Christopher Sherman

Christopher Sherman, PhD 2013
Advisor: Paul Wright, Richard White
Email: ctsherman@berkeley.edu
Proximity-Based Current Sensors for Smart Grid Applications

Upcoming Smart Grid initiative necessitates the distribution of thousands of sensors to monitor the operation of the future U.S. power grid. Our group is developing small and inexpensive self powered sensor modules that can be non-intrusively deployed (simply attached to equipment) throughout the grid (in residential/commercial, distribution and transmission circuits) to wirelessly monitor current and voltage, as well as other operational and diagnostic parameters. The work being undertaken here focuses on the continued development of self-powered, MEMS piezoelectric proximity-based current sensors as part of the above framework.
Current work is focused on model refinement and design optimization for next iteration of MEMS current sensors. Test work has been done using meso-scale devices to validate a lumped parameter model for non-resonant rectangular beams, showing good agreement (R2=0.9991) between the model and experimental data. The model is presently being extended to account for non-constant (trapezoidal) beam shapes, after which point an improved design will be generated for micro-fabrication. Differential sensing has also been shown to function for meso-scale sensors placed suitably close (within 45mm from center of a 25mm diameter wire) to an AC current carrying conductor.

Figure 1: Differential Sensor test apparatus. Meso-scale test
system.

Figure 2: 3500 experimental data points vs. analytic model.