Page 35 - Mathematical Models and Algorithms for Power System Optimization

Daily Economic Dispatch Optimization With Pumped Storage Plant 25

2.4.1 Validity Test of the Input Data

Reasonability of original input data is a precondition for obtaining a feasible solution for the
optimization calculation. To meet the optimization calculation requirements, computational
personnel sets a series of limits according to the operation schedule, such as unit operating
conditions (shutdown, maintenance, and startup), and also defines the upper and lower limits of
the area output, power plant output and energy generated by power plants, and water balancing
constraint, as well as reservoir capacity constraint, all of which shall be checked to ensure all are
within a reasonable range. Thus, it is quite necessary to verify the reasonableness of the input
data. The main contents of validity testing of data include:

(1) Solve the allowable output range of each area under the given operating conditions, and
compare the range with the manual setting for upper and lower output limits of each area;
if the given upper and lower output limits of the area do not satisfy the allowable range,
then the name of the area and corresponding over limit value will be output, allowing
calculation personnel to make necessary modifications.
(2) Solve the allowable output range of each power plant under the given operating
conditions, and compare the range with the manual setting for upper and lower output
limits of each power plant; if the given upper and lower output limits of power plant do not
satisfy the allowable range, then the name of the power plant and corresponding over limit
value will be output, allowing calculation personnel to make necessary modifications.
(3) Solve the allowable generated energy range of each power plant under the given operating
conditions, and compare the range with the manual setting for upper and lower generated
energy limit of each power plant; if the given upper and lower generated energy limit does
not satisfy the allowable generated energy range, then the name of the power plant and
corresponding over limit value will be output, allowing calculation personnel to make
necessary modifications.
(4) Sum all upper limits and lower limits of all unit outputs. First check whether the sum
complies with the varying range of the load curve (especially the sum of upper limits); if
not, check whether the sum can comply with the varying range of load curve with the
operation of the pumped storage units. Otherwise, calculation personnel will be notified to
make necessary modifications.

2.4.2 Validity for the Rationality of the Constraints

As previously mentioned, when manually setting generated output and energy constraints for
power plants and generated output constraints for areas, the constraints should be within a
reasonable range, otherwise feasible solutions in the optimization calculation cannot be
obtained. Therefore, the reasonability of the specified constraints should be confirmed by the
necessary modifications as follows: