  The complexity and cost of building and running high-power electrical systems
make the use of simulations unavoidable. The simulations available today
provide great understanding about how systems really operate. This paper helps
the reader to gain an insight into simulation in the field of power converters
for particle accelerators. Starting with the definition and basic principles of
simulation, two simulation types, as well as their leading tools, are
presented: analog and numerical simulations. Some practical applications of
each simulation type are also considered. The final conclusion then summarizes
the main important items to keep in mind before opting for a simulation tool or
before performing a simulation.
