A Batteryless Inductive Energy Harvesting System

Abstract

This thesis presents the design and development of an energy harvesting system enabling a batteryless, wireless temperature-sensing data logger, intended for monitoring cargo conditions during maritime transport. The system harvests energy via inductive coupling, where a low-profile receiver coil captures power from an alternating magnetic field generated by a ceiling-mounted transmitter coil. This study specifically addresses key design considerations such as coil design, resonance-matching, Schottkydiode-based rectifification, robust voltage regulation by means of a buck-boost converter and a dual-capacitor energy storage scheme for reliable energy storage and voltage stability. The design overcomes core challenges in long-range wireless power transfer (WPT) including efficient energy extraction under low-power conditions, stable voltage regulation, and reliable start-up and operation within the constraints of a shipping container. The prototype achieves stable 2.1 V output from harvested energy alone, operating effectively at distances up to 1.4 m, while simulations confirm feasibile operation at the required 2.4 m range intended for its real-life application. The proposed solution achieves a self-sustaining, maintenance-free approach to temperature monitoring, enhancing cargo safety and contributing to the reduction of electronic and food waste. This system offers a scalable, adaptable, low-maintenance alternative to disposable battery-powered sensors, Improving sustainable cold-chain conditions monitoring and adhering to EU electromagnetic exposure limits.