A Fast and Accurate Inertia Identification Approach for Dual Three-Phase PMSM Drives

There is a contradictory relationship between the convergence speed and the steady-state accuracy of the conventional model reference adaptive system-based (MRAS-based) inertia identification method. To solve this issue, this paper proposes a fast and accurate inertia identification approach for dual three-phase permanent magnet synchronous machine (DTP-PMSM). The conventional MRAS-based inertia identification method for DTP-PMSM is given, and the detailed analysis points out that the selection of its gain coefficient requires a tradeoff between the convergence speed and the steady-state accuracy. An error-adaptive gain coefficient based on the integral increment of the mechanical angular speed error is proposed, which resolves the contradictory relationship between the convergence speed and the steady-state accuracy. Then the effects of switching coefficient, period of the error integral, and amplification coefficient on the inertia identification results are analyzed thoroughly, based on which the coefficient selection process of the proposed approach is provided. Furthermore, the block diagram of the DTP-PMSM drives with the proposed inertia identification is presented. Finally, the feasibility and effectiveness of the proposed approach are verified through a prototype DTP-PMSM experimental platform.