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This paper proposes a current-fed single-phase inverter without constant intermediate DC link. It eliminates electrolytic capacitor from the DC-link and introduces an intermediate pulsating DC bus. The proposed topology is modular with three full-bridges making it scalable for high-power applications. New pulsating-DC-modulation for back-end pulsating DC-link inverter and secondary modulation (SM) for front-end DC-to-pulsating DC converter is proposed. Soft-switching and device voltage clamping of both primary side and secondary side devices of front-end current-fed full-bridge converter is realized. A rotating partial hybrid pulsewidth modulation has been introduced. One leg of inverter is commutated at a low switching frequency, while the other leg is operated at a high switching frequency for partial period of a line frequency cycle. Thus, switching losses of the back-end inverter are considerably reduced. Rotating mechanism is used to equalize the switching losses of four switches of the inverter. This paper presents detailed operation and analysis of the topology with a proposed modulation scheme. Simulation and experimental results validate the effectiveness and accuracy of the proposed modulation scheme as well as soft-switching and performance of the converter. [ABSTRACT FROM PUBLISHER]

This paper presents a fuel cell (FC)–supercapacitor traction drive and its power control. The proposed solution allows increasing efficiency and performances of an FC-based powertrain by means of a dual cascaded voltage source inverter and a supercapacitor bank. An optimal control algorithm allows avoiding the fast transition of the FC output power under whatever operating condition. It is based on five operation modes, which are selected as a function of the actual traction power request. This way, both power peaks and slopes are controlled during vehicle accelerations. A supercapacitor charge stabilization strategy, which uses the same cascaded converter power circuit, is also proposed. Experimental implementation has been performed for validation. [ABSTRACT FROM PUBLISHER]