In this article, a novel bidirectional dc-dc converter (BDC) consisting of an active switched-inductor (A-SL) cell, a zero current ripple cell and an auxiliary capacitor cell is proposed for the battery energy storage system. The proposed BDC integrates with the advantages of high voltage conversion ratio, low power switch voltage stresses, zero ripple current on the low voltage side (LVS), and constant potential difference between the grounds of LVS and high voltage side. Thanks to the use of synchronous rectification technology, the efficiency of the proposed BDC is increased. The operating principles, the characteristics analysis and the parameter design of the proposed BDC are given. In addition, to show the merits of the proposed BDC, a comparison study involves the proposed converter and other BDCs is demonstrated. Finally, some experimental results obtained using a 1000 W prototype are presented to valid the effectiveness of the proposed BDC. 96.43% and 96.67% maximum conversion efficiencies can be achieved in the step-up and step-down modes, respectively.

A decentralized improved I-V droop control strategy for battery-supercapacitor (SC) hybrid energy storage system (HESS) is proposed in this paper. The dynamic power-sharing between battery and SC is realized by replacing the constant droop coefficient in I-V droop control with virtual impedance, i.e. virtual inductance for battery side converter and virtual resistance for SC side converter. Besides, by injecting the virtual inductance in the battery side converter, negligible DC bus voltage deviation can be achieved without extra voltage compensator. Moreover, the state-of-charge (SoC) recovery is also considered to extend the service life of the HESS. Furthermore, in the proposed regulated power system, since the power allocation, DC bus stability and SoC recovery are decoupled from each other, the design of control parameter is simple. The corresponding design guideline is demonstrated in this paper. Finally, to verify the accuracy and feasibility of theoretical analyses, hardware in the loop simulations have been conducted

This paper presents a new soft switching high voltage gain interleaved dc-dc converter with a three-windings coupled inductor for a fuel cell vehicle. Two interleaved and intercoupled boost cells are connected by the input parallel and output series (IPOS) configuration, realizing low input current ripple and high voltage gain simultaneously. All power switches can operate under soft switching conditions by only adding a simple auxiliary circuit composed of one auxiliary inductor and one power switch. Besides, the auxiliary inductor is coupled with the main inductors, which results in a rapid zero convergence of the auxiliary current and a small conduction loss of the auxiliary circuit. The operating principle, steady state characteristic, comparison with other converters, and parameter design are analyzed in this paper. Finally, the main characteristics of the proposed converter are verified by a 1-kW laboratory prototype.

In this paper, a decentralized P-V ² droop-based energy management strategy for the hybrid energy storage systems (HESSs), including multiple batteries/supercapacitors (SCs), in the DC microgrid is proposed. By using the output voltage of the SC converter as the unified feedback voltage in each HESS, the impacts of non-negligible and mismatched line impedance on the power allocation performance and bus voltage tracking are eliminated. Compared with the I-V droop-based method, the adopted P-V ² droop technique improves the stability of the HESS, especially considering the constant power loads (CPLs). In addition, the state-of-charge (SoC) recovery is considered for the SCs to prolong the service life of the HESSs. Finally, the experiment and hardware-in-the-loop (HIL) simulations have been carried out for the studied system to verify the effectiveness of the proposed control strategy

The second-order ripple power of single-phase converter causes second-order ripple voltages on the DC bus. For eliminating second-order ripple components, passive power decoupling methods including DC bus electrolytic capacitors have some shortcomings, such as low power density and poor stability of converters. Thus, an active power decoupling method based on a single-phase converter is proposed in this paper. The control method, taking single-phase voltage source pulse width modulation (PWM) rectifier (single-phase VSR) as the basic converter and adopting a buck-boost power decoupling circuit, introduces second-order ripple of DC bus voltage into a power decoupling circuit. The ripple acts as compensation of the phase deviation between the command value and the actual value of the second-order ripple current. Therefore, estimation of the second-order ripple current is more accurate, the power decoupling circuit absorbs the second-order ripple power behind the H-bridge more completely, and the DC bus voltage ripple is effectively suppressed accordingly. Finally, experimental results of the single-phase VSR are given to verify the validity of the proposed method.

The features of low current ripple and high voltage gain make the interleaved multilevel boost converter (IMBC) a promising topology to link low-voltage and high-power energy sources and the dc bus of the microgrid (MG). Considering the modern dc MG is highly penetrated by the constant power loads that threaten the system stability, a large-signal stabilization scheme for the IMBC-based dc MG is proposed in this article. An adaptive sliding mode observer (ASMO) is developed to estimate both matched and mismatched disturbances and, further, improve the control performance. Since the knowledge of the bounds of the disturbances and their derivatives is not required in the ASMO, a wide range of disturbances can be estimated. In addition, a unified reduced-order state–space model of the IMBC is derived to facilitate the design of the proposed control law. Moreover, a novel phase current balancing compensator is designed to balance the input phase currents of the IMBC. Finally, simulation and experimental results are demonstrated to show the effectiveness of the proposed method.