+02 ! Z(3,3) Imaginary 0.107533374E-05 ! Y(3,3) Real 0.291619617E-03 ! Y(3,3) Imaginary 300.0 ! Second frequency (F2) [Hz] 1.137373233E+02 ! Z(1,1) Real 1.781467701E+02 ! Z(1,1) Imaginary 0.107533374E-08 ! Y(1,1) Real ...
|
NOTE: If the Bergeron model is selected and damping approximation is enabled, the first frequency (F1) is the frequency used for damping approximation (ex. 2000.0 Hz). The second frequency (F2) is the steady-state frequency (ex. 60 Hz). If damping approximation is disabled then F1 is the steady-state frequency. Hence for the Bergeron model, the Z and Y data is required only for one or two frequency samples. For the Frequency Dependent (Phase) Model options, the number of frequency samples may be much higher (ex. 20 or 100). The minimum number of frequencies is 2.