The necessity of usage of electrical complexes for power quality improvement on the basis of active and passive filters is proved in the paper. The main tasks, which must be solved by these complexes in the area of power quality improvement, are indicated. The mathematical models and relationships of the main topologies of these complexes are developed and proved. The computer simulation models have been developed on the basis of the mentioned mathematical models and relationships. The results, which have been obtained during simulation, showed the satisfactory level of power quality improvement. Also the obtained results should be considered as the theoretical basis for the structural and parametrical synthesis of the electrical complexes for power quality improvement on the basis of active and passive filters in centralized, distributed and combined power supply systems.