Mario Lucio da Silva Martins

Low Reactive Energy ZCZVT PWM Converters: Synthesis, Analysis and Comparison

In this paper a novel methodology to synthesize zero-current zero-voltage transition (ZCZVT) topologies is presented. The proposed methodology is based on the auxiliary voltage source (AVS) concept, which permits to generate not only a new topology but an entire class of converters. As the AVS concept is derived from the Resonant Transition mechanism, the new class of ZCZVT converters resembles some of the well-known zero-voltage transition (ZVT) converters, holding their characteristics, as simplicity, low reactive energy and high performance. The experimental results have been obtained from three boost converter laboratory prototypes rated to 1 kW, 50 kHz, and confirm the novel synthesis concept and also the high performance of the new ZCZVT converters at both: efficiency and, di/dt and dv/dt control

High Step-Up PV Module Integrated Converter for PV Energy Harvest in FREEDM Systems

This paper proposes a novel single-switch dc/dc converter for the future renewable electric energy delivery and management system to implement the distributed renewable energy resources (DRER). The DRER is responsible for the maximum power point tracking of the photovoltaic panel (PV) module and also for the control of central energy storage device. Due to the characteristics of the PV module and the dc-bus, the single power stage must provide low current ripple in the input and output terminals, must operate with output current and voltage regulation, and present a high-voltage conversion ratio. To achieve such features, this paper proposes a novel integrated Boost–Zeta converter. To avoid a complex modeling and control, we propose a disaggregation concept for this. Experimental results are presented for the purpose of operating the converter and also for the operation of the system.

A design criterion to ZVT DC-DC PWM converters with constant auxiliary voltage source

This paper proposes a design criterion to calculate the resonant auxiliary elements of ZVT DC-DC PWM converters that use a DC auxiliary voltage source. The proposed criterion is based on stored energy in resonant auxiliary elements and takes into account the influence of the auxiliary voltage source value. By means of this criterion the reactive energy can be kept at a minimum level and a reduction of the auxiliary elements current ratings is achieved, which leads to lower conduction losses and improved converter efficiency. In addition, a reduction in auxiliary magnetic elements size can be accomplished. To illustrate the usefulness of the design criterion proposed, comparative results obtained from the true pulse-width modulated (PWM) zero-voltage switching (ZVS) pole boost converter designed by proposed criterion and its original design guidelines are presented. Experimental results show an efficiency gain of about 1% for a wide range and 1.5% at full load. In addition, a reduction of about 52% in the auxiliary transformer volume for the implemented prototype was achieved, ensuring a reduction in overall converter size. Experimental results were obtained from 1 kW, 100 kHz laboratory prototype.

Synthesis Methodology for Multi-Pole ZVT Converters

This paper proposes a novel synthesis methodology to generate integrated ZVT topologies, as well to systematize the topologies already known. It is presented an approach to classify the single pole ZVT converters. This approach can be expanded to multi-pole systems, such as poly-phase inverters and rectifiers. Uninterruptible Power Supplies and Variable-Speed Drives. The connections among several topologies presented so far are easily seen by means of the general diagrams shown in this paper. The analysis and understanding of advantages, disadvantages, merits and limitations of each converter is made easier since these converters are obtained from a common approach presented in this paper.

PV module-integrated single-switch DC/DC converter for PV energy harvest with battery charge capability

This paper proposes a novel PV module integrated system with energy storage capability. The topology is based on the Future Renewable Electric Energy Delivery and Management (FREEDM) System, where Distributed Renewable Energy Resources (DRER) comprised by a single power stage, are responsible for the Maximum Power Point Tracking (MPPT) of each PV module and also the charging method of a centralized battery pack. Due to the characteristics of the PV module and the DC-bus, the single power stage must provide low current ripple in the input and output terminals, must operate with output current and voltage regulation and present a high voltage conversion ratio. To achieve such features, this paper proposes a novel boost-Zeta integrated converter. The analysis of the operation of this converter is carried out in details. The MPPT algorithm and the charging method are discussed in detail. The DC-DC converter is designed to ensure low ripple and limited charging current, as well as voltage regulation when the batteries are fully charged. In this version of the paper, simulation results are presented for the converters confirming the theoretical analysis. In final version of the paper, experimental results will be presented.

