High-efficiency energy harvesting interface and corresponding energy harvesting system

摘要

An electrical-energy harvesting system envisages a transducer for converting energy from an environmental energy source into a transduced signal, an electrical energy harvesting interface for receiving the transduced signal and for supplying a harvesting signal, and an energy storage element coupled to the electrical energy harvesting interface for receiving the harvesting signal. The electrical-energy harvesting system also includes a voltage converter connected to the electrical energy harvesting interface for generating a regulated voltage. The harvesting interface samples an open-circuit voltage value of the transduced signal, generates an optimized voltage value starting from the open-circuit voltage value, and generates an upper threshold voltage and a lower threshold voltage on the basis of the optimized voltage value. The harvesting interface controls the voltage converter in switching mode so that the harvesting signal has a value between the upper and lower threshold voltages in at least one operating condition.

主权项

1. An electrical-energy harvesting system, comprising:
a transducer to convert energy from an environmental energy source into a transduced signal; a harvesting interface to receive the transduced signal on an input terminal and to supply an electrical-energy harvesting signal on an output terminal; an energy storage element coupled to the output terminal of the harvesting interface to receive the electrical-energy harvesting signal; a voltage converter coupled to the output terminal to generate a regulated voltage, wherein the harvesting interface is configured to:
sample an open-circuit voltage value of the transduced signal;generate an optimized voltage value starting from the open-circuit voltage value;generate an upper threshold voltage based on the optimized voltage value;generate a lower threshold voltage based on the optimized voltage value; andcontrol the voltage converter in a switching mode to thereby maintain the electrical-energy harvesting signal between the upper and lower threshold voltages in a first operating condition; a first holding element to store said optimized voltage value; a second holding element to store said upper threshold voltage; a third holding element to store said lower threshold voltage during said first operating condition; and controllable decoupling-switching elements to selectively decouple said first, second, and third holding elements during a storage condition of each respective voltage value.