CONTROL PERFORMANCES OF THE BI-BUCK INTERFACE USED FOR INVERTER CURRENT RIPPLE COMPENSATION

The control of the bi-buck structure used as active power interface between fuel cells stack and inverter system is further analysed in this paper. The objective of this analysis is to determine the control performances of the proposed bi-buck power interface [1] concerning the low frequency fuel cell current ripple compensation. Therefore two feedback control loops are used: a DC output voltage control for buck converter which operates as controlled DC voltage source, and a current ripple active compensation loop for buck converter operates controlled AC current source. The operation of the nonlinear loops gain is shown by simulation. Matlab-Simulink models and some designing aspects are presented, too.