Adaptive AC Line Current Modulation for Active Power Conditioners

The objective of this paper is to propose an adaptive ac line current modulation (ACM) for the active power conditioner (APC). The proposed ACM is able to determine the appropriate input current to stabilize the dc-bus voltage as soon as an abrupt power change of the APC occurred. By adopting the proposed ACM, the dc-bus voltage fluctuation can be minimized so that the required dc-bus capacitance can be reduced. On the other hand, in order to regulate the voltage variation under different power changing scenarios, the regulating slope of the dc-bus voltage under different operation conditions are discussed. Mathematical equations for the proposed ACM are also derived thoroughly in this paper. Finally, experimental measurements obtained from a 5kVA prototype circuit are presented to verify the performances of the proposed adaptive ac line current modulation.