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.

Current Compensators for Unbalanced Electric Distribution Systems

Abstract: Inherent current imbalances are often present in electric distribution systems due to the increase of single-phase generation in the form of renewables and the existence of single-phase loads. The continued expansion of non-linear load usage is also increasing the levels of harmonics through the power transformers servicing these distribution systems. The issues that arise from these operating conditions are widely known and standard solutions used by utilities are as well. However, they are often bulky and do not provide a level of control or versatility appropriate for these challenges. This paper gives an overview of many of the problems that are faced on distribution systems and how an active shunt compensator may be used to mitigate or eliminate them.

Sinusoidal waveform synthesis for parallel active power filter applications

Abstract: This paper proposes a novel method to generate a sinusoidal waveform for synthesizing a sinusoidal reference current in certain applications of parallel active power filters. The method, based on the behavior of a three-dimensional dynamical system, avoids employing the usual combination of look up table and PLL found in most parallel active filters synthesizing a sinusoidal source current. The method produces two high-quality sinusoidal waveforms in quadrature, applicable to those parallel active filters whose control methodology is in the /spl alpha///spl beta/ frame, or alternatively, three sinusoidal waveforms shifted 120 degrees from each other for designs that work in the abc frame.

Operating characteristics of MCTs in resonant DC link inverters

Abstract: Improved performance of inverters may be obtained by increasing the switching frequency of the power semiconductor devices. Switching frequencies greater than the hard-switched limits may be obtained by using soft-switching techniques, The MOS-controlled thyristor (MCT) is a relatively new device showing a great potential in soft-switching applications involving high-power densities. Hence, the main objective of this paper is to extend the research work done on both soft-switched (resonant) inverters and MCTs by evaluating the operating characteristics of MCTs for switching frequencies up to approximately 75 kHz under a zero-voltage switching condition. A PCB is developed to subject the MCTs and passive components to stresses similar to those actually occurring in the resonant and actively-clamped resonant DC link inverter topologies. In addition, operation results of the operation of the MCT-based active clamp in the actively-clamp resonant DC link inverter and some practical implementation considerations are included. >

Variable-Frequency Controlled Interleaved Boost Converter

Abstract: Efficiency over the entire power range is an important performance metric for traction applications since electric vehicles (EVs) operate at very different power levels, in particular, lower power levels are more common for city driving. DC-DC converters operated under conventional pulse-width modulation (PWM) techniques at constant switching frequency experience significantly lower efficiencies at low power levels. To cope with this issue, this work addresses a bidirectional discontinuous-conduction mode (DCM) and variable-frequency control strategy for a three-phase interleaved boost converter to provide an improvement of the system efficiency at low power levels. The validity and effectiveness of the proposed approach are demonstrated by both simulation and experimental results on a 10-kW prototype.

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.