Constant power loads system control scheme based on the virtual damping compensation

The motor loads, existing in many industrial fields, behave as constant power loads (CPLs) with negative incremental impendence which may destabilize the system when tightly regulated. In this paper, the stability of BUCK converter with constant power load (CPL) is studied. The model of the motor driving system based pre-BUCK converter was established. The mechanism of the stability impact of the system was analyzed. A new control scheme of neutralizing the negative impedance degenerating the bus voltage based virtual damping compensation was proposed, and the process of compensating coefficient design was given. The simulation and experimental results demonstrate that the proposed method improves the stability of the system with constant power loads.