PROJECT TITLE:

An Electrolytic-Capacitor-Free Single-Phase High-Power Fuel Cell Converter with Direct Double-Frequency Ripple Current Control - 2015

ABSTRACT:

This paper proposes a right away double-frequency ripple current management in a single-part high-power fuel cell converter which will achieve low-frequency ripple-free input current without using large electrolytic capacitors. To eliminate the double-frequency ripple current disturbance introduced by the single-phase inverter load, a proportional-resonant controller is developed to realize an extra high control gain at designed resonant frequency. This high gain can be viewed as the virtual high impedance for blocking the double-frequency ripple energy propagation from inverter load to fuel cell stack. More significantly, the proposed Control System will understand the employment of all capacitive ripple energy sources within the system by regulating all the capacitors to own massive voltage swing. In addition, this voltage swing is synchronized to keep real-time balancing of the transformer primary- and secondary-side voltages. Consequently, the zero-voltage-switching operation for all switching devices within the dc-dc stage will be guaranteed. The controller style tips are derived primarily based on the system small-signal model. The experimental results are presented to validate the theoretical analysis and proposed technology.