Decomposition Of Power Flow Used For Optimizing Zonal Configuration Of Energy Market

Document Type : Primary Research paper

Authors

1 Associate professor, Department of Electrical and Electronics Engineering, Siddhartha Institute of Science and Technology Puttur, Andhrapradesh, India,

2 Assistant Professor, Department of Electrical and Electronics Engineering, Siddhartha Institute of Science and Technology Puttur, Andhrapradesh, India,

3 Professor, ECE department, Siddharth Institute of Engineering & technology, Puttur, Andhrapradesh, India

Abstract

Zonal configuration of energy market is often a consequence of political borders. However
there are a few methods developed to help with zonal delimitation in respect to some
measures. Paper quantifies the impact of the number of bidding zones on the network
model, transmission flows and fuel shares. Towards this aim, a clustering algorithm is
deployed to group nodes into zones, and an economic dispatch model is developed to
determine the optimal electricity market outcome. A case study based on the central
European electricity sector is considered. It is shown that, for the case study discussed in
this paper, increasing the number of zones results in considerable improvements in market
outcome (i.e., the zonal market outcome moves towards the optimal nodal market
outcome). However, the marginal improvement decreases with increasing number of
bidding zones.
This work presents the approach aiming at reduction of the loop flow effect – an element of
unscheduled flows which introduces a loss of market efficiency. In order to undertake
zonal partitioning, a detailed decomposition of power flow is performed. Next, we identify
the zone which is a source of the problem and enhance delimitation by dividing it into two
zones. The procedure is illustrated by a study of simple case. The real power and reactive
power balances must be maintained in steady state operation of electrical power systems.
The presence of reactive power in the power system was considered as a relatively trouble
free phenomenon three decades ago. The regulator kept the reassigned set points of voltage
levels at certain load buses using the local reactive power sources such as synchronous
condensers and shunt capacitors in a decentralized manner. Things started to change
around twenty-five years ago when the real importance of the problem was felt due to some
reactive power problem becoming visible in heavily loaded long transmission systems.
Reactive power problems lead to the phenomenon of voltage instability. Therefore, powersystem engineers and researcher were motivated to understand and analyze the usage of
components and devices in an optimal manner to regulate the reactive power from voltage
stability point of view.
The responsibility of generation, transmission and distribution of electric energy was
entrusted to one organization (generally, owned and managed by local government) in
vertically integrated power utility structure up to late 90’s. Such a vertically integrated
power utility structure exhibits monopoly to serve the needs of the customers in their
service territories. Energy service was considered as the main service whereas the reactive
power support services were an integral part of the electricity supply and was not
separated. Reactive power support service was only considered as a technical/engineering
but not managerial/economic issue hence it was obligatory on part of all generators in the
power system to accomplish the local reactive power demand and further no extra incentive
was given for this service.

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