Passivity-based Controller Design and Stable Control Region Analysis of the Cascaded DSTATCOM

This paper proposes a novel passivity-based control scheme for the cascaded H-bridge (CHB) DSTATCOM. The mathematical model of the CHB-DSTATCOM is devised by partitioning the CHB-DSTATCOM into n-block subsystems, and the control algorithm is devised using the adaptive passivity controller. The power balancing mechanism and the stable control region are analyzed using the phasorial diagram representation. The Electromagnetic Transient Program (EMTP) is used for digital simulation, and the Transient Analysis of Control System (TACS) and the MODELS language of the EMTP are utilized for control algorithm implementation. The simulation results of the CHB-DSTATCOM under abrupt dc-link voltage variations are provided with comparative evaluations. The devised control scheme of the CHB-DSTATCOM is validated by the simulation and experimental results from the prototype system.