Application Cases

Experiment Name: Modeling and Experimental Study of a Vertically Moving Magnet Piezoelectric Vibration Energy Harvester Based on a Power Amplifier

Research Direction: To improve the performance of a single-cantilever piezoelectric energy harvester

Experimental Content:
To enhance the performance of a single-cantilever piezoelectric energy harvester, a vertically moving magnet piezoelectric vibration energy harvesting structure was designed. A lumped parameter piezoelectric coupling model was established for this structure, and numerical simulations were conducted. An experimental platform was built to evaluate the structural performance.

Testing Equipment: Oscilloscope, energy harvesting circuit, signal generator, power amplifier, electromagnetic shaker, accelerometer, etc.

Experimental Procedure:
The excitation part of the experimental platform consisted of a function generator, a voltage amplifier, and an electromagnetic shaker. During the experiment, the function generator was used to adjust the frequency for upward frequency sweep testing. The measurement part consisted of acceleration measurement and energy measurement functions. The acceleration measurement was performed by an accelerometer and an additional signal conditioner. The accelerometer was fixed on an acrylic base to calibrate and measure the excitation acceleration.

The piezoelectric material was connected to the energy harvesting circuit via wires. A resistor was added as a load in the circuit to facilitate performance testing of the energy harvesting device. The voltage across the load and the output of the IEPE accelerometer were directly connected to an oscilloscope to record the system's output voltage and acceleration status.

Experimental Results:

(1) The low-frequency repulsion and high-frequency attraction modes exhibited high peak and wide bandwidth characteristics. The high-frequency repulsion and low-frequency attraction modes exhibited double-peak characteristics. The low-frequency repulsion mode is more suitable for practical applications.

(2) The lumped parameter model can effectively predict the structural properties within an acceptable error range. The prediction error for amplitude is less than 7%, making it suitable for the design and parameter optimization of the VMM-PVEH.

(3) An optimal magnet distance exists for different magnetic flux densities. As the magnetic flux density increases, the optimal distance value increases, and the peak values at these optimal distances are similar.

(4) Under the optimal parameter conditions described in this paper, the peak power of the system can be increased by 42.7%, and the bandwidth can be increased by 40.6%.

Figure: Specifications of the ATA-2041 High-Voltage Amplifier