Improved control strategy of TFAPF in active distribution networks

In order to solve the deterioration of power quality caused by power electronic devices in active distribution networks, it is necessary to improve the three‐phase four‐wire active power filters (TFAPF) control strategy. This study adopts the non‐harmonic detection and proposes an improved control strategy of TFAPF based on the multi‐model principle. Firstly, the mathematical model of TFAPF in the stationary coordinate system is established by replacing the network side current and the DC bus voltage directly as the state variables. Secondly, TFAPF in active distribution networks requires the power fluctuation and fast dynamic response, the proposed control strategy of TFAPF in the stationary coordinate system is applied, namely proportional integral, vector resonant and repetitive control composite controller as the current loop controller of TFAPF with a fast dynamic response, high accuracy and small amount of calculation, provide guarantee for the power quality in active distribution networks. Finally, the feasibility of the proposed control strategy is verified by simulation.