Soft-Switched Interleaved DC/DC Converter as Front-End of Multi-Inverter Structure for Micro Grid Applications
01 Sep 2018-IEEE Transactions on Power Electronics (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 33, Iss: 9, pp 7645-7655
TL;DR: In this paper, an isolated four channel dc/dc converter with zero voltage switching is proposed as the front-end of multiple inverter structures to integrate renewable and other low voltage energy sources to micro grids.
Abstract: An isolated four channel dc/dc converter with zero voltage switching is proposed as the front-end of multiple inverter structures to integrate renewable and other low voltage energy sources to micro grids. The interleaving technique is adopted to connect each module of proposed converter to a common dc source. This dc source can be a fuel cell stack, PV panels, battery, or any other low voltage dc source. All four channels are interleaved and a phase shift of $90^{\circ }$ is provided between the gate signals of each channels, which reduces the input current ripple. The output port of the proposed converter provide four isolated and regulated dc voltages. These isolated dc sources can be connected in series or parallel or series-parallel manner to obtain required dc-link voltage of various inverter structure. Issues like capacitor voltage balancing of diode clamped multilevel inverters can overcome through the proposed converter. By incorporating a coupled inductor for isolation and energy storage along with voltage multiplier circuit, the proposed converter can achieve higher voltage step up with lower turns ratio and lower voltage stress at moderate duty ratio. Hence, mosfet s of low voltage rating (low $R_{DS}(\text{ON})$ ) can be utilized to reduce conduction loss. A 2 kW prototype of the proposed interleaved dc/dc converter is developed and tested with diode clamped three-level inverter, five-level inverter, and three-phase two-level inverter to verify the design.
Citations
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TL;DR: Hardware results obtained validates superior performance and higher efficiency compared to conventional existing topologies.
Abstract: High efficiency is an important requirement from DC–DC converter in DC microgrid system when integrated with renewable energy sources. This study proposes a new tri-switching state non-isolated high gain boost converter for 400 V DC microgrid applications. The proposed converter developed by modifying the conventional boost converter with advantageous features such as; high-voltage gain operation with two different duty pulses to overcome the restriction of high duty ratio and continuous input current. Moreover, semiconductor components in the proposed converter are subjected to reduced voltage stress for a shorter duration when compared to conventional existing topologies. Steady state (with and without non-idealities consideration) and performance analysis are presented to validate the viability of the proposed converter for high gain operation in grid-connected systems. For experimental validation, a prototype model of the proposed converter is developed for 31 V/400 V, 500 W and operated at 50 kHz switching frequency. The converter is tested for a power range of 100–500 W for two different duty range (case: 1–k 1 kept fixed and k 2 is varied, case: 2–k 2 kept fixed and k 1 is varied) to validate the consistency in output voltage. Hardware results obtained validates superior performance and higher efficiency compared to conventional existing topologies.
32 citations
TL;DR: An integrated battery storage interface with soft-switching capability for module-integrated PV systems and Experimental results on a 175-W proof-of-concept prototype are presented to demonstrate the features of the proposed converter.
Abstract: In conventional photovoltaic (PV)-battery systems, a centralized battery storage system (BSS) is typically connected through a separate bidirectional converter at the common dc link to support the PV system. It is known that a bidirectional converter typically requires more switches than a unidirectional converter, and hence, a complete PV-battery power interface will result in a high-cost system and will suffer high power losses. This paper proposed an integrated battery storage interface with soft-switching capability for module-integrated PV systems. In the proposed system, a multi-input converter (MIC) structure that consists of an integrated soft-switched quasi-resonant (QR) Cuk- and flyback-based circuit is presented. In this approach, the battery charging circuit is integrated with the input side of the PV power optimizer while the battery discharging circuit of the proposed system shares the output filter of the PV power optimizer, resulting in a compact and efficient system. The proposed converter is capable of tracking the maximum power point (MPP) and following the charging profile (constant voltage and constant current) of the battery. Moreover, all the switches in the proposed converter are able to achieve soft-switched turn on and turn off for different operating conditions. The operating principles and the theoretical analysis of the proposed system are presented. Experimental results on a 175-W proof-of-concept prototype are presented to demonstrate the features of the proposed converter.
23 citations
Cites background from "Soft-Switched Interleaved DC/DC Con..."
...Soft-switching converter solutions have also been presented for this application to achieve high circuit efficiency [7], [8], [23], [24]....
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...Different studies have been dedicated to develop efficient and reliable nonisolated [9], [10], [12], [21], [22] and isolated [7], [8], [11], [15], [23], [24] power converters for PV-battery systems with high...
