A reconfigurable multi-ratio charge pump with wide input/output voltage range for wireless energy harvesting system

Author(s):  
Shiquan Fan ◽  
Jun Dong ◽  
Rui Zhang ◽  
Zhongming Xue ◽  
Li Geng
2017 ◽  
Vol 26 (12) ◽  
pp. 1750196 ◽  
Author(s):  
Yanzhao Ma ◽  
Yinghui Zou ◽  
Shengbing Zhang ◽  
Xiaoya Fan

A fully-integrated self-startup circuit with ultra-low voltage for thermal energy harvesting is presented in this paper. The converter is composed of an enhanced swing LC oscillator and a charge pump with decreased equivalent input capacitance. The LC oscillator has ultra-low input voltage and high output voltage swing, and the charge pump has a fast charging speed and small equivalent input capacitance. This circuit is designed with 0.18[Formula: see text][Formula: see text]m standard CMOS process. The simulation results show that the output voltage is in the range of 0.14[Formula: see text]V and 2.97[Formula: see text]V when the input voltage is changed from 50[Formula: see text]mV to 150[Formula: see text]mV. The output voltage could reach 2.87[Formula: see text]V at the input voltage of 150[Formula: see text]mV and the load of 1[Formula: see text]M[Formula: see text]. The maximum efficiency is in the range of 10.0% and 14.8% when the input voltage is changed from 0.2[Formula: see text]V to 0.4[Formula: see text]V. The circuit is suitable for thermoelectric energy harvesting to start with ultra-low input voltage.


2019 ◽  
Vol 25 (16) ◽  
pp. 2191-2203 ◽  
Author(s):  
R. Dehghani ◽  
H. M. Khanlo

In this paper, an adaptive chaos control is proposed for a typical vibratory piezomagnetoelastic energy harvesting system to return the chaotic behavior to a periodic one. Piezomagnetoelastic energy harvesting systems show chaotic behaviors in spite of harmonic input. Although, the chaotic behavior of the system gives higher output voltage than the periodic motion, it is preferred to the output voltage as this is periodic for charging a battery or a capacitor efficiently. Therefore, the chaos control is important in this system. The physical model is composed of the upper and lower piezoelectric layers on a cantilever taper beam, one attached tip magnet, and two external magnets (EM). Position of the EM is controlled by inputs. Firstly, chaotic and periodic regions are detected by utilizing the bifurcation diagrams, phase plan portrait, and Poincaré maps. Then an adaptive controller is proposed for controlling of the chaotic behaviors in the presence of uncertainty due to magnetic forces. The control law is derived based on the inverse dynamic method and the uncertainty elements of the controller are estimated using radial basis function (RBF) network. The weights of the RBF network are obtained using an adaptation law. The adaptation laws are derived based on Lyapunov stability theory and a projection operator. The distance of the tip magnet and the EM as well as the gap distance of two EM are used to control the chaotic behavior. Simulation results show that the proposed controller can return the chaotic motion to a periodic one in spite of the uncertainties in the magnetic forces.


Author(s):  
Ngoc-Thinh Quach ◽  
Thieu Quang Quoc Viet ◽  
Pham Van Toan ◽  
Minh-Trung Dao

This paper presents a model of an intelligent energy harvesting system from microbial fuel cells (MFCs) in the wastewater treatment process. The model consists of two direct current (DC/DC) converters connected in a cascade. One DC/DC converter is used to capture energy from MFC and store it in a supercapacitor. The other DC/DC converter is responsible for increasing the low output voltage to a higher voltage level. In the paper, the MFC is modeled by a DC voltage source instead of a real MFC that contains wastewater inside it. The experimental results demonstrate that the model of an intelligent energy harvesting system can increase the low output voltage of MFC up to 3.3 V and achieve intermittent output power at a high level that can use in practice.


2021 ◽  
Vol 11 (21) ◽  
pp. 9979
Author(s):  
Ying Zhang ◽  
Xiaxia Duan ◽  
Yu Shi ◽  
Xiaole Yue

In the stage of modelling, measuring, mechanical processing and manufacturing of the nonlinear energy harvesting system, deviations and errors of system parameters are inevitable. Even slight variation of key parameters may have a significant influence on the output voltages, especially for the multi-stable nonlinear case. Therefore, the investigation of dynamic behaviors for the tristable energy harvesting system with uncertain parameters is of important value both for research and application. In this paper, the uncertainty of a tristable piezoelectric vibration energy harvester with a random coefficient ahead of the nonlinear term is studied. By using the Chebyshev polynomial approximation, this tristable energy harvesting system is first reduced into an equivalent deterministic form, the ensemble mean responses of which are derived to exhibit the stochastic behaviors. The periodic and chaotic motions, bifurcations and crises under different conditions are analyzed. The results show that the output voltage is sensitive to the uncertainty of the nonlinear coefficient, which leads to unstable behavior around the bifurcation and crisis points particularly. Exploring the influence pattern of uncertain parameters on the output voltage and avoiding the unstable parameter intervals are essential for optimizing the structure. It can further improve the efficiency of the nonlinear energy harvesting system.


Sign in / Sign up

Export Citation Format

Share Document