Torque control patching and anti-windup and bumpless transfer conditioning of current regulators for high-speed PMSM systems

In this paper, the authors consider important issues related to DC bus utilization in high speed permanent magnet synchronous machine (PMSM) motion control applications. The fast response torque control scheme constitutes a current regulator patch or temporary substitution for the sake of better DC bus utilization. Control substitution and DC bus voltage limiting both result in temporary discrepancy between current controller output and the actual voltage vector applied to the motor, and could lead to system transient performance or stability problems as shown in this paper. An anti-windup and bumpless transfer technique is applied to condition the current regulator to solve these problems. Experiments and simulations are conducted to verify the performance improvement. It is shown that application of this current regulator conditioning method solves the problem of bumpless transfer from these torque control patches back to normal regulator and also the system stability problem near the DC bus limit.