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TL;DR: A soft-switched modular nonisolated converter is proposed for distributed generation systems by integrating flyback energy delivering circuit to the interleaved boost converter, ultrahigh-voltage gain and high efficiency are achieved with reduced duty ratio.
Abstract: In this article, a soft-switched modular nonisolated converter is proposed for distributed generation systems. By integrating flyback energy delivering circuit to the interleaved boost converter, ultrahigh-voltage gain and high efficiency are achieved with reduced duty ratio. Cockcroft–Walton based multiplier cell extensively reduces voltage stress on the active switches. Voltage spikes across mosfet s caused by leakage inductance and interconnection of primary-secondary windings are alleviated by adjoining the active switch based auxiliary circuit. Thus, low voltage rating switches (small R ds ( on )) are employed. Furthermore, the clamp circuit realizes wide-load-range zero-voltage switching (ZVS) turn- on and, reduced falling current magnitudes ensures low turn- off losses for all the mosftet s. Also, leakage-energy is recycled to the load. Indeed, leakage-energy effectively limits the rate of fall-current ( dif / dt ) through power diodes and alleviates the reverse-recovery problem by turning- off them with zero-current switching. Furthermore, during turn- on , ZVS is achieved for all the diodes. Thus, voltage spikes across the diodes are suppressed without needing any snubber. Minimized voltage stresses, lowered on-state and switching losses of the semiconductor devices, altogether, improves the efficiency. A 600-W prototype working at 100 kHz is developed in the laboratory to validate the design analysis. Measured efficiency at rated-load is 95.81% and maximum efficiency is 96.65%.
20 citations
TL;DR: In this paper, a current fed interleaved high gain converter is proposed by utilizing the interleaving front-end structure and Cockcroft Walton (CW)-Voltage Multiplier (VM).
Abstract: As the voltage gain of converter increases with the same ratio, the current gain also increases, this increase in current gains will affect the size of the input and the output capacitor. To reduce the ripple in the input current with simultaneous decreasing the input current ripple, a novel current fed interleaved high gain converter is proposed by utilizing the interleaved front-end structure and Cockcroft Walton (CW)-Voltage Multiplier (VM). The “current fed” term is used because, in proposed circuitry, all the capacitors of CW-VM are energized by a current path via inductors of the interleaved structure. The proposed converter can be applied as an input boost up the stage for low voltage battery energy storage systems, photovoltaic (PV) and fuel cell (FC) based DC-AC applications. The anticipated topology consists of the two low voltage rating switches. The main benefits of the anticipated converter configuration are the continuous (ripple free) input current, high voltage gain, reduced switch rating, high reliability, easy control structure and a high percentage of efficiency. The proposed converter’s working principle, mathematical based steady-state analysis, and detailed component design are discussed. The parasitic of the components has been considered in the analysis to show the deviation from the ideal cases. A detailed comparison with the other available converters is presented. The experimental results of the 300W prototype are developed to confirm the performance and functionality of the anticipated DC-DC converter.
17 citations
TL;DR: The analytical procedure to select the inductance and capacitance values of both the input and output filters is described in the paper and the design and implementation of the input/output ICTs and inductors is discussed.
Abstract: This paper deals with a multilevel ac–ac double conversion system that uses the intercell transformer (ICT) for applications which include generating systems and the interfacing of renewable energy sources with the utility grids. Each phase of the proposed configuration is formed through the ICT interleaving operation of two multilevel 5-level E-type legs to achieve the 3-phase 5-level back-to-back E-type converter (3Φ5L BTB E-type converter). The analytical procedure to select the inductance and capacitance values of both the input and output filters is described in the paper. Furthermore, the design and implementation of the input/output ICTs and inductors is discussed. The simulation and the experimental results on the 20-kVA interleaved 3Φ5L BTB E-type converter prototype are presented to validate the proposed analysis.
13 citations
References
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TL;DR: In this article, power electronics, the technology of efficiently processing electric power, play an essential part in the integration of the dispersed generation units for good efficiency and high performance of the power systems.
Abstract: The global electrical energy consumption is rising and there is a steady increase of the demand on the power capacity, efficient production, distribution and utilization of energy. The traditional power systems are changing globally, a large number of dispersed generation (DG) units, including both renewable and nonrenewable energy sources such as wind turbines, photovoltaic (PV) generators, fuel cells, small hydro, wave generators, and gas/steam powered combined heat and power stations, are being integrated into power systems at the distribution level. Power electronics, the technology of efficiently processing electric power, play an essential part in the integration of the dispersed generation units for good efficiency and high performance of the power systems. This paper reviews the applications of power electronics in the integration of DG units, in particular, wind power, fuel cells and PV generators.
