Practical Approach to Digital Control System of Cooperative Active Power Filter Design

The paper considers a digital control system (DCS) of a cooperative active power filter (APF), developed on the basis of the STM32 microcontroller family. The features of DCS's work are analyzed. The results of physical modeling of the DCS channels are presented. It is shown that the resources of a general-purpose microcontroller are sufficient to solve a DCS objectives of cooperative APF. The restrictions on the order of the DCS's digital filter are considered. The order of the filter determined the frequency of the highest harmonic that can be resolved, on the other hand, the time it takes to calculate its output signal. The computation time determines both the physical feasibility of the filter, which is determined by its ratio with the PWM period, and the DCS error associated with the phase shift of the input and output signals of the filter. The designing a DCS of APF with taking into account these constraints are considered.