Photovoltaic battery charger based on the Zeta converter: Analysis, design and experimental results

In this paper, a complete analysis of the Zeta converter applied as a photovoltaic battery charger is carried out. The design methodology of the solar battery charger system, including the power circuit main devices and system controllers are presented in details. The solar battery charger includes an alternative Constant Current/Constant Voltage (CC/CV) charging method with inherent Perturb and Observe (P&O) maximum power point tracking algorithm. This way, the battery pack is properly charged as well as the maximum power is harvest from the solar module. In addition, continuous and overcurrent protection for the batteries features are implemented. Experimental results prove the reliability and the advantages of this proposal.

Design and implementation of PV power zeta converters for battery charger applications

The proposal of this paper is to present and analyze a charging station PV system of battery (PV-CS) with a wide range of output voltage buses, where is possible to make the charge of the batteries at the maximum power point tracking (MPPT), which increases the PV utilization. In this paper, a complete analysis of the Zeta converter applied as a photovoltaic battery charger is carried out. The solar battery charger includes a Constant Current/Constant Voltage charging method with inherent MPPT. The battery pack is properly charged as well as the maximum power is harvest from the solar module. Experimental results prove the feasibility of the design.

An imroved design for ZVT DC-DC PWM converters with snubber assisted auxiliary switch

This paper proposes an improved design to calculate the snubber auxiliary elements of ZVT DC-DC PWM converters with snubber assisted auxiliary switch. The proposed improved design guidelines are based on the reduction of the conduction losses through the auxiliary circuit. It is accomplished by the unique location of the turn-off snubber capacitor, which is shared by both active switches. By means of this improved design guidelines the converter efficiency can be increased. An efficiency comparative analysis is carried out and the experimental results, obtained from 1 kW, 100 kHz laboratory prototypes, show a relevant improvement in converter efficiency compared to the original converter design. In addition, experimental results also confirm that with the improved design the ZVT PWM converters with snubber assisted auxiliary switch can be competitive with ZVT PWM converters with constant auxiliary voltage source (True PWM ZVS pole).

Quadratic-Boost With Stacked Zeta Converter for High Voltage Gain Applications

This paper proposes a different approach to combine stacked and cascaded configuration of dc/dc pulse-width modulation converter cells in order to access the benefits of both structures in a single-stage topology with a single active switch. In addition to presenting and discussing the concepts of cascaded, stacked, and the combination of both, this paper also proposes a new topology derived from these concepts. It provides high voltage conversion ratio with improved efficiency. As the name implies, this converter is obtained from the combination of two well-known dc/dc converter circuits, the Isolated Zeta Converter and the Quadratic-Boost Converter. Hence, it presents the combined features of both, i.e., high step-up voltage conversion, low input current ripple (Quadratic Boost features), and low output current ripple (Zeta’s feature). In order to verify the feasibility and performance of the converter presented, two 250-W prototypes circuits have been implemented.

Integrated Quadratic-Boost-Zeta converter for high voltage gain applications

This paper proposes a novel high step-up DC/DC converter named Integrated Quadratic-Boost-Zeta converter. It is based on the combination of two well-known DC/DC converter circuits, the Isolated Zeta converter and the Quadratic-Boost converter. The output voltage boosting is accomplished by summing both output voltages of the Zeta and the Quadratic-Boost. The circuit is designed in such way that each part of the converter outputs keeps the same characteristic of its former converter, guaranteeing their well-known advantages. Furthermore, the proposed topology has a single-switch, maintaining a low component count. In addition, differently of the high current ripple presented in the quadratic-boost converter, the proposed circuit, with an adequate filter design, can ensure a low output current ripple due to the Zeta output inductor. The Integrated Quadratic-Boost-Zeta Converter is analyzed, and its feasibility and reliability are confirmed by experimental results obtained from laboratory prototype rated at 250W and 100 kHz.