This article presents the design strategy and experimental validation of a battery-free power supply for wireless sensor nodes (WSN) on an industrial study case. The power supply is based on the principle of vibration energy harvesting (VEH). The general architecture of the linear generator with electronic is presented. It is composed of commercially available components as a MIDE PPA 1014 piezoelectric cantilever beam and a LTC3588 circuit to extract and shape the electrical energy. The energy source comes from mechanical vibrations measured on the industrial environment in operation. A tunable mechanism of the resonance frequency is added in order to have a wider range of use than the natural range of a linear harvester. To adapt the VEH according with the source, it resonant frequency range can be tuned with a dedicated tipmass. Then a fine adjustment within a range of about 20 Hz is set using both a moving clamping device and a temporarily wired electronic device working as a maximum power point finder (MPPF). To achieve a long lifetime, the storage is done using balanced supercapacitors. Two operational demonstrators are shown. The test benches as well as numerous experimental tests are presented. Shaped according to the industrial environment (49.0 Hz @ 2.7 m/s²), the VEH is capable of delivering continuously 100mA@3.3V with 200 mA peaks. When the power harvested (≈ 2.9 mW) is upper than the sensor average power, it offers the capability to store 17.5 J at 18.5 V. As a result, from this work, a WSN can successfully operate over a significantly long period of time despite fluctuations in the vibration source.

Nowadays, the electricity production with renewable energy plays an increasingly important role in which photovoltaic (PV) systems play significant role as well. This kind of technology is predominant on the household level for. The reason, that a wide output range can be created, and each of the individual consumers can be customized, furthermore its aesthetic, manageability and financial characteristics are also positive. In this publication the simultaneity of the production of a household size small power plant and the quarter-hourly consumption of a household was analyzed, and the sizing of an energy store system (ESS) in the event of power supply interruption was shown. Analysis of the data shows the impact of production and consumption in individual seasons, and illustrates the extent of it. In addition the simultaneity of production and consumption was shown on diagrams in each month and season. The simultaneity has been very low, but it could be improved by using ESS. In this study the sizing methodology and the financial aspect of an ESS has been displayed.

We designed and realized a novel vibration energy harvester based on a P(VDF-TrFE) membrane. The mechanical arrangement consists in an incompressible fluid confined between two thin P(VDF-TrFE) piezoelectric membranes. It is called piezoelectric hybrid fluid diaphragm (PHFD). Compared with conventional vibration harvester, this solution appears to be simple and suitable for miniaturization and integration. The fluid-structure interaction allows a drastic reduction of the resonant frequency of the membrane whose mechanical tension is used to generate electrical power. Consequently, the realization of compact generators for low frequencies excitation (typically under 100 Hz) using membranes are possible. Moreover, nonlinear hardening behavior offers wideband capability. A theoretical model is established and allows the performance of the generator to be estimated. A first prototype has been fabricated and tested. The influence of the electric load,the amplitude and the frequency of the excitation on the voltage and the generated power have been investigated. A maximum output power of 158.33 µW per cubic centimeter of active material was obtained at 119.56 Hz for 40 m/s 2 amplitude acceleration.