Isolated Boost Converter Research Articles

Linear and Non-Linear Carrier Control of Soft Switched Isolated Boost Converter for Low Voltage Fuel Cell Applications

In recent years fuel cells have become prominent as a renewable source of energy to meet the society’s energy requirements. Isolated Full Bridge Boost topology was mostly used for fuel cell systems. To increase the efficiency of the converter for low voltage fuel cell applications many soft switching techniques were proposed. This paper presents detailed study and control of Zero current switching Isolated Full Bridge Boost DC-DC Converter (ZCS IFBC). Linear peak current mode control (LPCM) and Non- Linear Carrier Control (NLC) techniques were applied to the converter for regulating output voltage dynamics. Simulated results of converter with and without ZCS are presented. Losses and efficiencies at various loads are measured. The results show that losses are decreased and efficiency was increased from 62.4% to 96.5% at full load with ZCS technique and output voltage is regulated to 400V with LPCM and NLC control topology.

Interleave Isolated Boost Converter as a Front End Converter for Solar/Fuel Cell Application to Attain Maximum Voltage in MATLAB

Objectives: Solar power or fuel cell produces a very low output voltage (~20 v to 60 v), so we need to boost up voltage with high efficient converter. Method Analysis: Here an isolated converter is used in order to overcome back EMF problem from the load. Designing an Isolated DC low voltage to DC high voltage converter will be of great challenge because converter must handle high input current at the supply side and high output voltage at the loads side. For efficient way, we will be connecting the input parallel and connect the output in series. Findings: Based on this concept two inductors connected in parallel at the input side to share the input current and the capacitor are connected in series at output side to share output voltage in an interleaved manner. Thus the two boost converter cells are demagnetizing by repelling each other, therefore the transformer structure is simplified. By using interleaved operation ripple current will reduced, therefore capacitor and inductor size is reduced both at input and output side. Improvements: And features make on this interleaved isolated boost converter, then it desirable for high power low to high DC application, 40 V DC is boosted to 680 V DC is simulated using MATLAB.

Modelling and Simulation of Current Fed Interleaved Isolated DC-DC Boost Converter for Fuel Cell Applications

In this a paper, a current fed, interleaved, high gain, DC-DC converter is proposed for fuel cell applications. The converter also provides electrical isolation between the load and the source by using a transformer. The input features two current fed, full bridge inverters in parallel while the output features two full bridge diode rectifiers in series. By using this topology, the high input current is shared between the two inverters. These enables the use of lower current rating semiconductor devices, reduces switching stresses and reduces the size of magnetic components. It also results in reducing the input current ripple and the output voltage ripple.

Analysis of the Interleaved Isolated Boost Converter With Coupled Inductors

This paper analyzes the interleaved boost with coupled inductors (IBCI) converter, which is an isolated topology that is suitable for high step-up applications. Two main contributions are given: an exhaustive steady-state analysis and an accurate small-signal model. The former allows for deriving a closed-form noniterative design procedure for the power-stage active and passive components. In addition, it reveals an interesting equivalence with an apparently different converter, i.e., the single active bridge. Subsequently, the IBCI converter dynamic behavior is investigated, deriving a nonlinear average model that, under small-signal approximation, can be linearized around a given operating point and used for feedback controller design. A single photovoltaic module interface converter, rated for 300-W output power, is considered as a case study to validate the analysis outcome and the design procedure. Both are fully validated by measurements taken on the laboratory prototype.

Resonance Analysis and Soft-Switching Design of Isolated Boost Converter With Coupled Inductors for Vehicle Inverter Application

The comprehensive resonance analysis and soft-switching design of the isolated boost converter with coupled inductors are investigated in this paper. Due to the resonance participated by the voltage doubler capacitor, clamping capacitor, and leakage inductance of coupled inductors, the reverse-recovery problem of the secondary diodes is restrained within the whole operation range. By choosing appropriate magnetic inductance of the coupled inductors, zero-voltage switching on of the main mosfets is obtained collectively at the same working conditions without any additional devices. Moreover, the range of duty ratio is enlarged to achieve soft switching and an optimal operation point is obtained with minimal input current ripple, when duty ratio approaches 0.5. Additionally, two kinds of resonances are analyzed and an optimized resonance is utilized to achieve better power density. The prototype is implemented for the vehicle inverter requiring a 150 W output power, input voltage range varying from 10.8 to 16 V, and 360 V output voltage. Experiment results verify the design and show that the minimum efficiency is about 93.55% and 90.53% at low load and full load, respectively.