2,296 citations
"Soft-Switched Interleaved DC/DC Con..." refers background in this paper
...For efficient extraction of energy from these intermitted sources, power electronics converters are required [1], [2]....
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Journal Article•
TL;DR: In this article, power electronics, the technology of efficiently processing electric power, play an essential part in the integration of the dispersed generation units for good efficiency and high performance of the power systems.
Abstract: The global electrical energy consumption is rising and there is a steady increase of the demand on the power capacity, efficient production, distribution and utilization of energy. The traditional power systems are changing globally, a large number of dispersed generation (DG) units, including both renewable and nonrenewable energy sources such as wind turbines, photovoltaic (PV) generators, fuel cells, small hydro, wave generators, and gas/steam powered combined heat and power stations, are being integrated into power systems at the distribution level. Power electronics, the technology of efficiently processing electric power, play an essential part in the integration of the dispersed generation units for good efficiency and high performance of the power systems. This paper reviews the applications of power electronics in the integration of DG units, in particular, wind power, fuel cells and PV generators.
2,076 citations
TL;DR: In this article, a family of high-efficiency, high step-up DC-DC converters with simple topologies is proposed, which use diodes and coupled windings instead of active switches to realize functions similar to those of active clamps.
Abstract: Many applications call for high step-up DC-DC converters that do not require isolation. Some DC-DC converters can provide high step-up voltage gain, but with the penalty of either an extreme duty ratio or a large amount of circulating energy. DC-DC converters with coupled inductors can provide high voltage gain, but their efficiency is degraded by the losses associated with leakage inductors. Converters with active clamps recycle the leakage energy at the price of increasing topology complexity. A family of high-efficiency, high step-up DC-DC converters with simple topologies is proposed in this paper. The proposed converters, which use diodes and coupled windings instead of active switches to realize functions similar to those of active clamps, perform better than their active-clamp counterparts. High efficiency is achieved because the leakage energy is recycled and the output rectifier reverse-recovery problem is alleviated.
974 citations
"Soft-Switched Interleaved DC/DC Con..." refers background in this paper
...Use of coupled inductor for high step applications is a good solution [9], [12], [13]....
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...To overcome the drawbacks of basic boost converter for high voltage step up applications, numerous high voltage gain dc/dc converters are presented in [9], [11]–[18]....
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TL;DR: In this article, the authors discuss about integrating renewable energy sources into the smart power grid through industrial electronics, including photovoltaic power, wind energy conversion, hybrid energy systems, and tidal energy conversion.
Abstract: This paper discusses about integrating renewable energy sources into the smart power grid through industrial electronics. This paper discusses photovoltaic power, wind energy conversion, hybrid energy systems, and tidal energy conversion.
933 citations
"Soft-Switched Interleaved DC/DC Con..." refers background in this paper
...For efficient extraction of energy from these intermitted sources, power electronics converters are required [1], [2]....
[...]
TL;DR: In this article, the use of the voltage multiplier technique applied to the classical non-isolated dc-dc converters in order to obtain high step-up static gain, reduction of the maximum switch voltage, zero current switching turn-on was introduced.
Abstract: This paper introduces the use of the voltage multiplier technique applied to the classical non-isolated dc-dc converters in order to obtain high step-up static gain, reduction of the maximum switch voltage, zero current switching turn-on. The diodes reverse recovery current problem is minimized and the voltage multiplier also operates as a regenerative clamping circuit, reducing the problems with layout and the EMI generation. These characteristics allows the operation with high static again and high efficiency, making possible to design a compact circuit for applications where the isolation is not required. The operation principle, the design procedure and practical results obtained from the implemented prototypes are presented for the single-phase and multiphase dc-dc converters. A boost converter was tested with the single-phase technique, for an application requiring an output power of 100 W, operating with 12 V input voltage and 100 V output voltage, obtaining efficiency equal to 93%. The multiphase technique was tested with a boost interleaved converter operating with an output power equal to 400 W, 24 V input voltage and 400 V output voltage, obtaining efficiency equal to 95%.
702 citations
"Soft-Switched Interleaved DC/DC Con..." refers background in this paper
...Converters in [11] incorporate voltage multiplier circuit in basic boost converter structure to achieve high voltage step up with lower stress....
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...To overcome the drawbacks of basic boost converter for high voltage step up applications, numerous high voltage gain dc/dc converters are presented in [9], [11]–[18]....
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