Page 142 - Mathematical Models and Algorithms for Power System Optimization

Load Optimization for Power Network 133

Fig. 5.1

5-Bus test system.

Tables 5.10–5.12 provide the basic data of the bus, line, and transformer in the 5-bus system and
conducts per-unit calculation using SB¼100MVA as the system reference values.

Table 5.10 Bus data
Current Load or
Output (MW) [lower
Bus Voltage Class (kV) Bus Type limit, upper limit] Per-Unit Value

1 110 Load bus 120 1.2
2 110 Load bus 60 0.6
3 110 Load bus 150 1.5
4 10 Output bus 100 [30, 140] 1.0 [0.3, 1.4]
5 10 Output bus (balance 230 [200, 300] 2.3 [2.0, 3.0]
bus)

5.5.1.2 Concrete expression of the LP model

A certain “state 1” in the previous 5-bus test system is given: one circuit of the double-circuit
line at bus 1 and bus 3 exits operation, as shown in Fig. 5.2.
To simplify, the weight coefficient of all loads is taken as 1; the upper limit of the line power is
converted according to the safe current; the upper limit of transformer load is considered based
on the transformation capacity.
Basic calculation procedure:

(1) Renumber the buses and branches of the 5-bus system, and balance bus (bus 5) is listed at
the end.