Performance of surge-induced synchronized switch harvesting on inductor as an efficient technique under strong electromechanical coupling and low amplitudes of vibration

The process of harvesting energy from ambient sources is key for various applications. This study examined the performance of two representative techniques from the surge-induced synchronized switch harvesting on inductor (S³HI) family under strong electromechanical coupling and compared this performance with that of some established techniques. S³HI techniques exploit the surge voltage to overcome the voltage barrier of diodes for rectifiers and storage capacitor voltages. One of their features, revealed in a previous study on weakly coupled systems, is that they can harvest substantial energy from low-level vibrations. This feature is desirable for certain use cases. This study aimed to clarify whether this feature is applicable even when the coupling is strong. The performance of various established techniques and two representatives from the S³HI group was studied by formulating an approximate analytical solution and performing numerical simulations and experiments. The theoretical results were confirmed to be consistent, and the discrepancy between experimental and theoretical results was minor. These results clearly demonstrate that the techniques from the S³HI family can effectively harvest substantial energy from small-amplitude vibrations, even when the coupling is strong. Moreover, the performance advantage of S³HI methods is even greater when the coupling is strong.