Field-Weakening Control Method on Induction Motor of Low-Speed Vehicle Using Look-Up Tables

Abstract

This paper presents a method for field-weakening control on the induction motor of a low-speed vehicle (LSV) using look-up tables (LUTs). In LSV induction motors that are characterized by low voltage and high current, field-weakening control involves complex calculations that consider stator resistance. This approach has limitations in accurately reflecting motor parameter variations, which impacts its ability to achieve the maximum torque. Therefore, we utilized LUTs to achieve the maximum torque by considering motor parameter changes. In field-weakening region I, a LUT of the d-axis feedforward current was created based on speed and the q-axis reference current. In addition, the d-axis feedback current was calculated to compensate for the parameter discrepancies. In field-weakening region II, a LUT of the q-axis current limit was created based on speed and the d-axis reference current. The design with the proposed method is robust against parameter changes, ensuring the maximum torque per ampere throughout the entire field-weakening region. The experimental results confirm the validity of the proposed method.