ABSTRACT. With the increased popularity of new devices such as GaN, and new topologies such as the LLC, power designers hope to make dramatic improvements to the power density and efficiency of their converters. Figures of merit of these new devices suggest huge possible gains, but reality often shows it is difficult to fully utilize the promise of these new devices and topologies.

This talk will examine the loss mechanisms and other performance metrics of power converters. While understanding the trends of individual loss components is valuable in gaining intuition, one can only optimize a design by simultaneous evaluation of all relevant metrics. A software solution will be presented which enables designers to optimize their converters by making individual design decisions while simultaneously examining whole-converter performance metrics. This methodology streamlines the design process while reducing the risk associated with implementing modern technologies.

Dr. Michael Seeman is the CEO and Founder of Eta One Power. Eta One Power develops advanced simulation and optimization software focusing on increasing power density and efficiency of power supplies. He was formerly the Systems and Applications Engineering Manager in the GaN Products Group at Texas Instruments. He has significant experience in cutting-edge power conversion solutions using wide-bandgap technologies and resonant converter architectures. He previously worked in two silicon-valley startups in the power electronics space. He received his S.B. degree from the Massachusetts Institute of Technology and his MS and Ph.D. degrees from UC Berkeley. He is a member of the IEEE.

ABSTRACT. In this practically oriented workshop we will walk through the design, testing, and validation of discrete time current controllers and different synchronization methods for grid-tied smart inverters. As an example, a complete controller for 700kVA grid connected three-level neutral point clamped (3L-NPC) inverter with an LCL filter will be designed and implemented.

We will demonstrate design, testing, and performance validation of a complete digital controller. First, we will detail the overall controller architecture and develop discrete time average model of the inverter. Subsequently we will discuss different current controller architectures, yet focus on the resonant controller design and how to design optimal parameters. In addition, we will review main PLL grid synchronization algorithms and detail design and tuning of one. We will focus on practical issues for digital implementation and complete controller will be demonstrated in Texas Instruments DSP-TMS320F28335 directly interfaced with ultra-high fidelity real-time simulation. The impact of the different controllers and synchronization parameters, on the overall performance of the systems, is demonstrated with the controller Hardware in the Loop (HIL). We will introduce the HIL based methodology to test and validate the performance and robustness of the inverter controller in realistic grid tie settings (i.e. weak and strong grid conditions) and we will introduce some of the key grid support requirements for the UL1741 SA and Rule 21.

Prof. Humberto Pinheiro received the B.S. degree from the Federal University of Santa Maria (UFSM), Santa Maria, Brazil, in 1983, the M.Eng. degree from the Federal University of Santa Catarina, Florianópolis, Brazil, in 1987, and the Ph.D. degree from Concordia University, Montreal, QC, Canada, in 1999. From 1987 to 1999, he was a Research Engineer with a Brazilian UPS company and a Professor with the Pontificia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil, where he lectured on power electronics. Since 1991, he has been with UFSM. His research interests include the modulation and control of static converters and drives, and power converters for wind energy conversion systems. Dr. Pinheiro is a member of the IEEE Power Electronics and IEEE Industrial Electronics Societies.