Enhanced-performance control of a DC-DC Z-Source converter

This work presents both an adapted topology and a high-performance control strategy for a DC-DC Z-Source converter used as the excitation-driver of a Flywheel Energy Storage System (FESS). The topology modifies the switches configuration of the Z-Source converter to allow the application of the shoot-through state by a unique concentrated pulse. This fact improves its hardware implementation because this pulse could be quite narrow for some operation states of the converter. The developed control strategy makes use of the standard duty cycle (D₁) and the shoot-through duty cycle (D_st) as independent manipulated inputs of the plant to perform a reference tracking problem. The proposed non-linear controller utilized is a combination of a multi-loop law with partial decoupling plus feed-forward cancellations. Simulation results show the potential of the controller for the tracking of typical waveforms with marked frequency separation components. Experiments are under progress.