Controller for portable intermediate depth ice core drilling system

The primary objective of ice core drilling is to obtain the highest quality core while minimizing the effort needed. This requires a control system with precision control and convenient operation. An intermediate-depth portable ice core drilling system designed and constructed at the Byrd Polar Research Center (BPRC) has been tested during four expeditions under different working conditions. Several design options were tested to both control and monitor performance of the winch, thermal and electro-mechanic drills. An attempt has been made to develop a universal controller that can be used with either thermal or electro-mechanical drills and with various power sources, ranging from a conventional alternating current (AC) portable generator, custom high voltage direct current (DC) generator or an array of solar panels. Currently, controller system built in two configurations: (1) to operate a 500m winch, dry hole electro-mechanical (EM) drill and fluid electro-thermal (ET) drill at low (1kW) power, and (2) to operate a 500m winch, EM and ET drills at high power (400Vdc and 6.0kW). To allow the use of different power sources and different drills a modular design was chosen. The control system includes three modules: (1) for measuring and indicating drill depth, drill rate, and cable tension, (2) for driving reversible winch and drill motors at the same time (225Vdc, 2.25kW), and (3) for driving a high power (400Vdc, 20kW) drill or winch motor. The controllers are built around industrial servo-amplifiers (SA) for DC brush motors and have over-voltage and over-current protection. This design permits convenient positioning of each module on the winch frame. This paper describes the details of the design and functional options of an ice drill control system.