Page 326 - Decision Making Applications in Modern Power Systems

Decision-making-based optimal generation-side Chapter | 11 287

VIU, all power system aspects such as generation, transmission, and distribu-
tion parts are under the control of one authority that is responsible for pro-
viding electrical energy with its ancillary services to consumers. On the
other hand, in restructured environment/deregulation structure, the above-
mentioned parts are owned by different companies. In the deregulated sys-
tems, providing ancillary services are based on the negotiations between
different generation companies (GENCOs) and distribution companies
(DISCOs) based on electricity markets’ negotiation [25].
In the restructured power systems, wherever a disturbance/change in the
demand-side occurs, the new demand is satisfied by electric power provided
from the GENCOS, which have contracted with the DISCOs of the load
change. In this way, DISCOs should forecast the demand of their consumers
and buy a sufficient electric energy for their consumers based on electricity
market competitive. In this new environment, DISCOs have the choice to
buy the energy from any GENCO. In addition, it can buy the energy from
more than one GENCO at the same time to meet the requirements of its con-
sumers [25].
Distributed power management (DPM) matrix is usually used to model
the various contracts between DISCOs and GENCOs. In this matrix the col-
umns models DISCOs and the rows correspond to GENCOs. Each entry of
the matrix, which is called contract participation factor, cpf, stands for a
specified contact between correspond DISCO and GENCO. It is clear that
the sum of all entries of one column should be one, which means the pro-
vided electrical energy from all GENCOs for one DISCOs equal to the
DISCO’s demand in each time interval [25].
Let’s consider a power system consists of n GENCOs and m DISCOs,
then the DPM is modeled by the following equation [1]:
2 3
cpf 11 :: cpf 1n
: :
6 7
:: ð11:18Þ
6 7
DPM 5 6 7
: :
4 5
::
cpf m1 cpf mn
It is worth mentioning that the change in the generated power from ith
GENCO in a specific time can be calculated as follows:
n d
X
ΔP g;i 5 cpf ik P k ð11:19Þ
k51
The abovementioned matrix can help with transmission system manage-
ment. In this regard the scheduled power flow in specific transmission line
or major tie-line between area i and area j can be calculated as follows:
ΔP sch 5 X X cpf lk ΔP Ll 2 X X ð11:20Þ
tie;ij cpf lk ΔP Ll
k 5 n g;i l 5 n d;j k 5 n g;j l 5 n d;i