Annals of Glaciology (Sep 2021)

Recoverable Autonomous Sonde for subglacial lakes exploration: heating control system design

  • Haibin Yu,
  • Tianxin Zhu,
  • Xiao Jiang,
  • Yongzhen Tang,
  • Xiaodong Li,
  • Chong Li,
  • Shengmiao Huang,
  • Jianguang Shi,
  • Youhong Sun,
  • Pavel Talalay,
  • Xiaopeng Fan,
  • Xiao Li,
  • Yazhou Li,
  • Shilin Peng

DOI
https://doi.org/10.1017/aog.2021.5
Journal volume & issue
Vol. 62
pp. 280 – 292

Abstract

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Drilling and sampling are the most direct and effective methods available to study Antarctic subglacial lakes. Based on the Philberth probe, a Recoverable Autonomous Sonde (RECAS) allows for in situ lake water measurement and sampling, through the addition of an upper thermal tip and a cable recoiling mechanism. RECAS-200, a prototype of RECAS, has a drilling depth of 200 m, a surface supply voltage of 800 VAC and a downhole power of ~9.6 kW during drilling. In this study, a heating control system for RECAS-200 was designed. The system avoids the need for high-power step-down converters, by separating heating power from control power, thereby reducing the overall weight of the probe and avoiding the need to increase cable diameter. We also introduce a self-developed, small, solid-state, 800 VAC power regulator and a fuzzy PID temperature control algorithm. Their purpose was to manage the power adjustment of each heating element and to provide closed-loop temperature control of certain heating elements which can easily burn out due to overheating. Test results indicated that the proposed RECAS-200 heating control system met all our design specifications and could be easily assembled into the RECAS-200 probe.

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