Interleaved Buck-Boost Converter with a Wide Conversion Ratio

This paper gives an intelligent MPPT controller based boost PFC converter topology for AC to DC conversion in the wind energy system. The single stage boost PFC circuit topology comprises of bridge rectifier plus boost converter, which is employed as AC to DC converter with wide conversion ratio, continuous input current, and low input current ripple. It can be widely used for AC to DC conversion with high efficiency and improved power factor. And a grid side converter is engaged for DC to AC conversion in the grid-connected mode, which includes the DC-link voltage control and grid side power control of the proposed system. In this paper, RBFN controller based single-stage PFC converter is designed for the grid-tied wind energy conversion system to supply the load demand of 1kW active power and 900VAr reactive power. The result analysis of both off-grid and grid-tied configurations is validated in MATLAB-Simulink.

This paper proposes novel bidirectional DC-DC converter that has the advantages of high voltage gain, low conduction losses and low input current ripple. Two paralleled current-fed full bridges are located in the low voltage side (LVS), sharing one voltage-fed full bride in high voltage side (HVS). A quadruple phase-shift control strategy is proposed to reduce input current ripple and conduction loss. The phase shift between the full-bridges of LVS is employed to greatly reduce current ripple and the auxiliary inductors are used to help the lag bridge extend the zero-voltage-switch (ZVS) range. Finally, an 800W simulation prototype is built to verify the proposed converter, the accordance between the analysis and simulation results testify the advantages.

In this paper, a novel nonisolated interleaved high step-up DC-DC converter is proposed based on the coupled inductor and voltage multiplier cell (VMC) methods. Due to the interleaved structure, its input current ripple is low. The low input current ripple and also high power efficiency make the proposed converter suitable for renewable energy applications like photovoltaic (PV) and fuel cell (FC) power generation systems. The windings of the coupled inductors are combined with VMCs to further increase the output voltage with a low power switch’s duty cycle. This combination also leads to obtaining a flexible voltage gain that can be adjusted by coupled inductors’ turns ratio and power switches’ duty cycle. The voltage peaks over semiconductors are much lower than the output voltage. Therefore, low-rated semiconductors can be used for the implementation of the proposed converter, which can reduce the cost and volume. Generally, high voltage gain, low voltage, current stress of power switches, low input current ripple, high efficiency, common ground between the input and output ports, and a low number of elements are the main benefits of the suggested structure. The operation principle, steady-state analysis, and comparison with other converters are presented to show the advantages of the suggested converter. Also, a prototype is built, and the experimental results are presented to prove the theoretical analysis. This prototype is implemented with 200 W rated power, 25 V∼400 V voltage conversion, and 50 kHz switching frequency. Additionally, the efficiency is measured at 95.3% at the rated power.

This work has adopted the concept of asymmetric inductor magnetization to develop a new quadratic converter with the advantages like a wide range quadratic voltage gain and low source current ripple. In addition, the proposed high quadratic converter has achieved reduced voltage stress due to the presence of switched capacitor cell at the output side. Initially, the operation of the converter and steady-state analysis, including efficiency calculations, are explained. In addition, the design and selection of converter components are presented along with a small-signal analysis. Further, a comprehensive comparison with recent high quadratic gain converters is presented. The comparison is made with regard to the total component count, voltage conversion ratio, effectiveness index, electric stress, current ripple, switching device power (SDP) rating, and input current ripple factor. Furthermore, the 150 W laboratory prototype is used to verify the performance of the proposed converter in terms of operation, dynamic response, and efficiency, and the corresponding experimental findings are reported. The wide range voltage gain, low current ripple, and low electric stress features of the proposed converter highlight its superiority in fuel cell electric vehicle applications.

Alternative energy systems (AES) are becoming popular for small scale power generation. Designing the converters which transform the DC power into AC is the main development area of AES. Conventional single-phase voltage source inverter (VSI) uses buck topology which gives lower average output voltage than the input DC voltage. However, where the output voltage requirement is larger than the input DC voltage, such as uninterruptible power supply, fuel cell (FC) and photovoltaic systems, boost inverters are used. The boost inverter applied in this study consists of two boost DC-DC converters, which provides sinusoidal AC voltage output. The key drawback of the inverter lies in its control structure. In this paper, a dual loop control method is applied to ensure pure sinusoidal output voltage with fast dynamic response and low input current ripple. The input voltage of the inverter is assumed to be stable at 48 V considering commercially available FC voltage and the output voltage is regulated at 110 Vrms. In this article, the operating principle, mathematical modelling, analysis and control strategy of the boost inverter is presented. The proposed control strategy is verified with simulation using MATLAB/Simulink®. Simulation results show that the output voltage is 110 Vrms pure sinusoidal and the input current has low ripples.

A soft-switching boost half-bridge converter with high voltage gain and low input current ripple is proposed in this paper. In the proposed converter, a coupled inductor is used at the boost converter stage to reduce the input current ripple. The half-bridge converter stage provides soft-switching operation and high voltage gain. Also, the reverse-recovery problem of output diodes is significantly alleviated by utilizing the leakage inductance of the transformer. Due to the soft-switching operation of all switching devices, the switching loss is significantly reduced and the high efficiency is obtained. The feasibility and performance of the proposed converter were verified on an experimental prototype

This paper deals with a new single-stage high boost quasi-Z-source inverter based on the active switched Z-impedance network. The proposed inverter provides higher voltage boost factor, draws continuous input current, and shares the same ground between the input source and the bridge inverter. Compared with the traditional enhanced boost (quasi-)Z-source inverters (EB-ZSI/EB-qZSI), for two less inductors, one less capacitor, and one additional active switch used at the impedance network, the output voltage boost factor of the proposed inverter is twice as much as the EB-ZSI and EB-qZSI, which implies that it can use a very higher modulation index to provide improved quality output waveforms. Besides, for obtaining the same dc-ac output voltage gain, the proposed method has lower active switching voltage stress, lower passive component voltage ratings, and lower shoot-through current stress with lower input current ripple. The operation theory analysis, power loss calculation, simulation results, and performance comparison with other high boost impedance source inverters are presented. To verify the operating theory of the proposed inverter, a laboratory prototype based on the TMS320F28335 DSP was constructed and tested with 60 V dc input and ac 110 Vrms phase output. Finally, both simulations and the experimental results confirmed that the proposed inverter has high boost voltage inversion capability.

Due to power time-varying characteristic of a single phase photovoltaic (PV) grid-connected inverter in grid side, its front-end dc/dc converter tends to draw a large ac ripple current with double grid frequency, which would decrease maxim power point tracking performance of PV side. A novel method is proposed for the low frequency input current ripple analysis of a boost converter in a non-isolated single phase PV inverter, based on back current gain A i (s) (input current to output current) model. Mathematical models with different control schemes are built and derived, which are verified in SABER environment. It is indicated and proved that average current mode control strategy is more effective than voltage mode control and open loop control methods. Design principles are also presented. Simulation and experimental results are provided for model verification. Bandwidth limitation is also discussed and improved with proposed PR controller with A i (s) model.

Small Signal Modeling of a DC-DC Type Double Boost Converter Integrated With SEPIC Converter Using State Space Averaging Approach

A zero input current ripple dc-dc converter is proposed which can be applied to two-stage system. A smaller capacitor of the auxiliary circuit that is introduced on the basis of flyback topology is responsible for dealing with the output power pulsation. Dual voltage loops are employed in the control system in order to keep both intermediate dc bus voltage and the voltage across the auxiliary capacitor stable. Indirect current control is adopted without current sampling. The low frequency input current ripple can be eliminated while the function of voltage conversion is achieved. In this paper, the operation principle of the circuit is analyzed in details. Besides, key design considerations and control strategy are also given. Finally, experimental results from a 75W prototype are presented to verify the advantages of the proposed converter.

