For the bearingless permanent magnet synchronous motor (BPMSM), to improve the sinusoidal degree of air-gap magnetic field, and solve the problem of difficulty in solving the air-gap magnetic field, a ...

New low-pass filter (LPF) architectures based on differential difference operational amplifiers (DDOA) are studied in this paper. The feature of the proposed LPF is that when tuning the cut-off ...