Brian Johnson
Washington Research Foundation Innovation Assistant Professor

Summary of ongoing research projects

Cascaded Architectures for Medium-voltage Transformerless Inverters

alt text 


We bridge advances in wide-bandgap power electronics with breakthroughs in distributed and decentralized control to produce low-cost medium-voltage transformerless inverters composed of stackable lightweight blocks. This project is sponsored by the DOE Solar Energy Technology Office in the Advanced Power Electronics Design for Solar Applications program.

Low-inertia Power Systems

alt text 


Renewable energy sources, storage devices, and electric vehicles are interfaced to the grid through power-electronics. These interfaces are fundamentally different from conventional synchronous generators in that they are based on electronics and do not have moving parts (i.e., no mechanical inertia). The future power grid will have low(er) mechanical inertia, and many more actuation nodes. These changes entail a multitude of technical challenges. This line of research is focused on i) developing controls that will enable sustainably powered and electronics-based grids, and ii) models that capture the networked interactions of many inverters and few conventional generators. This work is funded by the DOE Solar Energy Technology Office.

Wave Energy Conversion

alt text 


The energy in ocean waves and tides are largely untapped due to the unfilled need for reliable, cost-effective, and efficient energy conversion systems. To illustrate the depths of the underlying challenges, such systems entail multi-physics behavior across complex mechanical subsystems, electromechanical energy conversion, power electronics, and control systems. Our group is engaged in a multidisciplinary and collaborative effort funded by NAVFAC to engineer next-generation wave energy conversion systems.

Modular Power Electronics Systems

alt text 


Power electronics systems are commonly built by interconnecting multiple converters together. To name a few examples, such an approach is ubiquitous in computing power supplies, renewable energy interfaces, multilevel converters, and microgrids. Our group applies contemporary advances in theory to engineer decentralized, robust, communication-free, and practical implementations.