A new quasi-Z-source inverter called switched-inductor quasi-Z-source inverter was presented which employs a switched-inductor impedance network to couple power source and the invert main circuitCompared with the traditional quasi-Z-source inverter,the switched-inductor quasi-Z-source inverter increases the voltage conversion rations,has an obvious voltage boost ability,and for a given voltage conversion ration,a higher modulation index can be used to ensure a good output power qualityTheoretical analysis,the experimental and simulative results based on the simple boost control strategy and the third harmonic injection control strategy verify the superiority and rationality of the new quasi-Z-source inverter and demonstrate the features of the third harmonic injection control strategy

Switched-inductor Quasi-Z-source Inverter

High voltage gain DC-DC converter is a prime requirement for renewable applications, in particular for PV. Though numerous DC-DC converter is available for increasing the voltage gain, the passive elements requirement is higher which reduces the compactness, consequently, increases the cost of the system. To address this issue, a high gain DC-DC converter is reported recently. However, the number of passive elements is quite high which increases the size. To reduce the number of passive elements and maintain the same number of semiconductor devices, in this paper, a new switched inductor arrangement is proposed which is named as switched inductor double switch DC-DC converter (SL-DS-DC). Moreover, the proposed converter has a higher gain as compared to the recently reported converter. The proposed converter is analyzed in steady state and a comparative analysis is presented to prove the suitability. Finally, the proposed converter is validated experimentally.

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Switched Inductor Double Switch High Gain DC-DC Converter for Renewable Applications

High gain dc-dc converters are used in several applications which include solar photovoltaic system, switch-mode power supplies and fuel cells. In this paper, an ultra-high gain dc-dc boost converter is proposed and analyzed in detail. The converter has a gain of six times as compared with the boost converter. The high gain is achieved by utilizing switched inductors and switched capacitors. A modified voltage multiplier cell (VMC) with switched inductors is proposed. The converter has a single switch which makes its operation easy. Moreover, the voltage across the switch, diodes and capacitors are less than the output voltage which increases the overall efficiency of the converter. The converter performance in steady-state is analyzed in detail and it is compared with other latest high gain converters. The working of the converter in non-ideal conditions is also discussed in detail. The loss analysis is done using PLECS software by incorporating the real models of switches and diodes from the datasheet. To confirm and validate the working of the proposed converter a hardware prototype of 200 W is developed in the laboratory. The converter achieves high gain at low duty ratios and its performance is found to be good in open and closed loop conditions.

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A New Transformerless Ultra High Gain DC–DC Converter for DC Microgrid Application

In this article, three switched-capacitor-based Z-source equivalent dc–dc boost converter (SCZEBC) topologies are proposed. The basis for these topological evolutions is the shifted L-C-D cell of the fourth-order boost converter on the front-end side, whereas a charge-pump cell on the upstream side. This hybrid combination results in quasi-Z-source equivalent dc–dc boost conversion along with enhanced voltage boosting capability. The operating duty ratio of the proposed topologies is less than 0.5 like in the conventional Z-source dc–dc converter (ZSC) topologies. In comparison to the existing Z-source topologies, remarkable features of the proposed SCZEBC topologies are: low source current ripple, common ground, and low voltage stress on capacitors and active devices. A detailed steady-state analysis is presented to identify the salient features of the proposed topologies and is thereafter compared with the existing ZSCs. Small-signal analysis is established and a voltage-mode controller is designed. In the controller design stage, a modulus margin 0.5–0.75 is adopted to ensure tradeoff between robustness and performance of the proposed converter topologies. A 48 to 220 V, 100-W prototype is built to demonstrate the effectiveness of the SCZEBC. The steady-state and closed-loop response measurements validate the theoretical studies.

Analysis and Design of Quasi-Z-Source Equivalent DC–DC Boost Converters

A high gain noninverting DC–DC converter with low voltage stress for industrial applications

A compact high step up dc–dc converter with continuous input current and lower device voltage stress is a prime requirement for renewable application. In this article, a high gain dc–dc converter is proposed, which combines the concept of switched inductor and switched capacitor along with a unique interconnection of input–output. This arrangement reduces capacitor voltage stress. The proposed converter has reduced conduction losses, reduced components count, and low voltage stress across the devices. Besides, the proposed converter has lower inductor current ripple, which is suitable for renewable integration. The operation and steady-state analysis of the converter are done in continuous current mode. For the proposed converter, voltage and current stress and the losses are calculated analytically. A comparative analysis is presented to prove the potential of the proposed converter. The dynamic analysis of the proposed converter is performed to regulate the output voltage. Finally, an experimental set up is designed to test the converter under both distinct power ratings and closed loop.

Switched-LC Based High Gain Converter With Lower Component Count

The essential features of a DC–DC converter for fuel cell vehicle are to ensure the higher voltage gain to meet out the higher DC link voltage demand, continuous input current to improve the life span of the fuel cell, presence of common grounding to avoid electromagnetic interference issue and lower voltage stress with reduced components. This paper presents a high voltage gain DC–DC converter by combining the switched capacitor and quasi switched boost network modules. The proposed high voltage gain converter provides the continuous input current, lower voltage stress, utilizes a fewer number of elements and common grounding feature. The operating characteristics, steady-state analysis both in continuous current mode (CCM) and discontinuous current mode (DCM), comparative analysis with contemporary converters are discussed. The theoretical claimed analysis is validated by the simulation and experimental study. The proposed converter is operated for 200 W output power rating and tested for providing the voltage gain in the range of 5–8 times the input voltage gain by varying the input voltage from 25 V–40 V. The efficiency of the proposed converter is also reported for different output power rating which is in the range 91.3%–93.7%.

A High Voltage Gain DC–DC Converter With Common Grounding for Fuel Cell Vehicle

Bidirectional DC-DC converters are critical aspects of integrating energy storage units with hybrid electric vehicle. In this brief, a new bidirectional DC-DC converter is presented based on the quasi Z-source and switched capacitor network. The proposed converter can achieve higher voltage gain in a lower duty cycle as compared to existing converters reported in the literature. The proposed converter achieves high gain in low duty cycle range thus avoids the inductor core saturation problem in converters. In addition, the proposed converter exhibits lower voltage stress across capacitors. The proposed converter operation, steady-state analysis, voltage and current stress analysis are discussed along with comparative analysis is also presented. For validating the feasibility of the proposed converter, an simulation and experimental setup is designed.

A Wide Voltage Gain Bidirectional DC–DC Converter Based on Quasi Z-Source and Switched Capacitor Network

A high voltage gain inverter is a prime requirement for high voltage power application. Z-source inverter has attracted the attention widely. A lot of efforts has been made to improve the voltage gain with better design. However, still, there is a gap to achieve higher voltage gain with the optimum number of components. In this brief, a quasi Z-source inverter is proposed to achieve higher voltage gain. The proposed inverter utilizes the active switched network along with switched inductor cell. The proposed inverter offers continuous input current and higher voltage gain. The operation and steady-state analysis are presented to derive the voltage gain. A comparative analysis is presented to describe the features of the proposed inverter. Finally, an experimental analysis is conducted to validate the feasibility of the proposed inverter.

Avneet Kumar

Papers

Switched Inductor Double Switch High Gain DC-DC Converter for Renewable Applications

Switched-LC Based High Gain Converter With Lower Component Count

A High Voltage Gain DC–DC Converter With Common Grounding for Fuel Cell Vehicle

A Wide Voltage Gain Bidirectional DC–DC Converter Based on Quasi Z-Source and Switched Capacitor Network

An Ultra High Gain Quasi Z-Source Inverter Consisting Active Switched Network