# Modeling the Uncertainties Involved in Net Transmission Capacity Calculation

Abstract (Summary)

In a deregulated electricity market with area-pricing it is often desirable
to be able to transfer as much electric power as possible between
the areas, since this is the most cost efficient way to use the power grid.
However, due to limitations in the system there is a maximal amount
of power that is possible to transfer between the areas of the system,
this limit is called the total transfer capacity (TTC). When the transmission
system operator (TSO) is setting the trading limits between
the different areas of a multi-area power system he cannot, however,
consider only the TTC but also has to consider the uncertainties in the
system. The aim of this project is to find good methods for estimating
the risk of violating the TTC when keeping a certain margin on the
transfers in the system. To do this one will have to decide which uncertainties
are important to consider since a truly accurate calculation
is not possible to perform in normal power systems.
The method used to attack the problem of evaluating the risk of
violating the TTC will be Monte Carlo Simulation. To perform such a
simulation we need to find the probability distribution of the demand,
the production and the state of the grid. Finding the distributions
of the demand and the production will be the major concern of this
thesis. The demand will be modeled as the sum of a deterministic
curve representing the mean and the solution to a stochastic differential
equation (SDE). This is a method commonly used at for example the
weather derivatives market to model the outside temperature. Since
outside temperature and electric power consumption are closely related
this seems like a valid model. The production will be modeled as
the sum of the planned production minus outages in production, the
primary control and the secondary control. It is though not trivial to
find an adequate model for the secondary control. Two different models
for the secondary control were tested and showed different results for
the risk of violating the TTC and thus for the appropriate margin to
be kept.
Bibliographical Information:

Advisor:

School:Kungliga Tekniska högskolan

School Location:Sweden

Source Type:Master's Thesis

Keywords:TECHNOLOGY; Electrical engineering, electronics and photonics; Electric power engineering

ISBN:978-91-7415-308-8

Date of Publication:01/01/2009