Adaptive Flux Direct Torque Control for Permanent Magnet Synchronous Motor

In traditional direct torque control of permanent magnet synchronous motors, the flux reference is typically set to a constant value. However, the optimal flux reference varies depending on motor parameters and operating conditions, leading to potential inefficiencies. To address this issue, this paper proposes a direct torque control strategy with adaptive flux, enabling dynamic adjustment of the flux reference based on operating conditions. This approach reduces the stator current magnitude and improves motor efficiency. The proposed strategy introduces an adaptive flux observer based on speed, flux, and torque errors to achieve dynamic flux adjustment. The control structure is simple and enhances system robustness. Simulation results demonstrate that, compared to conventional DTC with a constant flux reference, the proposed strategy automatically adjusts the flux reference to its optimal value under non-ideal conditions. It also adapts the flux reference to varying operating conditions, significantly reducing current magnitude and improving motor efficiency.