Through the Soil Long Range Wireless Power Transfer for Agricultural IoT Networks

Abstract

Increasing the spatial and temporal density of data using networked sensors, known as the Internet of Things (IoT), can lead to enhanced productivity and cost savings in a host of industries. Where applications involve large outdoor expanses, such as farming, oil and gas, or defense, large regions of unelectrified land could yield significant benefits if instrumented with a high density of IoT systems. The major limitation of expanding IoT networks in such applications stems from the challenge of delivering power to each sensing device. Batteries, generators, and renewable sources have predominately been used to address the challenge, but these solutions require constant maintenance or are sensitive to environmental factors. This work presents a novel approach where conduction currents through soil are utilized for the wireless powering of sensor networks, initial investigation is within an 0.8-ha (2-acre) area. The technique is not line-of-sight, powers all devices simultaneously through near-field mechanics, and has the ability to be minimally invasive to the working environment. A theory of operation is presented and the technique is experimentally demonstrated in an agricultural setting. Scaling and transfer parameters are discussed. Keywords-Wireless power transfer, Through the Soil, Long Range, conduction I. INTRODUCTIONDecision making based on real-time/measured data is critically important to boosting revenue/productivity in many industries. Sensor installation throughout the industrial process plays a fundamental role in these tools. The number of sensors that can be installed is limited by two primary factors: (1) the cost (including installation/maintenance) of the sensor and Manuscript received Month xx, 2xxx; revised Month xx, xxxx; accepted Month x, xxxx.

High-Frequency Inductive Power Transfer Through Soil for Agricultural Applications

“…An alternative to IPT is capacitive power transfer, where the capacitance between two pairs of plates conforms a wireless link. This technology is well suited for a number of applications [21], and recent work has introduced new techniques to operate it in the presence of soil [22], [23]. Nonetheless, the application proposed in this work requires a small cross-sectional area, especially on the transmitter, relatively high power and large distance, which are challenges best addressed with IPT.…”