A New Isolated Boost Converter with Coupling Inductors

This paper proposes a new improved zero-voltage switching isolated boost converter with coupling inductors. With the traditional advantages of smaller input current ripple, low diode voltage rating, and low transformer turns ratio of boost half bridge topology [ being retained, the proposed converter makes it much easier to realize zero voltage switching of primary switches compared with conventional converters.

Isolated Boost Converter with Bidirectional Operation for Supercapacitor Applications

This paper presents an isolated bidirectional dc/dc converter based on primary parallel isolated boost converter (PPIBC). This topology is an efficient solution in low voltage high power applications due to its ability to handle high currents in the low voltage side. In this paper, the converter has been modeled using non-ideal components and operated without any additional circuitry for startup using a digital soft-start procedure. Simulated and measured loop gains have been compared for the validity of the model. On-the-fly current direction change has been achieved with a prototype interconnecting two battery banks. A second prototype has been constructed and tested for supercapacitor operation in constant power charge mode.

Analysis and Design of Fully Integrated Planar Magnetics for Primary–Parallel Isolated Boost Converter

A highly efficient planar integrated magnetic (PIM) design approach for primary–parallel isolated boost converters is presented. All magnetic components in the converter, including two input inductors and two transformers with primary–parallel and secondary–series windings, are integrated into an E–I–E-core geometry, reducing the total ferrite volume and core loss. The transformer windings are symmetrically distributed into the outer legs of E-cores, and the inductor windings are wound on the center legs of E-cores with air gaps. Therefore, the inductor and the transformer can be operated independently. Due to the low-reluctance path provided by the shared I-core, the two input inductors can be integrated independently, and also, the two transformers can be partially coupled to each other. Detailed characteristics of the integrated structure have been studied in this paper. AC losses in the windings and the leakage inductance of the transformer are kept low by interleaving the primary and secondary turns of the transformers substantially. Because of the combination of inductors and transformers, the maximum output power capability of the fully integrated module needs to be investigated. Winding loss, core loss, and switching loss of MOSFETs are analyzed in-depth in this work as well. To verify the validity of the design approach, a 2-kW prototype converter with two primary power stages is implemented for fuel-cell-fed traction applications with 20–50-V input and 400-V output. An efficiency of 95.9% can be achieved during 1.5-kW nominal operating conditions. Experimental comparisons between the PIM module and three separated cases have illustrated that the PIM module has advantages of lower footprint and higher efficiencies.

An Improved Current-Fed ZVS Isolated Boost Converter for Fuel Cell Applications

This paper proposes an improved current-fed zero-voltage switching isolated boost converter suitable for fuel cell applications. Preserving the inherent advantages of the current-fed converter which include smaller input current ripple, lower diode voltage rating, and lower transformer turns ratio, the proposed converter does not require any clamping and start-up circuits unlike the conventional current-fed converters. The voltage ratings of the primary switches and secondary diodes of the proposed converter are significantly reduced. Some alternative schemes of the proposed converter without the voltage-second unbalance are presented. These characteristics of the proposed converter lead to a high overall efficiency over wider load range. Experimental results on a 1 kW prototype are provided to validate the proposed concept.

자기구동 스위치를 이용한 절연된 부스트 변환기의 해석

절연된 부스트 변환기는 전기적인 절연과 매우 높은 승압을 필요로 하는 응용분야에 적합한 변환기이다. 낮은 입력전압을 높은 출력전압으로 승압하기 위해 필요한 변압기는 volt-sec 평형 조건을 만족하여야한다. 기존의 절연된 부스트 변환기는 도통구간을 오버랩하여 제어하였으며 이 경우 제어회로가 복잡해지는 문제가 있다. 본 논문에서는 변압기의 volt-sec 평형을 위해 리셋권선을 설치하고 자기구동 스위치를 이용하여 제어회로를 간단하게 구성할 수 있는 절연된 부스트 변환기를 제안하고 해석한다. 마지막으로 출력 10[W]급의 절연된 부스트 변환기를 구성하여 시뮬레이션하고 실험을 수행하여 제안한 변환기의 이론적 해석의 타당성을 입증하였다.