Comparative Study of PMSM Drive Systems Based on Current Control and Direct Torque Control in Flux-Weakening Control Region

This paper examines the control performance of permanent-magnet synchronous motor drive systems based on current control and direct torque control (DTC) when flux-weakening control is applied. The control law in the
M
-
T
frame, which is used in the DTC, requires only armature resistance, whereas the control law in the
d
-
q
frame, which is used in current control, requires many motor parameters for flux-weakening control. The experimental results clarify the influence of parameter variation on the control characteristics of flux weakening and torque limiting. The DTC-based motor drive system combined with the control laws in the
M
-
T
frame has several advantages, including insensitivity to parameter variation, simplicity of calculation, and stable control.