Vibrational energy in ambient environment can be transformed into electrical power through piezoelectric energy harvesters and using synchronized switch harvesting on inductor (SSHI) techniques can significantly improve energy extraction efficiency. To enhance energy harvesting efficiency, this study proposes an efficient self-powered parallel SSHI (ESP-PSSHI) interface circuit. It enhances the passive peak detection switch, simplifies the circuit topology, reduces switching delay, and minimizes the ‘second inversion’, contributing to increased energy harvesting efficiency. To improve the impedance-matching characteristics of the circuit, the proposed circuit is combined with a DC–DC converter module and finally, a stable electrical output is achieved. The performance of the ESP-PSSHI circuit in power generation is analyzed through simulation and subsequently verified via experimentation. Experiments show that the maximum output power of the ESP-PSSHI circuit is 2.42 and 1.16 times higher than the output power of the standard energy harvesting circuit and self-powered parallel SSHI (SP-PSSHI) circuit, respectively. Through capacitor charging experiments, it is concluded that the output power of the optimized ESP-PSSHI circuit is 1.5 times the output power of the LTC3588-1 circuit.

Accurate and simple magnetic material law is necessary to correctly model the complete electromagnetic systems. In this paper, a new formulation based on the scalar quasi-static hysteresis Jiles–Atherton model extended to dynamic behavior using fractional derivative dynamic contribution is proposed. The fractional contribution is solved using convolution which highly reduces the numerical issues. The order of the fractional derivation provides a new degree of freedom and allows obtaining correct simulation results on a very large frequency bandwidth. By using such a formulation, high-memory and time-consuming space discretization techniques (finite differences and finite elements) are avoided while keeping the global accurate simulation results.

Recycling ambient energies with electric generators instead of employing batteries with limited lifespans has motivated a large scientist community over two decades. Sea waves exhibit a large energy density. The amount of energy that could be extracted from the sea waves is very high. This work describes a technique of sea wave energy extraction based on a piezoelectric conversion and an analogy with thermodynamic Ericsson loops. By synchronizing external electric field to the maximum and the minimum of the sea wave mechanical stress excitations, the piezoelectric material dielectric hysteresis loop area is increased corresponding to the maximum of the energy available. In this article, technical solutions are proposed for the in site deployment of the proposed technique (maximum and minimum detection, external electric field source synchronization). Experimental measuring benches have been developed to monitor the sea wave mechanical excitation and to determine precisely the energy-harvesting potential. Adequate dielectric hysteresis model is proposed to numerically determine the best configuration (frequency, amplitude) of electric field to impose. Even if the Ericsson technique requires external electronic devices, the weak consumption of such components allows a large enhancement of the amount of energy extracted compared to a basic piezo element conversion.

Accurate and simple magnetic material behavior law is necessary to correctly model complete electromagnetic systems. In this paper, a new formulation based on the scalar quasi-static hysteresis Preisach model extended to dynamic behavior using fractional derivation dynamic contribution is proposed. The fractional contribution is solved using convolution which highly reduces the numerical issues. The order of the fractional derivation provides a new degree of freedom and allows to correctly obtain simulation results on a very large frequency bandwidth. By using such formulation, space discretization techniques (finite differences, finite elements) are avoided which are highly space and time consuming while keeping the global simulation results precise. The numerical implementation of the problem and some experimental validations are shown in this paper.

Due to its strong environmental robustness and high energy density, piezoelectric energy harvesting is considered one of the most promising methods to power wireless sensor nodes under extreme conditions. The interface circuit is essential to a piezoelectric energy harvester to reduce internal energy dissipation, achieve impedance matching, and improve energy conversion efficiency. Existing researches show that a parallel synchronized switch harvesting on inductor (P-SSHI) interface circuit compared with a standard energy harvesting (SEH) circuit can significantly improve the output power. Therefore, this paper proposes a self-powered optimized PSSHI (SP-OPSSHI) circuit, which adopts a new peak detection switching circuit to replace the switches in the P-SSHI circuit. It can realize switch control without an external starting power supply, i.e. cold start. Compared with an existing self-powered PSSHI (SP-PSSHI) circuit, it can effectively eliminate the ‘second inversion’ phenomenon caused by the parasitic capacitors of transistors after the voltage inversion process. The cause and effect of ‘second inversion’ on energy harvesting are analyzed in this study. Then, the working principle and process of the optimized circuit are discussed, and energy harvesting under the ideal state is conducted. Finally, the SP-OPSSHI circuit is developed and tested. The experimental waveforms show that the SP-OPSSHI circuit compared with the SP-PSSHI circuit can significantly reduce the impact of parasitic capacitors in the energy harvesting process. The output performance of the SP-OPSSH circuit is tested with the variation of resistance. The experimental results indicate that the SP-OPSSHI circuit has an optimal load resistance of 350 kΩ, achieving a maximum harvested power being 2.91 times that of the SEH circuit.