Title: Modelling and Stability Analysis of Berlin Geothermal Power Plant in El Salvador

Abstract

Power system stability can be defined as the property of a power system that enables it to remain
in a state of operating equilibrium under normal operating conditions and to regain an acceptable
state of equilibrium after being subjected to a disturbance. There are different forms of power
systems stability, but this project is focused on rotor angle stability.

Rotor angle stability is the ability of interconnected synchronous machines of a power system to
remain in synchronism. For convenience in analysis and for gaining useful insight into de nature of
stability problems, rotor angle stability phenomena are characterized in two categories:

• Small-signal stability: is the ability of the power system to maintain synchronism under small
disturbances like variation in load and generation.
• Transient stability is the ability of the power system to maintain synchronism when subjected to
a severe transient disturbance like short-circuits of different types.
Energy consumption in El Salvador has had an increase of 220.6% since 1995, caused by the
industrial and commercial growing in the country and the increase in the population. The peak power
demand in 1995 was 591.7 MW compared with peak power demand in 2011 of 962 MW. This power
consumption increase required the construction of new power plants to satisfy the demand (SIGET,
2011).

Since 2007, Berlin Geothermal power plant has had an installed capacity increase of 46 MW with the
installation of two new generators. There are also new plans about the installation of two more
generators around 2015, with a total capacity of 35 MW. This growing will cause changes in power
flow and dynamics characteristic of the power system that have to be taken into account for the
development of geothermal energy in El Salvador.

A dynamic simulation model of Berlin geothermal power plant in El Salvador is built with
Matlab/Simulink with the objective of doing a dynamic study of the system taking into account the
future generators. This study let us to analyse the dynamic behaviour of the power plant with small
and
rbances in the power system.