Piezoelectric and electromagnetic hybrid energy harvester for powering wireless sensor nodes in smart grid

A novel hybrid energy harvester integrated with piezoelectric and electromagnetic mechanism is designed for powering wireless sensor nodes in smart grid. In the proposed energy harvester device, four permanent magnets are attached on a piezoelectric cantilever array, and a Printed circuit board (PCB) with induction coils is mounted surrounding the magnets. The magnets couple to magnetic field of Alternating current (AC) carrying conductor and excite the piezoelectric cantilever array. Vibration energy is converted to electric energy via both piezoelectric and electromagnetic transduction mechanisms. A prototype in volume of 50x50x12 mm(3) was fabricated and tested. From current-carrying conductor of 2.5A at 50 Hz, the proposed energy harvester combined with piezoelectric components and electromagnetic elements can generate up to 295.3 mu W and 46.6 mu W, respectively. With the total output power of 341.9 mu W, the power density is much higher than the one generated only by conventional piezoelectric energy harvester under the same condition.