Hamiltom C. Sartori

A comparative design of an optmized boost inductor taking into account three magnetic materials technologies: Volume, cost and efficiency analysis

Reducing the volume with maximum efficiency, on equipment and systems, result in a high cost, making the optimized design a great challenge for engineers. On power factor correctors (PFCs) converters, magnetic elements as inductors and transformers have a strong influence on cost, volume, power density and performance, they become the more important elements in these systems. Thus, the need for an optimized design of these components is extremely important. With this purpose, this paper presents the inductor design for a 1kW, VIN 220VAC e VOUT 400VDC, PFC boost converter. The design is developed using different operating points (Δi @ fs) and different magnetic materials technologies (Molipermalloy, High Flux and KoolMμ) to perform a comparative analysis. These powder materials have extremely attractive characteristics for PFCs and this paper indicates which material offers the best cost / benefit relationship between the three technologies of magnetic materials aforementioned.

A static converter comparative study taking into account semiconductor tecnologies and swicth auxiliary circuits: Optimized design

The optimized static converter design is directly related to the appropriate choice of operation point (Δi @ fs). The magnetic elements like inductor and noise filter, and thermal elements like heat sink are which main influences in the converter volume. These elements are strongly influenced by the chosen operation point, showing a direct relationship among them [1]. With the increase of both the switching frequency and the input current ripple occurs reduction of the inductor volume. On the other hand, it increases the switching losses into semiconductors and influence on the EMI filter volume.

Integrated methodology design to improve the efficiency and reduce volume of the CCM PFC boost converters with pre-sizing settings

This paper presents an optimization design methodology for CCM PFC Boost converters with volume and efficiency objectives. The optimization methodology, achieved by mathematical interactions, is based on the concept of the converter integrated design, in other words, all the main physical converter components are designed simultaneously in the function of a pair of overall variables. The integrated design provides for the reduction of cost and time of the project design of the system and also gives complete and matched solutions with the objective of the proposed optimization. The proposed methodology is evaluated with a PFC Boost converter including an input EMI filter (1000-W output power, 400-VDC output voltage and 220-VAC input voltage). In this case study, three different magnetic materials are used in both inductors designs (Boost and EMI filter) in order to demonstrate how technology affects the volume and efficiency results. To confirm the theoretical analysis that was carried out, the experimental mechanical, electrical and thermal measurements are presented.

Efficiency optimization of DC/DC boost converter applied to the photovoltaic system

This work has as objective to maximize the efficiency of the DC/DC boost converter, used to track the maximum power of a PV system implemented by three panels, connected in series, with a total power of 600 W. The maximization is based on the selection of the magnetic material and of the operating point (Δi @ fs) that results in the best weighted average efficiency. Losses in the capacitors, semiconductors and magnetic devices are considered. Experimental results are presented to validate the simulated results obtained, as well as results of the efficiency of the boost converter. There different points will be presented to prove that operating point selected is the best among them.

Different optimum designs investigation of DC/DC boost converter applied to the photovoltaic system

This paper investigates different optimum designs of DC/DC boost converters applied to photovoltaic systems. The main goal of this work is to improve the total efficiency of a boost converter used to track the maximum power of a PV system, which is formed by three panels, connected in series yielding a total power of 600 W. Efficiency improvement is achieved by means of the selection of an operating point for the converter (Δi @ fs) and choosing the magnetic core and conductor diameter, which provide minimal losses. The losses in capacitors, semiconductors and magnetics are evaluated forall load range. After that, it is obtained the efficiency in 5%, 10%, 25%, 50%, 75% and 100% of nominal power in order to calculate the weighted average efficiency. From this evaluation, the operation point and the magnetic material that will result in the best efficiency are selected. Experimental results are presented to validate the simulated results obtained, as well as results of the total efficiency of the boost converter. Three different configurations will be presented to prove that the operating point and the magnetic core selected is the best among them. A discussion of the results is presented, where alternatives to improve efficiency throughout the power range are analyzed.

