Computer aided design of static reactive compensation for high voltage power systems.
This thesis describes the development of a detailed set
of step-by-step SVC system design procedures which allow
manufacturers and operators to plan and develop optimum SVC
systems for a given a.c. power transmission system. The
validity of a typical svc system designed using the
suggested procedures is investigated. The internationally
recognised software package EMTP has been used as the
primary Research tool, and principal features of this
software, including those observed in the Research study
also forms part of the discussion in the thesis.
Previous conventional approaches to SVC simUlation have
been restricted to simplified system models, and have only
provided partial solutions to the design problem. In
contrast, a detailed representation of three phase SVC
systems using a time-domain approach is used in this
research study in order to formulate a comprehensive design
methodology. The SVC considered is for high voltage
transmission applications, and is the TSC-TCR-FC type.
A new optimisation program termed "OPTI-SVC" has also
been developed to assist the SVC system design process. The
system compensation limits must first be derived, and then
for given equipment costs and system harmonic constraints,
the program evaluates the optimum arrangement of the SVC
primary system. Although certain simplifying assumptions are
made and only those factors that can be taken into account
analytically are considered, the program uses a worst case
design philosophy in order to ensure acceptable performanceIn particular, Cost of the the program can minimise either the total svc system or the total harmonic voltage produced in the transmission system. In order to derive optimum control system settings, in particular for the SVC regulator, a structured trial and error approach has been developed. wi th the aid of the Astrom relay tuning technique, a good first estimation on
optimum regulator settings for a given a.c. system condition
can be obtained. The results are then systematically trimmed
until a satisfactory system response is achieved.
A three phase SVC system has been designed using the
suggested approaches and applied to a generator fed
transmission system. Realistic system data has been supplied
by NEI Reyrolle Technology Limited. Simulated performance
tests carried out demonstrate the correct functioning of the
svc system against general accepted criteria, and hence the
validity of the design procedure is established.
As a primary research tool, the software EMTP has been
proved to be very versatile although not user-friendly.
Significant observations regarding the use of EMTP that are
necessary to assist general users of the software package,
are also revealed in the research study.