Extended Digital Programmable Low-Pass Filter for Direct Noise Filtering of Three-Phase Variables in Low-Cost AC Drives

This paper proposes an extended structure of a programmable low-pass filter (PLPF) for direct filtering three-phase variables in automotive AC drives. The PLPF adjusts its cut-off frequency according to the synchronous motors. Moreover, it compensates gain attenuation and phase delay fundamental component signal. conventional can only be applied stationary reference frame. In order obtain filtered variables, inverse frame transformation is required. However, structure, which includes transformations, directly remove noise earlier stage before transformation. more useful making signal flows clear intuitive when organizing algorithm that requires variables. moderate computational load corresponding with because formula simplified by use Kirchhoff’s law. reduction execution time critical implementing based on low-cost microcontrollers. Using case studies, dead-time compensations open-phase fault detection drives show effectiveness PLPF.