Page 85 - Mathematical Models and Algorithms for Power System Optimization

Optimization of Annual Generator Maintenance Scheduling 75

3.6.4 Description of the Output Results

The main outputs of generating an equipment maintenance scheduling program are the
scheduled maintenance start and end times of each generating unit, in which all the units in the
system can be sorted in a uniform order. Thus, the GMS personnel can have a comprehensive
understanding of the generator maintenance schedule of the whole system. Furthermore, the
maintenance schedule of generating units can be organized based on the sequence of power
plants. Generating units for each power plant can be listed in the order of maintenance start time
in a small separate table, so that the GMS personnel can clearly understand the generator
maintenance schedule in the power plant.

3.7 Implementation

This study, which is based on the real usage of a GMS in a domestic power system, fully
considers the special requirements of the different areas and derives the ES rules of
considerable adaptation. Therefore, the program is suitable for domestic conditions and is
easier to be executed and expanded. It provides a tool with simple operation condition, quick
computation, and reasonable results for power system dispatch engineers.

The solution procedure proposed in the chapter is tested by a real system with the conditions
shown in Tables 3.11 and 3.12 (study period is from 94-01-01 to 95-01-31). Where Equivalent
load¼Forecast Load – Hydro Exchange+Res. Cap., Res. Cap. (reserved capacity) is equal to
that of the total rated capacity minus the total real output capacity, which means some
generators may not be operated up to their rated capacity.
The examples of rules for the real case are given in Tables 3.13–3.15,where STARTtoEND
means the active period of rules; if START to END is defaulted, then the active period is all
over the study period. Table 3.13 shows the area maximum maintenance capacity constraints.
Table 3.14 provides simultaneous maintenance constraints in both one and two different
plants. In the table, PLANT 1 and PLANT 2 are the plant names. If the two names are the
same, then units in one plant cannot be simultaneously in maintenance outage. If the two
names are different, then units in the two plants cannot be simultaneously in outage for
maintenance. DT (default¼0) represents the interval time of maintenance between two units.
RPC represents the rule is active when unit capacity is larger than RPC (default¼0).
Table 3.15 suggests which two units cannot occur simultaneously. DT has the same meaning
as that in Table 3.14.