In order to obtain a high step-up voltage gain, high-efficiency converter, this paper proposed dual switches dc/dc converter with three-winding-coupled inductor and charge pump. The composed of structure, inductor, This combination facilitates realization gain low voltage/current stress on the power switches. Meanwhile, across diodes is diode reverse-recovery problem alleviated by leakage inductance inductor. Taking all these into consideration, efficiency can be high. illustrated operation...

Accurate state of charge (SOC) estimation is helpful for battery management systems to extend batteries’ lifespan and ensure the safety batteries. However, due pseudo-positive definiteness covariance matrix noise statistics error accumulation, SOC lithium-ion batteries usually inaccurate or even divergent using Kalman filters, such as unscented filter (UKF) square-root (SRUKF). To resolve this problem, an method based on dual-coefficient tracking improved developed. The composed (ISRUKF) a...

According to the requirement of fuel cell generation system, this paper presents a new single-stage and boost-voltage grid-connected inverter, as well signal modulation diagram in line cycle. In proposed one bridge legs is shared with boost converter. The inductor current designed discontinuous conduction mode, which can effectively decrease low-frequency ripple (LFCR) output cell. switching modes inverter are analyzed positive negative half cycles, respectively. LFCR analyzed, from design...

The output voltage of a traditional full-bridge inverter is lower than the input dc voltage. In applications when low, front-end step-up converter usually required, presenting two-stage power conversion. Dual boost (DBI) can realize single-stage conversion, which has advantages simple structure, less devices, and buck-boost ability. modulation strategy DBI makes all switches operate in high frequency sustain voltage/current stress, leads to heavy conduction switching loss. This paper...

A new voltage-fed isolated bidirectional dc/dc converter (BDC) based on immittance network (IMN) is proposed. The operations of the BDC are analyzed in buck mode and boost mode, respectively. Compared to conventional dual active bridges (DAB) BDC, proposed can obtain unity power factor at both ac terminals high voltage side (HVS) bridge low (LVS) bridge. working resulted from characteristic IMN it helpful improve converter's efficiency. quantitative relationship deduced. optimal design...

This paper presents a novel combined-synchronous-rectifier high-frequency-link (CSR-HFL) inverter. Three types of conventional HFL inverters are analyzed and their performance is summarized. According to one the inverters, i.e., cycloconverter-type (CHFL) inverter, combined rectifier topology deduced. To prevent shorted circuit, two additional switches used in new topology. The operation mode CSR-HFL inverter mathematical relationships given. difference correlation, advantages disadvantages,...

To support the development of high-frequency ac microgrids in terms compact design, high-voltage gain and low total harmonic distortion (THD), a buck-boost dual-leg-integrated step-up inverter is proposed this paper. The formed by integrating converter into conventional single-phase full-bridge sharing upper switch body diode lower both bridge-legs. Consequently, component count significantly reduced over counterparts. In addition, to address drawbacks hybrid modulation methods adopted...

High step-up dc/dc converters are widely used in many industrial applications, especially green energy power generation and uninterruptible systems. The circuit configuration of a dual-switch high converter is very simple the can achieve voltage gain by operating parallel charge series discharge. However, this has strict requirement parameter's consistency or it will lead to stress switches due parasitic capacitance inductor's resonance. Although passive lossless clamp be adopted realize...

For grid-connected inverter, an LCL-type filter is widely used to suppress switching harmonics, and the capacitor current feedback LCL resonance. In published literatures, relation among parameters, resonance damping was discussed; however, their with low-order distortion not seriously considered. Considering that main objective of using fulfill quality standard, optimized design for harmonic suppression deeply discussed in this paper. It demonstrated grid-induced harmonics closely related...

This study proposes a pre-stage flexible DC–DC converter (PFDDC) for PV micro-inverter. The PFDDC can be operated in different modes automatically, i.e. the improved full-bridge mode when output power is higher than threshold value or two-transistor forward lower value. operational principles of are analysed. design key parameters, such as turns ratio transformer and buffering inductance, presented at first. Then loss analysis used to determine power, based on which switch control strategy...

A simple current-fed full-bridge converter (CF-FBC) is proposed as a prestage for photovoltaic (PV) microinverter after comparing it with the existing topologies. modulation strategy based on CF-FBC two control freedoms presented in this article. One freedom boost duty cycle, which controls voltage of PV panel. The power cycle other freedom, low-voltage side. operational principle analyzed. composing three closed loops proposed. regulator parameters are designed small signals model...

In order to realize more optimized current stress of switches and soft switching in a wider range, this paper proposes unified high-frequency AC buck/boost (UHFBB) control strategy for dual active-bridge bidirectional converter (DAB-BDC). The evolution UHFBB theory is derived from buck boost DC/DC operated DCM. A multi-variable solving method proposed achieve the duty ratios driven signals modulation. calculation flow chart given, which basis closed-loop control. analysis verified by...

This article proposes a double-line-frequency current ripple (DLFCR) reduction strategy for the photovoltaic microinverter. A power predictive scheme is established according to output mathematical model of prestage full-bridge dc-dc converter (PFDDC), which basis proposed DLFCR strategy. The control effect analyzed with considering parameter estimation error, and analysis results show that has good dynamic performance robust performance. small-signal PFDDC been design voltage-loop...

The energy flow is step-by-step among Lithium-ion-battery when an equalizer based on the buck-boost converter adopted, resulting in a long transmission path and low equalization efficiency. First, dual active half-bridge studied this paper. Second, key parameters of between cells same group different groups are analyzed. Third, phase shift control strategy put forward according to analysis results. with proposed not only can realize but also work at high frequency. Therefore, transformer be...

In the distributed AC supply system without control interconnection, parameters unbalance because of nonuniformity between unit inverters is inevitable. The supplier difficult to share power properly. Based on digital inverter with instantaneous capacitor-current feedback, affection sharing filter inductance and equivalent line impedance are analyzed. Theory simulation prove that active can be shared averagely, phase-shift units changes along load variation, reactive cannot properly when...

The elimination of leakage current is first importance for transformerless grid-tied photovoltaic (PV) inverters. A unified analytical model single phase inverters, which unifies topologies both transformer and transformerless, presented in this paper. It suitable the analysis mechanism all bridge topologies, are systematically analyzed categorized. After that, H5, Heric a H6-type configuration optimized. these optimized inverters can be better eliminated by changing topology substituting...

Unity power factor can be obtained if phase lock loop (PLL) with droop characteristic is used for grid-connected inverter. However, the non-detection zones (NDZ) of PLL too wide to satisfy some standard. In order decrease NDZ, an improved proposed, which introduces disturbance into control strategy. The operating principle analyzed and selecting rule parameter given. anti-islanding capacity NDZ significant decreased. Moreover, biggest advantage that quality grid current not affected by...