In applications where the high voltage gain is required, such as photovoltaic grid-connected system, fuel-cell and high-intensity discharge lamps for automobile, step-up dc-dc converters have been introduced to boost low a bus voltage. The of traditional converter limited, considering issues system efficiency current ripple. This paper proposes class hybrid switched-inductor (H-SLCs) conversion. First, topological derivation H-SLCs deduced by combining passive active unit; second, this...

This paper proposes an improved Z-source inverter topology. Compared to the traditional inverter, it can reduce capacitor voltage stress significantly perform same boost, and has inherent limitation inrush current at startup. The control strategy of proposed is exactly as one, so all existing be used directly. A soft-start also suppress surge resonance capacitors inductors. operation principle topology comparison with are analyzed in detail. Simulation experimental results given demonstrate...

The voltage gain of traditional boost converter is limited due to the high current ripple, stress across active switch and diode, low efficiency associated with large duty ratio operation. High required in applications, such as renewable energy power systems input voltage. A step-up active-network switched-capacitor technique proposed this paper. can achieve without extremely ratio. In addition, switches output diodes low. Therefore, components be adopted reduce conduction loss cost....

High step-up voltage gain dc/dc converters are widely used in renewable energy power generation, uninterruptible system, etc. In order to avoid the influence of leakage inductor coupled inductors based converters, switched-inductor boost converter (SL-boost), switched-capacitor (SC-boost) and active-network (ANC) have been developed. With transition series parallel connection capacitors, high conversion ratio can be achieved. This paper discusses characteristics switched cell; makes some...

This paper proposes the pulsewidth modulation (PWM) strategy of Z-source inverters (ZSIs) with minimum inductor current ripple. In existing PWM single-phase shoot-through, shoot-through time interval is divided into six equal parts, therefore three phase legs bear interval. this manner, allotment and arrangement state easy to realize, but ripple not optimized. causes use relatively large inductors. proposed strategy, intervals are calculated rearranged according active zero achieve across...

A new family of Z-source ac-ac converters with buck-boost ability are proposed, including four switches single-phase structure and six three-phase structure. New commutation strategies for these proposed safe can be achieved without snubber circuit. The easily to realize by sampling only voltage signals, two always turned on, so switching loss reduced. Analysis based on state-space averaging reveals the relationship between inductor current filter as well ratio. design considerations...

The voltage range of a renewable energy source, such as the photovoltaic cell, is influenced by environment, light, temperature, and so on. power conditioning system should adapt to wide input have buck-boost ability. Based on structure “ac/ac unit,” this paper presents novel active inverter (ABI) topology suitable for wide-range input, which can realize conversion in quasi-single-stage inverter. ac/ac unit composed switches utilized perform boost without introducing additional passive...

High step-up dc–dc converters are widely used in new energy applications such as photovoltaic cell, fuel dc microgrid, etc. Active switched-inductor (ASL) converter has simple operation and low stress on switches. To further increase the voltage gain, some SC (switched-capacitor)/ASL have been proposed recently. However, these SC/ASL oscillation switches, which leads to switches is higher than theoretical value. In this article, a novel high proposed. Compared with other converters, lower...

This paper proposes a novel single-phase Z-source inverter topology with input and output sharing the same ground. It is simple in structure only utilizes two switches while keeping voltage transfer ratio as for full-bridge inverter. One-cycle control adopted. Highly efficient constant-frequency can be achieved without an accurate model of converter. The unique feature proposed verified by operating principle, simulation experimental results. used distributed power systems where dual...

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...

Carrier-based discontinuous pulsewidth modulation (PWM) is widely used in three-level ac/dc converters due to its features of higher efficiency and simpler implementation. However, the problems switching losses, current distortion around zero-crossing points, neutral-point (NP) voltage fluctuation are mutually coupled for Vienna rectifier. Therefore, this article proposes a modified carrier-based (MCB-DPWM) scheme rectifier with improved zero-sequence injection. The clamping range mode that...

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...

High step-up voltage gain dc-dc converters are widely applied in fuel cell stacks, photovoltaic arrays, battery sources, and high intensity discharge lamps power systems. Active-network with coupled inductors (CL-ANC) derived from switched inductor active-network (SL-ANC). The proposed converter contains two which can be integrated into one magnetic core switches. provide a relatively conversion ratio small duty cycle; the current stress of switches low is helpful to reduce losses. This...

Under the unbalanced condition of grid voltages, second-order harmonic voltage ripple will <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">appear on</b> DC bus three-phase PWM rectifier due to existence negative sequence voltages. In addition, total distortion (THD) currents increase correspondingly. this paper, coupling mechanism between and is revealed. Based on situation above, a current suppression method proposed. Compared with existing...

A high step-up integrated coupled inductor-capacitor DC-DC converter for renewable energy applications has been proposed in this paper. Because of relative low output voltage systems, a is necessary. In paper, new configuration given by integrating to get the desire gain. The gain dramatically boosted up using inductor charge capacitor and across switch are clamped inherently. possesses only six components, which makes it uncomplicated more efficient. derivation steady state operation's...

A photoanode material ZnO nanoflower (ZNFs) for efficient dye-sensitized solar cell (DSSC) was prepared. This unique structure can significantly increase the specific surface area and amount of light absorption, leading to a higher short-circuit current density. Furthermore, ZNFs resulted in closer spacing between nanorods more direct conduction paths electrons, open-circuit voltage. The overall promising power conversion efficiency 5.96% obtained with photoanodes 8.5 μm thickness. work...

Affected by the equivalent series resistance (ESR) of devices in circuit, voltage-conversion ratio traditional boost converter is limited. Various topologies have been developed to provide a high step-up voltage gain. An inherent gain can be achieved dual-switch with advantages low and current stress on switches. However, this has strict requirement parameters' consistency. This paper discusses steady-state operation principle detail under condition that parameters are inconsistent then...

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,...

A model for the online estimation of junction temperature based on gate pre-threshold voltage in high-power insulated-gate bipolar transistors (IGBTs) was proposed. First, turn-on behavior and dependence gate-emitter during delay period were studied. It revealed that waveform exhibits a point inflection after which between emitter increases significantly; at this point, relationship changes from positive correlation to negative correlation. Meanwhile, analyses basis semiconductor physics is...