P.C. Rossin College of
Engineering and Applied Science

Traditional, centralized power grids—where power is generated, transmitted and then distributed to users—is fast becoming a thing of the past. Such systems are inefficient and vulnerable to attack. In addition, renewable energy sources, such as wind and solar, have led to more compact generators. For all these reasons, the future of power is power electronics-based microgrids.

A microgrid is exactly what it sounds like: a small grid. It consists of multiple distributed generators and loads and can work in both grid-connected- or autonomous- modes.

Rather than a centralized system, multiple microgrids are likely to be the future of power, according Wenxin Liu, assistant professor of electrical engineering at Lehigh University, because they allow for more flexibility.

Power electronics techniques, says Liu, have significantly improved the flexibility, reliability and power density of microgrids. However, control of microgrids remains a challenge due to reduced inertia, increased uncertainties and a wide range of operating conditions.

Liu is working on a novel concept: developing “LEGO-like” power electronic systems that are easily—and inexpensively—customized. This involves developing advanced hardware to improve a system’s capability and potential—in this case, through the development of modular power converters and advanced controller hardware for high-performance component-level and system-level applications.

It also involves advanced software design to unlock hardware potential, improve performance and lower cost.

“What I want is to develop something that is small, modular,” says Liu.  “If an application needs higher voltage, we can connect them in a series. If an application requires a higher current, we can connect them in parallel. If both, then we can connect them in a series and in parallel. So, we can customize it for different applications.”

The goal, says Liu, is to reduce the time and expense it takes to construct or customize a equipment or a microgrid.

“With a modular system, if something is not working, we can just replace that part, reducing maintenance costs,” says Liu. “Because we always have two priorities: first we want to make it work—and then we want to make it work better.”

Read the full story at the Lehigh University News Center.

Wenxin Liu

Wenxin Liu, Assistant Professor, Electrical and Computer Engineering