This paper presents an isolated DC to single-phase AC converter using a matrix converter for HVDC (higher voltage direct current) power feeding system. The proposed converter comprises a full bridge inverter, a high frequency transformer and a matrix converter and does not use a bulky electrolytic capacitor. Then, in order to reduce a ripple component in a DC bus current caused by the single-phase load, this paper also proposes a power decoupling method. The power decoupling method employs a center-tapped transformer and a small LC buffer instead of additional switches, which aims to achieve high efficiency. Moreover, modulation methods of the full bridge inverter and the matrix converter, and a control strategy of the power decoupling are described. As an experimental result, the power decoupling method reduces the DC bus current ripple to 2/3. In addition, a validity of a parameter design method of the proposed control is confirmed in simulations.
This study presents a novel circuit topology for a single-phase inverter using an active power decoupling circuit operated in discontinuous current mode (DCM). In a conventional single-phase grid-tied inverter, bulky capacitors are used in a DC-link to absorb a power ripple with twice the grid frequency. However, electrolytic capacitors limit a converter's lifetime. In contrast, ceramic capacitors are used in the proposed circuit since the required capacitance is reduced. Furthermore, the active power decoupling circuit in DCM has no inductor inside by utilizing the current zero cross featured in DCM for power ripple compensation modes. An experimental verification using a 1-kW prototype shows a 90.2% current ripple reduction caused by the power ripple with twice the grid frequency. The efficiency exceeds 94% in the 20% region of the rated power to 1-kW through 96.0% of the 650 W maximum. According to a theoretical evaluation using a Pareto-front optimization assumed as a 3-kW system, the proposed circuit reaches the maximum power density at 20 kHz which is 115 % higher than that of the passive power decoupling method. The inductor volume in the proposed circuit is reduced by 30.4% compared to a conventional buck-type active power decoupling circuit.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.