Multiinput Direct DC–AC Converter With High-Frequency Link for Clean Power-Generation Systems

Abstract

This paper proposes a new topology for bidirectional multiinput direct dc-ac converter for clean-power-generation system, therefore, at the input port, a boost converter is used to meet the requirement of many distributed generation systems, such as photovoltaic, and fuel cell systems. The boost converter can increase the dc input voltage. This point results in a turn ratio reduction of high-frequency isolating link transformer. Furthermore, the boost inductor reduces the input current ripple, therefore, the saturation of the transformer can be avoided for higher output currents. The count of used devices has been reduced in the proposed converter. As a result, the cost, size, and the volume of the converter can be reduced. The reduced conversion steps increase the efficiency of the converter. The converter is analyzed step by step to show the principles of the operation in providing energy management based on duty-cycle variations. The system capability in different operation conditions has been simulated, and the simulation results have been compared with measurement results. Dynamic analysis and control design of the bidirectional dc-ac converter is presented based on nonlinear control by input-output feedback linearization.Index Terms-Clean power generation (CPG), dc-ac converter, distributed generation (DG) interface, high-frequency isolating link (HFIL), input-output feedback linearization (IOL), multiinput converter, steady-state analysis.

Overview of control, integration and energy management of microgrids

“…Multiple-port power converters are used to connect various power sources (DGs or energy storage elements) to the grid and load through a single converter structure with lower cost and compact size [9][10][11][12][13]. The schematic diagram of this multiple-port interfacing converter is shown in Fig.…”

“…This constraint is the main drawback of electrically-coupled multiple-port converters [13]. In magnetically-coupled topologies, the energy sources are coupled through magnetic coupling (mainly high frequency ac-link), which provide electrical isolation between the power ports [9,11]. In these topologies, because of the use of multi-winding transformers, DGs with different operating voltage levels can be connected to power ports.…”

High frequency inverter topologies integrated with the coupled inductor bridge arm

“…High frequency alternating current (HFAC) systems are widely applied for induction heating [1], aerospace [2], vehicles [3], microgrids [4] [5], power distribution systems [6]- [8], telecommunication [9], computer power supplies [9] and medium/high voltage gate driving systems [10] owing to their merits of simple transforming structure, low cost and low component count, and effective ground noise isolation [10].…”

New Single-Stage Single-Phase Three-Input DC-AC Boost Converter for Stand-Alone Hybrid PV/FC/UC Systems

“…It gives high boost gain and reduced switching losses due to soft-switching operation. In [24], an isolated DC-AC bidirectional multi-input converter has been controlled by the input-output feedback linearization method. An isolated three-port full-bridge topology has been proposed in [25] for hybrid FC/Battery system, which aims at feeding a small autonomous load.…”