Project Data

In figure 1 we considered a power system consists of::

- a power plat equipped with two generator-transformer block groups of 50 MW, with the parameters in Tables 1 and 2;

- a 110 kV grid, consisting of three overhead power lines, , which is design to consume energy from the central and to supply electricity to the power consumption area, with the parameters presented in Table 3;

- transformer substation of 110 kV / 20 kV equipped with two 63 MVA transformers ;

Fig. 1. Single line power system diagram.

For a given power system treat the following aspectes:

- Operating system analysis;

- The study of voltage stability;

- Simulation of the schematic using the NEPLAN software.

We will consider the following system operating conditions:

- T1 and T2 transformers of the CET are working on the nominal plot, and T3 , T4 transformers from the drop-down station are working on plot -5;

- automatic voltage regulators of generators from CET, controls the node voltage CET-IT;

- nodal quantities values - voltage, active power, reactive power - are reported to the basic voltage , respectively the basic power ;

- L2 line is withdrawn from service for repairs.

Tabel 1. Electrical generators parameters

Gen SN

[MVA] PN

[MW] UN

[kV] cos? Xd, Xq

[%] Xd', Xq'

[%] T0'

[s] Tq'

[s] H

[s]

G1, G2 62.5 50 10.5 0.8 220 20 6 0.4 6.4

Tabel 2. Transformers parameters:

Trafo Pn [MVA] Umt [kV] Uit [kV] Usc [%] ?P0=?PFe [kW] ?Psc=?PCu [kW] Reglaj IT [%] I0

[%] plot

T1, T2 80 11 121 11.5 81 351 ?9x1.78 0.4 0

T3, T4 63 22 121 12 60 260 ?9x1.78 0.9 -5