Comparison of frequency domain and time domain model of a distributed power supplying system with active power filters (APFs)

The growing complexity of modern power systems has been forcing the use of advanced methods of computer modeling and simulation. In case of medium to large scale systems, or when a great number of repeated simulations are performed, the frequency domain model is preferred. The frequency domain approach reduces the required computational effort (algebraic equations are used instead of differential equations), which is particularly important in tasks such as size optimization and the allocation of active power filters (APFs). The main disadvantage of the presented frequency domain method is a significant simplification of the system's model. This work presents a comparison of frequency domain and time domain models of the same distributed power system. Both types of models are described along with their implementation. Simulation results for an exemplary power system with and without the APFs are included, as well as a comparison of the computational effort. The research revealed that the frequency domain model is accurate enough for many applications and definitely much more efficient in comparison with the time domain approach.