Auto-Optimized Maximum Torque Per Ampere Control of IPMSM Using Dual Control for Exploration and Exploitation

TL;DR

This work tackles copper-loss minimization in IPMSM by enhancing MTPA control with a dual control for exploration and exploitation (DCEE) framework. It reformulates the torque relation as a linear-in-parameters model and uses multiple forgetting-factor RLS estimators to identify the permanent magnet flux $ψ_f$ and the inductance gap $L_d-L_q$, guiding the MTPA operating point. The method jointly optimizes current trajectories and parameter estimation, yielding improved transient performance over traditional extremum-seeking approaches and demonstrating robustness to using observed torque. The approach promises better copper-loss management in IPMSM-driven applications, with planned experimental validation and handling of parameter variability.

Abstract

In this paper, a maximum torque per ampere (MTPA) control strategy for the interior permanent magnet synchronous motor (IPMSM) using dual control for exploration and exploitation (DCEE). In the proposed method, the permanent magnet flux and the difference between the $d$- and $q$-axis inductance are identified by multiple estimators using the recursive least square method. The initial values of the estimated parameters in different estimators are different. By using multiple estimators, exploration of the operational environment to reduce knowledge uncertainty can be realized. Compared to those MTPA control strategies based on the extremum-seeking method, the proposed method has better dynamic performance when speed or load varies. The effectiveness of the proposed method is verified by simulations.

Figures (7)

• Figure 1: Current Trajectory
• Figure 2: Block diagram of the IPMSM servo control system
• Figure 3: Block diagram of the MTPA control system using DCEE
• Figure 4: Block diagram of the DCEE controller
• Figure 5: Simulation results when using extremum seeking. (a) Ideal torque. (b) Observed torque.