Adaptive piezoelectric energy harvesting circuit for wireless remote power supply

Abstract

This paper describes an approach to harvesting electrical energy from a mechanically excited piezoelectric element. A vibrating piezoelectric device differs from a typical electrical power source in that it has a capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. An analytical expression for the optimal power flow from a rectified piezoelectric device is derived, and an "energy harvesting" circuit is proposed which can achieve this optimal power flow. The harvesting circuit consists of an ac-dc rectifier with an output capacitor, an electrochemical battery, and a switch-mode dc-dc converter that controls the energy flow into the battery. An adaptive control technique for the dc-dc converter is used to continuously implement the optimal power transfer theory and maximize the power stored by the battery. Experimental results reveal that use of the adaptive dc-dc converter increases power transfer by over 400% as compared to when the dc-dc converter is not used.

Nonlinear piezoelectricity in electroelastic energy harvesters: Modeling and experimental identification

“…3,4 In addition, selfsustaining energy harvesting systems are viewed as an enabling technology for cost-effective wireless sensor networks whose proposed application venues ͑i.e., remote-area, in vivo, bridges, etc.͒ render regular maintenance and battery replacement problematic. [5][6][7][8] To date, most piezoelectric harvesters presume linear response and thus seek electromechanical resonance to extract maximum energy. 2,[9][10][11] However, considering many environmental excitation sources are instead broadband, strategies ranging from control theoretic [12][13][14] to purposeful inclusion of nonlinearity [15][16][17][18][19][20][21][22] are gaining momentum.…”

Analysis of Bistable and Chaotic Piezoelectric Energy Harvesting Device Coupled With Diode Bridge Rectifier

“…According to [12], systems are coupled assuming a condition of continuity between current and voltage of both:…”

Power processing circuits for electromagnetic, electrostatic and piezoelectric inertial energy scavengers

“…For example, Ottman et al designed an optimised power processing circuit for a piezoelectric transducer (Ottman et al, 2002). In this case relatively large voltages were obtained from the transducer (up to 100 V), so that full-wave diode rectification was practical, followed by a conventional DC-DC step-down convertor.…”

“…Roundy (Roundy et al, 2003) and Ottman (Ottman et al, 2002) have both shown that piezoelectric generators can achieve higher power densities when driving resistive loads than when they are connected to a simple power supply consisting of a bridge rectifier and smoothing capacitor. We have shown that the same is true for electromagnetic devices (Mitcheson et al, 2004a), and the circuit presented in section 2 satisfies this requirement.…”