  In this paper, we describe a novel turbine failsafe system designed for a
pico-hydroelectric power generation. We designed and built a pico-hydroelectric
system in a remote rural Himalayan village. We developed a Prioritized Load
Control System (PLCS) that diverts excess electrical power to useful purposes
such as heating up bath water and the air in the community center when the
electrical demand from the village is low; instead of dumping the excess
electricity back into the river in the form of heat. A critical part of the
PLCS system is the failsafe mechanism where the turbines and electrical
components on the grid are protected in case any part of the PLCS system stops
functioning, possibly intermittently. Our novel failsafe system contains the
following enhancements compared to previous systems: (1) adjustable threshold
voltage, (2) controllable fractional power diversion with adjustable
parameters, (3) automatic reset with adjustable parameters. In addition, the
failsafe subsystem uses the widely available Arduino platform and programming
environment, and JSON for human readable and writable communications,
demonstrating their suitability for critical applications.
