Juan Carlos Balda

Bio: Juan Carlos Balda is an academic researcher from University of Arkansas. The author has contributed to research in topics: Power module & Converters. The author has an hindex of 29, co-authored 180 publications receiving 3468 citations. Previous affiliations of Juan Carlos Balda include Clemson University & University of Arkansas at Little Rock.

Static and Dynamic Characterization of 3.3-kV SiC MOSFET Modules With and Without External Anti- Parallel SiC JBS Diode

Abstract: The innovation pace of modern and future power electronic systems such as energy storage systems and D-FACTs is driving the utilization of H.V. SiC MOSFETs. This paper presents the static and dynamic characterization of two configurations of a 3.3-kV SiC MOSFET half-bridge power module. The freewheeling diode in the first configuration is the body diode of the MOSFET. In contrast, the second configuration consists of both the body diode and an external anti-parallel SiC junction barrier Schottky (JBS) diode per switching position. The static and dynamic characteristics of these two configurations are investigated and compared at different junction temperatures. Unlike other evaluations, the comparison shows that the second configuration increased switching losses, switching times, and drain current overshoots. However, it decreased drain-to-source voltage overshoot and slew rates compared with the first configuration.

Complexity analysis and verification of real-time operation for a semi-Markov model of photovoltaic intermittency

Abstract: Photovoltaic (PV) penetration levels in the power grid have significantly increased during the last few years. However, issues such as cloud-induced intermittency in PV generation forces equipment on the electrical grid to cycle excessively, preventing PV generation from being a reliable or dispatchable source of power, particularly for utilities. To mitigate this intermittency, the PV must be coordinated with either dispatchable generation, energy storage, or demand response. In order to do so economically, it is necessary to develop a model of PV power that can be included in design and control problems. A semi-Markov process model is proposed for PV power. Unlike existing models of PV power, the proposed model has a wide range of applicability across both small and large timescales. These applications include simulating PV power, short-term forecasting of PV power, design of rule-based controllers for energy storage units (ESU), and stochastic scheduling of ESU in conjunction with other resources. This paper investigates the suitability of the model implemented in algorithms in real-time. To this end, the complexity of four algorithms involving the model is analyzed in terms of the number of operations required vs. number of samples processed. This is validated by implementing the algorithms on a representative target platform, demonstrating that they can complete within reasonable deadlines.

Curriculum restructure to answer critical needs in packaging for energy efficiency/renewable energy systems, wireless, and mixed-signal systems areas

Abstract: The Electrical Engineering Department at University of Arkansas has been building considerable strength in Energy Efficiency/Renewable Energy Systems, Mixed-Signal, and Wireless Packaging areas. This effort is in coordination with critical other Departments within the College of Engineering; specifically Industrial Engineering and Mechanical Engineering Departments, in addition to the Physics Department within the College of Arts and Science. The High Density Electronics Center (HiDEC), established in 1992 with DARPA funds to conduct research on advanced electronic packaging technologies, enables the educators to interact within the various disciplines to achieve the set objectives of packaging in these areas. The paper will outline the mission of each area, the vision and objectives of the administration, the technical issues to be addressed, the technological challenges and barriers for the Department to face and overcome to make this vision a true reality, and the curriculum restructure. The paper will also outline how critical these strategic areas are for a national academic institution recognition and fulfillment of critical needs for our nation's global competitiveness.

N-series modules based on SST for mobile power substation

Abstract: Mobile power substations (MPSs) are optimally designed to be installed on a truck bed for ease of transportation in order to provide an interface between two medium-voltage distribution systems under emergency or maintenance conditions. Based on the solid-state transformer (SST), a topology of N-series modules concept is proposed for MPS. The average control methods are used to balance the voltage and power for each SST module. The device losses are analyzed to estimate an upper limit to the theoretical system efficiency for a 5 MW–100 kHz MPS with 1.7-kV SiC MOSFET. Simulation results of three series-connected modules demonstrate the proposed MPS. A scale down prototype with three-series modules SST is build and parts of the system is tested.

Direct Cooling of Propulsion Drives for High Power Density and Low Volume

Abstract: : This final report summarizes the research work and conclusions related to ONR Award N00014-01-1-0634 under the DoD DESPCoR Program. The main objective of this grant was to investigate the feasibility of using spray cooling as the thermal management technology for power semiconductor devices used in power converter applications. this report covers the following: Basics of spray cooling, a novel power packaging methodology for power semiconductor devices that is compatible with spray cooling, the design of a power module serving as a technology demonstrator, and laboratory experimental results. Initial results seems to be superior to other approaches like cold-plate cooling.

A Survey of Wide Bandgap Power Semiconductor Devices

Abstract: Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC- and GaN-based power semiconductor devices together with an overall view of the state of the art of this new device generation.

Overview of Dual-Active-Bridge Isolated Bidirectional DC–DC Converter for High-Frequency-Link Power-Conversion System

Abstract: High-frequency-link (HFL) power conversion systems (PCSs) are attracting more and more attentions in academia and industry for high power density, reduced weight, and low noise without compromising efficiency, cost, and reliability. In HFL PCSs, dual-active-bridge (DAB) isolated bidirectional dc-dc converter (IBDC) serves as the core circuit. This paper gives an overview of DAB-IBDC for HFL PCSs. First, the research necessity and development history are introduced. Second, the research subjects about basic characterization, control strategy, soft-switching solution and variant, as well as hardware design and optimization are reviewed and analyzed. On this basis, several typical application schemes of DAB-IBDC for HPL PCSs are presented in a worldwide scope. Finally, design recommendations and future trends are presented. As the core circuit of HFL PCSs, DAB-IBDC has wide prospects. The large-scale practical application of DAB-IBDC for HFL PCSs is expected with the recent advances in solid-state semiconductors, magnetic and capacitive materials, and microelectronic technologies.

Step-Up DC–DC Converters: A Comprehensive Review of Voltage-Boosting Techniques, Topologies, and Applications

Abstract: DC–DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which fundamental energy storing elements (inductors and capacitors) and/or transformers in conjunction with switch(es) and diode(s) are utilized in the circuit. These techniques include switched capacitor (charge pump), voltage multiplier, switched inductor/voltage lift, magnetic coupling, and multistage/-level, and each has its own merits and demerits depending on application, in terms of cost, complexity, power density, reliability, and efficiency. To meet the growing demand for such applications, new power converter topologies that use the above voltage-boosting techniques, as well as some active and passive components, are continuously being proposed. The permutations and combinations of the various voltage-boosting techniques with additional components in a circuit allow for numerous new topologies and configurations, which are often confusing and difficult to follow. Therefore, to present a clear picture on the general law and framework of the development of next-generation step-up dc–dc converters, this paper aims to comprehensively review and classify various step-up dc–dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc–dc converters are presented and summarized with comparative study of different voltage-boosting techniques.

Energy Storage Systems for Transport and Grid Applications

Abstract: Energy storage systems (ESSs) are enabling technologies for well-established and new applications such as power peak shaving, electric vehicles, integration of renewable energies, etc. This paper presents a review of ESSs for transport and grid applications, covering several aspects as the storage technology, the main applications, and the power converters used to operate some of the energy storage technologies. Special attention is given to the different applications, providing a deep description of the system and addressing the most suitable storage technology. The main objective of this paper is to introduce the subject and to give an updated reference to nonspecialist, academic, and engineers in the field of power electronics.