Virtual capacitor based DBVC and active damping method for cascaded power converters stabilization control

It is known that the constant power load (CPL) property of load converter can degrade the stability of DC bus voltage of cascaded power converters system. An idea by combining virtual capacitor (VC) based active damping control (ADC) method with DC bus voltage conditioner (DBVC) technique for load converter is proposed in this paper. Through implementing common virtual capacitance volume requirement, the DC bus voltage can be stabilized with reduced DC bus capacitor, the impact from DC bus voltage fluctuation to the load converter output voltage can be reduced compared with the case by using ADC method only, and because the VC method shares part of the compensation, the power volume of DBVC can be decreased accordingly, this might result in higher power density and lower power loss potentially compared to the case with DBVC only. Simulation results are provided to demonstrate the validation of the proposed method.