Piezoelectrically Actuated Fast Mechanical Switches
Hybrid DC circuit breakers utilize fast mechanical switches ( a.k.a ultrafast disconnect switches) in their normal conduction paths to minimize on-state conduction losses and achieve ultrafast circuit switching within 1 millisecond. Most fast mechanical switches are actuated by Thomson coil actuators, a kind of electromagnetic actuators which are relatively bulky, lossy and uncontrollable in their travel curves.
Our lab has been developing a novel kind of fast mechanical switch with piezoelectric actuators for faster switching speed, higher actuation power density, and better controllability to yield more precise travel curves. So far, there have been at least three versions of 15 kV-class prototypes being developed by our team in past 5+ years, and I’m proudly taking major research responsibilities in two switch prototypes about following topics:
- Innovated a thermosyphon bushing prototype which achieved over 8000 W/(mK) of equivalent thermal conductivity
- Optimized thermal performance of a switch prototype and boosted its continuous current rating from 100 A to 500 A
- Prototyped a switch prototype out of drawings
- (Ongoing, thesis topic)Accomplishing the switching motion control in fast mechanical switches with real-time monitoring
Team members are from Georgia Tech Plasma and Dielectrics Laboratory, Georgia Tech VentureLab and Florida State University. The projects have been sponsoring by NSF and ARPA-E.
Insulation Coordination of Solid-State Transformer
Grid-connected solid-state transformers are promising solutions to interconnect renewable energy sources with AC transmission grid in an efficient, versatile and controllable manner. However, from the electrical insulation perspective, solid-state devices are inherently weak to withstand overvoltage transients, such as lighting strikes. Therefore, addtional protective devices are needed to improve solid-state transformer’s insulation and transient-withstand capabilities.
Team members are from Georgia Tech Center for Distributed Energy and Georgia Tech Plasma and Dielectrics Laboratory. This project has been sponsoring by ARPA-E