Damping Controller Integrated into Output Current Control Loop and Design for Multiple Servo Drive Systems Connected to Common DC-Bus Line

This paper proposes a damping control to stabilize multiple servo drive systems connected to a common DC-bus line. The DC-bus servo drive system has a system instability problem due to interference between a constant power load and bus impedance. The damping controller integrated into the output current control loop evaluates the influence of the damping controller on the current response compared with the second-order standard form. The parameters of the damping controller for the multiple units are designed by the impedance method. The experimental results mention that the output current response almost agrees with that of the simulation within a 1% error. Furthermore, the stable operation range with the proposed damping control is expanded by 28% of the motor-rated power.