Design of Full-Order State Observer for Motor Drive Systems Based on the Fixed Gain Filter

Abstract

This paper mainly discusses about the full-order state observation technology for the permanent magnet synchronous motor (PMSM) drive system. First, the concept of the Kalman filter (KF) is synthesized to design a novel fixed gain filter (FGF) with an optimal fixed feedback gain matrix, which ensures a fast and accurate observation for position, speed, acceleration, and load torque. To alleviate the heavy computational load of the KF, second, the feedback gain is configured as a single tunable parameter only, which can be calculated offline. The regulation parameter is refined within a certain small range by fulfilling the system stability criterion. Furthermore, the system dynamic performance indexes, such as noise smoothing capability and bandwidth, are both analyzed to deduce the expected exact value of the regulation parameter. The proposed FGF can provide an accurate observation equivalent to the conventional KF, while the proposed FGF provides a faster tracking performance, an easier parameter tuning mechanism, and a lower program complexity. The performance of the FGF is verified by simulations and experiments in all cases.

Keywords

• Permanent magnet synchronous motor (PMSM)
• fixed gain filter (FGF)
• motor drive
• state estimation
• load torque observation