Design of control strategy for active filter with 5-level CHB topology in delta connection

Active filters are necessary devices in the infrastructure of power grid. The active filters improve the quality of electrical energy. This paper describes design of control strategy for active filter, which uses three delta connected 5-level CHB converters. The proposed control strategy is based on finite control set model predictive control. The mathematical model of active filter is derived. The analysis of power grid is based on PQ theory, which calculates instantaneous active and reactive power. The reference values of compensation currents can be set due to PQ theory. The proposed control strategy is verified by simulations where dynamic changes in power grid occurs.