Research on novel high frequency signal extraction method based on Extended Kalman Filter theory

Based on simplified Extended Kalman Filter (EKF), a novel signal extraction method based on FPGA was presented, which can not only extract rotor position information but also filter fundamental frequency control current. Compared with traditional IIR and FIR filter, the novel EKF, adopting iterative algorithm, has faster filter speed and better filter performance. It can eliminate low-pass filter in control feedback loop. So the dynamic performance and stability of the system is enhanced and the design of system controller is simplified. At the same time, since there is no high frequency signal component in control circuit, the controller affection to high frequency position estimation is decreased. The design of position estimator is unaffected by control regulator and simplified. Finally, Simulation and experiment test was adopted to verify this method.