Advanced Design System for Power Converters - ADPC

Currently research efforts are employed in algorithms, techniques and methods for static converters design, mainly exploring the minimization of volume, losses and costs. Taking into account the previous considerations, this work presents a computational tool to perform quickly and effective the design of static converters having as objective function to minimize its volume, losses, and cost. It was developed a computational prototype called ADPC - Advanced Design System for Power Converters, where the design of a static converter is performed from the choice of its topology, of the input specification data, recommendations and standards, and a database of components and devices. The language used for the development was JAVA 8 and the database management system was PostgreSQL. The results obtained through graphics and reports allow to the designer to view different designs and results for a chosen set of technologies and components combinations for the assembly of a static converter prototype. Hence, making the design task less complex and quick according to the restrictions and input data set by the designer.

CubeSat electrical power supplies optimization — Comparison between conventional and optimal design methodology

Satellites and space application devices demands high efficiency with size, volume, mass and losses reduced simultaneously due to low power generation in space orbit and the relation between mass and the overall space mission cost. To minimize costs and promote high acess to universities, small companies and institutes a nanosatellite was developed in early 2000, the CubeSat class. Therefore the need to save energy is mandatory in all systems due to low power generation and reduced size. This work focuses in the electrical power supply (EPS), system responsible to generate, store, conditioning and supply electrical power for the whole satellite. Thus is presented a comparison between a conventional power converter design and an optimization design methodology for boost power converters in order to improve efficiency, to reduce volume and mass for 1U CubeSat EPS. Results have shown the method effectiveness and efficiency maximization was achieved respecting the 1U CubeSat constraints.

DC-link electrolyte capacitor lifetime analysis for a PV boost converter

A lifetime analysis was performed on the DC-link capacitor of a photovoltaic power-processing system composed of a boost converter in the first stage. It was investigated how the switching frequency and ripple current design choice affect the capacitor lifetime. Through an electro-thermal modeling, the capacitor operating condition was obtained for various levels of power processing, based on a real photovoltaic mission profile built for ten years period of weather data. The lifetime of three different designs of electrolyte capacitor bank was analyzed and discussed. Analyzed results showed that the increase of the converters current ripple diminishes much the of capacitors lifetime. A discussion is presented about the tradeoff between choosing capacitors with low equivalent series resistance and increasing the number of capacitors on the DC-link.

Design metodology to improve the efficiency of ZVS double half-bridge DC/DC converter

This paper presents a design methodology of isolated Zero-Voltage-Switching Phase-Shifted Double Half Bridge DC/DC converter (ZVS-PS-DHB), which has one transformer associated to each leg. DHB topology is presented as an alternative to the well-known ZVS Phase-Shifted Full-Bridge DC/DC Converter (ZVS-PS-FB), it employing a minimum number of components. Parameter values of transformers, such as leakage and magnetizing inductances, are analyzed to operate under ZVS condition from non-load to full-load. The main objective of the design methodology used has been to find out converter parameters operating at ZVS for full load range. This has been carried out to minimize the converter losses. Through the developed methodology the converter reaches efficiency close to 99%. Converter operating stages and ZVS behavior analysis for different design trade-offs are presented and discussed. Finally, results are presented to prove the performance and operating of the ZVS-PS-DHB converter.

Designing power converters based on trade-offs and constrains

Nowadays several researches are focused on computational systems development to aid engineering designs, building virtual models and/or perform simulations to solve a real world problem, for example. A variety of algorithms, techniques, methods, and tools are available to the engineers to perform their designs, minimizing the errors/fails on the final product or maximizing the improvements of the techniques employed. Designing static converters is not different; so that this paper presents a computer-aided design and optimization tool (Advanced Design System for Power Converters -ADPC), which allows a design space for pre-sizing power converters, aiming to maximize their efficiencies, power volumetric densities and relative costs. Designing power converters through the ADPC is performed from input parameters selected by designer, as power, voltage and current levels. In order to demonstrate the effectiveness of ADCP, some designs have been established and presented through graphics and reports.