In this paper, a novel non-isolated interleaved DC/DC boost converter is presented in which coupled inductors and a passive clamp circuit are employed. ZCS turn-on condition for main switches is provided, and the stored energy in leakage inductance is recycled by means of a passive clamp circuit. Therefore, the voltage stress across switches is reduced resulting in circuit efficiency improvement. Due to interleaved structure and cross-coupled inductors, the input current ripple is reduced and the input current is continuous. To achieve ZCS turn-on condition, the intrinsic leakage inductance of the coupled inductors is used which leads to improving the power density and reducing the switching losses. In order to confirm the theoretical analysis, a prototype with 30 V input voltage, 300 V output voltage, and 300 W is implemented and tested.

In this paper, residential loads are modeled in order to analyze low frequency current ripples of residential fuel cell applications. A difference of low frequency current ripples between simple resistor load condition and actual residential load conditions is compared. Aspect of generation and propagation of low frequency current ripples are analyzed in order to design an optimal power conditioning system. Theoretical analysis has been performed and informative simulation and experimental results are provided.

In recent years, the trend in converter technology has been towards higher efficiency. This trend often involves using advanced semiconductor materials and better control algorithms to mitigate potential failure modes. Despite these advancements, converter failures can still occur due to various factors including design flaws, manufacturing defects, inadequate cooling, improper operation, and external environmental conditions. This paper provides the novel approach to enhance fault tolerance in DC-DC converter systems by introducing parallel switches that activate in response to faults occurring in primary switches. It Examine the effectiveness of this fault-tolerant design in three popular converter configurations like Boost converter, Luo converter, and Super lift Luo converter with a focus on achieving the best output voltage characteristics. The Super Lift Luo Converter (SLLC) is a type of DC/DC converter that combines the advantages of a conventional boost converter and a Luo converter. It offers features such as high voltage gain, reduced switch stress, and low input current ripple. The output voltage quality is a critical aspect in power electronics applications, influencing the stability and reliability of the power supply. Theoretical analysis, simulation, experimental validation and comparative assessment for Luo and super lift Luo converter are done. The objective is to maintain consistent output voltage despite faults occurring in primary switches, thereby ensuring system reliability and stability for renewable and EV applications. As the electrical vehicles mostly deals with 48 V these converters are predominant in providing this value of supply.

This paper formulates a positive output double gain buck-boost converter with a low input current ripple. Compared with the conventional buck-boost and quadratic buck-boost configuration, this converter’s voltage conversion ratio is higher with low voltage stress on the intermediate semiconductor devices, diodes and capacitors. Additionally, it exhibits low current stress on the intermediate inductors and power switching devices. The detailed current and voltage relations of active and passive elements are derived using time-domain analysis. The state-space matrices are formulated through the circuit analysis and based on the estimated transfer function of the converter configuration, the closed-loop digital controller is designed. The theoretical analysis is validated through the key steady-state and closed-loop dynamic results obtained from the PSIM simulation.

The basic operation of a solar cell, module or photovoltaic generator under different irradiation and temperature conditions is characterized by its I-V characteristic curve. Only the experimental measurement of the I-V curve allows us to know with precision the electrical parameters of a photovoltaic cell, module or array. This measure provides very relevant information for the design, installation and maintenance of photovoltaic systems. Currently, the I-V characteristic curve is obtained by connecting a variable charge to the panel terminals in order to achieve that the current of the terminals ranges from zero to the short circuit current. In this paper we propose a new experimental way to measure this characteristic curve by using Buck-Boost-Derived DC-DC converters. It has been proved that the optimal topologies for this purpose are the SEPIC (Single-Ended Primary Inductance Converter) and Cuk converters. The theoretical analysis performed has been validated by means of simulation and experimentally. Additionally, a comparison between three known conventional methods and the proposed one is provided.